Initial

15 files changed, 6471 insertions, 0 deletions

diff --git a/Makefile b/Makefile
new file mode 100644
index 0000000..365a902
--- /dev/null
+++ b/Makefile
@@ -0,0 +1,34 @@
+CC=gcc
+CFLAGS=
+INCLUDE=-I./include 
+INCLUDE+=-I../librusb/src
+LDFLAGS=
+LDFLAGS+=-Lrusb
+
+SOURCES=
+SRC_LIB=
+OBJ_LIB=
+SRC_UTILS=
+OBJ_UTILS=
+
+BUILD_DIR=build/
+
+include src/make.mk
+
+
+OBJECTS=$(SOURCES:.c=.o)
+
+utils: $(DIR)-pre $(OBJ_UTILS)
+
+all: $(OBJECTS)
+
+make: $(OBJECTS)
+	echo $(OBJECTS)
+	echo $(SRC_LIB)
+
+
+%.o: %.c
+	$(CC) $(CFLAGS) $(INCLUDE) -Wl,-rpath=. -c $< -o $(BUILD_DIR)$@
+
+clean:
+	rm -rf build/src/rtl_*
diff --git a/README.md b/README.md
new file mode 100644
index 0000000..e69de29
--- /dev/null
+++ b/README.md
diff --git a/src/convenience/convenience.c b/src/convenience/convenience.c
new file mode 100644
index 0000000..00cc2cc
--- /dev/null
+++ b/src/convenience/convenience.c
@@ -0,0 +1,308 @@
+/*
+ * Copyright (C) 2014 by Kyle Keen <keenerd@gmail.com>
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+/* a collection of user friendly tools
+ * todo: use strtol for more flexible int parsing
+ * */
+
+#include <string.h>
+#include <stdio.h>
+#include <stdlib.h>
+
+#ifndef _WIN32
+#include <unistd.h>
+#else
+#include <windows.h>
+#include <fcntl.h>
+#include <io.h>
+#define _USE_MATH_DEFINES
+#endif
+
+#include <math.h>
+
+#include "rtl-sdr.h"
+
+double atofs(char *s)
+/* standard suffixes */
+{
+	char last;
+	int len;
+	double suff = 1.0;
+	len = strlen(s);
+	last = s[len-1];
+	s[len-1] = '\0';
+	switch (last) {
+		case 'g':
+		case 'G':
+			suff *= 1e3;
+			/* fall-through */
+		case 'm':
+		case 'M':
+			suff *= 1e3;
+			/* fall-through */
+		case 'k':
+		case 'K':
+			suff *= 1e3;
+			suff *= atof(s);
+			s[len-1] = last;
+			return suff;
+	}
+	s[len-1] = last;
+	return atof(s);
+}
+
+double atoft(char *s)
+/* time suffixes, returns seconds */
+{
+	char last;
+	int len;
+	double suff = 1.0;
+	len = strlen(s);
+	last = s[len-1];
+	s[len-1] = '\0';
+	switch (last) {
+		case 'h':
+		case 'H':
+			suff *= 60;
+			/* fall-through */
+		case 'm':
+		case 'M':
+			suff *= 60;
+			/* fall-through */
+		case 's':
+		case 'S':
+			suff *= atof(s);
+			s[len-1] = last;
+			return suff;
+	}
+	s[len-1] = last;
+	return atof(s);
+}
+
+double atofp(char *s)
+/* percent suffixes */
+{
+	char last;
+	int len;
+	double suff = 1.0;
+	len = strlen(s);
+	last = s[len-1];
+	s[len-1] = '\0';
+	switch (last) {
+		case '%':
+			suff *= 0.01;
+			suff *= atof(s);
+			s[len-1] = last;
+			return suff;
+	}
+	s[len-1] = last;
+	return atof(s);
+}
+
+int nearest_gain(rtlsdr_dev_t *dev, int target_gain)
+{
+	int i, r, err1, err2, count, nearest;
+	int* gains;
+	r = rtlsdr_set_tuner_gain_mode(dev, 1);
+	if (r < 0) {
+		fprintf(stderr, "WARNING: Failed to enable manual gain.\n");
+		return r;
+	}
+	count = rtlsdr_get_tuner_gains(dev, NULL);
+	if (count <= 0) {
+		return 0;
+	}
+	gains = malloc(sizeof(int) * count);
+	count = rtlsdr_get_tuner_gains(dev, gains);
+	nearest = gains[0];
+	for (i=0; i<count; i++) {
+		err1 = abs(target_gain - nearest);
+		err2 = abs(target_gain - gains[i]);
+		if (err2 < err1) {
+			nearest = gains[i];
+		}
+	}
+	free(gains);
+	return nearest;
+}
+
+int verbose_set_frequency(rtlsdr_dev_t *dev, uint32_t frequency)
+{
+	int r;
+	r = rtlsdr_set_center_freq(dev, frequency);
+	if (r < 0) {
+		fprintf(stderr, "WARNING: Failed to set center freq.\n");
+	} else {
+		fprintf(stderr, "Tuned to %u Hz.\n", frequency);
+	}
+	return r;
+}
+
+int verbose_set_sample_rate(rtlsdr_dev_t *dev, uint32_t samp_rate)
+{
+	int r;
+	r = rtlsdr_set_sample_rate(dev, samp_rate);
+	if (r < 0) {
+		fprintf(stderr, "WARNING: Failed to set sample rate.\n");
+	} else {
+		fprintf(stderr, "Sampling at %u S/s.\n", samp_rate);
+	}
+	return r;
+}
+
+int verbose_direct_sampling(rtlsdr_dev_t *dev, int on)
+{
+	int r;
+	r = rtlsdr_set_direct_sampling(dev, on);
+	if (r != 0) {
+		fprintf(stderr, "WARNING: Failed to set direct sampling mode.\n");
+		return r;
+	}
+	if (on == 0) {
+		fprintf(stderr, "Direct sampling mode disabled.\n");}
+	if (on == 1) {
+		fprintf(stderr, "Enabled direct sampling mode, input 1/I.\n");}
+	if (on == 2) {
+		fprintf(stderr, "Enabled direct sampling mode, input 2/Q.\n");}
+	return r;
+}
+
+int verbose_offset_tuning(rtlsdr_dev_t *dev)
+{
+	int r;
+	r = rtlsdr_set_offset_tuning(dev, 1);
+	if (r != 0) {
+		fprintf(stderr, "WARNING: Failed to set offset tuning.\n");
+	} else {
+		fprintf(stderr, "Offset tuning mode enabled.\n");
+	}
+	return r;
+}
+
+int verbose_auto_gain(rtlsdr_dev_t *dev)
+{
+	int r;
+	r = rtlsdr_set_tuner_gain_mode(dev, 0);
+	if (r != 0) {
+		fprintf(stderr, "WARNING: Failed to set tuner gain.\n");
+	} else {
+		fprintf(stderr, "Tuner gain set to automatic.\n");
+	}
+	return r;
+}
+
+int verbose_gain_set(rtlsdr_dev_t *dev, int gain)
+{
+	int r;
+	r = rtlsdr_set_tuner_gain_mode(dev, 1);
+	if (r < 0) {
+		fprintf(stderr, "WARNING: Failed to enable manual gain.\n");
+		return r;
+	}
+	r = rtlsdr_set_tuner_gain(dev, gain);
+	if (r != 0) {
+		fprintf(stderr, "WARNING: Failed to set tuner gain.\n");
+	} else {
+		fprintf(stderr, "Tuner gain set to %0.2f dB.\n", gain/10.0);
+	}
+	return r;
+}
+
+int verbose_ppm_set(rtlsdr_dev_t *dev, int ppm_error)
+{
+	int r;
+	if (ppm_error == 0) {
+		return 0;}
+	r = rtlsdr_set_freq_correction(dev, ppm_error);
+	if (r < 0) {
+		fprintf(stderr, "WARNING: Failed to set ppm error.\n");
+	} else {
+		fprintf(stderr, "Tuner error set to %i ppm.\n", ppm_error);
+	}
+	return r;
+}
+
+int verbose_reset_buffer(rtlsdr_dev_t *dev)
+{
+	int r;
+	r = rtlsdr_reset_buffer(dev);
+	if (r < 0) {
+		fprintf(stderr, "WARNING: Failed to reset buffers.\n");}
+	return r;
+}
+
+int verbose_device_search(char *s)
+{
+	int i, device_count, device, offset;
+	char *s2;
+	char vendor[256], product[256], serial[256];
+	device_count = rtlsdr_get_device_count();
+	if (!device_count) {
+		fprintf(stderr, "No supported devices found.\n");
+		return -1;
+	}
+	fprintf(stderr, "Found %d device(s):\n", device_count);
+	for (i = 0; i < device_count; i++) {
+		rtlsdr_get_device_usb_strings(i, vendor, product, serial);
+		fprintf(stderr, "  %d:  %s, %s, SN: %s\n", i, vendor, product, serial);
+	}
+	fprintf(stderr, "\n");
+	/* does string look like raw id number */
+	device = (int)strtol(s, &s2, 0);
+	if (s2[0] == '\0' && device >= 0 && device < device_count) {
+		fprintf(stderr, "Using device %d: %s\n",
+			device, rtlsdr_get_device_name((uint32_t)device));
+		return device;
+	}
+	/* does string exact match a serial */
+	for (i = 0; i < device_count; i++) {
+		rtlsdr_get_device_usb_strings(i, vendor, product, serial);
+		if (strcmp(s, serial) != 0) {
+			continue;}
+		device = i;
+		fprintf(stderr, "Using device %d: %s\n",
+			device, rtlsdr_get_device_name((uint32_t)device));
+		return device;
+	}
+	/* does string prefix match a serial */
+	for (i = 0; i < device_count; i++) {
+		rtlsdr_get_device_usb_strings(i, vendor, product, serial);
+		if (strncmp(s, serial, strlen(s)) != 0) {
+			continue;}
+		device = i;
+		fprintf(stderr, "Using device %d: %s\n",
+			device, rtlsdr_get_device_name((uint32_t)device));
+		return device;
+	}
+	/* does string suffix match a serial */
+	for (i = 0; i < device_count; i++) {
+		rtlsdr_get_device_usb_strings(i, vendor, product, serial);
+		offset = strlen(serial) - strlen(s);
+		if (offset < 0) {
+			continue;}
+		if (strncmp(s, serial+offset, strlen(s)) != 0) {
+			continue;}
+		device = i;
+		fprintf(stderr, "Using device %d: %s\n",
+			device, rtlsdr_get_device_name((uint32_t)device));
+		return device;
+	}
+	fprintf(stderr, "No matching devices found.\n");
+	return -1;
+}
+
+// vim: tabstop=8:softtabstop=8:shiftwidth=8:noexpandtab
diff --git a/src/convenience/convenience.h b/src/convenience/convenience.h
new file mode 100644
index 0000000..1faa2af
--- /dev/null
+++ b/src/convenience/convenience.h
@@ -0,0 +1,142 @@
+/*
+ * Copyright (C) 2014 by Kyle Keen <keenerd@gmail.com>
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+/* a collection of user friendly tools */
+
+/*!
+ * Convert standard suffixes (k, M, G) to double
+ *
+ * \param s a string to be parsed
+ * \return double
+ */
+
+double atofs(char *s);
+
+/*!
+ * Convert time suffixes (s, m, h) to double
+ *
+ * \param s a string to be parsed
+ * \return seconds as double
+ */
+
+double atoft(char *s);
+
+/*!
+ * Convert percent suffixe (%) to double
+ *
+ * \param s a string to be parsed
+ * \return double
+ */
+
+double atofp(char *s);
+
+/*!
+ * Find nearest supported gain
+ *
+ * \param dev the device handle given by rtlsdr_open()
+ * \param target_gain in tenths of a dB
+ * \return 0 on success
+ */
+
+int nearest_gain(rtlsdr_dev_t *dev, int target_gain);
+
+/*!
+ * Set device frequency and report status on stderr
+ *
+ * \param dev the device handle given by rtlsdr_open()
+ * \param frequency in Hz
+ * \return 0 on success
+ */
+
+int verbose_set_frequency(rtlsdr_dev_t *dev, uint32_t frequency);
+
+/*!
+ * Set device sample rate and report status on stderr
+ *
+ * \param dev the device handle given by rtlsdr_open()
+ * \param samp_rate in samples/second
+ * \return 0 on success
+ */
+
+int verbose_set_sample_rate(rtlsdr_dev_t *dev, uint32_t samp_rate);
+
+/*!
+ * Enable or disable the direct sampling mode and report status on stderr
+ *
+ * \param dev the device handle given by rtlsdr_open()
+ * \param on 0 means disabled, 1 I-ADC input enabled, 2 Q-ADC input enabled
+ * \return 0 on success
+ */
+
+int verbose_direct_sampling(rtlsdr_dev_t *dev, int on);
+
+/*!
+ * Enable offset tuning and report status on stderr
+ *
+ * \param dev the device handle given by rtlsdr_open()
+ * \return 0 on success
+ */
+
+int verbose_offset_tuning(rtlsdr_dev_t *dev);
+
+/*!
+ * Enable auto gain and report status on stderr
+ *
+ * \param dev the device handle given by rtlsdr_open()
+ * \return 0 on success
+ */
+
+int verbose_auto_gain(rtlsdr_dev_t *dev);
+
+/*!
+ * Set tuner gain and report status on stderr
+ *
+ * \param dev the device handle given by rtlsdr_open()
+ * \param gain in tenths of a dB
+ * \return 0 on success
+ */
+
+int verbose_gain_set(rtlsdr_dev_t *dev, int gain);
+
+/*!
+ * Set the frequency correction value for the device and report status on stderr.
+ *
+ * \param dev the device handle given by rtlsdr_open()
+ * \param ppm_error correction value in parts per million (ppm)
+ * \return 0 on success
+ */
+
+int verbose_ppm_set(rtlsdr_dev_t *dev, int ppm_error);
+
+/*!
+ * Reset buffer
+ *
+ * \param dev the device handle given by rtlsdr_open()
+ * \return 0 on success
+ */
+
+int verbose_reset_buffer(rtlsdr_dev_t *dev);
+
+/*!
+ * Find the closest matching device.
+ *
+ * \param s a string to be parsed
+ * \return dev_index int, -1 on error
+ */
+
+int verbose_device_search(char *s);
+
diff --git a/src/getopt/getopt.c b/src/getopt/getopt.c
new file mode 100644
index 0000000..f1d461a
--- /dev/null
+++ b/src/getopt/getopt.c
@@ -0,0 +1,1059 @@
+/* Getopt for GNU.
+   NOTE: getopt is now part of the C library, so if you don't know what
+   "Keep this file name-space clean" means, talk to drepper@gnu.org
+   before changing it!
+   Copyright (C) 1987,88,89,90,91,92,93,94,95,96,98,99,2000,2001
+   Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Lesser General Public
+   License as published by the Free Software Foundation; either
+   version 2.1 of the License, or (at your option) any later version.
+
+   The GNU C Library is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public
+   License along with the GNU C Library; if not, write to the Free
+   Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
+   02111-1307 USA.  */
+/* This tells Alpha OSF/1 not to define a getopt prototype in <stdio.h>.
+   Ditto for AIX 3.2 and <stdlib.h>.  */
+#ifndef _NO_PROTO
+# define _NO_PROTO
+#endif
+
+#ifdef HAVE_CONFIG_H
+# include <config.h>
+#endif
+
+#if !defined __STDC__ || !__STDC__
+/* This is a separate conditional since some stdc systems
+   reject `defined (const)'.  */
+# ifndef const
+#  define const
+# endif
+#endif
+
+#include <stdio.h>
+
+/* Comment out all this code if we are using the GNU C Library, and are not
+   actually compiling the library itself.  This code is part of the GNU C
+   Library, but also included in many other GNU distributions.  Compiling
+   and linking in this code is a waste when using the GNU C library
+   (especially if it is a shared library).  Rather than having every GNU
+   program understand `configure --with-gnu-libc' and omit the object files,
+   it is simpler to just do this in the source for each such file.  */
+
+#define GETOPT_INTERFACE_VERSION 2
+#if !defined _LIBC && defined __GLIBC__ && __GLIBC__ >= 2
+# include <gnu-versions.h>
+# if _GNU_GETOPT_INTERFACE_VERSION == GETOPT_INTERFACE_VERSION
+#  define ELIDE_CODE
+# endif
+#endif
+
+#ifndef ELIDE_CODE
+
+
+/* This needs to come after some library #include
+   to get __GNU_LIBRARY__ defined.  */
+#ifdef	__GNU_LIBRARY__
+/* Don't include stdlib.h for non-GNU C libraries because some of them
+   contain conflicting prototypes for getopt.  */
+# include <stdlib.h>
+# include <unistd.h>
+#endif	/* GNU C library.  */
+
+#ifdef VMS
+# include <unixlib.h>
+# if HAVE_STRING_H - 0
+#  include <string.h>
+# endif
+#endif
+
+#ifndef _
+/* This is for other GNU distributions with internationalized messages.  */
+# if (HAVE_LIBINTL_H && ENABLE_NLS) || defined _LIBC
+#  include <libintl.h>
+#  ifndef _
+#   define _(msgid)	gettext (msgid)
+#  endif
+# else
+#  define _(msgid)	(msgid)
+# endif
+#endif
+
+/* This version of `getopt' appears to the caller like standard Unix `getopt'
+   but it behaves differently for the user, since it allows the user
+   to intersperse the options with the other arguments.
+
+   As `getopt' works, it permutes the elements of ARGV so that,
+   when it is done, all the options precede everything else.  Thus
+   all application programs are extended to handle flexible argument order.
+
+   Setting the environment variable POSIXLY_CORRECT disables permutation.
+   Then the behavior is completely standard.
+
+   GNU application programs can use a third alternative mode in which
+   they can distinguish the relative order of options and other arguments.  */
+
+#include "getopt.h"
+
+/* For communication from `getopt' to the caller.
+   When `getopt' finds an option that takes an argument,
+   the argument value is returned here.
+   Also, when `ordering' is RETURN_IN_ORDER,
+   each non-option ARGV-element is returned here.  */
+
+char *optarg;
+
+/* Index in ARGV of the next element to be scanned.
+   This is used for communication to and from the caller
+   and for communication between successive calls to `getopt'.
+
+   On entry to `getopt', zero means this is the first call; initialize.
+
+   When `getopt' returns -1, this is the index of the first of the
+   non-option elements that the caller should itself scan.
+
+   Otherwise, `optind' communicates from one call to the next
+   how much of ARGV has been scanned so far.  */
+
+/* 1003.2 says this must be 1 before any call.  */
+int optind = 1;
+
+/* Formerly, initialization of getopt depended on optind==0, which
+   causes problems with re-calling getopt as programs generally don't
+   know that. */
+
+int __getopt_initialized;
+
+/* The next char to be scanned in the option-element
+   in which the last option character we returned was found.
+   This allows us to pick up the scan where we left off.
+
+   If this is zero, or a null string, it means resume the scan
+   by advancing to the next ARGV-element.  */
+
+static char *nextchar;
+
+/* Callers store zero here to inhibit the error message
+   for unrecognized options.  */
+
+int opterr = 1;
+
+/* Set to an option character which was unrecognized.
+   This must be initialized on some systems to avoid linking in the
+   system's own getopt implementation.  */
+
+int optopt = '?';
+
+/* Describe how to deal with options that follow non-option ARGV-elements.
+
+   If the caller did not specify anything,
+   the default is REQUIRE_ORDER if the environment variable
+   POSIXLY_CORRECT is defined, PERMUTE otherwise.
+
+   REQUIRE_ORDER means don't recognize them as options;
+   stop option processing when the first non-option is seen.
+   This is what Unix does.
+   This mode of operation is selected by either setting the environment
+   variable POSIXLY_CORRECT, or using `+' as the first character
+   of the list of option characters.
+
+   PERMUTE is the default.  We permute the contents of ARGV as we scan,
+   so that eventually all the non-options are at the end.  This allows options
+   to be given in any order, even with programs that were not written to
+   expect this.
+
+   RETURN_IN_ORDER is an option available to programs that were written
+   to expect options and other ARGV-elements in any order and that care about
+   the ordering of the two.  We describe each non-option ARGV-element
+   as if it were the argument of an option with character code 1.
+   Using `-' as the first character of the list of option characters
+   selects this mode of operation.
+
+   The special argument `--' forces an end of option-scanning regardless
+   of the value of `ordering'.  In the case of RETURN_IN_ORDER, only
+   `--' can cause `getopt' to return -1 with `optind' != ARGC.  */
+
+static enum
+{
+  REQUIRE_ORDER, PERMUTE, RETURN_IN_ORDER
+} ordering;
+
+/* Value of POSIXLY_CORRECT environment variable.  */
+static char *posixly_correct;
+
+#ifdef	__GNU_LIBRARY__
+/* We want to avoid inclusion of string.h with non-GNU libraries
+   because there are many ways it can cause trouble.
+   On some systems, it contains special magic macros that don't work
+   in GCC.  */
+# include <string.h>
+# define my_index	strchr
+#else
+
+# if 1 //HAVE_STRING_H
+#  include <string.h>
+# else
+#  include <strings.h>
+# endif
+
+/* Avoid depending on library functions or files
+   whose names are inconsistent.  */
+
+#ifndef getenv
+#ifdef _MSC_VER
+// DDK will complain if you don't use the stdlib defined getenv
+#include <stdlib.h>
+#else
+extern char *getenv ();
+#endif
+#endif
+
+static char *
+my_index (str, chr)
+     const char *str;
+     int chr;
+{
+  while (*str)
+    {
+      if (*str == chr)
+	return (char *) str;
+      str++;
+    }
+  return 0;
+}
+
+/* If using GCC, we can safely declare strlen this way.
+   If not using GCC, it is ok not to declare it.  */
+#ifdef __GNUC__
+/* Note that Motorola Delta 68k R3V7 comes with GCC but not stddef.h.
+   That was relevant to code that was here before.  */
+# if (!defined __STDC__ || !__STDC__) && !defined strlen
+/* gcc with -traditional declares the built-in strlen to return int,
+   and has done so at least since version 2.4.5. -- rms.  */
+extern int strlen (const char *);
+# endif /* not __STDC__ */
+#endif /* __GNUC__ */
+
+#endif /* not __GNU_LIBRARY__ */
+
+/* Handle permutation of arguments.  */
+
+/* Describe the part of ARGV that contains non-options that have
+   been skipped.  `first_nonopt' is the index in ARGV of the first of them;
+   `last_nonopt' is the index after the last of them.  */
+
+static int first_nonopt;
+static int last_nonopt;
+
+#ifdef _LIBC
+/* Stored original parameters.
+   XXX This is no good solution.  We should rather copy the args so
+   that we can compare them later.  But we must not use malloc(3).  */
+extern int __libc_argc;
+extern char **__libc_argv;
+
+/* Bash 2.0 gives us an environment variable containing flags
+   indicating ARGV elements that should not be considered arguments.  */
+
+# ifdef USE_NONOPTION_FLAGS
+/* Defined in getopt_init.c  */
+extern char *__getopt_nonoption_flags;
+
+static int nonoption_flags_max_len;
+static int nonoption_flags_len;
+# endif
+
+# ifdef USE_NONOPTION_FLAGS
+#  define SWAP_FLAGS(ch1, ch2) \
+  if (nonoption_flags_len > 0)						      \
+    {									      \
+      char __tmp = __getopt_nonoption_flags[ch1];			      \
+      __getopt_nonoption_flags[ch1] = __getopt_nonoption_flags[ch2];	      \
+      __getopt_nonoption_flags[ch2] = __tmp;				      \
+    }
+# else
+#  define SWAP_FLAGS(ch1, ch2)
+# endif
+#else	/* !_LIBC */
+# define SWAP_FLAGS(ch1, ch2)
+#endif	/* _LIBC */
+
+/* Exchange two adjacent subsequences of ARGV.
+   One subsequence is elements [first_nonopt,last_nonopt)
+   which contains all the non-options that have been skipped so far.
+   The other is elements [last_nonopt,optind), which contains all
+   the options processed since those non-options were skipped.
+
+   `first_nonopt' and `last_nonopt' are relocated so that they describe
+   the new indices of the non-options in ARGV after they are moved.  */
+
+#if defined __STDC__ && __STDC__
+static void exchange (char **);
+#endif
+
+static void
+exchange (argv)
+     char **argv;
+{
+  int bottom = first_nonopt;
+  int middle = last_nonopt;
+  int top = optind;
+  char *tem;
+
+  /* Exchange the shorter segment with the far end of the longer segment.
+     That puts the shorter segment into the right place.
+     It leaves the longer segment in the right place overall,
+     but it consists of two parts that need to be swapped next.  */
+
+#if defined _LIBC && defined USE_NONOPTION_FLAGS
+  /* First make sure the handling of the `__getopt_nonoption_flags'
+     string can work normally.  Our top argument must be in the range
+     of the string.  */
+  if (nonoption_flags_len > 0 && top >= nonoption_flags_max_len)
+    {
+      /* We must extend the array.  The user plays games with us and
+	 presents new arguments.  */
+      char *new_str = malloc (top + 1);
+      if (new_str == NULL)
+	nonoption_flags_len = nonoption_flags_max_len = 0;
+      else
+	{
+	  memset (__mempcpy (new_str, __getopt_nonoption_flags,
+			     nonoption_flags_max_len),
+		  '\0', top + 1 - nonoption_flags_max_len);
+	  nonoption_flags_max_len = top + 1;
+	  __getopt_nonoption_flags = new_str;
+	}
+    }
+#endif
+
+  while (top > middle && middle > bottom)
+    {
+      if (top - middle > middle - bottom)
+	{
+	  /* Bottom segment is the short one.  */
+	  int len = middle - bottom;
+	  register int i;
+
+	  /* Swap it with the top part of the top segment.  */
+	  for (i = 0; i < len; i++)
+	    {
+	      tem = argv[bottom + i];
+	      argv[bottom + i] = argv[top - (middle - bottom) + i];
+	      argv[top - (middle - bottom) + i] = tem;
+	      SWAP_FLAGS (bottom + i, top - (middle - bottom) + i);
+	    }
+	  /* Exclude the moved bottom segment from further swapping.  */
+	  top -= len;
+	}
+      else
+	{
+	  /* Top segment is the short one.  */
+	  int len = top - middle;
+	  register int i;
+
+	  /* Swap it with the bottom part of the bottom segment.  */
+	  for (i = 0; i < len; i++)
+	    {
+	      tem = argv[bottom + i];
+	      argv[bottom + i] = argv[middle + i];
+	      argv[middle + i] = tem;
+	      SWAP_FLAGS (bottom + i, middle + i);
+	    }
+	  /* Exclude the moved top segment from further swapping.  */
+	  bottom += len;
+	}
+    }
+
+  /* Update records for the slots the non-options now occupy.  */
+
+  first_nonopt += (optind - last_nonopt);
+  last_nonopt = optind;
+}
+
+/* Initialize the internal data when the first call is made.  */
+
+#if defined __STDC__ && __STDC__
+static const char *_getopt_initialize (int, char *const *, const char *);
+#endif
+static const char *
+_getopt_initialize (argc, argv, optstring)
+     int argc;
+     char *const *argv;
+     const char *optstring;
+{
+  /* Start processing options with ARGV-element 1 (since ARGV-element 0
+     is the program name); the sequence of previously skipped
+     non-option ARGV-elements is empty.  */
+
+  first_nonopt = last_nonopt = optind;
+
+  nextchar = NULL;
+
+  posixly_correct = getenv ("POSIXLY_CORRECT");
+
+  /* Determine how to handle the ordering of options and nonoptions.  */
+
+  if (optstring[0] == '-')
+    {
+      ordering = RETURN_IN_ORDER;
+      ++optstring;
+    }
+  else if (optstring[0] == '+')
+    {
+      ordering = REQUIRE_ORDER;
+      ++optstring;
+    }
+  else if (posixly_correct != NULL)
+    ordering = REQUIRE_ORDER;
+  else
+    ordering = PERMUTE;
+
+#if defined _LIBC && defined USE_NONOPTION_FLAGS
+  if (posixly_correct == NULL
+      && argc == __libc_argc && argv == __libc_argv)
+    {
+      if (nonoption_flags_max_len == 0)
+	{
+	  if (__getopt_nonoption_flags == NULL
+	      || __getopt_nonoption_flags[0] == '\0')
+	    nonoption_flags_max_len = -1;
+	  else
+	    {
+	      const char *orig_str = __getopt_nonoption_flags;
+	      int len = nonoption_flags_max_len = strlen (orig_str);
+	      if (nonoption_flags_max_len < argc)
+		nonoption_flags_max_len = argc;
+	      __getopt_nonoption_flags =
+		(char *) malloc (nonoption_flags_max_len);
+	      if (__getopt_nonoption_flags == NULL)
+		nonoption_flags_max_len = -1;
+	      else
+		memset (__mempcpy (__getopt_nonoption_flags, orig_str, len),
+			'\0', nonoption_flags_max_len - len);
+	    }
+	}
+      nonoption_flags_len = nonoption_flags_max_len;
+    }
+  else
+    nonoption_flags_len = 0;
+#endif
+
+  return optstring;
+}
+
+/* Scan elements of ARGV (whose length is ARGC) for option characters
+   given in OPTSTRING.
+
+   If an element of ARGV starts with '-', and is not exactly "-" or "--",
+   then it is an option element.  The characters of this element
+   (aside from the initial '-') are option characters.  If `getopt'
+   is called repeatedly, it returns successively each of the option characters
+   from each of the option elements.
+
+   If `getopt' finds another option character, it returns that character,
+   updating `optind' and `nextchar' so that the next call to `getopt' can
+   resume the scan with the following option character or ARGV-element.
+
+   If there are no more option characters, `getopt' returns -1.
+   Then `optind' is the index in ARGV of the first ARGV-element
+   that is not an option.  (The ARGV-elements have been permuted
+   so that those that are not options now come last.)
+
+   OPTSTRING is a string containing the legitimate option characters.
+   If an option character is seen that is not listed in OPTSTRING,
+   return '?' after printing an error message.  If you set `opterr' to
+   zero, the error message is suppressed but we still return '?'.
+
+   If a char in OPTSTRING is followed by a colon, that means it wants an arg,
+   so the following text in the same ARGV-element, or the text of the following
+   ARGV-element, is returned in `optarg'.  Two colons mean an option that
+   wants an optional arg; if there is text in the current ARGV-element,
+   it is returned in `optarg', otherwise `optarg' is set to zero.
+
+   If OPTSTRING starts with `-' or `+', it requests different methods of
+   handling the non-option ARGV-elements.
+   See the comments about RETURN_IN_ORDER and REQUIRE_ORDER, above.
+
+   Long-named options begin with `--' instead of `-'.
+   Their names may be abbreviated as long as the abbreviation is unique
+   or is an exact match for some defined option.  If they have an
+   argument, it follows the option name in the same ARGV-element, separated
+   from the option name by a `=', or else the in next ARGV-element.
+   When `getopt' finds a long-named option, it returns 0 if that option's
+   `flag' field is nonzero, the value of the option's `val' field
+   if the `flag' field is zero.
+
+   The elements of ARGV aren't really const, because we permute them.
+   But we pretend they're const in the prototype to be compatible
+   with other systems.
+
+   LONGOPTS is a vector of `struct option' terminated by an
+   element containing a name which is zero.
+
+   LONGIND returns the index in LONGOPT of the long-named option found.
+   It is only valid when a long-named option has been found by the most
+   recent call.
+
+   If LONG_ONLY is nonzero, '-' as well as '--' can introduce
+   long-named options.  */
+
+int
+_getopt_internal (argc, argv, optstring, longopts, longind, long_only)
+     int argc;
+     char *const *argv;
+     const char *optstring;
+     const struct option *longopts;
+     int *longind;
+     int long_only;
+{
+  int print_errors = opterr;
+  if (optstring[0] == ':')
+    print_errors = 0;
+
+  if (argc < 1)
+    return -1;
+
+  optarg = NULL;
+
+  if (optind == 0 || !__getopt_initialized)
+    {
+      if (optind == 0)
+	optind = 1;	/* Don't scan ARGV[0], the program name.  */
+      optstring = _getopt_initialize (argc, argv, optstring);
+      __getopt_initialized = 1;
+    }
+
+  /* Test whether ARGV[optind] points to a non-option argument.
+     Either it does not have option syntax, or there is an environment flag
+     from the shell indicating it is not an option.  The later information
+     is only used when the used in the GNU libc.  */
+#if defined _LIBC && defined USE_NONOPTION_FLAGS
+# define NONOPTION_P (argv[optind][0] != '-' || argv[optind][1] == '\0'	      \
+		      || (optind < nonoption_flags_len			      \
+			  && __getopt_nonoption_flags[optind] == '1'))
+#else
+# define NONOPTION_P (argv[optind][0] != '-' || argv[optind][1] == '\0')
+#endif
+
+  if (nextchar == NULL || *nextchar == '\0')
+    {
+      /* Advance to the next ARGV-element.  */
+
+      /* Give FIRST_NONOPT & LAST_NONOPT rational values if OPTIND has been
+	 moved back by the user (who may also have changed the arguments).  */
+      if (last_nonopt > optind)
+	last_nonopt = optind;
+      if (first_nonopt > optind)
+	first_nonopt = optind;
+
+      if (ordering == PERMUTE)
+	{
+	  /* If we have just processed some options following some non-options,
+	     exchange them so that the options come first.  */
+
+	  if (first_nonopt != last_nonopt && last_nonopt != optind)
+	    exchange ((char **) argv);
+	  else if (last_nonopt != optind)
+	    first_nonopt = optind;
+
+	  /* Skip any additional non-options
+	     and extend the range of non-options previously skipped.  */
+
+	  while (optind < argc && NONOPTION_P)
+	    optind++;
+	  last_nonopt = optind;
+	}
+
+      /* The special ARGV-element `--' means premature end of options.
+	 Skip it like a null option,
+	 then exchange with previous non-options as if it were an option,
+	 then skip everything else like a non-option.  */
+
+      if (optind != argc && !strcmp (argv[optind], "--"))
+	{
+	  optind++;
+
+	  if (first_nonopt != last_nonopt && last_nonopt != optind)
+	    exchange ((char **) argv);
+	  else if (first_nonopt == last_nonopt)
+	    first_nonopt = optind;
+	  last_nonopt = argc;
+
+	  optind = argc;
+	}
+
+      /* If we have done all the ARGV-elements, stop the scan
+	 and back over any non-options that we skipped and permuted.  */
+
+      if (optind == argc)
+	{
+	  /* Set the next-arg-index to point at the non-options
+	     that we previously skipped, so the caller will digest them.  */
+	  if (first_nonopt != last_nonopt)
+	    optind = first_nonopt;
+	  return -1;
+	}
+
+      /* If we have come to a non-option and did not permute it,
+	 either stop the scan or describe it to the caller and pass it by.  */
+
+      if (NONOPTION_P)
+	{
+	  if (ordering == REQUIRE_ORDER)
+	    return -1;
+	  optarg = argv[optind++];
+	  return 1;
+	}
+
+      /* We have found another option-ARGV-element.
+	 Skip the initial punctuation.  */
+
+      nextchar = (argv[optind] + 1
+		  + (longopts != NULL && argv[optind][1] == '-'));
+    }
+
+  /* Decode the current option-ARGV-element.  */
+
+  /* Check whether the ARGV-element is a long option.
+
+     If long_only and the ARGV-element has the form "-f", where f is
+     a valid short option, don't consider it an abbreviated form of
+     a long option that starts with f.  Otherwise there would be no
+     way to give the -f short option.
+
+     On the other hand, if there's a long option "fubar" and
+     the ARGV-element is "-fu", do consider that an abbreviation of
+     the long option, just like "--fu", and not "-f" with arg "u".
+
+     This distinction seems to be the most useful approach.  */
+
+  if (longopts != NULL
+      && (argv[optind][1] == '-'
+	  || (long_only && (argv[optind][2] || !my_index (optstring, argv[optind][1])))))
+    {
+      char *nameend;
+      const struct option *p;
+      const struct option *pfound = NULL;
+      int exact = 0;
+      int ambig = 0;
+      int indfound = -1;
+      int option_index;
+
+      for (nameend = nextchar; *nameend && *nameend != '='; nameend++)
+	/* Do nothing.  */ ;
+
+      /* Test all long options for either exact match
+	 or abbreviated matches.  */
+      for (p = longopts, option_index = 0; p->name; p++, option_index++)
+	if (!strncmp (p->name, nextchar, nameend - nextchar))
+	  {
+	    if ((unsigned int) (nameend - nextchar)
+		== (unsigned int) strlen (p->name))
+	      {
+		/* Exact match found.  */
+		pfound = p;
+		indfound = option_index;
+		exact = 1;
+		break;
+	      }
+	    else if (pfound == NULL)
+	      {
+		/* First nonexact match found.  */
+		pfound = p;
+		indfound = option_index;
+	      }
+	    else if (long_only
+		     || pfound->has_arg != p->has_arg
+		     || pfound->flag != p->flag
+		     || pfound->val != p->val)
+	      /* Second or later nonexact match found.  */
+	      ambig = 1;
+	  }
+
+      if (ambig && !exact)
+	{
+	  if (print_errors)
+	    fprintf (stderr, _("%s: option `%s' is ambiguous\n"),
+		     argv[0], argv[optind]);
+	  nextchar += strlen (nextchar);
+	  optind++;
+	  optopt = 0;
+	  return '?';
+	}
+
+      if (pfound != NULL)
+	{
+	  option_index = indfound;
+	  optind++;
+	  if (*nameend)
+	    {
+	      /* Don't test has_arg with >, because some C compilers don't
+		 allow it to be used on enums.  */
+	      if (pfound->has_arg)
+		optarg = nameend + 1;
+	      else
+		{
+		  if (print_errors)
+		    {
+		      if (argv[optind - 1][1] == '-')
+			/* --option */
+			fprintf (stderr,
+				 _("%s: option `--%s' doesn't allow an argument\n"),
+				 argv[0], pfound->name);
+		      else
+			/* +option or -option */
+			fprintf (stderr,
+				 _("%s: option `%c%s' doesn't allow an argument\n"),
+				 argv[0], argv[optind - 1][0], pfound->name);
+		    }
+
+		  nextchar += strlen (nextchar);
+
+		  optopt = pfound->val;
+		  return '?';
+		}
+	    }
+	  else if (pfound->has_arg == 1)
+	    {
+	      if (optind < argc)
+		optarg = argv[optind++];
+	      else
+		{
+		  if (print_errors)
+		    fprintf (stderr,
+			   _("%s: option `%s' requires an argument\n"),
+			   argv[0], argv[optind - 1]);
+		  nextchar += strlen (nextchar);
+		  optopt = pfound->val;
+		  return optstring[0] == ':' ? ':' : '?';
+		}
+	    }
+	  nextchar += strlen (nextchar);
+	  if (longind != NULL)
+	    *longind = option_index;
+	  if (pfound->flag)
+	    {
+	      *(pfound->flag) = pfound->val;
+	      return 0;
+	    }
+	  return pfound->val;
+	}
+
+      /* Can't find it as a long option.  If this is not getopt_long_only,
+	 or the option starts with '--' or is not a valid short
+	 option, then it's an error.
+	 Otherwise interpret it as a short option.  */
+      if (!long_only || argv[optind][1] == '-'
+	  || my_index (optstring, *nextchar) == NULL)
+	{
+	  if (print_errors)
+	    {
+	      if (argv[optind][1] == '-')
+		/* --option */
+		fprintf (stderr, _("%s: unrecognized option `--%s'\n"),
+			 argv[0], nextchar);
+	      else
+		/* +option or -option */
+		fprintf (stderr, _("%s: unrecognized option `%c%s'\n"),
+			 argv[0], argv[optind][0], nextchar);
+	    }
+	  nextchar = (char *) "";
+	  optind++;
+	  optopt = 0;
+	  return '?';
+	}
+    }
+
+  /* Look at and handle the next short option-character.  */
+
+  {
+    char c = *nextchar++;
+    char *temp = my_index (optstring, c);
+
+    /* Increment `optind' when we start to process its last character.  */
+    if (*nextchar == '\0')
+      ++optind;
+
+    if (temp == NULL || c == ':')
+      {
+	if (print_errors)
+	  {
+	    if (posixly_correct)
+	      /* 1003.2 specifies the format of this message.  */
+	      fprintf (stderr, _("%s: illegal option -- %c\n"),
+		       argv[0], c);
+	    else
+	      fprintf (stderr, _("%s: invalid option -- %c\n"),
+		       argv[0], c);
+	  }
+	optopt = c;
+	return '?';
+      }
+    /* Convenience. Treat POSIX -W foo same as long option --foo */
+    if (temp[0] == 'W' && temp[1] == ';')
+      {
+	char *nameend;
+	const struct option *p;
+	const struct option *pfound = NULL;
+	int exact = 0;
+	int ambig = 0;
+	int indfound = 0;
+	int option_index;
+
+	/* This is an option that requires an argument.  */
+	if (*nextchar != '\0')
+	  {
+	    optarg = nextchar;
+	    /* If we end this ARGV-element by taking the rest as an arg,
+	       we must advance to the next element now.  */
+	    optind++;
+	  }
+	else if (optind == argc)
+	  {
+	    if (print_errors)
+	      {
+		/* 1003.2 specifies the format of this message.  */
+		fprintf (stderr, _("%s: option requires an argument -- %c\n"),
+			 argv[0], c);
+	      }
+	    optopt = c;
+	    if (optstring[0] == ':')
+	      c = ':';
+	    else
+	      c = '?';
+	    return c;
+	  }
+	else
+	  /* We already incremented `optind' once;
+	     increment it again when taking next ARGV-elt as argument.  */
+	  optarg = argv[optind++];
+
+	/* optarg is now the argument, see if it's in the
+	   table of longopts.  */
+
+	for (nextchar = nameend = optarg; *nameend && *nameend != '='; nameend++)
+	  /* Do nothing.  */ ;
+
+	/* Test all long options for either exact match
+	   or abbreviated matches.  */
+	for (p = longopts, option_index = 0; p->name; p++, option_index++)
+	  if (!strncmp (p->name, nextchar, nameend - nextchar))
+	    {
+	      if ((unsigned int) (nameend - nextchar) == strlen (p->name))
+		{
+		  /* Exact match found.  */
+		  pfound = p;
+		  indfound = option_index;
+		  exact = 1;
+		  break;
+		}
+	      else if (pfound == NULL)
+		{
+		  /* First nonexact match found.  */
+		  pfound = p;
+		  indfound = option_index;
+		}
+	      else
+		/* Second or later nonexact match found.  */
+		ambig = 1;
+	    }
+	if (ambig && !exact)
+	  {
+	    if (print_errors)
+	      fprintf (stderr, _("%s: option `-W %s' is ambiguous\n"),
+		       argv[0], argv[optind]);
+	    nextchar += strlen (nextchar);
+	    optind++;
+	    return '?';
+	  }
+	if (pfound != NULL)
+	  {
+	    option_index = indfound;
+	    if (*nameend)
+	      {
+		/* Don't test has_arg with >, because some C compilers don't
+		   allow it to be used on enums.  */
+		if (pfound->has_arg)
+		  optarg = nameend + 1;
+		else
+		  {
+		    if (print_errors)
+		      fprintf (stderr, _("\
+			%s: option `-W %s' doesn't allow an argument\n"),
+			       argv[0], pfound->name);
+
+		    nextchar += strlen (nextchar);
+		    return '?';
+		  }
+	      }
+	    else if (pfound->has_arg == 1)
+	      {
+		if (optind < argc)
+		  optarg = argv[optind++];
+		else
+		  {
+		    if (print_errors)
+		      fprintf (stderr,
+			       _("%s: option `%s' requires an argument\n"),
+			       argv[0], argv[optind - 1]);
+		    nextchar += strlen (nextchar);
+		    return optstring[0] == ':' ? ':' : '?';
+		  }
+	      }
+	    nextchar += strlen (nextchar);
+	    if (longind != NULL)
+	      *longind = option_index;
+	    if (pfound->flag)
+	      {
+		*(pfound->flag) = pfound->val;
+		return 0;
+	      }
+	    return pfound->val;
+	  }
+	  nextchar = NULL;
+	  return 'W';	/* Let the application handle it.   */
+      }
+    if (temp[1] == ':')
+      {
+	if (temp[2] == ':')
+	  {
+	    /* This is an option that accepts an argument optionally.  */
+	    if (*nextchar != '\0')
+	      {
+		optarg = nextchar;
+		optind++;
+	      }
+	    else
+	      optarg = NULL;
+	    nextchar = NULL;
+	  }
+	else
+	  {
+	    /* This is an option that requires an argument.  */
+	    if (*nextchar != '\0')
+	      {
+		optarg = nextchar;
+		/* If we end this ARGV-element by taking the rest as an arg,
+		   we must advance to the next element now.  */
+		optind++;
+	      }
+	    else if (optind == argc)
+	      {
+		if (print_errors)
+		  {
+		    /* 1003.2 specifies the format of this message.  */
+		    fprintf (stderr,
+			     _("%s: option requires an argument -- %c\n"),
+			     argv[0], c);
+		  }
+		optopt = c;
+		if (optstring[0] == ':')
+		  c = ':';
+		else
+		  c = '?';
+	      }
+	    else
+	      /* We already incremented `optind' once;
+		 increment it again when taking next ARGV-elt as argument.  */
+	      optarg = argv[optind++];
+	    nextchar = NULL;
+	  }
+      }
+    return c;
+  }
+}
+
+int
+getopt (argc, argv, optstring)
+     int argc;
+     char *const *argv;
+     const char *optstring;
+{
+  return _getopt_internal (argc, argv, optstring,
+			   (const struct option *) 0,
+			   (int *) 0,
+			   0);
+}
+
+#endif	/* Not ELIDE_CODE.  */
+
+#ifdef TEST
+
+/* Compile with -DTEST to make an executable for use in testing
+   the above definition of `getopt'.  */
+
+int
+main (argc, argv)
+     int argc;
+     char **argv;
+{
+  int c;
+  int digit_optind = 0;
+
+  while (1)
+    {
+      int this_option_optind = optind ? optind : 1;
+
+      c = getopt (argc, argv, "abc:d:0123456789");
+      if (c == -1)
+	break;
+
+      switch (c)
+	{
+	case '0':
+	case '1':
+	case '2':
+	case '3':
+	case '4':
+	case '5':
+	case '6':
+	case '7':
+	case '8':
+	case '9':
+	  if (digit_optind != 0 && digit_optind != this_option_optind)
+	    printf ("digits occur in two different argv-elements.\n");
+	  digit_optind = this_option_optind;
+	  printf ("option %c\n", c);
+	  break;
+
+	case 'a':
+	  printf ("option a\n");
+	  break;
+
+	case 'b':
+	  printf ("option b\n");
+	  break;
+
+	case 'c':
+	  printf ("option c with value `%s'\n", optarg);
+	  break;
+
+	case '?':
+	  break;
+
+	default:
+	  printf ("?? getopt returned character code 0%o ??\n", c);
+	}
+    }
+
+  if (optind < argc)
+    {
+      printf ("non-option ARGV-elements: ");
+      while (optind < argc)
+	printf ("%s ", argv[optind++]);
+      printf ("\n");
+    }
+
+  exit (0);
+}
+
+#endif /* TEST */
diff --git a/src/getopt/getopt.h b/src/getopt/getopt.h
new file mode 100644
index 0000000..a1b8dd6
--- /dev/null
+++ b/src/getopt/getopt.h
@@ -0,0 +1,180 @@
+/* Declarations for getopt.
+   Copyright (C) 1989-1994, 1996-1999, 2001 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Lesser General Public
+   License as published by the Free Software Foundation; either
+   version 2.1 of the License, or (at your option) any later version.
+
+   The GNU C Library is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+   Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public
+   License along with the GNU C Library; if not, write to the Free
+   Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
+   02111-1307 USA.  */
+
+#ifndef _GETOPT_H
+
+#ifndef __need_getopt
+# define _GETOPT_H 1
+#endif
+
+/* If __GNU_LIBRARY__ is not already defined, either we are being used
+   standalone, or this is the first header included in the source file.
+   If we are being used with glibc, we need to include <features.h>, but
+   that does not exist if we are standalone.  So: if __GNU_LIBRARY__ is
+   not defined, include <ctype.h>, which will pull in <features.h> for us
+   if it's from glibc.  (Why ctype.h?  It's guaranteed to exist and it
+   doesn't flood the namespace with stuff the way some other headers do.)  */
+#if !defined __GNU_LIBRARY__
+# include <ctype.h>
+#endif
+
+#ifdef	__cplusplus
+extern "C" {
+#endif
+
+/* For communication from `getopt' to the caller.
+   When `getopt' finds an option that takes an argument,
+   the argument value is returned here.
+   Also, when `ordering' is RETURN_IN_ORDER,
+   each non-option ARGV-element is returned here.  */
+
+extern char *optarg;
+
+/* Index in ARGV of the next element to be scanned.
+   This is used for communication to and from the caller
+   and for communication between successive calls to `getopt'.
+
+   On entry to `getopt', zero means this is the first call; initialize.
+
+   When `getopt' returns -1, this is the index of the first of the
+   non-option elements that the caller should itself scan.
+
+   Otherwise, `optind' communicates from one call to the next
+   how much of ARGV has been scanned so far.  */
+
+extern int optind;
+
+/* Callers store zero here to inhibit the error message `getopt' prints
+   for unrecognized options.  */
+
+extern int opterr;
+
+/* Set to an option character which was unrecognized.  */
+
+extern int optopt;
+
+#ifndef __need_getopt
+/* Describe the long-named options requested by the application.
+   The LONG_OPTIONS argument to getopt_long or getopt_long_only is a vector
+   of `struct option' terminated by an element containing a name which is
+   zero.
+
+   The field `has_arg' is:
+   no_argument		(or 0) if the option does not take an argument,
+   required_argument	(or 1) if the option requires an argument,
+   optional_argument 	(or 2) if the option takes an optional argument.
+
+   If the field `flag' is not NULL, it points to a variable that is set
+   to the value given in the field `val' when the option is found, but
+   left unchanged if the option is not found.
+
+   To have a long-named option do something other than set an `int' to
+   a compiled-in constant, such as set a value from `optarg', set the
+   option's `flag' field to zero and its `val' field to a nonzero
+   value (the equivalent single-letter option character, if there is
+   one).  For long options that have a zero `flag' field, `getopt'
+   returns the contents of the `val' field.  */
+
+struct option
+{
+# if (defined __STDC__ && __STDC__) || defined __cplusplus
+  const char *name;
+# else
+  char *name;
+# endif
+  /* has_arg can't be an enum because some compilers complain about
+     type mismatches in all the code that assumes it is an int.  */
+  int has_arg;
+  int *flag;
+  int val;
+};
+
+/* Names for the values of the `has_arg' field of `struct option'.  */
+
+# define no_argument		0
+# define required_argument	1
+# define optional_argument	2
+#endif	/* need getopt */
+
+
+/* Get definitions and prototypes for functions to process the
+   arguments in ARGV (ARGC of them, minus the program name) for
+   options given in OPTS.
+
+   Return the option character from OPTS just read.  Return -1 when
+   there are no more options.  For unrecognized options, or options
+   missing arguments, `optopt' is set to the option letter, and '?' is
+   returned.
+
+   The OPTS string is a list of characters which are recognized option
+   letters, optionally followed by colons, specifying that that letter
+   takes an argument, to be placed in `optarg'.
+
+   If a letter in OPTS is followed by two colons, its argument is
+   optional.  This behavior is specific to the GNU `getopt'.
+
+   The argument `--' causes premature termination of argument
+   scanning, explicitly telling `getopt' that there are no more
+   options.
+
+   If OPTS begins with `--', then non-option arguments are treated as
+   arguments to the option '\0'.  This behavior is specific to the GNU
+   `getopt'.  */
+
+#if (defined __STDC__ && __STDC__) || defined __cplusplus
+# ifdef __GNU_LIBRARY__
+/* Many other libraries have conflicting prototypes for getopt, with
+   differences in the consts, in stdlib.h.  To avoid compilation
+   errors, only prototype getopt for the GNU C library.  */
+extern int getopt (int __argc, char *const *__argv, const char *__shortopts);
+# else /* not __GNU_LIBRARY__ */
+extern int getopt ();
+# endif /* __GNU_LIBRARY__ */
+
+# ifndef __need_getopt
+extern int getopt_long (int __argc, char *const *__argv, const char *__shortopts,
+		        const struct option *__longopts, int *__longind);
+extern int getopt_long_only (int __argc, char *const *__argv,
+			     const char *__shortopts,
+		             const struct option *__longopts, int *__longind);
+
+/* Internal only.  Users should not call this directly.  */
+extern int _getopt_internal (int __argc, char *const *__argv,
+			     const char *__shortopts,
+		             const struct option *__longopts, int *__longind,
+			     int __long_only);
+# endif
+#else /* not __STDC__ */
+extern int getopt ();
+# ifndef __need_getopt
+extern int getopt_long ();
+extern int getopt_long_only ();
+
+extern int _getopt_internal ();
+# endif
+#endif /* __STDC__ */
+
+#ifdef	__cplusplus
+}
+#endif
+
+/* Make sure we later can get all the definitions and declarations.  */
+#undef __need_getopt
+
+#endif /* getopt.h */
diff --git a/src/make.mk b/src/make.mk
new file mode 100644
index 0000000..0d5e4f8
--- /dev/null
+++ b/src/make.mk
@@ -0,0 +1,15 @@
+DIR=src
+
+SRC_UTILS     += $(wildcard $(DIR)/*.c)
+SRC_UTILS_PRE += $(wildcard $(DIR)/convenience/*.c)
+OBJ_UTILS     += $(SRC_UTILS:.c=)
+OBJ_UTILS_PRE += $(SRC_UTILS_PRE:.c=.o)
+LDFLAGS_UTILS = -pthread  -lr820t -lrusb -lm -L.
+
+$(DIR)-pre: $(OBJ_UTILS_PRE) $(OBJ_UTILS)
+
+$(DIR)/convenience/%.o: $(DIR)/convenience/%.c
+	$(CC) $(CFLAGS) $(INCLUDE) -c $< -o $(BUILD_DIR)$@
+
+$(DIR)/%:  $(DIR)/%.c
+	$(CC) $(CFLAGS) $(INCLUDE) -Wl,-rpath=. $(BUILD_DIR)$(OBJ_UTILS_PRE)  $< -o $(BUILD_DIR)$@ $(LDFLAGS_UTILS) 
diff --git a/src/rtl_adsb.c b/src/rtl_adsb.c
new file mode 100644
index 0000000..7aea8dd
--- /dev/null
+++ b/src/rtl_adsb.c
@@ -0,0 +1,507 @@
+/*
+ * rtl-sdr, turns your Realtek RTL2832 based DVB dongle into a SDR receiver
+ * Copyright (C) 2012 by Steve Markgraf <steve@steve-m.de>
+ * Copyright (C) 2012 by Hoernchen <la@tfc-server.de>
+ * Copyright (C) 2012 by Kyle Keen <keenerd@gmail.com>
+ * Copyright (C) 2012 by Youssef Touil <youssef@sdrsharp.com>
+ * Copyright (C) 2012 by Ian Gilmour <ian@sdrsharp.com>
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+
+#include <errno.h>
+#include <signal.h>
+#include <string.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <math.h>
+
+#ifndef _WIN32
+#include <unistd.h>
+#else
+#include <windows.h>
+#include <fcntl.h>
+#include <io.h>
+#include "getopt/getopt.h"
+#endif
+
+#include <pthread.h>
+#include <libusb.h>
+
+#include "rtl-sdr.h"
+#include "convenience/convenience.h"
+
+#ifdef _WIN32
+#define sleep Sleep
+#if defined(_MSC_VER) && (_MSC_VER < 1800)
+#define round(x) (x > 0.0 ? floor(x + 0.5): ceil(x - 0.5))
+#endif
+#endif
+
+#define ADSB_RATE			2000000
+#define ADSB_FREQ			1090000000
+#define DEFAULT_ASYNC_BUF_NUMBER	12
+#define DEFAULT_BUF_LENGTH		(16 * 16384)
+#define AUTO_GAIN			-100
+
+#define MESSAGEGO    253
+#define OVERWRITE    254
+#define BADSAMPLE    255
+
+static pthread_t demod_thread;
+static pthread_cond_t ready;
+static pthread_mutex_t ready_m;
+static volatile int do_exit = 0;
+static rtlsdr_dev_t *dev = NULL;
+
+uint16_t squares[256];
+
+/* todo, bundle these up in a struct */
+uint8_t *buffer;  /* also abused for uint16_t */
+int verbose_output = 0;
+int short_output = 0;
+int quality = 10;
+int allowed_errors = 5;
+FILE *file;
+int adsb_frame[14];
+#define preamble_len		16
+#define long_frame		112
+#define short_frame		56
+
+/* signals are not threadsafe by default */
+#define safe_cond_signal(n, m) pthread_mutex_lock(m); pthread_cond_signal(n); pthread_mutex_unlock(m)
+#define safe_cond_wait(n, m) pthread_mutex_lock(m); pthread_cond_wait(n, m); pthread_mutex_unlock(m)
+
+void usage(void)
+{
+	fprintf(stderr,
+		"rtl_adsb, a simple ADS-B decoder\n\n"
+		"Use:\trtl_adsb [-R] [-g gain] [-p ppm] [output file]\n"
+		"\t[-d device_index (default: 0)]\n"
+		"\t[-V verbove output (default: off)]\n"
+		"\t[-S show short frames (default: off)]\n"
+		"\t[-Q quality (0: no sanity checks, 0.5: half bit, 1: one bit (default), 2: two bits)]\n"
+		"\t[-e allowed_errors (default: 5)]\n"
+		"\t[-g tuner_gain (default: automatic)]\n"
+		"\t[-p ppm_error (default: 0)]\n"
+		"\t[-T enable bias-T on GPIO PIN 0 (works for rtl-sdr.com v3 dongles)]\n"
+		"\tfilename (a '-' dumps samples to stdout)\n"
+		"\t (omitting the filename also uses stdout)\n\n"
+		"Streaming with netcat:\n"
+		"\trtl_adsb | netcat -lp 8080\n"
+		"\twhile true; do rtl_adsb | nc -lp 8080; done\n"
+		"Streaming with socat:\n"
+		"\trtl_adsb | socat -u - TCP4:sdrsharp.com:47806\n"
+		"\n");
+	exit(1);
+}
+
+#ifdef _WIN32
+BOOL WINAPI
+sighandler(int signum)
+{
+	if (CTRL_C_EVENT == signum) {
+		fprintf(stderr, "Signal caught, exiting!\n");
+		do_exit = 1;
+		rtlsdr_cancel_async(dev);
+		return TRUE;
+	}
+	return FALSE;
+}
+#else
+static void sighandler(int signum)
+{
+	fprintf(stderr, "Signal caught, exiting!\n");
+	do_exit = 1;
+	rtlsdr_cancel_async(dev);
+}
+#endif
+
+void display(int *frame, int len)
+{
+	int i, df;
+	if (!short_output && len <= short_frame) {
+		return;}
+	df = (frame[0] >> 3) & 0x1f;
+	if (quality == 0 && !(df==11 || df==17 || df==18 || df==19)) {
+		return;}
+	fprintf(file, "*");
+	for (i=0; i<((len+7)/8); i++) {
+		fprintf(file, "%02x", frame[i]);}
+	fprintf(file, ";\r\n");
+	if (!verbose_output) {
+		return;}
+	fprintf(file, "DF=%i CA=%i\n", df, frame[0] & 0x07);
+	fprintf(file, "ICAO Address=%06x\n", frame[1] << 16 | frame[2] << 8 | frame[3]);
+	if (len <= short_frame) {
+		return;}
+	fprintf(file, "PI=0x%06x\n",  frame[11] << 16 | frame[12] << 8 | frame[13]);
+	fprintf(file, "Type Code=%i S.Type/Ant.=%x\n", (frame[4] >> 3) & 0x1f, frame[4] & 0x07);
+	fprintf(file, "--------------\n");
+}
+
+int abs8(int x)
+/* do not subtract 127 from the raw iq, this handles it */
+{
+	if (x >= 127) {
+		return x - 127;}
+	return 127 - x;
+}
+
+void squares_precompute(void)
+/* equiv to abs(x-128) ^ 2 */
+{
+	int i, j;
+	// todo, check if this LUT is actually any faster
+	for (i=0; i<256; i++) {
+		j = abs8(i);
+		squares[i] = (uint16_t)(j*j);
+	}
+}
+
+int magnitute(uint8_t *buf, int len)
+/* takes i/q, changes buf in place (16 bit), returns new len (16 bit) */
+{
+	int i;
+	uint16_t *m;
+	for (i=0; i<len; i+=2) {
+		m = (uint16_t*)(&buf[i]);
+		*m = squares[buf[i]] + squares[buf[i+1]];
+	}
+	return len/2;
+}
+
+static inline uint16_t single_manchester(uint16_t a, uint16_t b, uint16_t c, uint16_t d)
+/* takes 4 consecutive real samples, return 0 or 1, BADSAMPLE on error */
+{
+	int bit, bit_p;
+	bit_p = a > b;
+	bit   = c > d;
+
+	if (quality == 0) {
+		return bit;}
+
+	if (quality == 5) {
+		if ( bit &&  bit_p && b > c) {
+			return BADSAMPLE;}
+		if (!bit && !bit_p && b < c) {
+			return BADSAMPLE;}
+		return bit;
+	}
+
+	if (quality == 10) {
+		if ( bit &&  bit_p && c > b) {
+			return 1;}
+		if ( bit && !bit_p && d < b) {
+			return 1;}
+		if (!bit &&  bit_p && d > b) {
+			return 0;}
+		if (!bit && !bit_p && c < b) {
+			return 0;}
+		return BADSAMPLE;
+	}
+
+	if ( bit &&  bit_p && c > b && d < a) {
+		return 1;}
+	if ( bit && !bit_p && c > a && d < b) {
+		return 1;}
+	if (!bit &&  bit_p && c < a && d > b) {
+		return 0;}
+	if (!bit && !bit_p && c < b && d > a) {
+		return 0;}
+	return BADSAMPLE;
+}
+
+static inline uint16_t min16(uint16_t a, uint16_t b)
+{
+	return a<b ? a : b;
+}
+
+static inline uint16_t max16(uint16_t a, uint16_t b)
+{
+	return a>b ? a : b;
+}
+
+static inline int preamble(uint16_t *buf, int i)
+/* returns 0/1 for preamble at index i */
+{
+	int i2;
+	uint16_t low  = 0;
+	uint16_t high = 65535;
+	for (i2=0; i2<preamble_len; i2++) {
+		switch (i2) {
+			case 0:
+			case 2:
+			case 7:
+			case 9:
+				//high = min16(high, buf[i+i2]);
+				high = buf[i+i2];
+				break;
+			default:
+				//low  = max16(low,  buf[i+i2]);
+				low = buf[i+i2];
+				break;
+		}
+		if (high <= low) {
+			return 0;}
+	}
+	return 1;
+}
+
+void manchester(uint16_t *buf, int len)
+/* overwrites magnitude buffer with valid bits (BADSAMPLE on errors) */
+{
+	/* a and b hold old values to verify local manchester */
+	uint16_t a=0, b=0;
+	uint16_t bit;
+	int i, i2, start, errors;
+	int maximum_i = len - 1;        // len-1 since we look at i and i+1
+	// todo, allow wrap across buffers
+	i = 0;
+	while (i < maximum_i) {
+		/* find preamble */
+		for ( ; i < (len - preamble_len); i++) {
+			if (!preamble(buf, i)) {
+				continue;}
+			a = buf[i];
+			b = buf[i+1];
+			for (i2=0; i2<preamble_len; i2++) {
+				buf[i+i2] = MESSAGEGO;}
+			i += preamble_len;
+			break;
+		}
+		i2 = start = i;
+		errors = 0;
+		/* mark bits until encoding breaks */
+		for ( ; i < maximum_i; i+=2, i2++) {
+			bit = single_manchester(a, b, buf[i], buf[i+1]);
+			a = buf[i];
+			b = buf[i+1];
+			if (bit == BADSAMPLE) {
+				errors += 1;
+				if (errors > allowed_errors) {
+					buf[i2] = BADSAMPLE;
+					break;
+				} else {
+					bit = a > b;
+					/* these don't have to match the bit */
+					a = 0;
+					b = 65535;
+				}
+			}
+			buf[i] = buf[i+1] = OVERWRITE;
+			buf[i2] = bit;
+		}
+	}
+}
+
+void messages(uint16_t *buf, int len)
+{
+	int i, data_i, index, shift, frame_len;
+	// todo, allow wrap across buffers
+	for (i=0; i<len; i++) {
+		if (buf[i] > 1) {
+			continue;}
+		frame_len = long_frame;
+		data_i = 0;
+		for (index=0; index<14; index++) {
+			adsb_frame[index] = 0;}
+		for(; i<len && buf[i]<=1 && data_i<frame_len; i++, data_i++) {
+			if (buf[i]) {
+				index = data_i / 8;
+				shift = 7 - (data_i % 8);
+				adsb_frame[index] |= (uint8_t)(1<<shift);
+			}
+			if (data_i == 7) {
+				if (adsb_frame[0] == 0) {
+				    break;}
+				if (adsb_frame[0] & 0x80) {
+					frame_len = long_frame;}
+				else {
+					frame_len = short_frame;}
+			}
+		}
+		if (data_i < (frame_len-1)) {
+			continue;}
+		display(adsb_frame, frame_len);
+		fflush(file);
+	}
+}
+
+static void rtlsdr_callback(unsigned char *buf, uint32_t len, void *ctx)
+{
+	if (do_exit) {
+		return;}
+	memcpy(buffer, buf, len);
+	safe_cond_signal(&ready, &ready_m);
+}
+
+static void *demod_thread_fn(void *arg)
+{
+	int len;
+	while (!do_exit) {
+		safe_cond_wait(&ready, &ready_m);
+		len = magnitute(buffer, DEFAULT_BUF_LENGTH);
+		manchester((uint16_t*)buffer, len);
+		messages((uint16_t*)buffer, len);
+	}
+	rtlsdr_cancel_async(dev);
+	return 0;
+}
+
+int main(int argc, char **argv)
+{
+#ifndef _WIN32
+	struct sigaction sigact;
+#endif
+	char *filename = NULL;
+	int r, opt;
+	int gain = AUTO_GAIN; /* tenths of a dB */
+	int dev_index = 0;
+	int dev_given = 0;
+	int ppm_error = 0;
+	int enable_biastee = 0;
+	pthread_cond_init(&ready, NULL);
+	pthread_mutex_init(&ready_m, NULL);
+	squares_precompute();
+
+	while ((opt = getopt(argc, argv, "d:g:p:e:Q:VST")) != -1)
+	{
+		switch (opt) {
+		case 'd':
+			dev_index = verbose_device_search(optarg);
+			dev_given = 1;
+			break;
+		case 'g':
+			gain = (int)(atof(optarg) * 10);
+			break;
+		case 'p':
+			ppm_error = atoi(optarg);
+			break;
+		case 'V':
+			verbose_output = 1;
+			break;
+		case 'S':
+			short_output = 1;
+			break;
+		case 'e':
+			allowed_errors = atoi(optarg);
+			break;
+		case 'Q':
+			quality = (int)(atof(optarg) * 10);
+			break;
+		case 'T':
+			enable_biastee = 1;
+			break;
+		default:
+			usage();
+			return 0;
+		}
+	}
+
+	if (argc <= optind) {
+		filename = "-";
+	} else {
+		filename = argv[optind];
+	}
+
+	buffer = malloc(DEFAULT_BUF_LENGTH * sizeof(uint8_t));
+
+	if (!dev_given) {
+		dev_index = verbose_device_search("0");
+	}
+
+	if (dev_index < 0) {
+		exit(1);
+	}
+
+	r = rtlsdr_open(&dev, (uint32_t)dev_index);
+	if (r < 0) {
+		fprintf(stderr, "Failed to open rtlsdr device #%d.\n", dev_index);
+		exit(1);
+	}
+#ifndef _WIN32
+	sigact.sa_handler = sighandler;
+	sigemptyset(&sigact.sa_mask);
+	sigact.sa_flags = 0;
+	sigaction(SIGINT, &sigact, NULL);
+	sigaction(SIGTERM, &sigact, NULL);
+	sigaction(SIGQUIT, &sigact, NULL);
+	sigaction(SIGPIPE, &sigact, NULL);
+#else
+	SetConsoleCtrlHandler( (PHANDLER_ROUTINE) sighandler, TRUE );
+#endif
+
+	if (strcmp(filename, "-") == 0) { /* Write samples to stdout */
+		file = stdout;
+		setvbuf(stdout, NULL, _IONBF, 0);
+#ifdef _WIN32
+		_setmode(_fileno(file), _O_BINARY);
+#endif
+	} else {
+		file = fopen(filename, "wb");
+		if (!file) {
+			fprintf(stderr, "Failed to open %s\n", filename);
+			exit(1);
+		}
+	}
+
+	/* Set the tuner gain */
+	if (gain == AUTO_GAIN) {
+		verbose_auto_gain(dev);
+	} else {
+		gain = nearest_gain(dev, gain);
+		verbose_gain_set(dev, gain);
+	}
+
+	verbose_ppm_set(dev, ppm_error);
+	r = rtlsdr_set_agc_mode(dev, 1);
+
+	/* Set the tuner frequency */
+	verbose_set_frequency(dev, ADSB_FREQ);
+
+	/* Set the sample rate */
+	verbose_set_sample_rate(dev, ADSB_RATE);
+
+	rtlsdr_set_bias_tee(dev, enable_biastee);
+	if (enable_biastee)
+		fprintf(stderr, "activated bias-T on GPIO PIN 0\n");
+
+	/* Reset endpoint before we start reading from it (mandatory) */
+	verbose_reset_buffer(dev);
+
+	pthread_create(&demod_thread, NULL, demod_thread_fn, (void *)(NULL));
+	rtlsdr_read_async(dev, rtlsdr_callback, (void *)(NULL),
+			      DEFAULT_ASYNC_BUF_NUMBER,
+			      DEFAULT_BUF_LENGTH);
+
+	if (do_exit) {
+		fprintf(stderr, "\nUser cancel, exiting...\n");}
+	else {
+		fprintf(stderr, "\nLibrary error %d, exiting...\n", r);}
+	rtlsdr_cancel_async(dev);
+	pthread_cancel(demod_thread);
+	pthread_join(demod_thread, NULL);
+	pthread_cond_destroy(&ready);
+	pthread_mutex_destroy(&ready_m);
+
+	if (file != stdout) {
+		fclose(file);}
+
+	rtlsdr_close(dev);
+	free(buffer);
+	return r >= 0 ? r : -r;
+}
+
diff --git a/src/rtl_biast.c b/src/rtl_biast.c
new file mode 100644
index 0000000..185e838
--- /dev/null
+++ b/src/rtl_biast.c
@@ -0,0 +1,101 @@
+/*
+ * rtl-sdr, turns your Realtek RTL2832 based DVB dongle into a SDR receiver
+ * rtl_biast, tool to set bias tee gpio output
+ * Copyright (C) 2012 by Steve Markgraf <steve@steve-m.de>
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include <string.h>
+#include <stdio.h>
+#include <stdlib.h>
+
+#ifndef _WIN32
+#include <unistd.h>
+#else
+#include <windows.h>
+#include "getopt/getopt.h"
+#endif
+
+#include "rtl-sdr.h"
+#include "convenience/convenience.h"
+
+static rtlsdr_dev_t *dev = NULL;
+
+void usage(void)
+{
+	fprintf(stderr,
+		"rtl_biast, a tool for turning the RTL-SDR.com \n"
+		"bias tee or any GPIO ON and OFF. Example to turn on the \n"
+		"bias tee: rtl_biast -d 0 -b 1\n"
+		"Any GPIO: rtl_biast -d 0 -g 1 -b 1\n\n"
+		"Usage:\n"
+		"\t[-d device_index (default: 0)]\n"
+		"\t[-b bias_on (default: 0)]\n"
+		"\t[-g GPIO select (default: 0)]\n");
+	exit(1);
+}
+
+int main(int argc, char **argv)
+{
+	int i, r, opt;
+	int dev_index = 0;
+	int dev_given = 0;
+	uint32_t bias_on = 0;
+	uint32_t gpio_pin = 0;
+	int device_count;
+
+	while ((opt = getopt(argc, argv, "d:b:g:h?")) != -1) {
+		switch (opt) {
+		case 'd':
+			dev_index = verbose_device_search(optarg);
+			dev_given = 1;
+			break;
+		case 'b':
+			bias_on = atoi(optarg);
+			break;
+		case 'g':
+			gpio_pin = atoi(optarg);
+			break;
+		default:
+			usage();
+			break;
+		}
+	}
+
+	if (!dev_given) {
+		dev_index = verbose_device_search("0");
+	}
+
+	if (dev_index < 0) {
+		exit(1);
+	}
+
+	r = rtlsdr_open(&dev, dev_index);
+	rtlsdr_set_bias_tee_gpio(dev, gpio_pin, bias_on);
+
+exit:
+	/*
+	 * Note - rtlsdr_close() in this tree does not clear the bias tee
+	 * GPIO line, so it leaves the bias tee enabled if a client program
+	 * doesn't explictly disable it.
+	 *
+	 * If that behaviour changes then another rtlsdr_close() will be
+	 * needed that takes some extension flags, and one of them should
+	 * be to either explicitly close the biast or leave it alone.
+	 */
+	rtlsdr_close(dev);
+
+	return r >= 0 ? r : -r;
+}
diff --git a/src/rtl_eeprom.c b/src/rtl_eeprom.c
new file mode 100644
index 0000000..24be900
--- /dev/null
+++ b/src/rtl_eeprom.c
@@ -0,0 +1,426 @@
+/*
+ * rtl-sdr, turns your Realtek RTL2832 based DVB dongle into a SDR receiver
+ * rtl_eeprom, EEPROM modification tool
+ * Copyright (C) 2012 by Steve Markgraf <steve@steve-m.de>
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include <string.h>
+#include <stdio.h>
+#include <stdlib.h>
+
+#ifndef _WIN32
+#include <unistd.h>
+#else
+#include <windows.h>
+#include "getopt/getopt.h"
+#endif
+
+#include "rtl-sdr.h"
+
+#define EEPROM_SIZE	256
+#define MAX_STR_SIZE	256
+#define STR_OFFSET	0x09
+
+static rtlsdr_dev_t *dev = NULL;
+
+typedef struct rtlsdr_config {
+	uint16_t vendor_id;
+	uint16_t product_id;
+	char manufacturer[MAX_STR_SIZE];
+	char product[MAX_STR_SIZE];
+	char serial[MAX_STR_SIZE];
+	int have_serial;
+	int enable_ir;
+	int remote_wakeup;
+} rtlsdr_config_t;
+
+void dump_config(rtlsdr_config_t *conf)
+{
+	fprintf(stderr, "__________________________________________\n");
+	fprintf(stderr, "Vendor ID:\t\t0x%04x\n", conf->vendor_id);
+	fprintf(stderr, "Product ID:\t\t0x%04x\n", conf->product_id);
+	fprintf(stderr, "Manufacturer:\t\t%s\n", conf->manufacturer);
+	fprintf(stderr, "Product:\t\t%s\n", conf->product);
+	fprintf(stderr, "Serial number:\t\t%s\n", conf->serial);
+	fprintf(stderr, "Serial number enabled:\t");
+	fprintf(stderr, conf->have_serial ? "yes\n": "no\n");
+	fprintf(stderr, "IR endpoint enabled:\t");
+	fprintf(stderr, conf->enable_ir ? "yes\n": "no\n");
+	fprintf(stderr, "Remote wakeup enabled:\t");
+	fprintf(stderr, conf->remote_wakeup ? "yes\n": "no\n");
+	fprintf(stderr, "__________________________________________\n");
+}
+
+void usage(void)
+{
+	fprintf(stderr,
+		"rtl_eeprom, an EEPROM programming tool for "
+		"RTL2832 based DVB-T receivers\n\n"
+		"Usage:\n"
+		"\t[-d device_index (default: 0)]\n"
+		"\t[-m <str> set manufacturer string]\n"
+		"\t[-p <str> set product string]\n"
+		"\t[-s <str> set serial number string]\n"
+		"\t[-i <0,1> disable/enable IR-endpoint]\n"
+		"\t[-g <conf> generate default config and write to device]\n"
+		"\t[   <conf> can be one of:]\n"
+		"\t[   realtek\t\tRealtek default (as without EEPROM)]\n"
+		"\t[   realtek_oem\t\tRealtek default OEM with EEPROM]\n"
+		"\t[   noxon\t\tTerratec NOXON DAB Stick]\n"
+		"\t[   terratec_black\tTerratec T Stick Black]\n"
+		"\t[   terratec_plus\tTerratec T Stick+ (DVB-T/DAB)]\n"
+		"\t[-w <filename> write dumped file to device]\n"
+		"\t[-r <filename> dump EEPROM to file]\n"
+		"\t[-h display this help text]\n"
+		"\nUse on your own risk, especially -w!\n");
+	exit(1);
+}
+
+int get_string_descriptor(int pos, uint8_t *data, char *str)
+{
+	int len, i, j = 0;
+
+	len = data[pos];
+
+	if (data[pos + 1] != 0x03)
+		fprintf(stderr, "Error: invalid string descriptor!\n");
+
+	for (i = 2; i < len; i += 2)
+		str[j++] = data[pos + i];
+
+	str[j] = 0x00;
+
+	return pos + i;
+}
+
+int set_string_descriptor(int pos, uint8_t *data, char *str)
+{
+	int i = 0, j = 2;
+
+	if (pos < 0)
+		return -1;
+
+	data[pos + 1] = 0x03;
+
+	while (str[i] != 0x00) {
+		if ((pos + j) >= 78) {
+			fprintf(stderr, "Error: string too long, truncated!\n");
+			return -1;
+		}
+		data[pos + j++] = str[i++];
+		data[pos + j++] = 0x00;
+	}
+
+	data[pos] = j;
+
+	return pos + j;
+}
+
+int parse_eeprom_to_conf(rtlsdr_config_t *conf, uint8_t *dat)
+{
+	int pos;
+
+	if ((dat[0] != 0x28) || (dat[1] != 0x32))
+		fprintf(stderr, "Error: invalid RTL2832 EEPROM header!\n");
+
+	conf->vendor_id = dat[2] | (dat[3] << 8);
+	conf->product_id = dat[4] | (dat[5] << 8);
+	conf->have_serial = (dat[6] == 0xa5) ? 1 : 0;
+	conf->remote_wakeup = (dat[7] & 0x01) ? 1 : 0;
+	conf->enable_ir = (dat[7] & 0x02) ? 1 : 0;
+
+	pos = get_string_descriptor(STR_OFFSET, dat, conf->manufacturer);
+	pos = get_string_descriptor(pos, dat, conf->product);
+	get_string_descriptor(pos, dat, conf->serial);
+
+	return 0;
+}
+
+int gen_eeprom_from_conf(rtlsdr_config_t *conf, uint8_t *dat)
+{
+	int pos;
+
+	dat[0] = 0x28;
+	dat[1] = 0x32;
+	dat[2] = conf->vendor_id & 0xff;
+	dat[3] = (conf->vendor_id >> 8) & 0xff ;
+	dat[4] = conf->product_id & 0xff;
+	dat[5] = (conf->product_id >> 8) & 0xff;
+	dat[6] = conf->have_serial ? 0xa5 : 0x00;
+	dat[7] = 0x14;
+	dat[7] |= conf->remote_wakeup ? 0x01 : 0x00;
+	dat[7] |= conf->enable_ir ? 0x02 : 0x00;
+	dat[8] = 0x02;
+
+	pos = set_string_descriptor(STR_OFFSET, dat, conf->manufacturer);
+	pos = set_string_descriptor(pos, dat, conf->product);
+	pos = set_string_descriptor(pos, dat, conf->serial);
+
+	dat[78] = 0x00;		/* length of IR config */
+
+	return pos;
+}
+
+enum configs {
+	CONF_NONE = 0,
+	REALTEK,
+	REALTEK_EEPROM,
+	TERRATEC_NOXON,
+	TERRATEC_T_BLACK,
+	TERRATEC_T_PLUS,
+};
+
+void gen_default_conf(rtlsdr_config_t *conf, int config)
+{
+	switch (config) {
+	case REALTEK:
+		fprintf(stderr, "Realtek default (as without EEPROM)\n");
+		conf->vendor_id = 0x0bda;
+		conf->product_id = 0x2832;
+		strcpy(conf->manufacturer, "Generic");
+		strcpy(conf->product, "RTL2832U DVB-T");
+		strcpy(conf->serial, "0");
+		conf->have_serial = 1;
+		conf->enable_ir = 0;
+		conf->remote_wakeup = 1;
+		break;
+	case REALTEK_EEPROM:
+		fprintf(stderr, "Realtek default OEM with EEPROM\n");
+		conf->vendor_id = 0x0bda;
+		conf->product_id = 0x2838;
+		strcpy(conf->manufacturer, "Realtek");
+		strcpy(conf->product, "RTL2838UHIDIR");
+		strcpy(conf->serial, "00000001");
+		conf->have_serial = 1;
+		conf->enable_ir = 1;
+		conf->remote_wakeup = 0;
+		break;
+	case TERRATEC_NOXON:
+		fprintf(stderr, "Terratec NOXON DAB Stick\n");
+		conf->vendor_id = 0x0ccd;
+		conf->product_id = 0x00b3;
+		strcpy(conf->manufacturer, "NOXON");
+		strcpy(conf->product, "DAB Stick");
+		strcpy(conf->serial, "0");
+		conf->have_serial = 1;
+		conf->enable_ir = 0;
+		conf->remote_wakeup = 1;
+		break;
+	case TERRATEC_T_BLACK:
+		fprintf(stderr, "Terratec T Stick Black\n");
+		conf->vendor_id = 0x0ccd;
+		conf->product_id = 0x00a9;
+		strcpy(conf->manufacturer, "Realtek");
+		strcpy(conf->product, "RTL2838UHIDIR");
+		strcpy(conf->serial, "00000001");
+		conf->have_serial = 1;
+		conf->enable_ir = 1;
+		conf->remote_wakeup = 0;
+		break;
+	case TERRATEC_T_PLUS:
+		fprintf(stderr, "Terratec ran T Stick+\n");
+		conf->vendor_id = 0x0ccd;
+		conf->product_id = 0x00d7;
+		strcpy(conf->manufacturer, "Realtek");
+		strcpy(conf->product, "RTL2838UHIDIR");
+		strcpy(conf->serial, "00000001");
+		conf->have_serial = 1;
+		conf->enable_ir = 1;
+		conf->remote_wakeup = 0;
+		break;
+	default:
+		break;
+	};
+}
+
+int main(int argc, char **argv)
+{
+	int i, r, opt;
+	uint32_t dev_index = 0;
+	int device_count;
+	char *filename = NULL;
+	FILE *file = NULL;
+	char *manuf_str = NULL;
+	char *product_str = NULL;
+	char *serial_str = NULL;
+	uint8_t buf[EEPROM_SIZE];
+	rtlsdr_config_t conf;
+	int flash_file = 0;
+	int default_config = 0;
+	int change = 0;
+	int ir_endpoint = 0;
+	char ch;
+
+	while ((opt = getopt(argc, argv, "d:m:p:s:i:g:w:r:h?")) != -1) {
+		switch (opt) {
+		case 'd':
+			dev_index = atoi(optarg);
+			break;
+		case 'm':
+			manuf_str = optarg;
+			change = 1;
+			break;
+		case 'p':
+			product_str = optarg;
+			change = 1;
+			break;
+		case 's':
+			serial_str = optarg;
+			change = 1;
+			break;
+		case 'i':
+			ir_endpoint = (atoi(optarg) > 0) ? 1 : -1;
+			change = 1;
+			break;
+		case 'g':
+			if (!strcmp(optarg, "realtek"))
+				default_config = REALTEK;
+			else if (!strcmp(optarg, "realtek_oem"))
+				default_config = REALTEK_EEPROM;
+			else if (!strcmp(optarg, "noxon"))
+				default_config = TERRATEC_NOXON;
+			else if (!strcmp(optarg, "terratec_black"))
+				default_config = TERRATEC_T_BLACK;
+			else if (!strcmp(optarg, "terratec_plus"))
+				default_config = TERRATEC_T_PLUS;
+
+			if (default_config != CONF_NONE)
+				change = 1;
+			break;
+		case 'w':
+			flash_file = 1;
+			change = 1;
+			/* fall-through */
+		case 'r':
+			filename = optarg;
+			break;
+		default:
+			usage();
+			break;
+		}
+	}
+
+	device_count = rtlsdr_get_device_count();
+	if (!device_count) {
+		fprintf(stderr, "No supported devices found.\n");
+		exit(1);
+	}
+
+	fprintf(stderr, "Found %d device(s):\n", device_count);
+	for (i = 0; i < device_count; i++)
+		fprintf(stderr, "  %d:  %s\n", i, rtlsdr_get_device_name(i));
+	fprintf(stderr, "\n");
+
+	fprintf(stderr, "Using device %d: %s\n",
+		dev_index,
+		rtlsdr_get_device_name(dev_index));
+
+	r = rtlsdr_open(&dev, dev_index);
+	if (r < 0) {
+		fprintf(stderr, "Failed to open rtlsdr device #%d.\n", dev_index);
+		exit(1);
+	}
+
+	fprintf(stderr, "\n");
+
+	r = rtlsdr_read_eeprom(dev, buf, 0, EEPROM_SIZE);
+	if (r < 0) {
+		if (r == -3)
+			fprintf(stderr, "No EEPROM has been found.\n");
+		else
+			fprintf(stderr, "Failed to read EEPROM, err %i.\n", r);
+		goto exit;
+	}
+
+	if (r < 0)
+		return -1;
+
+	fprintf(stderr, "Current configuration:\n");
+	parse_eeprom_to_conf(&conf, buf);
+	dump_config(&conf);
+
+	if (filename) {
+		file = fopen(filename, flash_file ? "rb" : "wb");
+		if (!file) {
+			fprintf(stderr, "Error opening file!\n");
+			goto exit;
+		}
+		if (flash_file) {
+			if (fread(buf, 1, sizeof(buf), file) != sizeof(buf))
+				fprintf(stderr, "Error reading file!\n");
+		} else {
+			if (fwrite(buf, 1, sizeof(buf), file) != sizeof(buf))
+				fprintf(stderr, "Short write, exiting!\n");
+			else
+				fprintf(stderr, "\nDump to %s successful.\n", filename);
+		}
+	}
+
+	if (manuf_str)
+		strncpy((char*)&conf.manufacturer, manuf_str, MAX_STR_SIZE - 1);
+
+	if (product_str)
+		strncpy((char*)&conf.product, product_str, MAX_STR_SIZE - 1);
+
+	if (serial_str) {
+		conf.have_serial = 1;
+		strncpy((char*)&conf.serial, serial_str, MAX_STR_SIZE - 1);
+	}
+
+	if (ir_endpoint != 0)
+		 conf.enable_ir = (ir_endpoint > 0) ? 1 : 0;
+
+	if (!change)
+		goto exit;
+
+	fprintf(stderr, "\nNew configuration:\n");
+
+	if (default_config != CONF_NONE)
+		gen_default_conf(&conf, default_config);
+
+	if (!flash_file) {
+		if (gen_eeprom_from_conf(&conf, buf) < 0)
+			goto exit;
+	}
+
+	parse_eeprom_to_conf(&conf, buf);
+	dump_config(&conf);
+
+	fprintf(stderr, "Write new configuration to device [y/n]? ");
+
+	while ((ch = getchar())) {
+		if (ch != 'y')
+			goto exit;
+		else
+			break;
+	}
+
+	r = rtlsdr_write_eeprom(dev, buf, 0, flash_file ? EEPROM_SIZE : 128);
+	if (r < 0)
+		fprintf(stderr, "Error while writing EEPROM: %i\n", r);
+	else
+		fprintf(stderr, "\nConfiguration successfully written.\n"
+				"Please replug the device for changes"
+				" to take effect.\n");
+
+exit:
+	if (file)
+		fclose(file);
+
+	rtlsdr_close(dev);
+
+	return r >= 0 ? r : -r;
+}
diff --git a/src/rtl_fm.c b/src/rtl_fm.c
new file mode 100644
index 0000000..7c84332
--- /dev/null
+++ b/src/rtl_fm.c
@@ -0,0 +1,1289 @@
+/*
+ * rtl-sdr, turns your Realtek RTL2832 based DVB dongle into a SDR receiver
+ * Copyright (C) 2012 by Steve Markgraf <steve@steve-m.de>
+ * Copyright (C) 2012 by Hoernchen <la@tfc-server.de>
+ * Copyright (C) 2012 by Kyle Keen <keenerd@gmail.com>
+ * Copyright (C) 2013 by Elias Oenal <EliasOenal@gmail.com>
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+
+/*
+ * written because people could not do real time
+ * FM demod on Atom hardware with GNU radio
+ * based on rtl_sdr.c and rtl_tcp.c
+ *
+ * lots of locks, but that is okay
+ * (no many-to-many locks)
+ *
+ * todo:
+ *       sanity checks
+ *       scale squelch to other input parameters
+ *       test all the demodulations
+ *       pad output on hop
+ *       frequency ranges could be stored better
+ *       scaled AM demod amplification
+ *       auto-hop after time limit
+ *       peak detector to tune onto stronger signals
+ *       fifo for active hop frequency
+ *       clips
+ *       noise squelch
+ *       merge stereo patch
+ *       merge soft agc patch
+ *       merge udp patch
+ *       testmode to detect overruns
+ *       watchdog to reset bad dongle
+ *       fix oversampling
+ */
+
+#include <errno.h>
+#include <signal.h>
+#include <string.h>
+#include <stdio.h>
+#include <stdlib.h>
+
+#ifndef _WIN32
+#include <unistd.h>
+#else
+#include <windows.h>
+#include <fcntl.h>
+#include <io.h>
+#include "getopt/getopt.h"
+#define usleep(x) Sleep(x/1000)
+#if defined(_MSC_VER) && (_MSC_VER < 1800)
+#define round(x) (x > 0.0 ? floor(x + 0.5): ceil(x - 0.5))
+#endif
+#define _USE_MATH_DEFINES
+#endif
+
+#include <math.h>
+#include <pthread.h>
+#include <libusb.h>
+
+#include "rtl-sdr.h"
+#include "convenience/convenience.h"
+
+#define DEFAULT_SAMPLE_RATE		24000
+#define DEFAULT_BUF_LENGTH		(1 * 16384)
+#define MAXIMUM_OVERSAMPLE		16
+#define MAXIMUM_BUF_LENGTH		(MAXIMUM_OVERSAMPLE * DEFAULT_BUF_LENGTH)
+#define AUTO_GAIN			-100
+#define BUFFER_DUMP			4096
+
+#define FREQUENCIES_LIMIT		1000
+
+static volatile int do_exit = 0;
+static int lcm_post[17] = {1,1,1,3,1,5,3,7,1,9,5,11,3,13,7,15,1};
+static int ACTUAL_BUF_LENGTH;
+
+static int *atan_lut = NULL;
+static int atan_lut_size = 131072; /* 512 KB */
+static int atan_lut_coef = 8;
+
+struct dongle_state
+{
+	int      exit_flag;
+	pthread_t thread;
+	rtlsdr_dev_t *dev;
+	int      dev_index;
+	uint32_t freq;
+	uint32_t rate;
+	int      gain;
+	uint16_t buf16[MAXIMUM_BUF_LENGTH];
+	uint32_t buf_len;
+	int      ppm_error;
+	int      offset_tuning;
+	int      direct_sampling;
+	int      mute;
+	struct demod_state *demod_target;
+};
+
+struct demod_state
+{
+	int      exit_flag;
+	pthread_t thread;
+	int16_t  lowpassed[MAXIMUM_BUF_LENGTH];
+	int      lp_len;
+	int16_t  lp_i_hist[10][6];
+	int16_t  lp_q_hist[10][6];
+	int16_t  result[MAXIMUM_BUF_LENGTH];
+	int16_t  droop_i_hist[9];
+	int16_t  droop_q_hist[9];
+	int      result_len;
+	int      rate_in;
+	int      rate_out;
+	int      rate_out2;
+	int      now_r, now_j;
+	int      pre_r, pre_j;
+	int      prev_index;
+	int      downsample;    /* min 1, max 256 */
+	int      post_downsample;
+	int      output_scale;
+	int      squelch_level, conseq_squelch, squelch_hits, terminate_on_squelch;
+	int      downsample_passes;
+	int      comp_fir_size;
+	int      custom_atan;
+	int      deemph, deemph_a;
+	int      now_lpr;
+	int      prev_lpr_index;
+	int      dc_block, dc_avg;
+	void     (*mode_demod)(struct demod_state*);
+	pthread_rwlock_t rw;
+	pthread_cond_t ready;
+	pthread_mutex_t ready_m;
+	struct output_state *output_target;
+};
+
+struct output_state
+{
+	int      exit_flag;
+	pthread_t thread;
+	FILE     *file;
+	char     *filename;
+	int16_t  result[MAXIMUM_BUF_LENGTH];
+	int      result_len;
+	int      rate;
+	pthread_rwlock_t rw;
+	pthread_cond_t ready;
+	pthread_mutex_t ready_m;
+};
+
+struct controller_state
+{
+	int      exit_flag;
+	pthread_t thread;
+	uint32_t freqs[FREQUENCIES_LIMIT];
+	int      freq_len;
+	int      freq_now;
+	int      edge;
+	int      wb_mode;
+	pthread_cond_t hop;
+	pthread_mutex_t hop_m;
+};
+
+// multiple of these, eventually
+struct dongle_state dongle;
+struct demod_state demod;
+struct output_state output;
+struct controller_state controller;
+
+void usage(void)
+{
+	fprintf(stderr,
+		"rtl_fm, a simple narrow band FM demodulator for RTL2832 based DVB-T receivers\n\n"
+		"Use:\trtl_fm -f freq [-options] [filename]\n"
+		"\t-f frequency_to_tune_to [Hz]\n"
+		"\t    use multiple -f for scanning (requires squelch)\n"
+		"\t    ranges supported, -f 118M:137M:25k\n"
+		"\t[-M modulation (default: fm)]\n"
+		"\t    fm, wbfm, raw, am, usb, lsb\n"
+		"\t    wbfm == -M fm -s 170k -o 4 -A fast -r 32k -l 0 -E deemp\n"
+		"\t    raw mode outputs 2x16 bit IQ pairs\n"
+		"\t[-s sample_rate (default: 24k)]\n"
+		"\t[-d device_index (default: 0)]\n"
+		"\t[-T enable bias-T on GPIO PIN 0 (works for rtl-sdr.com v3 dongles)]\n"
+		"\t[-g tuner_gain (default: automatic)]\n"
+		"\t[-l squelch_level (default: 0/off)]\n"
+		//"\t    for fm squelch is inverted\n"
+		//"\t[-o oversampling (default: 1, 4 recommended)]\n"
+		"\t[-p ppm_error (default: 0)]\n"
+		"\t[-E enable_option (default: none)]\n"
+		"\t    use multiple -E to enable multiple options\n"
+		"\t    edge:    enable lower edge tuning\n"
+		"\t    dc:      enable dc blocking filter\n"
+		"\t    deemp:   enable de-emphasis filter\n"
+		"\t    direct:  enable direct sampling 1 (usually I)\n"
+		"\t    direct2: enable direct sampling 2 (usually Q)\n"
+		"\t    offset:  enable offset tuning\n"
+		"\tfilename ('-' means stdout)\n"
+		"\t    omitting the filename also uses stdout\n\n"
+		"Experimental options:\n"
+		"\t[-r resample_rate (default: none / same as -s)]\n"
+		"\t[-t squelch_delay (default: 10)]\n"
+		"\t    +values will mute/scan, -values will exit\n"
+		"\t[-F fir_size (default: off)]\n"
+		"\t    enables low-leakage downsample filter\n"
+		"\t    size can be 0 or 9.  0 has bad roll off\n"
+		"\t[-A std/fast/lut choose atan math (default: std)]\n"
+		//"\t[-C clip_path (default: off)\n"
+		//"\t (create time stamped raw clips, requires squelch)\n"
+		//"\t (path must have '\%s' and will expand to date_time_freq)\n"
+		//"\t[-H hop_fifo (default: off)\n"
+		//"\t (fifo will contain the active frequency)\n"
+		"\n"
+		"Produces signed 16 bit ints, use Sox or aplay to hear them.\n"
+		"\trtl_fm ... | play -t raw -r 24k -es -b 16 -c 1 -V1 -\n"
+		"\t           | aplay -r 24k -f S16_LE -t raw -c 1\n"
+		"\t  -M wbfm  | play -r 32k ... \n"
+		"\t  -s 22050 | multimon -t raw /dev/stdin\n\n");
+	exit(1);
+}
+
+#ifdef _WIN32
+BOOL WINAPI
+sighandler(int signum)
+{
+	if (CTRL_C_EVENT == signum) {
+		fprintf(stderr, "Signal caught, exiting!\n");
+		do_exit = 1;
+		rtlsdr_cancel_async(dongle.dev);
+		return TRUE;
+	}
+	return FALSE;
+}
+#else
+static void sighandler(int signum)
+{
+	fprintf(stderr, "Signal caught, exiting!\n");
+	do_exit = 1;
+	rtlsdr_cancel_async(dongle.dev);
+}
+#endif
+
+/* more cond dumbness */
+#define safe_cond_signal(n, m) pthread_mutex_lock(m); pthread_cond_signal(n); pthread_mutex_unlock(m)
+#define safe_cond_wait(n, m) pthread_mutex_lock(m); pthread_cond_wait(n, m); pthread_mutex_unlock(m)
+
+/* {length, coef, coef, coef}  and scaled by 2^15
+   for now, only length 9, optimal way to get +85% bandwidth */
+#define CIC_TABLE_MAX 10
+int cic_9_tables[][10] = {
+	{0,},
+	{9, -156,  -97, 2798, -15489, 61019, -15489, 2798,  -97, -156},
+	{9, -128, -568, 5593, -24125, 74126, -24125, 5593, -568, -128},
+	{9, -129, -639, 6187, -26281, 77511, -26281, 6187, -639, -129},
+	{9, -122, -612, 6082, -26353, 77818, -26353, 6082, -612, -122},
+	{9, -120, -602, 6015, -26269, 77757, -26269, 6015, -602, -120},
+	{9, -120, -582, 5951, -26128, 77542, -26128, 5951, -582, -120},
+	{9, -119, -580, 5931, -26094, 77505, -26094, 5931, -580, -119},
+	{9, -119, -578, 5921, -26077, 77484, -26077, 5921, -578, -119},
+	{9, -119, -577, 5917, -26067, 77473, -26067, 5917, -577, -119},
+	{9, -199, -362, 5303, -25505, 77489, -25505, 5303, -362, -199},
+};
+
+#if defined(_MSC_VER) && (_MSC_VER < 1800)
+double log2(double n)
+{
+	return log(n) / log(2.0);
+}
+#endif
+
+void rotate_90(unsigned char *buf, uint32_t len)
+/* 90 rotation is 1+0j, 0+1j, -1+0j, 0-1j
+   or [0, 1, -3, 2, -4, -5, 7, -6] */
+{
+	uint32_t i;
+	unsigned char tmp;
+	for (i=0; i<len; i+=8) {
+		/* uint8_t negation = 255 - x */
+		tmp = 255 - buf[i+3];
+		buf[i+3] = buf[i+2];
+		buf[i+2] = tmp;
+
+		buf[i+4] = 255 - buf[i+4];
+		buf[i+5] = 255 - buf[i+5];
+
+		tmp = 255 - buf[i+6];
+		buf[i+6] = buf[i+7];
+		buf[i+7] = tmp;
+	}
+}
+
+void low_pass(struct demod_state *d)
+/* simple square window FIR */
+{
+	int i=0, i2=0;
+	while (i < d->lp_len) {
+		d->now_r += d->lowpassed[i];
+		d->now_j += d->lowpassed[i+1];
+		i += 2;
+		d->prev_index++;
+		if (d->prev_index < d->downsample) {
+			continue;
+		}
+		d->lowpassed[i2]   = d->now_r; // * d->output_scale;
+		d->lowpassed[i2+1] = d->now_j; // * d->output_scale;
+		d->prev_index = 0;
+		d->now_r = 0;
+		d->now_j = 0;
+		i2 += 2;
+	}
+	d->lp_len = i2;
+}
+
+int low_pass_simple(int16_t *signal2, int len, int step)
+// no wrap around, length must be multiple of step
+{
+	int i, i2, sum;
+	for(i=0; i < len; i+=step) {
+		sum = 0;
+		for(i2=0; i2<step; i2++) {
+			sum += (int)signal2[i + i2];
+		}
+		//signal2[i/step] = (int16_t)(sum / step);
+		signal2[i/step] = (int16_t)(sum);
+	}
+	signal2[i/step + 1] = signal2[i/step];
+	return len / step;
+}
+
+void low_pass_real(struct demod_state *s)
+/* simple square window FIR */
+// add support for upsampling?
+{
+	int i=0, i2=0;
+	int fast = (int)s->rate_out;
+	int slow = s->rate_out2;
+	while (i < s->result_len) {
+		s->now_lpr += s->result[i];
+		i++;
+		s->prev_lpr_index += slow;
+		if (s->prev_lpr_index < fast) {
+			continue;
+		}
+		s->result[i2] = (int16_t)(s->now_lpr / (fast/slow));
+		s->prev_lpr_index -= fast;
+		s->now_lpr = 0;
+		i2 += 1;
+	}
+	s->result_len = i2;
+}
+
+void fifth_order(int16_t *data, int length, int16_t *hist)
+/* for half of interleaved data */
+{
+	int i;
+	int16_t a, b, c, d, e, f;
+	a = hist[1];
+	b = hist[2];
+	c = hist[3];
+	d = hist[4];
+	e = hist[5];
+	f = data[0];
+	/* a downsample should improve resolution, so don't fully shift */
+	data[0] = (a + (b+e)*5 + (c+d)*10 + f) >> 4;
+	for (i=4; i<length; i+=4) {
+		a = c;
+		b = d;
+		c = e;
+		d = f;
+		e = data[i-2];
+		f = data[i];
+		data[i/2] = (a + (b+e)*5 + (c+d)*10 + f) >> 4;
+	}
+	/* archive */
+	hist[0] = a;
+	hist[1] = b;
+	hist[2] = c;
+	hist[3] = d;
+	hist[4] = e;
+	hist[5] = f;
+}
+
+void generic_fir(int16_t *data, int length, int *fir, int16_t *hist)
+/* Okay, not at all generic.  Assumes length 9, fix that eventually. */
+{
+	int d, temp, sum;
+	for (d=0; d<length; d+=2) {
+		temp = data[d];
+		sum = 0;
+		sum += (hist[0] + hist[8]) * fir[1];
+		sum += (hist[1] + hist[7]) * fir[2];
+		sum += (hist[2] + hist[6]) * fir[3];
+		sum += (hist[3] + hist[5]) * fir[4];
+		sum +=            hist[4]  * fir[5];
+		data[d] = sum >> 15 ;
+		hist[0] = hist[1];
+		hist[1] = hist[2];
+		hist[2] = hist[3];
+		hist[3] = hist[4];
+		hist[4] = hist[5];
+		hist[5] = hist[6];
+		hist[6] = hist[7];
+		hist[7] = hist[8];
+		hist[8] = temp;
+	}
+}
+
+/* define our own complex math ops
+   because ARMv5 has no hardware float */
+
+void multiply(int ar, int aj, int br, int bj, int *cr, int *cj)
+{
+	*cr = ar*br - aj*bj;
+	*cj = aj*br + ar*bj;
+}
+
+int polar_discriminant(int ar, int aj, int br, int bj)
+{
+	int cr, cj;
+	double angle;
+	multiply(ar, aj, br, -bj, &cr, &cj);
+	angle = atan2((double)cj, (double)cr);
+	return (int)(angle / 3.14159 * (1<<14));
+}
+
+int fast_atan2(int y, int x)
+/* pre scaled for int16 */
+{
+	int yabs, angle;
+	int pi4=(1<<12), pi34=3*(1<<12);  // note pi = 1<<14
+	if (x==0 && y==0) {
+		return 0;
+	}
+	yabs = y;
+	if (yabs < 0) {
+		yabs = -yabs;
+	}
+	if (x >= 0) {
+		angle = pi4  - pi4 * (x-yabs) / (x+yabs);
+	} else {
+		angle = pi34 - pi4 * (x+yabs) / (yabs-x);
+	}
+	if (y < 0) {
+		return -angle;
+	}
+	return angle;
+}
+
+int polar_disc_fast(int ar, int aj, int br, int bj)
+{
+	int cr, cj;
+	multiply(ar, aj, br, -bj, &cr, &cj);
+	return fast_atan2(cj, cr);
+}
+
+int atan_lut_init(void)
+{
+	int i = 0;
+
+	atan_lut = malloc(atan_lut_size * sizeof(int));
+
+	for (i = 0; i < atan_lut_size; i++) {
+		atan_lut[i] = (int) (atan((double) i / (1<<atan_lut_coef)) / 3.14159 * (1<<14));
+	}
+
+	return 0;
+}
+
+int polar_disc_lut(int ar, int aj, int br, int bj)
+{
+	int cr, cj, x, x_abs;
+
+	multiply(ar, aj, br, -bj, &cr, &cj);
+
+	/* special cases */
+	if (cr == 0 || cj == 0) {
+		if (cr == 0 && cj == 0)
+			{return 0;}
+		if (cr == 0 && cj > 0)
+			{return 1 << 13;}
+		if (cr == 0 && cj < 0)
+			{return -(1 << 13);}
+		if (cj == 0 && cr > 0)
+			{return 0;}
+		if (cj == 0 && cr < 0)
+			{return 1 << 14;}
+	}
+
+	/* real range -32768 - 32768 use 64x range -> absolute maximum: 2097152 */
+	x = (cj << atan_lut_coef) / cr;
+	x_abs = abs(x);
+
+	if (x_abs >= atan_lut_size) {
+		/* we can use linear range, but it is not necessary */
+		return (cj > 0) ? 1<<13 : -(1<<13);
+	}
+
+	if (x > 0) {
+		return (cj > 0) ? atan_lut[x] : atan_lut[x] - (1<<14);
+	} else {
+		return (cj > 0) ? (1<<14) - atan_lut[-x] : -atan_lut[-x];
+	}
+
+	return 0;
+}
+
+void fm_demod(struct demod_state *fm)
+{
+	int i, pcm;
+	int16_t *lp = fm->lowpassed;
+	pcm = polar_discriminant(lp[0], lp[1],
+		fm->pre_r, fm->pre_j);
+	fm->result[0] = (int16_t)pcm;
+	for (i = 2; i < (fm->lp_len-1); i += 2) {
+		switch (fm->custom_atan) {
+		case 0:
+			pcm = polar_discriminant(lp[i], lp[i+1],
+				lp[i-2], lp[i-1]);
+			break;
+		case 1:
+			pcm = polar_disc_fast(lp[i], lp[i+1],
+				lp[i-2], lp[i-1]);
+			break;
+		case 2:
+			pcm = polar_disc_lut(lp[i], lp[i+1],
+				lp[i-2], lp[i-1]);
+			break;
+		}
+		fm->result[i/2] = (int16_t)pcm;
+	}
+	fm->pre_r = lp[fm->lp_len - 2];
+	fm->pre_j = lp[fm->lp_len - 1];
+	fm->result_len = fm->lp_len/2;
+}
+
+void am_demod(struct demod_state *fm)
+// todo, fix this extreme laziness
+{
+	int i, pcm;
+	int16_t *lp = fm->lowpassed;
+	int16_t *r  = fm->result;
+	for (i = 0; i < fm->lp_len; i += 2) {
+		// hypot uses floats but won't overflow
+		//r[i/2] = (int16_t)hypot(lp[i], lp[i+1]);
+		pcm = lp[i] * lp[i];
+		pcm += lp[i+1] * lp[i+1];
+		r[i/2] = (int16_t)sqrt(pcm) * fm->output_scale;
+	}
+	fm->result_len = fm->lp_len/2;
+	// lowpass? (3khz)  highpass?  (dc)
+}
+
+void usb_demod(struct demod_state *fm)
+{
+	int i, pcm;
+	int16_t *lp = fm->lowpassed;
+	int16_t *r  = fm->result;
+	for (i = 0; i < fm->lp_len; i += 2) {
+		pcm = lp[i] + lp[i+1];
+		r[i/2] = (int16_t)pcm * fm->output_scale;
+	}
+	fm->result_len = fm->lp_len/2;
+}
+
+void lsb_demod(struct demod_state *fm)
+{
+	int i, pcm;
+	int16_t *lp = fm->lowpassed;
+	int16_t *r  = fm->result;
+	for (i = 0; i < fm->lp_len; i += 2) {
+		pcm = lp[i] - lp[i+1];
+		r[i/2] = (int16_t)pcm * fm->output_scale;
+	}
+	fm->result_len = fm->lp_len/2;
+}
+
+void raw_demod(struct demod_state *fm)
+{
+	int i;
+	for (i = 0; i < fm->lp_len; i++) {
+		fm->result[i] = (int16_t)fm->lowpassed[i];
+	}
+	fm->result_len = fm->lp_len;
+}
+
+void deemph_filter(struct demod_state *fm)
+{
+	static int avg;  // cheating...
+	int i, d;
+	// de-emph IIR
+	// avg = avg * (1 - alpha) + sample * alpha;
+	for (i = 0; i < fm->result_len; i++) {
+		d = fm->result[i] - avg;
+		if (d > 0) {
+			avg += (d + fm->deemph_a/2) / fm->deemph_a;
+		} else {
+			avg += (d - fm->deemph_a/2) / fm->deemph_a;
+		}
+		fm->result[i] = (int16_t)avg;
+	}
+}
+
+void dc_block_filter(struct demod_state *fm)
+{
+	int i, avg;
+	int64_t sum = 0;
+	for (i=0; i < fm->result_len; i++) {
+		sum += fm->result[i];
+	}
+	avg = sum / fm->result_len;
+	avg = (avg + fm->dc_avg * 9) / 10;
+	for (i=0; i < fm->result_len; i++) {
+		fm->result[i] -= avg;
+	}
+	fm->dc_avg = avg;
+}
+
+int mad(int16_t *samples, int len, int step)
+/* mean average deviation */
+{
+	int i=0, sum=0, ave=0;
+	if (len == 0)
+		{return 0;}
+	for (i=0; i<len; i+=step) {
+		sum += samples[i];
+	}
+	ave = sum / (len * step);
+	sum = 0;
+	for (i=0; i<len; i+=step) {
+		sum += abs(samples[i] - ave);
+	}
+	return sum / (len / step);
+}
+
+int rms(int16_t *samples, int len, int step)
+/* largely lifted from rtl_power */
+{
+	int i;
+	long p, t, s;
+	double dc, err;
+
+	p = t = 0L;
+	for (i=0; i<len; i+=step) {
+		s = (long)samples[i];
+		t += s;
+		p += s * s;
+	}
+	/* correct for dc offset in squares */
+	dc = (double)(t*step) / (double)len;
+	err = t * 2 * dc - dc * dc * len;
+
+	return (int)sqrt((p-err) / len);
+}
+
+void arbitrary_upsample(int16_t *buf1, int16_t *buf2, int len1, int len2)
+/* linear interpolation, len1 < len2 */
+{
+	int i = 1;
+	int j = 0;
+	int tick = 0;
+	double frac;  // use integers...
+	while (j < len2) {
+		frac = (double)tick / (double)len2;
+		buf2[j] = (int16_t)(buf1[i-1]*(1-frac) + buf1[i]*frac);
+		j++;
+		tick += len1;
+		if (tick > len2) {
+			tick -= len2;
+			i++;
+		}
+		if (i >= len1) {
+			i = len1 - 1;
+			tick = len2;
+		}
+	}
+}
+
+void arbitrary_downsample(int16_t *buf1, int16_t *buf2, int len1, int len2)
+/* fractional boxcar lowpass, len1 > len2 */
+{
+	int i = 1;
+	int j = 0;
+	int tick = 0;
+	double remainder = 0;
+	double frac;  // use integers...
+	buf2[0] = 0;
+	while (j < len2) {
+		frac = 1.0;
+		if ((tick + len2) > len1) {
+			frac = (double)(len1 - tick) / (double)len2;}
+		buf2[j] += (int16_t)((double)buf1[i] * frac + remainder);
+		remainder = (double)buf1[i] * (1.0-frac);
+		tick += len2;
+		i++;
+		if (tick > len1) {
+			j++;
+			buf2[j] = 0;
+			tick -= len1;
+		}
+		if (i >= len1) {
+			i = len1 - 1;
+			tick = len1;
+		}
+	}
+	for (j=0; j<len2; j++) {
+		buf2[j] = buf2[j] * len2 / len1;}
+}
+
+void arbitrary_resample(int16_t *buf1, int16_t *buf2, int len1, int len2)
+/* up to you to calculate lengths and make sure it does not go OOB
+ * okay for buffers to overlap, if you are downsampling */
+{
+	if (len1 < len2) {
+		arbitrary_upsample(buf1, buf2, len1, len2);
+	} else {
+		arbitrary_downsample(buf1, buf2, len1, len2);
+	}
+}
+
+void full_demod(struct demod_state *d)
+{
+	int i, ds_p;
+	int sr = 0;
+	ds_p = d->downsample_passes;
+	if (ds_p) {
+		for (i=0; i < ds_p; i++) {
+			fifth_order(d->lowpassed,   (d->lp_len >> i), d->lp_i_hist[i]);
+			fifth_order(d->lowpassed+1, (d->lp_len >> i) - 1, d->lp_q_hist[i]);
+		}
+		d->lp_len = d->lp_len >> ds_p;
+		/* droop compensation */
+		if (d->comp_fir_size == 9 && ds_p <= CIC_TABLE_MAX) {
+			generic_fir(d->lowpassed, d->lp_len,
+				cic_9_tables[ds_p], d->droop_i_hist);
+			generic_fir(d->lowpassed+1, d->lp_len-1,
+				cic_9_tables[ds_p], d->droop_q_hist);
+		}
+	} else {
+		low_pass(d);
+	}
+	/* power squelch */
+	if (d->squelch_level) {
+		sr = rms(d->lowpassed, d->lp_len, 1);
+		if (sr < d->squelch_level) {
+			d->squelch_hits++;
+			for (i=0; i<d->lp_len; i++) {
+				d->lowpassed[i] = 0;
+			}
+		} else {
+			d->squelch_hits = 0;}
+	}
+	d->mode_demod(d);  /* lowpassed -> result */
+	if (d->mode_demod == &raw_demod) {
+		return;
+	}
+	/* todo, fm noise squelch */
+	// use nicer filter here too?
+	if (d->post_downsample > 1) {
+		d->result_len = low_pass_simple(d->result, d->result_len, d->post_downsample);}
+	if (d->deemph) {
+		deemph_filter(d);}
+	if (d->dc_block) {
+		dc_block_filter(d);}
+	if (d->rate_out2 > 0) {
+		low_pass_real(d);
+		//arbitrary_resample(d->result, d->result, d->result_len, d->result_len * d->rate_out2 / d->rate_out);
+	}
+}
+
+static void rtlsdr_callback(unsigned char *buf, uint32_t len, void *ctx)
+{
+	int i;
+	struct dongle_state *s = ctx;
+	struct demod_state *d = s->demod_target;
+
+	if (do_exit) {
+		return;}
+	if (!ctx) {
+		return;}
+	if (s->mute) {
+		for (i=0; i<s->mute; i++) {
+			buf[i] = 127;}
+		s->mute = 0;
+	}
+	if (!s->offset_tuning) {
+		rotate_90(buf, len);}
+	for (i=0; i<(int)len; i++) {
+		s->buf16[i] = (int16_t)buf[i] - 127;}
+	pthread_rwlock_wrlock(&d->rw);
+	memcpy(d->lowpassed, s->buf16, 2*len);
+	d->lp_len = len;
+	pthread_rwlock_unlock(&d->rw);
+	safe_cond_signal(&d->ready, &d->ready_m);
+}
+
+static void *dongle_thread_fn(void *arg)
+{
+	struct dongle_state *s = arg;
+	rtlsdr_read_async(s->dev, rtlsdr_callback, s, 0, s->buf_len);
+	return 0;
+}
+
+static void *demod_thread_fn(void *arg)
+{
+	struct demod_state *d = arg;
+	struct output_state *o = d->output_target;
+	while (!do_exit) {
+		safe_cond_wait(&d->ready, &d->ready_m);
+		pthread_rwlock_wrlock(&d->rw);
+		full_demod(d);
+		pthread_rwlock_unlock(&d->rw);
+		if (d->exit_flag) {
+			do_exit = 1;
+		}
+		if (d->squelch_level && d->squelch_hits > d->conseq_squelch) {
+			d->squelch_hits = d->conseq_squelch + 1;  /* hair trigger */
+			safe_cond_signal(&controller.hop, &controller.hop_m);
+			continue;
+		}
+		pthread_rwlock_wrlock(&o->rw);
+		memcpy(o->result, d->result, 2*d->result_len);
+		o->result_len = d->result_len;
+		pthread_rwlock_unlock(&o->rw);
+		safe_cond_signal(&o->ready, &o->ready_m);
+	}
+	return 0;
+}
+
+static void *output_thread_fn(void *arg)
+{
+	struct output_state *s = arg;
+	while (!do_exit) {
+		// use timedwait and pad out under runs
+		safe_cond_wait(&s->ready, &s->ready_m);
+		pthread_rwlock_rdlock(&s->rw);
+		fwrite(s->result, 2, s->result_len, s->file);
+		pthread_rwlock_unlock(&s->rw);
+	}
+	return 0;
+}
+
+static void optimal_settings(int freq, int rate)
+{
+	// giant ball of hacks
+	// seems unable to do a single pass, 2:1
+	int capture_freq, capture_rate;
+	struct dongle_state *d = &dongle;
+	struct demod_state *dm = &demod;
+	struct controller_state *cs = &controller;
+	dm->downsample = (1000000 / dm->rate_in) + 1;
+	if (dm->downsample_passes) {
+		dm->downsample_passes = (int)log2(dm->downsample) + 1;
+		dm->downsample = 1 << dm->downsample_passes;
+	}
+	capture_freq = freq;
+	capture_rate = dm->downsample * dm->rate_in;
+	if (!d->offset_tuning) {
+		capture_freq = freq + capture_rate/4;}
+	capture_freq += cs->edge * dm->rate_in / 2;
+	dm->output_scale = (1<<15) / (128 * dm->downsample);
+	if (dm->output_scale < 1) {
+		dm->output_scale = 1;}
+	if (dm->mode_demod == &fm_demod) {
+		dm->output_scale = 1;}
+	d->freq = (uint32_t)capture_freq;
+	d->rate = (uint32_t)capture_rate;
+}
+
+static void *controller_thread_fn(void *arg)
+{
+	// thoughts for multiple dongles
+	// might be no good using a controller thread if retune/rate blocks
+	int i;
+	struct controller_state *s = arg;
+
+	if (s->wb_mode) {
+		for (i=0; i < s->freq_len; i++) {
+			s->freqs[i] += 16000;}
+	}
+
+	/* set up primary channel */
+	optimal_settings(s->freqs[0], demod.rate_in);
+	if (dongle.direct_sampling) {
+		verbose_direct_sampling(dongle.dev, dongle.direct_sampling);}
+	if (dongle.offset_tuning) {
+		verbose_offset_tuning(dongle.dev);}
+
+	/* Set the frequency */
+	verbose_set_frequency(dongle.dev, dongle.freq);
+	fprintf(stderr, "Oversampling input by: %ix.\n", demod.downsample);
+	fprintf(stderr, "Oversampling output by: %ix.\n", demod.post_downsample);
+	fprintf(stderr, "Buffer size: %0.2fms\n",
+		1000 * 0.5 * (float)ACTUAL_BUF_LENGTH / (float)dongle.rate);
+
+	/* Set the sample rate */
+	verbose_set_sample_rate(dongle.dev, dongle.rate);
+	fprintf(stderr, "Output at %u Hz.\n", demod.rate_in/demod.post_downsample);
+
+	while (!do_exit) {
+		safe_cond_wait(&s->hop, &s->hop_m);
+		if (s->freq_len <= 1) {
+			continue;}
+		/* hacky hopping */
+		s->freq_now = (s->freq_now + 1) % s->freq_len;
+		optimal_settings(s->freqs[s->freq_now], demod.rate_in);
+		rtlsdr_set_center_freq(dongle.dev, dongle.freq);
+		dongle.mute = BUFFER_DUMP;
+	}
+	return 0;
+}
+
+void frequency_range(struct controller_state *s, char *arg)
+{
+	char *start, *stop, *step;
+	int i;
+	start = arg;
+	stop = strchr(start, ':') + 1;
+	if (stop == (char *)1) { // no stop or step given
+		s->freqs[s->freq_len] = (uint32_t) atofs(start);
+		s->freq_len++;
+		return;
+	}
+	stop[-1] = '\0';
+	step = strchr(stop, ':') + 1;
+	if (step == (char *)1) { // no step given
+		s->freqs[s->freq_len] = (uint32_t) atofs(start);
+		s->freq_len++;
+		s->freqs[s->freq_len] = (uint32_t) atofs(stop);
+		s->freq_len++;
+		stop[-1] = ':';
+		return;
+	}
+	step[-1] = '\0';
+	for(i=(int)atofs(start); i<=(int)atofs(stop); i+=(int)atofs(step))
+	{
+		s->freqs[s->freq_len] = (uint32_t)i;
+		s->freq_len++;
+		if (s->freq_len >= FREQUENCIES_LIMIT) {
+			break;}
+	}
+	stop[-1] = ':';
+	step[-1] = ':';
+}
+
+void dongle_init(struct dongle_state *s)
+{
+	s->rate = DEFAULT_SAMPLE_RATE;
+	s->gain = AUTO_GAIN; // tenths of a dB
+	s->mute = 0;
+	s->direct_sampling = 0;
+	s->offset_tuning = 0;
+	s->demod_target = &demod;
+}
+
+void demod_init(struct demod_state *s)
+{
+	s->rate_in = DEFAULT_SAMPLE_RATE;
+	s->rate_out = DEFAULT_SAMPLE_RATE;
+	s->squelch_level = 0;
+	s->conseq_squelch = 10;
+	s->terminate_on_squelch = 0;
+	s->squelch_hits = 11;
+	s->downsample_passes = 0;
+	s->comp_fir_size = 0;
+	s->prev_index = 0;
+	s->post_downsample = 1;  // once this works, default = 4
+	s->custom_atan = 0;
+	s->deemph = 0;
+	s->rate_out2 = -1;  // flag for disabled
+	s->mode_demod = &fm_demod;
+	s->pre_j = s->pre_r = s->now_r = s->now_j = 0;
+	s->prev_lpr_index = 0;
+	s->deemph_a = 0;
+	s->now_lpr = 0;
+	s->dc_block = 0;
+	s->dc_avg = 0;
+	pthread_rwlock_init(&s->rw, NULL);
+	pthread_cond_init(&s->ready, NULL);
+	pthread_mutex_init(&s->ready_m, NULL);
+	s->output_target = &output;
+}
+
+void demod_cleanup(struct demod_state *s)
+{
+	pthread_rwlock_destroy(&s->rw);
+	pthread_cond_destroy(&s->ready);
+	pthread_mutex_destroy(&s->ready_m);
+}
+
+void output_init(struct output_state *s)
+{
+	s->rate = DEFAULT_SAMPLE_RATE;
+	pthread_rwlock_init(&s->rw, NULL);
+	pthread_cond_init(&s->ready, NULL);
+	pthread_mutex_init(&s->ready_m, NULL);
+}
+
+void output_cleanup(struct output_state *s)
+{
+	pthread_rwlock_destroy(&s->rw);
+	pthread_cond_destroy(&s->ready);
+	pthread_mutex_destroy(&s->ready_m);
+}
+
+void controller_init(struct controller_state *s)
+{
+	s->freqs[0] = 100000000;
+	s->freq_len = 0;
+	s->edge = 0;
+	s->wb_mode = 0;
+	pthread_cond_init(&s->hop, NULL);
+	pthread_mutex_init(&s->hop_m, NULL);
+}
+
+void controller_cleanup(struct controller_state *s)
+{
+	pthread_cond_destroy(&s->hop);
+	pthread_mutex_destroy(&s->hop_m);
+}
+
+void sanity_checks(void)
+{
+	if (controller.freq_len == 0) {
+		fprintf(stderr, "Please specify a frequency.\n");
+		exit(1);
+	}
+
+	if (controller.freq_len >= FREQUENCIES_LIMIT) {
+		fprintf(stderr, "Too many channels, maximum %i.\n", FREQUENCIES_LIMIT);
+		exit(1);
+	}
+
+	if (controller.freq_len > 1 && demod.squelch_level == 0) {
+		fprintf(stderr, "Please specify a squelch level.  Required for scanning multiple frequencies.\n");
+		exit(1);
+	}
+
+}
+
+int main(int argc, char **argv)
+{
+#ifndef _WIN32
+	struct sigaction sigact;
+#endif
+	int r, opt;
+	int dev_given = 0;
+	int custom_ppm = 0;
+    int enable_biastee = 0;
+	dongle_init(&dongle);
+	demod_init(&demod);
+	output_init(&output);
+	controller_init(&controller);
+
+	while ((opt = getopt(argc, argv, "d:f:g:s:b:l:o:t:r:p:E:F:A:M:hT")) != -1) {
+		switch (opt) {
+		case 'd':
+			dongle.dev_index = verbose_device_search(optarg);
+			dev_given = 1;
+			break;
+		case 'f':
+			if (controller.freq_len >= FREQUENCIES_LIMIT) {
+				break;}
+			if (strchr(optarg, ':'))
+				{frequency_range(&controller, optarg);}
+			else
+			{
+				controller.freqs[controller.freq_len] = (uint32_t)atofs(optarg);
+				controller.freq_len++;
+			}
+			break;
+		case 'g':
+			dongle.gain = (int)(atof(optarg) * 10);
+			break;
+		case 'l':
+			demod.squelch_level = (int)atof(optarg);
+			break;
+		case 's':
+			demod.rate_in = (uint32_t)atofs(optarg);
+			demod.rate_out = (uint32_t)atofs(optarg);
+			break;
+		case 'r':
+			output.rate = (int)atofs(optarg);
+			demod.rate_out2 = (int)atofs(optarg);
+			break;
+		case 'o':
+			fprintf(stderr, "Warning: -o is very buggy\n");
+			demod.post_downsample = (int)atof(optarg);
+			if (demod.post_downsample < 1 || demod.post_downsample > MAXIMUM_OVERSAMPLE) {
+				fprintf(stderr, "Oversample must be between 1 and %i\n", MAXIMUM_OVERSAMPLE);}
+			break;
+		case 't':
+			demod.conseq_squelch = (int)atof(optarg);
+			if (demod.conseq_squelch < 0) {
+				demod.conseq_squelch = -demod.conseq_squelch;
+				demod.terminate_on_squelch = 1;
+			}
+			break;
+		case 'p':
+			dongle.ppm_error = atoi(optarg);
+			custom_ppm = 1;
+			break;
+		case 'E':
+			if (strcmp("edge",  optarg) == 0) {
+				controller.edge = 1;}
+			if (strcmp("dc", optarg) == 0) {
+				demod.dc_block = 1;}
+			if (strcmp("deemp",  optarg) == 0) {
+				demod.deemph = 1;}
+			if (strcmp("direct",  optarg) == 0) {
+				dongle.direct_sampling = 1;}
+			if (strcmp("direct2", optarg) == 0) {
+				dongle.direct_sampling = 2;}
+			if (strcmp("offset",  optarg) == 0) {
+				dongle.offset_tuning = 1;}
+			break;
+		case 'F':
+			demod.downsample_passes = 1;  /* truthy placeholder */
+			demod.comp_fir_size = atoi(optarg);
+			break;
+		case 'A':
+			if (strcmp("std",  optarg) == 0) {
+				demod.custom_atan = 0;}
+			if (strcmp("fast", optarg) == 0) {
+				demod.custom_atan = 1;}
+			if (strcmp("lut",  optarg) == 0) {
+				atan_lut_init();
+				demod.custom_atan = 2;}
+			break;
+		case 'M':
+			if (strcmp("fm",  optarg) == 0) {
+				demod.mode_demod = &fm_demod;}
+			if (strcmp("raw",  optarg) == 0) {
+				demod.mode_demod = &raw_demod;}
+			if (strcmp("am",  optarg) == 0) {
+				demod.mode_demod = &am_demod;}
+			if (strcmp("usb", optarg) == 0) {
+				demod.mode_demod = &usb_demod;}
+			if (strcmp("lsb", optarg) == 0) {
+				demod.mode_demod = &lsb_demod;}
+			if (strcmp("wbfm",  optarg) == 0) {
+				controller.wb_mode = 1;
+				demod.mode_demod = &fm_demod;
+				demod.rate_in = 170000;
+				demod.rate_out = 170000;
+				demod.rate_out2 = 32000;
+				demod.custom_atan = 1;
+				//demod.post_downsample = 4;
+				demod.deemph = 1;
+				demod.squelch_level = 0;}
+			break;
+		case 'T':
+			enable_biastee = 1;
+			break;
+		case 'h':
+		default:
+			usage();
+			break;
+		}
+	}
+
+	/* quadruple sample_rate to limit to Δθ to ±π/2 */
+	demod.rate_in *= demod.post_downsample;
+
+	if (!output.rate) {
+		output.rate = demod.rate_out;}
+
+	sanity_checks();
+
+	if (controller.freq_len > 1) {
+		demod.terminate_on_squelch = 0;}
+
+	if (argc <= optind) {
+		output.filename = "-";
+	} else {
+		output.filename = argv[optind];
+	}
+
+	ACTUAL_BUF_LENGTH = lcm_post[demod.post_downsample] * DEFAULT_BUF_LENGTH;
+
+	if (!dev_given) {
+		dongle.dev_index = verbose_device_search("0");
+	}
+
+	if (dongle.dev_index < 0) {
+		exit(1);
+	}
+
+	r = rtlsdr_open(&dongle.dev, (uint32_t)dongle.dev_index);
+	if (r < 0) {
+		fprintf(stderr, "Failed to open rtlsdr device #%d.\n", dongle.dev_index);
+		exit(1);
+	}
+#ifndef _WIN32
+	sigact.sa_handler = sighandler;
+	sigemptyset(&sigact.sa_mask);
+	sigact.sa_flags = 0;
+	sigaction(SIGINT, &sigact, NULL);
+	sigaction(SIGTERM, &sigact, NULL);
+	sigaction(SIGQUIT, &sigact, NULL);
+	sigaction(SIGPIPE, &sigact, NULL);
+#else
+	SetConsoleCtrlHandler( (PHANDLER_ROUTINE) sighandler, TRUE );
+#endif
+
+	if (demod.deemph) {
+		demod.deemph_a = (int)round(1.0/((1.0-exp(-1.0/(demod.rate_out * 75e-6)))));
+	}
+
+	/* Set the tuner gain */
+	if (dongle.gain == AUTO_GAIN) {
+		verbose_auto_gain(dongle.dev);
+	} else {
+		dongle.gain = nearest_gain(dongle.dev, dongle.gain);
+		verbose_gain_set(dongle.dev, dongle.gain);
+	}
+
+	rtlsdr_set_bias_tee(dongle.dev, enable_biastee);
+	if (enable_biastee)
+		fprintf(stderr, "activated bias-T on GPIO PIN 0\n");
+
+	verbose_ppm_set(dongle.dev, dongle.ppm_error);
+
+	if (strcmp(output.filename, "-") == 0) { /* Write samples to stdout */
+		output.file = stdout;
+#ifdef _WIN32
+		_setmode(_fileno(output.file), _O_BINARY);
+#endif
+	} else {
+		output.file = fopen(output.filename, "wb");
+		if (!output.file) {
+			fprintf(stderr, "Failed to open %s\n", output.filename);
+			exit(1);
+		}
+	}
+
+	//r = rtlsdr_set_testmode(dongle.dev, 1);
+
+	/* Reset endpoint before we start reading from it (mandatory) */
+	verbose_reset_buffer(dongle.dev);
+
+	pthread_create(&controller.thread, NULL, controller_thread_fn, (void *)(&controller));
+	usleep(100000);
+	pthread_create(&output.thread, NULL, output_thread_fn, (void *)(&output));
+	pthread_create(&demod.thread, NULL, demod_thread_fn, (void *)(&demod));
+	pthread_create(&dongle.thread, NULL, dongle_thread_fn, (void *)(&dongle));
+
+	while (!do_exit) {
+		usleep(100000);
+	}
+
+	if (do_exit) {
+		fprintf(stderr, "\nUser cancel, exiting...\n");}
+	else {
+		fprintf(stderr, "\nLibrary error %d, exiting...\n", r);}
+
+	rtlsdr_cancel_async(dongle.dev);
+	pthread_join(dongle.thread, NULL);
+	safe_cond_signal(&demod.ready, &demod.ready_m);
+	pthread_join(demod.thread, NULL);
+	safe_cond_signal(&output.ready, &output.ready_m);
+	pthread_join(output.thread, NULL);
+	safe_cond_signal(&controller.hop, &controller.hop_m);
+	pthread_join(controller.thread, NULL);
+
+	//dongle_cleanup(&dongle);
+	demod_cleanup(&demod);
+	output_cleanup(&output);
+	controller_cleanup(&controller);
+
+	if (output.file != stdout) {
+		fclose(output.file);}
+
+	rtlsdr_close(dongle.dev);
+	return r >= 0 ? r : -r;
+}
+
+// vim: tabstop=8:softtabstop=8:shiftwidth=8:noexpandtab
diff --git a/src/rtl_power.c b/src/rtl_power.c
new file mode 100644
index 0000000..6204de2
--- /dev/null
+++ b/src/rtl_power.c
@@ -0,0 +1,1015 @@
+/*
+ * rtl-sdr, turns your Realtek RTL2832 based DVB dongle into a SDR receiver
+ * Copyright (C) 2012 by Steve Markgraf <steve@steve-m.de>
+ * Copyright (C) 2012 by Hoernchen <la@tfc-server.de>
+ * Copyright (C) 2012 by Kyle Keen <keenerd@gmail.com>
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+
+/*
+ * rtl_power: general purpose FFT integrator
+ * -f low_freq:high_freq:max_bin_size
+ * -i seconds
+ * outputs CSV
+ * time, low, high, step, db, db, db ...
+ * db optional?  raw output might be better for noise correction
+ * todo:
+ *	threading
+ *	randomized hopping
+ *	noise correction
+ *	continuous IIR
+ *	general astronomy usefulness
+ *	multiple dongles
+ *	multiple FFT workers
+ *	check edge cropping for off-by-one and rounding errors
+ *	1.8MS/s for hiding xtal harmonics
+ */
+
+#include <errno.h>
+#include <signal.h>
+#include <string.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <time.h>
+
+#ifndef _WIN32
+#include <unistd.h>
+#else
+#include <windows.h>
+#include <fcntl.h>
+#include <io.h>
+#include "getopt/getopt.h"
+#define usleep(x) Sleep(x/1000)
+#if defined(_MSC_VER) && (_MSC_VER < 1800)
+#define round(x) (x > 0.0 ? floor(x + 0.5): ceil(x - 0.5))
+#endif
+#define _USE_MATH_DEFINES
+#endif
+
+#include <math.h>
+#include <pthread.h>
+#include <libusb.h>
+
+#include "rtl-sdr.h"
+#include "convenience/convenience.h"
+
+#define MAX(x, y) (((x) > (y)) ? (x) : (y))
+
+#define DEFAULT_BUF_LENGTH		(1 * 16384)
+#define AUTO_GAIN			-100
+#define BUFFER_DUMP			(1<<12)
+
+#define MAXIMUM_RATE			2800000
+#define MINIMUM_RATE			1000000
+
+static volatile int do_exit = 0;
+static rtlsdr_dev_t *dev = NULL;
+FILE *file;
+
+int16_t* Sinewave;
+double* power_table;
+int N_WAVE, LOG2_N_WAVE;
+int next_power;
+int16_t *fft_buf;
+int *window_coefs;
+
+struct tuning_state
+/* one per tuning range */
+{
+	int freq;
+	int rate;
+	int bin_e;
+	long *avg;  /* length == 2^bin_e */
+	int samples;
+	int downsample;
+	int downsample_passes;  /* for the recursive filter */
+	double crop;
+	//pthread_rwlock_t avg_lock;
+	//pthread_mutex_t avg_mutex;
+	/* having the iq buffer here is wasteful, but will avoid contention */
+	uint8_t *buf8;
+	int buf_len;
+	//int *comp_fir;
+	//pthread_rwlock_t buf_lock;
+	//pthread_mutex_t buf_mutex;
+};
+
+/* 3000 is enough for 3GHz b/w worst case */
+#define MAX_TUNES	3000
+struct tuning_state tunes[MAX_TUNES];
+int tune_count = 0;
+
+int boxcar = 1;
+int comp_fir_size = 0;
+int peak_hold = 0;
+
+void usage(void)
+{
+	fprintf(stderr,
+		"rtl_power, a simple FFT logger for RTL2832 based DVB-T receivers\n\n"
+		"Use:\trtl_power -f freq_range [-options] [filename]\n"
+		"\t-f lower:upper:bin_size [Hz]\n"
+		"\t (bin size is a maximum, smaller more convenient bins\n"
+		"\t  will be used.  valid range 1Hz - 2.8MHz)\n"
+		"\t[-i integration_interval (default: 10 seconds)]\n"
+		"\t (buggy if a full sweep takes longer than the interval)\n"
+		"\t[-1 enables single-shot mode (default: off)]\n"
+		"\t[-e exit_timer (default: off/0)]\n"
+		//"\t[-s avg/iir smoothing (default: avg)]\n"
+		//"\t[-t threads (default: 1)]\n"
+		"\t[-d device_index (default: 0)]\n"
+		"\t[-g tuner_gain (default: automatic)]\n"
+		"\t[-p ppm_error (default: 0)]\n"
+		"\t[-T enable bias-T on GPIO PIN 0 (works for rtl-sdr.com v3 dongles)]\n"
+		"\tfilename (a '-' dumps samples to stdout)\n"
+		"\t (omitting the filename also uses stdout)\n"
+		"\n"
+		"Experimental options:\n"
+		"\t[-w window (default: rectangle)]\n"
+		"\t (hamming, blackman, blackman-harris, hann-poisson, bartlett, youssef)\n"
+		// kaiser
+		"\t[-c crop_percent (default: 0%%, recommended: 20%%-50%%)]\n"
+		"\t (discards data at the edges, 100%% discards everything)\n"
+		"\t (has no effect for bins larger than 1MHz)\n"
+		"\t[-F fir_size (default: disabled)]\n"
+		"\t (enables low-leakage downsample filter,\n"
+		"\t  fir_size can be 0 or 9.  0 has bad roll off,\n"
+		"\t  try with '-c 50%%')\n"
+		"\t[-P enables peak hold (default: off)]\n"
+		"\t[-D enable direct sampling (default: off)]\n"
+		"\t[-O enable offset tuning (default: off)]\n"
+		"\n"
+		"CSV FFT output columns:\n"
+		"\tdate, time, Hz low, Hz high, Hz step, samples, dbm, dbm, ...\n\n"
+		"Examples:\n"
+		"\trtl_power -f 88M:108M:125k fm_stations.csv\n"
+		"\t (creates 160 bins across the FM band,\n"
+		"\t  individual stations should be visible)\n"
+		"\trtl_power -f 100M:1G:1M -i 5m -1 survey.csv\n"
+		"\t (a five minute low res scan of nearly everything)\n"
+		"\trtl_power -f ... -i 15m -1 log.csv\n"
+		"\t (integrate for 15 minutes and exit afterwards)\n"
+		"\trtl_power -f ... -e 1h | gzip > log.csv.gz\n"
+		"\t (collect data for one hour and compress it on the fly)\n\n"
+		"Convert CSV to a waterfall graphic with:\n"
+		"\t http://kmkeen.com/tmp/heatmap.py.txt \n");
+	exit(1);
+}
+
+void multi_bail(void)
+{
+	if (do_exit == 1)
+	{
+		fprintf(stderr, "Signal caught, finishing scan pass.\n");
+	}
+	if (do_exit >= 2)
+	{
+		fprintf(stderr, "Signal caught, aborting immediately.\n");
+	}
+}
+
+#ifdef _WIN32
+BOOL WINAPI
+sighandler(int signum)
+{
+	if (CTRL_C_EVENT == signum) {
+		do_exit++;
+		multi_bail();
+		return TRUE;
+	}
+	return FALSE;
+}
+#else
+static void sighandler(int signum)
+{
+	do_exit++;
+	multi_bail();
+}
+#endif
+
+/* more cond dumbness */
+#define safe_cond_signal(n, m) pthread_mutex_lock(m); pthread_cond_signal(n); pthread_mutex_unlock(m)
+#define safe_cond_wait(n, m) pthread_mutex_lock(m); pthread_cond_wait(n, m); pthread_mutex_unlock(m)
+
+/* {length, coef, coef, coef}  and scaled by 2^15
+   for now, only length 9, optimal way to get +85% bandwidth */
+#define CIC_TABLE_MAX 10
+int cic_9_tables[][10] = {
+	{0,},
+	{9, -156,  -97, 2798, -15489, 61019, -15489, 2798,  -97, -156},
+	{9, -128, -568, 5593, -24125, 74126, -24125, 5593, -568, -128},
+	{9, -129, -639, 6187, -26281, 77511, -26281, 6187, -639, -129},
+	{9, -122, -612, 6082, -26353, 77818, -26353, 6082, -612, -122},
+	{9, -120, -602, 6015, -26269, 77757, -26269, 6015, -602, -120},
+	{9, -120, -582, 5951, -26128, 77542, -26128, 5951, -582, -120},
+	{9, -119, -580, 5931, -26094, 77505, -26094, 5931, -580, -119},
+	{9, -119, -578, 5921, -26077, 77484, -26077, 5921, -578, -119},
+	{9, -119, -577, 5917, -26067, 77473, -26067, 5917, -577, -119},
+	{9, -199, -362, 5303, -25505, 77489, -25505, 5303, -362, -199},
+};
+
+#if defined(_MSC_VER) && (_MSC_VER < 1800)
+double log2(double n)
+{
+	return log(n) / log(2.0);
+}
+#endif
+
+/* FFT based on fix_fft.c by Roberts, Slaney and Bouras
+   http://www.jjj.de/fft/fftpage.html
+   16 bit ints for everything
+   -32768..+32768 maps to -1.0..+1.0
+*/
+
+void sine_table(int size)
+{
+	int i;
+	double d;
+	LOG2_N_WAVE = size;
+	N_WAVE = 1 << LOG2_N_WAVE;
+	Sinewave = malloc(sizeof(int16_t) * N_WAVE*3/4);
+	power_table = malloc(sizeof(double) * N_WAVE);
+	for (i=0; i<N_WAVE*3/4; i++)
+	{
+		d = (double)i * 2.0 * M_PI / N_WAVE;
+		Sinewave[i] = (int)round(32767*sin(d));
+		//printf("%i\n", Sinewave[i]);
+	}
+}
+
+static inline int16_t FIX_MPY(int16_t a, int16_t b)
+/* fixed point multiply and scale */
+{
+	int c = ((int)a * (int)b) >> 14;
+	b = c & 0x01;
+	return (c >> 1) + b;
+}
+
+int fix_fft(int16_t iq[], int m)
+/* interleaved iq[], 0 <= n < 2**m, changes in place */
+{
+	int mr, nn, i, j, l, k, istep, n, shift;
+	int16_t qr, qi, tr, ti, wr, wi;
+	n = 1 << m;
+	if (n > N_WAVE)
+		{return -1;}
+	mr = 0;
+	nn = n - 1;
+	/* decimation in time - re-order data */
+	for (m=1; m<=nn; ++m) {
+		l = n;
+		do
+			{l >>= 1;}
+		while (mr+l > nn);
+		mr = (mr & (l-1)) + l;
+		if (mr <= m)
+			{continue;}
+		// real = 2*m, imag = 2*m+1
+		tr = iq[2*m];
+		iq[2*m] = iq[2*mr];
+		iq[2*mr] = tr;
+		ti = iq[2*m+1];
+		iq[2*m+1] = iq[2*mr+1];
+		iq[2*mr+1] = ti;
+	}
+	l = 1;
+	k = LOG2_N_WAVE-1;
+	while (l < n) {
+		shift = 1;
+		istep = l << 1;
+		for (m=0; m<l; ++m) {
+			j = m << k;
+			wr =  Sinewave[j+N_WAVE/4];
+			wi = -Sinewave[j];
+			if (shift) {
+				wr >>= 1; wi >>= 1;}
+			for (i=m; i<n; i+=istep) {
+				j = i + l;
+				tr = FIX_MPY(wr,iq[2*j]) - FIX_MPY(wi,iq[2*j+1]);
+				ti = FIX_MPY(wr,iq[2*j+1]) + FIX_MPY(wi,iq[2*j]);
+				qr = iq[2*i];
+				qi = iq[2*i+1];
+				if (shift) {
+					qr >>= 1; qi >>= 1;}
+				iq[2*j] = qr - tr;
+				iq[2*j+1] = qi - ti;
+				iq[2*i] = qr + tr;
+				iq[2*i+1] = qi + ti;
+			}
+		}
+		--k;
+		l = istep;
+	}
+	return 0;
+}
+
+double rectangle(int i, int length)
+{
+	return 1.0;
+}
+
+double hamming(int i, int length)
+{
+	double a, b, w, N1;
+	a = 25.0/46.0;
+	b = 21.0/46.0;
+	N1 = (double)(length-1);
+	w = a - b*cos(2*i*M_PI/N1);
+	return w;
+}
+
+double blackman(int i, int length)
+{
+	double a0, a1, a2, w, N1;
+	a0 = 7938.0/18608.0;
+	a1 = 9240.0/18608.0;
+	a2 = 1430.0/18608.0;
+	N1 = (double)(length-1);
+	w = a0 - a1*cos(2*i*M_PI/N1) + a2*cos(4*i*M_PI/N1);
+	return w;
+}
+
+double blackman_harris(int i, int length)
+{
+	double a0, a1, a2, a3, w, N1;
+	a0 = 0.35875;
+	a1 = 0.48829;
+	a2 = 0.14128;
+	a3 = 0.01168;
+	N1 = (double)(length-1);
+	w = a0 - a1*cos(2*i*M_PI/N1) + a2*cos(4*i*M_PI/N1) - a3*cos(6*i*M_PI/N1);
+	return w;
+}
+
+double hann_poisson(int i, int length)
+{
+	double a, N1, w;
+	a = 2.0;
+	N1 = (double)(length-1);
+	w = 0.5 * (1 - cos(2*M_PI*i/N1)) * \
+	    pow(M_E, (-a*(double)abs((int)(N1-1-2*i)))/N1);
+	return w;
+}
+
+double youssef(int i, int length)
+/* really a blackman-harris-poisson window, but that is a mouthful */
+{
+	double a, a0, a1, a2, a3, w, N1;
+	a0 = 0.35875;
+	a1 = 0.48829;
+	a2 = 0.14128;
+	a3 = 0.01168;
+	N1 = (double)(length-1);
+	w = a0 - a1*cos(2*i*M_PI/N1) + a2*cos(4*i*M_PI/N1) - a3*cos(6*i*M_PI/N1);
+	a = 0.0025;
+	w *= pow(M_E, (-a*(double)abs((int)(N1-1-2*i)))/N1);
+	return w;
+}
+
+double kaiser(int i, int length)
+// todo, become more smart
+{
+	return 1.0;
+}
+
+double bartlett(int i, int length)
+{
+	double N1, L, w;
+	L = (double)length;
+	N1 = L - 1;
+	w = (i - N1/2) / (L/2);
+	if (w < 0) {
+		w = -w;}
+	w = 1 - w;
+	return w;
+}
+
+void rms_power(struct tuning_state *ts)
+/* for bins between 1MHz and 2MHz */
+{
+	int i, s;
+	uint8_t *buf = ts->buf8;
+	int buf_len = ts->buf_len;
+	long p, t;
+	double dc, err;
+
+	p = t = 0L;
+	for (i=0; i<buf_len; i++) {
+		s = (int)buf[i] - 127;
+		t += (long)s;
+		p += (long)(s * s);
+	}
+	/* correct for dc offset in squares */
+	dc = (double)t / (double)buf_len;
+	err = t * 2 * dc - dc * dc * buf_len;
+	p -= (long)round(err);
+
+	if (!peak_hold) {
+		ts->avg[0] += p;
+	} else {
+		ts->avg[0] = MAX(ts->avg[0], p);
+	}
+	ts->samples += 1;
+}
+
+void frequency_range(char *arg, double crop)
+/* flesh out the tunes[] for scanning */
+// do we want the fewest ranges (easy) or the fewest bins (harder)?
+{
+	char *start, *stop, *step;
+	int i, j, upper, lower, max_size, bw_seen, bw_used, bin_e, buf_len;
+	int downsample, downsample_passes;
+	double bin_size;
+	struct tuning_state *ts;
+	/* hacky string parsing */
+	start = arg;
+	stop = strchr(start, ':') + 1;
+	if (stop == (char *)1) {
+		fprintf(stderr, "Bad frequency range specification: %s\n", arg);
+		exit(1);
+	}
+	stop[-1] = '\0';
+	step = strchr(stop, ':') + 1;
+	if (step == (char *)1) {
+		fprintf(stderr, "Bad frequency range specification: %s\n", arg);
+		exit(1);
+	}
+	step[-1] = '\0';
+	lower = (int)atofs(start);
+	upper = (int)atofs(stop);
+	max_size = (int)atofs(step);
+	stop[-1] = ':';
+	step[-1] = ':';
+	downsample = 1;
+	downsample_passes = 0;
+	/* evenly sized ranges, as close to MAXIMUM_RATE as possible */
+	// todo, replace loop with algebra
+	for (i=1; i<1500; i++) {
+		bw_seen = (upper - lower) / i;
+		bw_used = (int)((double)(bw_seen) / (1.0 - crop));
+		if (bw_used > MAXIMUM_RATE) {
+			continue;}
+		tune_count = i;
+		break;
+	}
+	/* unless small bandwidth */
+	if (bw_used < MINIMUM_RATE) {
+		tune_count = 1;
+		downsample = MAXIMUM_RATE / bw_used;
+		bw_used = bw_used * downsample;
+	}
+	if (!boxcar && downsample > 1) {
+		downsample_passes = (int)log2(downsample);
+		downsample = 1 << downsample_passes;
+		bw_used = (int)((double)(bw_seen * downsample) / (1.0 - crop));
+	}
+	/* number of bins is power-of-two, bin size is under limit */
+	// todo, replace loop with log2
+	for (i=1; i<=21; i++) {
+		bin_e = i;
+		bin_size = (double)bw_used / (double)((1<<i) * downsample);
+		if (bin_size <= (double)max_size) {
+			break;}
+	}
+	/* unless giant bins */
+	if (max_size >= MINIMUM_RATE) {
+		bw_seen = max_size;
+		bw_used = max_size;
+		tune_count = (upper - lower) / bw_seen;
+		bin_e = 0;
+		crop = 0;
+	}
+	if (tune_count > MAX_TUNES) {
+		fprintf(stderr, "Error: bandwidth too wide.\n");
+		exit(1);
+	}
+	buf_len = 2 * (1<<bin_e) * downsample;
+	if (buf_len < DEFAULT_BUF_LENGTH) {
+		buf_len = DEFAULT_BUF_LENGTH;
+	}
+	/* build the array */
+	for (i=0; i<tune_count; i++) {
+		ts = &tunes[i];
+		ts->freq = lower + i*bw_seen + bw_seen/2;
+		ts->rate = bw_used;
+		ts->bin_e = bin_e;
+		ts->samples = 0;
+		ts->crop = crop;
+		ts->downsample = downsample;
+		ts->downsample_passes = downsample_passes;
+		ts->avg = (long*)malloc((1<<bin_e) * sizeof(long));
+		if (!ts->avg) {
+			fprintf(stderr, "Error: malloc.\n");
+			exit(1);
+		}
+		for (j=0; j<(1<<bin_e); j++) {
+			ts->avg[j] = 0L;
+		}
+		ts->buf8 = (uint8_t*)malloc(buf_len * sizeof(uint8_t));
+		if (!ts->buf8) {
+			fprintf(stderr, "Error: malloc.\n");
+			exit(1);
+		}
+		ts->buf_len = buf_len;
+	}
+	/* report */
+	fprintf(stderr, "Number of frequency hops: %i\n", tune_count);
+	fprintf(stderr, "Dongle bandwidth: %iHz\n", bw_used);
+	fprintf(stderr, "Downsampling by: %ix\n", downsample);
+	fprintf(stderr, "Cropping by: %0.2f%%\n", crop*100);
+	fprintf(stderr, "Total FFT bins: %i\n", tune_count * (1<<bin_e));
+	fprintf(stderr, "Logged FFT bins: %i\n", \
+	  (int)((double)(tune_count * (1<<bin_e)) * (1.0-crop)));
+	fprintf(stderr, "FFT bin size: %0.2fHz\n", bin_size);
+	fprintf(stderr, "Buffer size: %i bytes (%0.2fms)\n", buf_len, 1000 * 0.5 * (float)buf_len / (float)bw_used);
+}
+
+void retune(rtlsdr_dev_t *d, int freq)
+{
+	uint8_t dump[BUFFER_DUMP];
+	int n_read;
+	rtlsdr_set_center_freq(d, (uint32_t)freq);
+	/* wait for settling and flush buffer */
+	usleep(5000);
+	rtlsdr_read_sync(d, &dump, BUFFER_DUMP, &n_read);
+	if (n_read != BUFFER_DUMP) {
+		fprintf(stderr, "Error: bad retune.\n");}
+}
+
+void fifth_order(int16_t *data, int length)
+/* for half of interleaved data */
+{
+	int i;
+	int a, b, c, d, e, f;
+	a = data[0];
+	b = data[2];
+	c = data[4];
+	d = data[6];
+	e = data[8];
+	f = data[10];
+	/* a downsample should improve resolution, so don't fully shift */
+	/* ease in instead of being stateful */
+	data[0] = ((a+b)*10 + (c+d)*5 + d + f) >> 4;
+	data[2] = ((b+c)*10 + (a+d)*5 + e + f) >> 4;
+	data[4] = (a + (b+e)*5 + (c+d)*10 + f) >> 4;
+	for (i=12; i<length; i+=4) {
+		a = c;
+		b = d;
+		c = e;
+		d = f;
+		e = data[i-2];
+		f = data[i];
+		data[i/2] = (a + (b+e)*5 + (c+d)*10 + f) >> 4;
+	}
+}
+
+void remove_dc(int16_t *data, int length)
+/* works on interleaved data */
+{
+	int i;
+	int16_t ave;
+	long sum = 0L;
+	for (i=0; i < length; i+=2) {
+		sum += data[i];
+	}
+	ave = (int16_t)(sum / (long)(length));
+	if (ave == 0) {
+		return;}
+	for (i=0; i < length; i+=2) {
+		data[i] -= ave;
+	}
+}
+
+void generic_fir(int16_t *data, int length, int *fir)
+/* Okay, not at all generic.  Assumes length 9, fix that eventually. */
+{
+	int d, temp, sum;
+	int hist[9] = {0,};
+	/* cheat on the beginning, let it go unfiltered */
+	for (d=0; d<18; d+=2) {
+		hist[d/2] = data[d];
+	}
+	for (d=18; d<length; d+=2) {
+		temp = data[d];
+		sum = 0;
+		sum += (hist[0] + hist[8]) * fir[1];
+		sum += (hist[1] + hist[7]) * fir[2];
+		sum += (hist[2] + hist[6]) * fir[3];
+		sum += (hist[3] + hist[5]) * fir[4];
+		sum +=            hist[4]  * fir[5];
+		data[d] = (int16_t)(sum >> 15) ;
+		hist[0] = hist[1];
+		hist[1] = hist[2];
+		hist[2] = hist[3];
+		hist[3] = hist[4];
+		hist[4] = hist[5];
+		hist[5] = hist[6];
+		hist[6] = hist[7];
+		hist[7] = hist[8];
+		hist[8] = temp;
+	}
+}
+
+void downsample_iq(int16_t *data, int length)
+{
+	fifth_order(data, length);
+	//remove_dc(data, length);
+	fifth_order(data+1, length-1);
+	//remove_dc(data+1, length-1);
+}
+
+long real_conj(int16_t real, int16_t imag)
+/* real(n * conj(n)) */
+{
+	return ((long)real*(long)real + (long)imag*(long)imag);
+}
+
+void scanner(void)
+{
+	int i, j, j2, f, n_read, offset, bin_e, bin_len, buf_len, ds, ds_p;
+	int32_t w;
+	struct tuning_state *ts;
+	bin_e = tunes[0].bin_e;
+	bin_len = 1 << bin_e;
+	buf_len = tunes[0].buf_len;
+	for (i=0; i<tune_count; i++) {
+		if (do_exit >= 2)
+			{return;}
+		ts = &tunes[i];
+		f = (int)rtlsdr_get_center_freq(dev);
+		if (f != ts->freq) {
+			retune(dev, ts->freq);}
+		rtlsdr_read_sync(dev, ts->buf8, buf_len, &n_read);
+		if (n_read != buf_len) {
+			fprintf(stderr, "Error: dropped samples.\n");}
+		/* rms */
+		if (bin_len == 1) {
+			rms_power(ts);
+			continue;
+		}
+		/* prep for fft */
+		for (j=0; j<buf_len; j++) {
+			fft_buf[j] = (int16_t)ts->buf8[j] - 127;
+		}
+		ds = ts->downsample;
+		ds_p = ts->downsample_passes;
+		if (boxcar && ds > 1) {
+			j=2, j2=0;
+			while (j < buf_len) {
+				fft_buf[j2]   += fft_buf[j];
+				fft_buf[j2+1] += fft_buf[j+1];
+				fft_buf[j] = 0;
+				fft_buf[j+1] = 0;
+				j += 2;
+				if (j % (ds*2) == 0) {
+					j2 += 2;}
+			}
+		} else if (ds_p) {  /* recursive */
+			for (j=0; j < ds_p; j++) {
+				downsample_iq(fft_buf, buf_len >> j);
+			}
+			/* droop compensation */
+			if (comp_fir_size == 9 && ds_p <= CIC_TABLE_MAX) {
+				generic_fir(fft_buf, buf_len >> j, cic_9_tables[ds_p]);
+				generic_fir(fft_buf+1, (buf_len >> j)-1, cic_9_tables[ds_p]);
+			}
+		}
+		remove_dc(fft_buf, buf_len / ds);
+		remove_dc(fft_buf+1, (buf_len / ds) - 1);
+		/* window function and fft */
+		for (offset=0; offset<(buf_len/ds); offset+=(2*bin_len)) {
+			// todo, let rect skip this
+			for (j=0; j<bin_len; j++) {
+				w =  (int32_t)fft_buf[offset+j*2];
+				w *= (int32_t)(window_coefs[j]);
+				//w /= (int32_t)(ds);
+				fft_buf[offset+j*2]   = (int16_t)w;
+				w =  (int32_t)fft_buf[offset+j*2+1];
+				w *= (int32_t)(window_coefs[j]);
+				//w /= (int32_t)(ds);
+				fft_buf[offset+j*2+1] = (int16_t)w;
+			}
+			fix_fft(fft_buf+offset, bin_e);
+			if (!peak_hold) {
+				for (j=0; j<bin_len; j++) {
+					ts->avg[j] += real_conj(fft_buf[offset+j*2], fft_buf[offset+j*2+1]);
+				}
+			} else {
+				for (j=0; j<bin_len; j++) {
+					ts->avg[j] = MAX(real_conj(fft_buf[offset+j*2], fft_buf[offset+j*2+1]), ts->avg[j]);
+				}
+			}
+			ts->samples += ds;
+		}
+	}
+}
+
+void csv_dbm(struct tuning_state *ts)
+{
+	int i, len, ds, i1, i2, bw2, bin_count;
+	long tmp;
+	double dbm;
+	len = 1 << ts->bin_e;
+	ds = ts->downsample;
+	/* fix FFT stuff quirks */
+	if (ts->bin_e > 0) {
+		/* nuke DC component (not effective for all windows) */
+		ts->avg[0] = ts->avg[1];
+		/* FFT is translated by 180 degrees */
+		for (i=0; i<len/2; i++) {
+			tmp = ts->avg[i];
+			ts->avg[i] = ts->avg[i+len/2];
+			ts->avg[i+len/2] = tmp;
+		}
+	}
+	/* Hz low, Hz high, Hz step, samples, dbm, dbm, ... */
+	bin_count = (int)((double)len * (1.0 - ts->crop));
+	bw2 = (int)(((double)ts->rate * (double)bin_count) / (len * 2 * ds));
+	fprintf(file, "%i, %i, %.2f, %i, ", ts->freq - bw2, ts->freq + bw2,
+		(double)ts->rate / (double)(len*ds), ts->samples);
+	// something seems off with the dbm math
+	i1 = 0 + (int)((double)len * ts->crop * 0.5);
+	i2 = (len-1) - (int)((double)len * ts->crop * 0.5);
+	for (i=i1; i<=i2; i++) {
+		dbm  = (double)ts->avg[i];
+		dbm /= (double)ts->rate;
+		dbm /= (double)ts->samples;
+		dbm  = 10 * log10(dbm);
+		fprintf(file, "%.2f, ", dbm);
+	}
+	dbm = (double)ts->avg[i2] / ((double)ts->rate * (double)ts->samples);
+	if (ts->bin_e == 0) {
+		dbm = ((double)ts->avg[0] / \
+		((double)ts->rate * (double)ts->samples));}
+	dbm  = 10 * log10(dbm);
+	fprintf(file, "%.2f\n", dbm);
+	for (i=0; i<len; i++) {
+		ts->avg[i] = 0L;
+	}
+	ts->samples = 0;
+}
+
+int main(int argc, char **argv)
+{
+#ifndef _WIN32
+	struct sigaction sigact;
+#endif
+	char *filename = NULL;
+	int i, length, r, opt, wb_mode = 0;
+	int f_set = 0;
+	int gain = AUTO_GAIN; // tenths of a dB
+	int dev_index = 0;
+	int dev_given = 0;
+	int ppm_error = 0;
+	int interval = 10;
+	int fft_threads = 1;
+	int smoothing = 0;
+	int single = 0;
+	int direct_sampling = 0;
+	int offset_tuning = 0;
+	int enable_biastee = 0;
+	double crop = 0.0;
+	char *freq_optarg;
+	time_t next_tick;
+	time_t time_now;
+	time_t exit_time = 0;
+	char t_str[50];
+	struct tm *cal_time;
+	double (*window_fn)(int, int) = rectangle;
+	freq_optarg = "";
+
+	while ((opt = getopt(argc, argv, "f:i:s:t:d:g:p:e:w:c:F:1PDOhT")) != -1) {
+		switch (opt) {
+		case 'f': // lower:upper:bin_size
+			freq_optarg = strdup(optarg);
+			f_set = 1;
+			break;
+		case 'd':
+			dev_index = verbose_device_search(optarg);
+			dev_given = 1;
+			break;
+		case 'g':
+			gain = (int)(atof(optarg) * 10);
+			break;
+		case 'c':
+			crop = atofp(optarg);
+			break;
+		case 'i':
+			interval = (int)round(atoft(optarg));
+			break;
+		case 'e':
+			exit_time = (time_t)((int)round(atoft(optarg)));
+			break;
+		case 's':
+			if (strcmp("avg",  optarg) == 0) {
+				smoothing = 0;}
+			if (strcmp("iir",  optarg) == 0) {
+				smoothing = 1;}
+			break;
+		case 'w':
+			if (strcmp("rectangle",  optarg) == 0) {
+				window_fn = rectangle;}
+			if (strcmp("hamming",  optarg) == 0) {
+				window_fn = hamming;}
+			if (strcmp("blackman",  optarg) == 0) {
+				window_fn = blackman;}
+			if (strcmp("blackman-harris",  optarg) == 0) {
+				window_fn = blackman_harris;}
+			if (strcmp("hann-poisson",  optarg) == 0) {
+				window_fn = hann_poisson;}
+			if (strcmp("youssef",  optarg) == 0) {
+				window_fn = youssef;}
+			if (strcmp("kaiser",  optarg) == 0) {
+				window_fn = kaiser;}
+			if (strcmp("bartlett",  optarg) == 0) {
+				window_fn = bartlett;}
+			break;
+		case 't':
+			fft_threads = atoi(optarg);
+			break;
+		case 'p':
+			ppm_error = atoi(optarg);
+			break;
+		case '1':
+			single = 1;
+			break;
+		case 'P':
+			peak_hold = 1;
+			break;
+		case 'D':
+			direct_sampling = 1;
+			break;
+		case 'O':
+			offset_tuning = 1;
+			break;
+		case 'F':
+			boxcar = 0;
+			comp_fir_size = atoi(optarg);
+			break;
+		case 'T':
+			enable_biastee = 1;
+			break;
+		case 'h':
+		default:
+			usage();
+			break;
+		}
+	}
+
+	if (!f_set) {
+		fprintf(stderr, "No frequency range provided.\n");
+		exit(1);
+	}
+
+	if ((crop < 0.0) || (crop > 1.0)) {
+		fprintf(stderr, "Crop value outside of 0 to 1.\n");
+		exit(1);
+	}
+
+	frequency_range(freq_optarg, crop);
+
+	if (tune_count == 0) {
+		usage();}
+
+	if (argc <= optind) {
+		filename = "-";
+	} else {
+		filename = argv[optind];
+	}
+
+	if (interval < 1) {
+		interval = 1;}
+
+	fprintf(stderr, "Reporting every %i seconds\n", interval);
+
+	if (!dev_given) {
+		dev_index = verbose_device_search("0");
+	}
+
+	if (dev_index < 0) {
+		exit(1);
+	}
+
+	r = rtlsdr_open(&dev, (uint32_t)dev_index);
+	if (r < 0) {
+		fprintf(stderr, "Failed to open rtlsdr device #%d.\n", dev_index);
+		exit(1);
+	}
+#ifndef _WIN32
+	sigact.sa_handler = sighandler;
+	sigemptyset(&sigact.sa_mask);
+	sigact.sa_flags = 0;
+	sigaction(SIGINT, &sigact, NULL);
+	sigaction(SIGTERM, &sigact, NULL);
+	sigaction(SIGQUIT, &sigact, NULL);
+	sigaction(SIGPIPE, &sigact, NULL);
+#else
+	SetConsoleCtrlHandler( (PHANDLER_ROUTINE) sighandler, TRUE );
+#endif
+
+	if (direct_sampling) {
+		verbose_direct_sampling(dev, 1);
+	}
+
+	if (offset_tuning) {
+		verbose_offset_tuning(dev);
+	}
+
+	/* Set the tuner gain */
+	if (gain == AUTO_GAIN) {
+		verbose_auto_gain(dev);
+	} else {
+		gain = nearest_gain(dev, gain);
+		verbose_gain_set(dev, gain);
+	}
+
+	verbose_ppm_set(dev, ppm_error);
+
+	rtlsdr_set_bias_tee(dev, enable_biastee);
+	if (enable_biastee)
+		fprintf(stderr, "activated bias-T on GPIO PIN 0\n");
+
+	if (strcmp(filename, "-") == 0) { /* Write log to stdout */
+		file = stdout;
+#ifdef _WIN32
+		// Is this necessary?  Output is ascii.
+		_setmode(_fileno(file), _O_BINARY);
+#endif
+	} else {
+		file = fopen(filename, "wb");
+		if (!file) {
+			fprintf(stderr, "Failed to open %s\n", filename);
+			exit(1);
+		}
+	}
+
+	/* Reset endpoint before we start reading from it (mandatory) */
+	verbose_reset_buffer(dev);
+
+	/* actually do stuff */
+	rtlsdr_set_sample_rate(dev, (uint32_t)tunes[0].rate);
+	sine_table(tunes[0].bin_e);
+	next_tick = time(NULL) + interval;
+	if (exit_time) {
+		exit_time = time(NULL) + exit_time;}
+	fft_buf = malloc(tunes[0].buf_len * sizeof(int16_t));
+	length = 1 << tunes[0].bin_e;
+	window_coefs = malloc(length * sizeof(int));
+	for (i=0; i<length; i++) {
+		window_coefs[i] = (int)(256*window_fn(i, length));
+	}
+	while (!do_exit) {
+		scanner();
+		time_now = time(NULL);
+		if (time_now < next_tick) {
+			continue;}
+		// time, Hz low, Hz high, Hz step, samples, dbm, dbm, ...
+		cal_time = localtime(&time_now);
+		strftime(t_str, 50, "%Y-%m-%d, %H:%M:%S", cal_time);
+		for (i=0; i<tune_count; i++) {
+			fprintf(file, "%s, ", t_str);
+			csv_dbm(&tunes[i]);
+		}
+		fflush(file);
+		while (time(NULL) >= next_tick) {
+			next_tick += interval;}
+		if (single) {
+			do_exit = 1;}
+		if (exit_time && time(NULL) >= exit_time) {
+			do_exit = 1;}
+	}
+
+	/* clean up */
+
+	if (do_exit) {
+		fprintf(stderr, "\nUser cancel, exiting...\n");}
+	else {
+		fprintf(stderr, "\nLibrary error %d, exiting...\n", r);}
+
+	if (file != stdout) {
+		fclose(file);}
+
+	rtlsdr_close(dev);
+	free(fft_buf);
+	free(window_coefs);
+	//for (i=0; i<tune_count; i++) {
+	//	free(tunes[i].avg);
+	//	free(tunes[i].buf8);
+	//}
+	return r >= 0 ? r : -r;
+}
+
+// vim: tabstop=8:softtabstop=8:shiftwidth=8:noexpandtab
diff --git a/src/rtl_sdr.c b/src/rtl_sdr.c
new file mode 100644
index 0000000..e6537ca
--- /dev/null
+++ b/src/rtl_sdr.c
@@ -0,0 +1,278 @@
+/*
+ * rtl-sdr, turns your Realtek RTL2832 based DVB dongle into a SDR receiver
+ * Copyright (C) 2012 by Steve Markgraf <steve@steve-m.de>
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include <errno.h>
+#include <signal.h>
+#include <string.h>
+#include <stdio.h>
+#include <stdlib.h>
+
+#ifndef _WIN32
+#include <unistd.h>
+#else
+#include <windows.h>
+#include <io.h>
+#include <fcntl.h>
+#include "getopt/getopt.h"
+#endif
+
+#include "rtl-sdr.h"
+#include "convenience/convenience.h"
+
+#define DEFAULT_SAMPLE_RATE		2048000
+#define DEFAULT_BUF_LENGTH		(16 * 16384)
+#define MINIMAL_BUF_LENGTH		512
+#define MAXIMAL_BUF_LENGTH		(256 * 16384)
+
+static int do_exit = 0;
+static uint32_t bytes_to_read = 0;
+static rtlsdr_dev_t *dev = NULL;
+
+void usage(void)
+{
+	fprintf(stderr,
+		"rtl_sdr, an I/Q recorder for RTL2832 based DVB-T receivers\n\n"
+		"Usage:\t -f frequency_to_tune_to [Hz]\n"
+		"\t[-s samplerate (default: 2048000 Hz)]\n"
+		"\t[-d device_index (default: 0)]\n"
+		"\t[-g gain (default: 0 for auto)]\n"
+		"\t[-p ppm_error (default: 0)]\n"
+		"\t[-b output_block_size (default: 16 * 16384)]\n"
+		"\t[-n number of samples to read (default: 0, infinite)]\n"
+		"\t[-S force sync output (default: async)]\n"
+		"\tfilename (a '-' dumps samples to stdout)\n\n");
+	exit(1);
+}
+
+#ifdef _WIN32
+BOOL WINAPI
+sighandler(int signum)
+{
+	if (CTRL_C_EVENT == signum) {
+		fprintf(stderr, "Signal caught, exiting!\n");
+		do_exit = 1;
+		rtlsdr_cancel_async(dev);
+		return TRUE;
+	}
+	return FALSE;
+}
+#else
+static void sighandler(int signum)
+{
+	fprintf(stderr, "Signal caught, exiting!\n");
+	do_exit = 1;
+	rtlsdr_cancel_async(dev);
+}
+#endif
+
+static void rtlsdr_callback(unsigned char *buf, uint32_t len, void *ctx)
+{
+	if (ctx) {
+		if (do_exit)
+			return;
+
+		if ((bytes_to_read > 0) && (bytes_to_read < len)) {
+			len = bytes_to_read;
+			do_exit = 1;
+			rtlsdr_cancel_async(dev);
+		}
+
+		if (fwrite(buf, 1, len, (FILE*)ctx) != len) {
+			fprintf(stderr, "Short write, samples lost, exiting!\n");
+			rtlsdr_cancel_async(dev);
+		}
+
+		if (bytes_to_read > 0)
+			bytes_to_read -= len;
+	}
+}
+
+int main(int argc, char **argv)
+{
+#ifndef _WIN32
+	struct sigaction sigact;
+#endif
+	char *filename = NULL;
+	int n_read;
+	int r, opt;
+	int gain = 0;
+	int ppm_error = 0;
+	int sync_mode = 0;
+	FILE *file;
+	uint8_t *buffer;
+	int dev_index = 0;
+	int dev_given = 0;
+	uint32_t frequency = 100000000;
+	uint32_t samp_rate = DEFAULT_SAMPLE_RATE;
+	uint32_t out_block_size = DEFAULT_BUF_LENGTH;
+
+	while ((opt = getopt(argc, argv, "d:f:g:s:b:n:p:S")) != -1) {
+		switch (opt) {
+		case 'd':
+			dev_index = verbose_device_search(optarg);
+			dev_given = 1;
+			break;
+		case 'f':
+			frequency = (uint32_t)atofs(optarg);
+			break;
+		case 'g':
+			gain = (int)(atof(optarg) * 10); /* tenths of a dB */
+			break;
+		case 's':
+			samp_rate = (uint32_t)atofs(optarg);
+			break;
+		case 'p':
+			ppm_error = atoi(optarg);
+			break;
+		case 'b':
+			out_block_size = (uint32_t)atof(optarg);
+			break;
+		case 'n':
+			bytes_to_read = (uint32_t)atof(optarg) * 2;
+			break;
+		case 'S':
+			sync_mode = 1;
+			break;
+		default:
+			usage();
+			break;
+		}
+	}
+
+	if (argc <= optind) {
+		usage();
+	} else {
+		filename = argv[optind];
+	}
+
+	if(out_block_size < MINIMAL_BUF_LENGTH ||
+	   out_block_size > MAXIMAL_BUF_LENGTH ){
+		fprintf(stderr,
+			"Output block size wrong value, falling back to default\n");
+		fprintf(stderr,
+			"Minimal length: %u\n", MINIMAL_BUF_LENGTH);
+		fprintf(stderr,
+			"Maximal length: %u\n", MAXIMAL_BUF_LENGTH);
+		out_block_size = DEFAULT_BUF_LENGTH;
+	}
+
+	buffer = malloc(out_block_size * sizeof(uint8_t));
+
+	if (!dev_given) {
+		dev_index = verbose_device_search("0");
+	}
+
+	if (dev_index < 0) {
+		exit(1);
+	}
+
+	r = rtlsdr_open(&dev, (uint32_t)dev_index);
+	if (r < 0) {
+		fprintf(stderr, "Failed to open rtlsdr device #%d.\n", dev_index);
+		exit(1);
+	}
+#ifndef _WIN32
+	sigact.sa_handler = sighandler;
+	sigemptyset(&sigact.sa_mask);
+	sigact.sa_flags = 0;
+	sigaction(SIGINT, &sigact, NULL);
+	sigaction(SIGTERM, &sigact, NULL);
+	sigaction(SIGQUIT, &sigact, NULL);
+	sigaction(SIGPIPE, &sigact, NULL);
+#else
+	SetConsoleCtrlHandler( (PHANDLER_ROUTINE) sighandler, TRUE );
+#endif
+	/* Set the sample rate */
+	verbose_set_sample_rate(dev, samp_rate);
+
+	/* Set the frequency */
+	verbose_set_frequency(dev, frequency);
+
+	if (0 == gain) {
+		 /* Enable automatic gain */
+		verbose_auto_gain(dev);
+	} else {
+		/* Enable manual gain */
+		gain = nearest_gain(dev, gain);
+		verbose_gain_set(dev, gain);
+	}
+
+	verbose_ppm_set(dev, ppm_error);
+
+	if(strcmp(filename, "-") == 0) { /* Write samples to stdout */
+		file = stdout;
+#ifdef _WIN32
+		_setmode(_fileno(stdin), _O_BINARY);
+#endif
+	} else {
+		file = fopen(filename, "wb");
+		if (!file) {
+			fprintf(stderr, "Failed to open %s\n", filename);
+			goto out;
+		}
+	}
+
+	/* Reset endpoint before we start reading from it (mandatory) */
+	verbose_reset_buffer(dev);
+
+	if (sync_mode) {
+		fprintf(stderr, "Reading samples in sync mode...\n");
+		while (!do_exit) {
+			r = rtlsdr_read_sync(dev, buffer, out_block_size, &n_read);
+			if (r < 0) {
+				fprintf(stderr, "WARNING: sync read failed.\n");
+				break;
+			}
+
+			if ((bytes_to_read > 0) && (bytes_to_read < (uint32_t)n_read)) {
+				n_read = bytes_to_read;
+				do_exit = 1;
+			}
+
+			if (fwrite(buffer, 1, n_read, file) != (size_t)n_read) {
+				fprintf(stderr, "Short write, samples lost, exiting!\n");
+				break;
+			}
+
+			if ((uint32_t)n_read < out_block_size) {
+				fprintf(stderr, "Short read, samples lost, exiting!\n");
+				break;
+			}
+
+			if (bytes_to_read > 0)
+				bytes_to_read -= n_read;
+		}
+	} else {
+		fprintf(stderr, "Reading samples in async mode...\n");
+		r = rtlsdr_read_async(dev, rtlsdr_callback, (void *)file,
+				      0, out_block_size);
+	}
+
+	if (do_exit)
+		fprintf(stderr, "\nUser cancel, exiting...\n");
+	else
+		fprintf(stderr, "\nLibrary error %d, exiting...\n", r);
+
+	if (file != stdout)
+		fclose(file);
+
+	rtlsdr_close(dev);
+	free (buffer);
+out:
+	return r >= 0 ? r : -r;
+}
diff --git a/src/rtl_tcp.c b/src/rtl_tcp.c
new file mode 100644
index 0000000..84f5591
--- /dev/null
+++ b/src/rtl_tcp.c
@@ -0,0 +1,660 @@
+/*
+ * rtl-sdr, turns your Realtek RTL2832 based DVB dongle into a SDR receiver
+ * Copyright (C) 2012 by Steve Markgraf <steve@steve-m.de>
+ * Copyright (C) 2012-2013 by Hoernchen <la@tfc-server.de>
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include <errno.h>
+#include <signal.h>
+#include <string.h>
+#include <stdio.h>
+#include <stdlib.h>
+
+#ifndef _WIN32
+#include <unistd.h>
+#include <arpa/inet.h>
+#include <sys/socket.h>
+#include <sys/types.h>
+#include <sys/socket.h>
+#include <sys/time.h>
+#include <netdb.h>
+#include <netinet/in.h>
+#include <fcntl.h>
+#else
+#include <winsock2.h>
+#include <ws2tcpip.h>
+#include "getopt/getopt.h"
+#endif
+
+#include <pthread.h>
+
+#include "rtl-sdr.h"
+#include "convenience/convenience.h"
+
+#ifdef _WIN32
+#pragma comment(lib, "ws2_32.lib")
+
+typedef int socklen_t;
+
+#else
+#define closesocket close
+#define SOCKADDR struct sockaddr
+#define SOCKET int
+#define SOCKET_ERROR -1
+#endif
+
+#define DEFAULT_PORT_STR "1234"
+#define DEFAULT_SAMPLE_RATE_HZ 2048000
+#define DEFAULT_MAX_NUM_BUFFERS 500
+
+static SOCKET s;
+
+static pthread_t tcp_worker_thread;
+static pthread_t command_thread;
+static pthread_cond_t exit_cond;
+static pthread_mutex_t exit_cond_lock;
+
+static pthread_mutex_t ll_mutex;
+static pthread_cond_t cond;
+
+struct llist {
+	char *data;
+	size_t len;
+	struct llist *next;
+};
+
+typedef struct { /* structure size must be multiple of 2 bytes */
+	char magic[4];
+	uint32_t tuner_type;
+	uint32_t tuner_gain_count;
+} dongle_info_t;
+
+static rtlsdr_dev_t *dev = NULL;
+
+static int enable_biastee = 0;
+static int global_numq = 0;
+static struct llist *ll_buffers = 0;
+static int llbuf_num = DEFAULT_MAX_NUM_BUFFERS;
+
+static volatile int do_exit = 0;
+
+
+void usage(void)
+{
+	printf("rtl_tcp, an I/Q spectrum server for RTL2832 based DVB-T receivers\n\n");
+	printf("Usage:\t[-a listen address]\n");
+	printf("\t[-p listen port (default: %s)]\n", DEFAULT_PORT_STR);
+	printf("\t[-f frequency to tune to [Hz]]\n");
+	printf("\t[-g gain (default: 0 for auto)]\n");
+	printf("\t[-s samplerate in Hz (default: %d Hz)]\n", DEFAULT_SAMPLE_RATE_HZ);
+	printf("\t[-b number of buffers (default: 15, set by library)]\n");
+	printf("\t[-n max number of linked list buffers to keep (default: %d)]\n", DEFAULT_MAX_NUM_BUFFERS);
+	printf("\t[-d device index (default: 0)]\n");
+	printf("\t[-P ppm_error (default: 0)]\n");
+	printf("\t[-T enable bias-T on GPIO PIN 0 (works for rtl-sdr.com v3 dongles)]\n");
+	exit(1);
+}
+
+#ifdef _WIN32
+int gettimeofday(struct timeval *tv, void* ignored)
+{
+	FILETIME ft;
+	unsigned __int64 tmp = 0;
+	if (NULL != tv) {
+		GetSystemTimeAsFileTime(&ft);
+		tmp |= ft.dwHighDateTime;
+		tmp <<= 32;
+		tmp |= ft.dwLowDateTime;
+		tmp /= 10;
+#ifdef _MSC_VER
+		tmp -= 11644473600000000Ui64;
+#else
+		tmp -= 11644473600000000ULL;
+#endif
+		tv->tv_sec = (long)(tmp / 1000000UL);
+		tv->tv_usec = (long)(tmp % 1000000UL);
+	}
+	return 0;
+}
+
+BOOL WINAPI
+sighandler(int signum)
+{
+	if (CTRL_C_EVENT == signum) {
+		fprintf(stderr, "Signal caught, exiting!\n");
+		do_exit = 1;
+		rtlsdr_cancel_async(dev);
+		return TRUE;
+	}
+	return FALSE;
+}
+#else
+static void sighandler(int signum)
+{
+	fprintf(stderr, "Signal caught, exiting!\n");
+	rtlsdr_cancel_async(dev);
+	do_exit = 1;
+}
+#endif
+
+void rtlsdr_callback(unsigned char *buf, uint32_t len, void *ctx)
+{
+	if(!do_exit) {
+		struct llist *rpt = (struct llist*)malloc(sizeof(struct llist));
+		rpt->data = (char*)malloc(len);
+		memcpy(rpt->data, buf, len);
+		rpt->len = len;
+		rpt->next = NULL;
+
+		pthread_mutex_lock(&ll_mutex);
+
+		if (ll_buffers == NULL) {
+			ll_buffers = rpt;
+		} else {
+			struct llist *cur = ll_buffers;
+			int num_queued = 0;
+
+			while (cur->next != NULL) {
+				cur = cur->next;
+				num_queued++;
+			}
+
+			if(llbuf_num && llbuf_num == num_queued-2){
+				struct llist *curelem;
+
+				free(ll_buffers->data);
+				curelem = ll_buffers->next;
+				free(ll_buffers);
+				ll_buffers = curelem;
+			}
+
+			cur->next = rpt;
+
+			if (num_queued > global_numq)
+				printf("ll+, now %d\n", num_queued);
+			else if (num_queued < global_numq)
+				printf("ll-, now %d\n", num_queued);
+
+			global_numq = num_queued;
+		}
+		pthread_cond_signal(&cond);
+		pthread_mutex_unlock(&ll_mutex);
+	}
+}
+
+static void *tcp_worker(void *arg)
+{
+	struct llist *curelem,*prev;
+	int bytesleft,bytessent, index;
+	struct timeval tv= {1,0};
+	struct timespec ts;
+	struct timeval tp;
+	fd_set writefds;
+	int r = 0;
+
+	while(1) {
+		if(do_exit)
+			pthread_exit(0);
+
+		pthread_mutex_lock(&ll_mutex);
+		gettimeofday(&tp, NULL);
+		ts.tv_sec  = tp.tv_sec+5;
+		ts.tv_nsec = tp.tv_usec * 1000;
+		r = pthread_cond_timedwait(&cond, &ll_mutex, &ts);
+		if(r == ETIMEDOUT) {
+			pthread_mutex_unlock(&ll_mutex);
+			printf("worker cond timeout\n");
+			sighandler(0);
+			pthread_exit(NULL);
+		}
+
+		curelem = ll_buffers;
+		ll_buffers = 0;
+		pthread_mutex_unlock(&ll_mutex);
+
+		while(curelem != 0) {
+			bytesleft = curelem->len;
+			index = 0;
+			bytessent = 0;
+			while(bytesleft > 0) {
+				FD_ZERO(&writefds);
+				FD_SET(s, &writefds);
+				tv.tv_sec = 1;
+				tv.tv_usec = 0;
+				r = select(s+1, NULL, &writefds, NULL, &tv);
+				if(r) {
+					bytessent = send(s,  &curelem->data[index], bytesleft, 0);
+					bytesleft -= bytessent;
+					index += bytessent;
+				}
+				if(bytessent == SOCKET_ERROR || do_exit) {
+						printf("worker socket bye\n");
+						sighandler(0);
+						pthread_exit(NULL);
+				}
+			}
+			prev = curelem;
+			curelem = curelem->next;
+			free(prev->data);
+			free(prev);
+		}
+	}
+}
+
+static int set_gain_by_index(rtlsdr_dev_t *_dev, unsigned int index)
+{
+	int res = 0;
+	int* gains;
+	int count = rtlsdr_get_tuner_gains(_dev, NULL);
+
+	if (count > 0 && (unsigned int)count > index) {
+		gains = malloc(sizeof(int) * count);
+		count = rtlsdr_get_tuner_gains(_dev, gains);
+
+		res = rtlsdr_set_tuner_gain(_dev, gains[index]);
+
+		free(gains);
+	}
+
+	return res;
+}
+
+#ifdef _WIN32
+#define __attribute__(x)
+#pragma pack(push, 1)
+#endif
+struct command{
+	unsigned char cmd;
+	unsigned int param;
+}__attribute__((packed));
+#ifdef _WIN32
+#pragma pack(pop)
+#endif
+static void *command_worker(void *arg)
+{
+	int left, received = 0;
+	fd_set readfds;
+	struct command cmd={0, 0};
+	struct timeval tv= {1, 0};
+	int r = 0;
+	uint32_t tmp;
+
+	while(1) {
+		left=sizeof(cmd);
+		while(left >0) {
+			FD_ZERO(&readfds);
+			FD_SET(s, &readfds);
+			tv.tv_sec = 1;
+			tv.tv_usec = 0;
+			r = select(s+1, &readfds, NULL, NULL, &tv);
+			if(r) {
+				received = recv(s, (char*)&cmd+(sizeof(cmd)-left), left, 0);
+				left -= received;
+			}
+			if(received == SOCKET_ERROR || do_exit) {
+				printf("comm recv bye\n");
+				sighandler(0);
+				pthread_exit(NULL);
+			}
+		}
+		switch(cmd.cmd) {
+		case 0x01:
+			printf("set freq %d\n", ntohl(cmd.param));
+			rtlsdr_set_center_freq(dev,ntohl(cmd.param));
+			break;
+		case 0x02:
+			printf("set sample rate %d\n", ntohl(cmd.param));
+			rtlsdr_set_sample_rate(dev, ntohl(cmd.param));
+			break;
+		case 0x03:
+			printf("set gain mode %d\n", ntohl(cmd.param));
+			rtlsdr_set_tuner_gain_mode(dev, ntohl(cmd.param));
+			break;
+		case 0x04:
+			printf("set gain %d\n", ntohl(cmd.param));
+			rtlsdr_set_tuner_gain(dev, ntohl(cmd.param));
+			break;
+		case 0x05:
+			printf("set freq correction %d\n", ntohl(cmd.param));
+			rtlsdr_set_freq_correction(dev, ntohl(cmd.param));
+			break;
+		case 0x06:
+			tmp = ntohl(cmd.param);
+			printf("set if stage %d gain %d\n", tmp >> 16, (short)(tmp & 0xffff));
+			rtlsdr_set_tuner_if_gain(dev, tmp >> 16, (short)(tmp & 0xffff));
+			break;
+		case 0x07:
+			printf("set test mode %d\n", ntohl(cmd.param));
+			rtlsdr_set_testmode(dev, ntohl(cmd.param));
+			break;
+		case 0x08:
+			printf("set agc mode %d\n", ntohl(cmd.param));
+			rtlsdr_set_agc_mode(dev, ntohl(cmd.param));
+			break;
+		case 0x09:
+			printf("set direct sampling %d\n", ntohl(cmd.param));
+			rtlsdr_set_direct_sampling(dev, ntohl(cmd.param));
+			break;
+		case 0x0a:
+			printf("set offset tuning %d\n", ntohl(cmd.param));
+			rtlsdr_set_offset_tuning(dev, ntohl(cmd.param));
+			break;
+		case 0x0b:
+			printf("set rtl xtal %d\n", ntohl(cmd.param));
+			rtlsdr_set_xtal_freq(dev, ntohl(cmd.param), 0);
+			break;
+		case 0x0c:
+			printf("set tuner xtal %d\n", ntohl(cmd.param));
+			rtlsdr_set_xtal_freq(dev, 0, ntohl(cmd.param));
+			break;
+		case 0x0d:
+			printf("set tuner gain by index %d\n", ntohl(cmd.param));
+			set_gain_by_index(dev, ntohl(cmd.param));
+			break;
+		case 0x0e:
+			printf("set bias tee %d\n", ntohl(cmd.param));
+			rtlsdr_set_bias_tee(dev, (int)ntohl(cmd.param));
+			break;
+		default:
+			break;
+		}
+		cmd.cmd = 0xff;
+	}
+}
+
+int main(int argc, char **argv)
+{
+	int r, opt, i;
+	char *addr = "127.0.0.1";
+	const char *port = DEFAULT_PORT_STR;
+	uint32_t frequency = 100000000, samp_rate = DEFAULT_SAMPLE_RATE_HZ;
+	struct sockaddr_storage local, remote;
+	struct addrinfo *ai;
+	struct addrinfo *aiHead;
+	struct addrinfo  hints;
+	char hostinfo[NI_MAXHOST];
+	char portinfo[NI_MAXSERV];
+	char remhostinfo[NI_MAXHOST];
+	char remportinfo[NI_MAXSERV];
+	int aiErr;
+	uint32_t buf_num = 0;
+	int dev_index = 0;
+	int dev_given = 0;
+	int gain = 0;
+	int ppm_error = 0;
+	struct llist *curelem,*prev;
+	pthread_attr_t attr;
+	void *status;
+	struct timeval tv = {1,0};
+	struct linger ling = {1,0};
+	SOCKET listensocket = 0;
+	socklen_t rlen;
+	fd_set readfds;
+	u_long blockmode = 1;
+	dongle_info_t dongle_info;
+#ifdef _WIN32
+	WSADATA wsd;
+	i = WSAStartup(MAKEWORD(2,2), &wsd);
+#else
+	struct sigaction sigact, sigign;
+#endif
+
+	while ((opt = getopt(argc, argv, "a:p:f:g:s:b:n:d:P:T")) != -1) {
+		switch (opt) {
+		case 'd':
+			dev_index = verbose_device_search(optarg);
+			dev_given = 1;
+			break;
+		case 'f':
+			frequency = (uint32_t)atofs(optarg);
+			break;
+		case 'g':
+			gain = (int)(atof(optarg) * 10); /* tenths of a dB */
+			break;
+		case 's':
+			samp_rate = (uint32_t)atofs(optarg);
+			break;
+		case 'a':
+		        addr = strdup(optarg);
+			break;
+		case 'p':
+		        port = strdup(optarg);
+			break;
+		case 'b':
+			buf_num = atoi(optarg);
+			break;
+		case 'n':
+			llbuf_num = atoi(optarg);
+			break;
+		case 'P':
+			ppm_error = atoi(optarg);
+			break;
+		case 'T':
+			enable_biastee = 1;
+			break;
+		default:
+			usage();
+			break;
+		}
+	}
+
+	if (argc < optind)
+		usage();
+
+	if (!dev_given) {
+		dev_index = verbose_device_search("0");
+	}
+
+	if (dev_index < 0) {
+	    exit(1);
+	}
+
+	rtlsdr_open(&dev, (uint32_t)dev_index);
+	if (NULL == dev) {
+	fprintf(stderr, "Failed to open rtlsdr device #%d.\n", dev_index);
+		exit(1);
+	}
+
+#ifndef _WIN32
+	sigact.sa_handler = sighandler;
+	sigemptyset(&sigact.sa_mask);
+	sigact.sa_flags = 0;
+	sigign.sa_handler = SIG_IGN;
+	sigaction(SIGINT, &sigact, NULL);
+	sigaction(SIGTERM, &sigact, NULL);
+	sigaction(SIGQUIT, &sigact, NULL);
+	sigaction(SIGPIPE, &sigign, NULL);
+#else
+	SetConsoleCtrlHandler( (PHANDLER_ROUTINE) sighandler, TRUE );
+#endif
+
+	/* Set the tuner error */
+	verbose_ppm_set(dev, ppm_error);
+
+	/* Set the sample rate */
+	r = rtlsdr_set_sample_rate(dev, samp_rate);
+	if (r < 0)
+		fprintf(stderr, "WARNING: Failed to set sample rate.\n");
+
+	/* Set the frequency */
+	r = rtlsdr_set_center_freq(dev, frequency);
+	if (r < 0)
+		fprintf(stderr, "WARNING: Failed to set center freq.\n");
+	else
+		fprintf(stderr, "Tuned to %i Hz.\n", frequency);
+
+	if (0 == gain) {
+		 /* Enable automatic gain */
+		r = rtlsdr_set_tuner_gain_mode(dev, 0);
+		if (r < 0)
+			fprintf(stderr, "WARNING: Failed to enable automatic gain.\n");
+	} else {
+		/* Enable manual gain */
+		r = rtlsdr_set_tuner_gain_mode(dev, 1);
+		if (r < 0)
+			fprintf(stderr, "WARNING: Failed to enable manual gain.\n");
+
+		/* Set the tuner gain */
+		r = rtlsdr_set_tuner_gain(dev, gain);
+		if (r < 0)
+			fprintf(stderr, "WARNING: Failed to set tuner gain.\n");
+		else
+			fprintf(stderr, "Tuner gain set to %f dB.\n", gain/10.0);
+	}
+
+	rtlsdr_set_bias_tee(dev, enable_biastee);
+	if (enable_biastee)
+		fprintf(stderr, "activated bias-T on GPIO PIN 0\n");
+
+	/* Reset endpoint before we start reading from it (mandatory) */
+	r = rtlsdr_reset_buffer(dev);
+	if (r < 0)
+		fprintf(stderr, "WARNING: Failed to reset buffers.\n");
+
+	pthread_mutex_init(&exit_cond_lock, NULL);
+	pthread_mutex_init(&ll_mutex, NULL);
+	pthread_mutex_init(&exit_cond_lock, NULL);
+	pthread_cond_init(&cond, NULL);
+	pthread_cond_init(&exit_cond, NULL);
+
+	hints.ai_flags  = AI_PASSIVE; /* Server mode. */
+	hints.ai_family = PF_UNSPEC;  /* IPv4 or IPv6. */
+	hints.ai_socktype = SOCK_STREAM;
+	hints.ai_protocol = IPPROTO_TCP;
+
+	if ((aiErr = getaddrinfo(addr,
+				 port,
+				 &hints,
+				 &aiHead )) != 0)
+	{
+		fprintf(stderr, "local address %s ERROR - %s.\n",
+		        addr, gai_strerror(aiErr));
+		return(-1);
+	}
+	memcpy(&local, aiHead->ai_addr, aiHead->ai_addrlen);
+
+	for (ai = aiHead; ai != NULL; ai = ai->ai_next) {
+		aiErr = getnameinfo((struct sockaddr *)ai->ai_addr, ai->ai_addrlen,
+				    hostinfo, NI_MAXHOST,
+				    portinfo, NI_MAXSERV, NI_NUMERICSERV | NI_NUMERICHOST);
+		if (aiErr)
+			fprintf( stderr, "getnameinfo ERROR - %s.\n",hostinfo);
+
+		listensocket = socket(ai->ai_family, ai->ai_socktype, ai->ai_protocol);
+		if (listensocket < 0)
+			continue;
+
+		r = 1;
+		setsockopt(listensocket, SOL_SOCKET, SO_REUSEADDR, (char *)&r, sizeof(int));
+		setsockopt(listensocket, SOL_SOCKET, SO_LINGER, (char *)&ling, sizeof(ling));
+
+		if (bind(listensocket, (struct sockaddr *)&local, sizeof(local)))
+			fprintf(stderr, "rtl_tcp bind error: %s", strerror(errno));
+		else
+			break;
+	}
+
+#ifdef _WIN32
+	ioctlsocket(listensocket, FIONBIO, &blockmode);
+#else
+	r = fcntl(listensocket, F_GETFL, 0);
+	r = fcntl(listensocket, F_SETFL, r | O_NONBLOCK);
+#endif
+
+	while(1) {
+		printf("listening...\n");
+		printf("Use the device argument 'rtl_tcp=%s:%s' in OsmoSDR "
+		       "(gr-osmosdr) source\n"
+		       "to receive samples in GRC and control "
+		       "rtl_tcp parameters (frequency, gain, ...).\n",
+		       hostinfo, portinfo);
+		listen(listensocket,1);
+
+		while(1) {
+			FD_ZERO(&readfds);
+			FD_SET(listensocket, &readfds);
+			tv.tv_sec = 1;
+			tv.tv_usec = 0;
+			r = select(listensocket+1, &readfds, NULL, NULL, &tv);
+			if(do_exit) {
+				goto out;
+			} else if(r) {
+				rlen = sizeof(remote);
+				s = accept(listensocket,(struct sockaddr *)&remote, &rlen);
+				break;
+			}
+		}
+
+		setsockopt(s, SOL_SOCKET, SO_LINGER, (char *)&ling, sizeof(ling));
+
+		getnameinfo((struct sockaddr *)&remote, rlen,
+			    remhostinfo, NI_MAXHOST,
+			    remportinfo, NI_MAXSERV, NI_NUMERICSERV);
+		printf("client accepted! %s %s\n", remhostinfo, remportinfo);
+
+		memset(&dongle_info, 0, sizeof(dongle_info));
+		memcpy(&dongle_info.magic, "RTL0", 4);
+
+		r = rtlsdr_get_tuner_type(dev);
+		if (r >= 0)
+			dongle_info.tuner_type = htonl(r);
+
+		r = rtlsdr_get_tuner_gains(dev, NULL);
+		if (r >= 0)
+			dongle_info.tuner_gain_count = htonl(r);
+
+		r = send(s, (const char *)&dongle_info, sizeof(dongle_info), 0);
+		if (sizeof(dongle_info) != r)
+			printf("failed to send dongle information\n");
+
+		pthread_attr_init(&attr);
+		pthread_attr_setdetachstate(&attr, PTHREAD_CREATE_JOINABLE);
+		r = pthread_create(&tcp_worker_thread, &attr, tcp_worker, NULL);
+		r = pthread_create(&command_thread, &attr, command_worker, NULL);
+		pthread_attr_destroy(&attr);
+
+		r = rtlsdr_read_async(dev, rtlsdr_callback, NULL, buf_num, 0);
+
+		pthread_join(tcp_worker_thread, &status);
+		pthread_join(command_thread, &status);
+
+		closesocket(s);
+
+		printf("all threads dead..\n");
+		curelem = ll_buffers;
+		ll_buffers = 0;
+
+		while(curelem != 0) {
+			prev = curelem;
+			curelem = curelem->next;
+			free(prev->data);
+			free(prev);
+		}
+
+		do_exit = 0;
+		global_numq = 0;
+	}
+
+out:
+	rtlsdr_close(dev);
+	closesocket(listensocket);
+	closesocket(s);
+#ifdef _WIN32
+	WSACleanup();
+#endif
+	printf("bye!\n");
+	return r >= 0 ? r : -r;
+}
diff --git a/src/rtl_test.c b/src/rtl_test.c
new file mode 100644
index 0000000..9b44097
--- /dev/null
+++ b/src/rtl_test.c
@@ -0,0 +1,457 @@
+/*
+ * rtl-sdr, turns your Realtek RTL2832 based DVB dongle into a SDR receiver
+ * rtl_test, test and benchmark tool
+ *
+ * Copyright (C) 2012-2014 by Steve Markgraf <steve@steve-m.de>
+ * Copyright (C) 2012-2014 by Kyle Keen <keenerd@gmail.com>
+ * Copyright (C) 2014 by Michael Tatarinov <kukabu@gmail.com>
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include <errno.h>
+#include <signal.h>
+#include <string.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <math.h>
+
+#ifdef __APPLE__
+#include <sys/time.h>
+#else
+#include <time.h>
+#endif
+
+#ifndef _WIN32
+#include <unistd.h>
+#else
+#include <windows.h>
+#include "getopt/getopt.h"
+#endif
+
+#include "rtl-sdr.h"
+#include "convenience/convenience.h"
+
+#define DEFAULT_SAMPLE_RATE		2048000
+#define DEFAULT_BUF_LENGTH		(16 * 16384)
+#define MINIMAL_BUF_LENGTH		512
+#define MAXIMAL_BUF_LENGTH		(256 * 16384)
+
+#define MHZ(x)	((x)*1000*1000)
+
+#define PPM_DURATION			10
+#define PPM_DUMP_TIME			5
+
+struct time_generic
+/* holds all the platform specific values */
+{
+#ifndef _WIN32
+	time_t tv_sec;
+	long tv_nsec;
+#else
+	long tv_sec;
+	long tv_nsec;
+	int init;
+	LARGE_INTEGER frequency;
+	LARGE_INTEGER ticks;
+#endif
+};
+
+static enum {
+	NO_BENCHMARK,
+	TUNER_BENCHMARK,
+	PPM_BENCHMARK
+} test_mode = NO_BENCHMARK;
+
+static int do_exit = 0;
+static rtlsdr_dev_t *dev = NULL;
+
+static uint32_t samp_rate = DEFAULT_SAMPLE_RATE;
+
+static uint32_t total_samples = 0;
+static uint32_t dropped_samples = 0;
+
+static unsigned int ppm_duration = PPM_DURATION;
+
+void usage(void)
+{
+	fprintf(stderr,
+		"rtl_test, a benchmark tool for RTL2832 based DVB-T receivers\n\n"
+		"Usage:\n"
+		"\t[-s samplerate (default: 2048000 Hz)]\n"
+		"\t[-d device_index (default: 0)]\n"
+		"\t[-t enable Elonics E4000 tuner benchmark]\n"
+#ifndef _WIN32
+		"\t[-p[seconds] enable PPM error measurement (default: 10 seconds)]\n"
+#endif
+		"\t[-b output_block_size (default: 16 * 16384)]\n"
+		"\t[-S force sync output (default: async)]\n");
+	exit(1);
+}
+
+#ifdef _WIN32
+BOOL WINAPI
+sighandler(int signum)
+{
+	if (CTRL_C_EVENT == signum) {
+		fprintf(stderr, "Signal caught, exiting!\n");
+		do_exit = 1;
+		rtlsdr_cancel_async(dev);
+		return TRUE;
+	}
+	return FALSE;
+}
+#else
+static void sighandler(int signum)
+{
+	fprintf(stderr, "Signal caught, exiting!\n");
+	do_exit = 1;
+	rtlsdr_cancel_async(dev);
+}
+#endif
+
+static void underrun_test(unsigned char *buf, uint32_t len, int mute)
+{
+	uint32_t i, lost = 0;
+	static uint8_t bcnt, uninit = 1;
+
+	if (uninit) {
+		bcnt = buf[0];
+		uninit = 0;
+	}
+	for (i = 0; i < len; i++) {
+		if(bcnt != buf[i]) {
+			lost += (buf[i] > bcnt) ? (buf[i] - bcnt) : (bcnt - buf[i]);
+			bcnt = buf[i];
+		}
+
+		bcnt++;
+	}
+
+	total_samples += len;
+	dropped_samples += lost;
+	if (mute)
+		return;
+	if (lost)
+		printf("lost at least %d bytes\n", lost);
+
+}
+
+#ifndef _WIN32
+static int ppm_gettime(struct time_generic *tg)
+{
+	int rv = ENOSYS;
+	struct timespec ts;
+
+#ifdef __unix__
+	rv = clock_gettime(CLOCK_MONOTONIC, &ts);
+	tg->tv_sec = ts.tv_sec;
+	tg->tv_nsec = ts.tv_nsec;
+#elif __APPLE__
+	struct timeval tv;
+
+	rv = gettimeofday(&tv, NULL);
+	tg->tv_sec = tv.tv_sec;
+	tg->tv_nsec = tv.tv_usec * 1000;
+#endif
+	return rv;
+}
+#endif
+
+#ifdef _WIN32
+static int ppm_gettime(struct time_generic *tg)
+{
+	int rv;
+	int64_t frac;
+	if (!tg->init) {
+		QueryPerformanceFrequency(&tg->frequency);
+		tg->init = 1;
+	}
+	rv = QueryPerformanceCounter(&tg->ticks);
+	tg->tv_sec = tg->ticks.QuadPart / tg->frequency.QuadPart;
+	frac = (int64_t)(tg->ticks.QuadPart - (tg->tv_sec * tg->frequency.QuadPart));
+	tg->tv_nsec = (long)(frac * 1000000000L / (int64_t)tg->frequency.QuadPart);
+	return !rv;
+}
+#endif
+
+static int ppm_report(uint64_t nsamples, uint64_t interval)
+{
+	double real_rate, ppm;
+
+	real_rate = nsamples * 1e9 / interval;
+	ppm = 1e6 * (real_rate / (double)samp_rate - 1.);
+	return (int)round(ppm);
+}
+
+static void ppm_test(uint32_t len)
+{
+	static uint64_t nsamples = 0;
+	static uint64_t interval = 0;
+	static uint64_t nsamples_total = 0;
+	static uint64_t interval_total = 0;
+	struct time_generic ppm_now;
+	static struct time_generic ppm_recent;
+	static enum {
+		PPM_INIT_NO,
+		PPM_INIT_DUMP,
+		PPM_INIT_RUN
+	} ppm_init = PPM_INIT_NO;
+
+	ppm_gettime(&ppm_now);
+
+	if (ppm_init != PPM_INIT_RUN) {
+		/*
+		 * Kyle Keen wrote:
+		 * PPM_DUMP_TIME throws out the first N seconds of data.
+		 * The dongle's PPM is usually very bad when first starting up,
+		 * typically incorrect by more than twice the final value.
+		 * Discarding the first few seconds allows the value to stabilize much faster.
+		*/
+		if (ppm_init == PPM_INIT_NO) {
+			ppm_recent.tv_sec = ppm_now.tv_sec + PPM_DUMP_TIME;
+			ppm_init = PPM_INIT_DUMP;
+			return;
+		}
+		if (ppm_init == PPM_INIT_DUMP && ppm_recent.tv_sec < ppm_now.tv_sec)
+			return;
+		ppm_recent = ppm_now;
+		ppm_init = PPM_INIT_RUN;
+		return;
+	}
+
+	nsamples += (uint64_t)(len / 2UL);
+	interval = (uint64_t)(ppm_now.tv_sec - ppm_recent.tv_sec);
+	if (interval < ppm_duration)
+		return;
+	interval *= 1000000000UL;
+	interval += (int64_t)(ppm_now.tv_nsec - ppm_recent.tv_nsec);
+	nsamples_total += nsamples;
+	interval_total += interval;
+	printf("real sample rate: %i current PPM: %i cumulative PPM: %i\n",
+		(int)((1000000000UL * nsamples) / interval),
+		ppm_report(nsamples, interval),
+		ppm_report(nsamples_total, interval_total));
+	ppm_recent = ppm_now;
+	nsamples = 0;
+}
+
+static void rtlsdr_callback(unsigned char *buf, uint32_t len, void *ctx)
+{
+	underrun_test(buf, len, 0);
+
+	if (test_mode == PPM_BENCHMARK)
+		ppm_test(len);
+}
+
+void e4k_benchmark(void)
+{
+	uint32_t freq, gap_start = 0, gap_end = 0;
+	uint32_t range_start = 0, range_end = 0;
+
+	fprintf(stderr, "Benchmarking E4000 PLL...\n");
+
+	/* find tuner range start */
+	for (freq = MHZ(70); freq > MHZ(1); freq -= MHZ(1)) {
+		if (rtlsdr_set_center_freq(dev, freq) < 0) {
+			range_start = freq;
+			break;
+		}
+	}
+
+	/* find tuner range end */
+	for (freq = MHZ(2000); freq < MHZ(2300UL); freq += MHZ(1)) {
+		if (rtlsdr_set_center_freq(dev, freq) < 0) {
+			range_end = freq;
+			break;
+		}
+	}
+
+	/* find start of L-band gap */
+	for (freq = MHZ(1000); freq < MHZ(1300); freq += MHZ(1)) {
+		if (rtlsdr_set_center_freq(dev, freq) < 0) {
+			gap_start = freq;
+			break;
+		}
+	}
+
+	/* find end of L-band gap */
+	for (freq = MHZ(1300); freq > MHZ(1000); freq -= MHZ(1)) {
+		if (rtlsdr_set_center_freq(dev, freq) < 0) {
+			gap_end = freq;
+			break;
+		}
+	}
+
+	fprintf(stderr, "E4K range: %i to %i MHz\n",
+		range_start/MHZ(1) + 1, range_end/MHZ(1) - 1);
+
+	fprintf(stderr, "E4K L-band gap: %i to %i MHz\n",
+		gap_start/MHZ(1), gap_end/MHZ(1));
+}
+
+int main(int argc, char **argv)
+{
+#ifndef _WIN32
+	struct sigaction sigact;
+#endif
+	int n_read, r, opt, i;
+	int sync_mode = 0;
+	uint8_t *buffer;
+	int dev_index = 0;
+	int dev_given = 0;
+	uint32_t out_block_size = DEFAULT_BUF_LENGTH;
+	int count;
+	int gains[100];
+
+	while ((opt = getopt(argc, argv, "d:s:b:tp::Sh")) != -1) {
+		switch (opt) {
+		case 'd':
+			dev_index = verbose_device_search(optarg);
+			dev_given = 1;
+			break;
+		case 's':
+			samp_rate = (uint32_t)atof(optarg);
+			break;
+		case 'b':
+			out_block_size = (uint32_t)atof(optarg);
+			break;
+		case 't':
+			test_mode = TUNER_BENCHMARK;
+			break;
+		case 'p':
+			test_mode = PPM_BENCHMARK;
+			if (optarg)
+				ppm_duration = atoi(optarg);
+			break;
+		case 'S':
+			sync_mode = 1;
+			break;
+		case 'h':
+		default:
+			usage();
+			break;
+		}
+	}
+
+	if(out_block_size < MINIMAL_BUF_LENGTH ||
+	   out_block_size > MAXIMAL_BUF_LENGTH ){
+		fprintf(stderr,
+			"Output block size wrong value, falling back to default\n");
+		fprintf(stderr,
+			"Minimal length: %u\n", MINIMAL_BUF_LENGTH);
+		fprintf(stderr,
+			"Maximal length: %u\n", MAXIMAL_BUF_LENGTH);
+		out_block_size = DEFAULT_BUF_LENGTH;
+	}
+
+	buffer = malloc(out_block_size * sizeof(uint8_t));
+
+	if (!dev_given) {
+		dev_index = verbose_device_search("0");
+	}
+
+	if (dev_index < 0) {
+		exit(1);
+	}
+
+	r = rtlsdr_open(&dev, (uint32_t)dev_index);
+	if (r < 0) {
+		fprintf(stderr, "Failed to open rtlsdr device #%d.\n", dev_index);
+		exit(1);
+	}
+#ifndef _WIN32
+	sigact.sa_handler = sighandler;
+	sigemptyset(&sigact.sa_mask);
+	sigact.sa_flags = 0;
+	sigaction(SIGINT, &sigact, NULL);
+	sigaction(SIGTERM, &sigact, NULL);
+	sigaction(SIGQUIT, &sigact, NULL);
+	sigaction(SIGPIPE, &sigact, NULL);
+#else
+	SetConsoleCtrlHandler( (PHANDLER_ROUTINE) sighandler, TRUE );
+#endif
+	count = rtlsdr_get_tuner_gains(dev, NULL);
+	fprintf(stderr, "Supported gain values (%d): ", count);
+
+	count = rtlsdr_get_tuner_gains(dev, gains);
+	for (i = 0; i < count; i++)
+		fprintf(stderr, "%.1f ", gains[i] / 10.0);
+	fprintf(stderr, "\n");
+
+	/* Set the sample rate */
+	verbose_set_sample_rate(dev, samp_rate);
+
+	if (test_mode == TUNER_BENCHMARK) {
+		if (rtlsdr_get_tuner_type(dev) == RTLSDR_TUNER_E4000)
+			e4k_benchmark();
+		else
+			fprintf(stderr, "No E4000 tuner found, aborting.\n");
+
+		goto exit;
+	}
+
+	/* Enable test mode */
+	r = rtlsdr_set_testmode(dev, 1);
+
+	/* Reset endpoint before we start reading from it (mandatory) */
+	verbose_reset_buffer(dev);
+
+	if ((test_mode == PPM_BENCHMARK) && !sync_mode) {
+		fprintf(stderr, "Reporting PPM error measurement every %u seconds...\n", ppm_duration);
+		fprintf(stderr, "Press ^C after a few minutes.\n");
+	}
+
+	if (test_mode == NO_BENCHMARK) {
+		fprintf(stderr, "\nInfo: This tool will continuously"
+				" read from the device, and report if\n"
+				"samples get lost. If you observe no "
+				"further output, everything is fine.\n\n");
+	}
+
+	if (sync_mode) {
+		fprintf(stderr, "Reading samples in sync mode...\n");
+		fprintf(stderr, "(Samples are being lost but not reported.)\n");
+		while (!do_exit) {
+			r = rtlsdr_read_sync(dev, buffer, out_block_size, &n_read);
+			if (r < 0) {
+				fprintf(stderr, "WARNING: sync read failed.\n");
+				break;
+			}
+
+			if ((uint32_t)n_read < out_block_size) {
+				fprintf(stderr, "Short read, samples lost, exiting!\n");
+				break;
+			}
+			underrun_test(buffer, n_read, 1);
+		}
+	} else {
+		fprintf(stderr, "Reading samples in async mode...\n");
+		r = rtlsdr_read_async(dev, rtlsdr_callback, NULL,
+				      0, out_block_size);
+	}
+
+	if (do_exit) {
+		fprintf(stderr, "\nUser cancel, exiting...\n");
+		fprintf(stderr, "Samples per million lost (minimum): %i\n", (int)(1000000L * dropped_samples / total_samples));
+	}
+	else
+		fprintf(stderr, "\nLibrary error %d, exiting...\n", r);
+
+exit:
+	rtlsdr_close(dev);
+	free (buffer);
+
+	return r >= 0 ? r : -r;
+}