rtlsdr library example compiles

1 files changed, 205 insertions, 0 deletions

diff --git a/Radio/HW/AirSpy/src/iqconverter_int16.c b/Radio/HW/AirSpy/src/iqconverter_int16.c
new file mode 100644
index 0000000..abb3109
--- /dev/null
+++ b/Radio/HW/AirSpy/src/iqconverter_int16.c
@@ -0,0 +1,205 @@
+/*
+Copyright (C) 2014, Youssef Touil <youssef@airspy.com>
+
+Permission is hereby granted, free of charge, to any person obtaining a copy
+of this software and associated documentation files (the "Software"), to deal
+in the Software without restriction, including without limitation the rights
+to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+copies of the Software, and to permit persons to whom the Software is
+furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in
+all copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+THE SOFTWARE.
+*/
+
+#include "iqconverter_int16.h"
+#include <stdlib.h>
+#include <string.h>
+
+#if defined(__MINGW32__) && !defined(__MINGW64_VERSION_MAJOR)
+  #include <malloc.h>
+  #define _aligned_malloc __mingw_aligned_malloc
+  #define _aligned_free  __mingw_aligned_free
+  #define _inline inline
+#elif defined(__APPLE__)
+  #include <malloc/malloc.h>
+  #define _aligned_malloc(size, alignment) malloc(size)
+  #define _aligned_free(mem) free(mem)
+  #define _inline inline
+#elif defined(__FreeBSD__)
+  #define _inline inline
+  #define _aligned_free(mem) free(mem)
+void * _aligned_malloc(size_t size, size_t alignment);
+#elif defined(__GNUC__) && !defined(__MINGW64_VERSION_MAJOR)
+  #include <malloc.h>
+  #define _aligned_malloc(size, alignment) memalign(alignment, size)
+  #define _aligned_free(mem) free(mem)
+  #define _inline inline
+#endif
+
+#define SIZE_FACTOR 16
+#define DEFAULT_ALIGNMENT 16
+
+iqconverter_int16_t *iqconverter_int16_create(const int16_t *hb_kernel, int len)
+{
+	int i;
+	size_t buffer_size;
+	iqconverter_int16_t *cnv = (iqconverter_int16_t *) _aligned_malloc(sizeof(iqconverter_int16_t), DEFAULT_ALIGNMENT);
+
+	cnv->len = len / 2 + 1;
+
+	buffer_size = cnv->len * sizeof(int32_t);
+
+	cnv->fir_kernel = (int32_t *) _aligned_malloc(buffer_size, DEFAULT_ALIGNMENT);
+	cnv->fir_queue = (int32_t *) _aligned_malloc(buffer_size * SIZE_FACTOR, DEFAULT_ALIGNMENT);
+	cnv->delay_line = (int16_t *) _aligned_malloc(buffer_size / 4, DEFAULT_ALIGNMENT);
+
+	iqconverter_int16_reset(cnv);
+
+	for (i = 0; i < cnv->len; i++)
+	{
+		cnv->fir_kernel[i] = hb_kernel[i * 2];
+	}
+
+	return cnv;
+}
+
+void iqconverter_int16_free(iqconverter_int16_t *cnv)
+{
+	_aligned_free(cnv->fir_kernel);
+	_aligned_free(cnv->fir_queue);
+	_aligned_free(cnv->delay_line);
+	_aligned_free(cnv);
+}
+
+void iqconverter_int16_reset(iqconverter_int16_t *cnv)
+{
+	cnv->fir_index = 0;
+	cnv->delay_index = 0;
+	cnv->old_x = 0;
+	cnv->old_y = 0;
+	cnv->old_e = 0;
+	memset(cnv->delay_line, 0, cnv->len * sizeof(int16_t) / 4);
+	memset(cnv->fir_queue, 0, cnv->len * sizeof(int16_t) * SIZE_FACTOR);
+}
+
+static void fir_interleaved(iqconverter_int16_t *cnv, int16_t *samples, int len)
+{
+	int i;
+	int j;
+	int fir_index;
+	int fir_len;
+	int32_t *queue;
+	int32_t acc;
+
+	fir_len = cnv->len;
+	fir_index = cnv->fir_index;
+
+	for (i = 0; i < len; i += 2)
+	{
+		queue = cnv->fir_queue + fir_index;
+
+		queue[0] = samples[i];
+
+		acc = 0;
+		
+		// Auto vectorization works on VS2012, VS2013 and GCC
+		for (j = 0; j < fir_len; j++)
+		{
+			acc += cnv->fir_kernel[j] * queue[j];
+		}
+
+		if (--fir_index < 0)
+		{
+			fir_index = cnv->len * (SIZE_FACTOR - 1);
+			memcpy(cnv->fir_queue + fir_index + 1, cnv->fir_queue, (cnv->len - 1) * sizeof(int32_t));
+		}
+
+		samples[i] = acc >> 15;
+	}
+
+	cnv->fir_index = fir_index;
+}
+
+static void delay_interleaved(iqconverter_int16_t *cnv, int16_t *samples, int len)
+{
+	int i;
+	int index;
+	int half_len;
+	int16_t res;
+	
+	half_len = cnv->len >> 1;
+	index = cnv->delay_index;
+
+	for (i = 0; i < len; i += 2)
+	{
+		res = cnv->delay_line[index];
+		cnv->delay_line[index] = samples[i];
+		samples[i] = res;
+
+		if (++index >= half_len)
+		{
+			index = 0;
+		}
+	}
+	
+	cnv->delay_index = index;
+}
+
+static void remove_dc(iqconverter_int16_t *cnv, int16_t *samples, int len)
+{
+	int i;
+	int32_t u, old_e;
+	int16_t x, y, w, s, old_x, old_y;
+
+	old_x = cnv->old_x;
+	old_y = cnv->old_y;
+	old_e = cnv->old_e;
+
+	for (i = 0; i < len; i++)
+	{
+		x = samples[i];
+		w = x - old_x;
+		u = old_e + (int32_t) old_y * 32100;
+		s = u >> 15;
+		y = w + s;
+		old_e = u - (s << 15);
+		old_x = x;
+		old_y = y;		
+		samples[i] = y;
+	}
+
+	cnv->old_x = old_x;
+	cnv->old_y = old_y;
+	cnv->old_e = old_e;
+}
+
+static void translate_fs_4(iqconverter_int16_t *cnv, int16_t *samples, int len)
+{
+	int i;
+
+	for (i = 0; i < len; i += 4)
+	{
+		samples[i + 0] = -samples[i + 0];
+		samples[i + 1] = -samples[i + 1] >> 1;
+		//samples[i + 2] = samples[i + 2];
+		samples[i + 3] = samples[i + 3] >> 1;
+	}
+
+	fir_interleaved(cnv, samples, len);
+	delay_interleaved(cnv, samples + 1, len);
+}
+
+void iqconverter_int16_process(iqconverter_int16_t *cnv, int16_t *samples, int len)
+{
+	remove_dc(cnv, samples, len);
+	translate_fs_4(cnv, samples, len);
+}