Added fir filter code and functions for buffer conversion

5 files changed, 729 insertions, 7 deletions

diff --git a/Build/Makefile b/Build/Makefile
index 40d6a2e..6fe2da3 100644
--- a/Build/Makefile
+++ b/Build/Makefile
@@ -5,13 +5,12 @@ LDFLAGS=-lSDL2 -lSDL2_ttf
 EM_LDFALGS=-s USE_SDL=2  -s MAX_WEBGL_VERSION=2 -s MIN_WEBGL_VERSION=2 -s LLD_REPORT_UNDEFINED -s USE_GLFW=3
 
 make:
+	$(CC) -c $(SOURCEDIR)/../FIR/firmath.c -g3
 	$(CC) -c $(SOURCEDIR)/main.c -g3
 
 emcc:
-	$(EMCC) $(SOURCEDIR)/main.c -s WASM=1 -O3 -o index.js $(EM_LDFALGS) -s EXTRA_EXPORTED_RUNTIME_METHODS='["ccall", "cwrap"]'
+	$(EMCC) $(SOURCEDIR)/main.c ../FIR/firmath.c -s WASM=1 -O3 -o index.js $(EM_LDFALGS) -s EXTRA_EXPORTED_RUNTIME_METHODS='["ccall", "cwrap"]'
 	
-
-
 web:
 	darkhttpd ./ --port 12345
 	
diff --git a/FIR/firmath.c b/FIR/firmath.c
new file mode 100644
index 0000000..3fdf20b
--- /dev/null
+++ b/FIR/firmath.c
@@ -0,0 +1,247 @@
+//
+//  firmath.c
+//  FIR_rect_win
+//
+//  Created by Jacky Jack on 04/07/2021.
+//
+
+#include "firmath.h"
+
+/*
+void window_func_rect(double *w, int N1) {
+    int j;
+    
+    for (j=0;j<N1;j++) {
+        w[j] = 1.0;
+    }
+}
+*/
+
+void fir_init(fir_t *fir, uint32_t taps) {
+    int i;
+    for (i=0;i<taps;i++) {
+        fir->fir_coef[i] = (double)0.0;
+    }
+    fir->num_taps = taps;
+}
+
+
+void firw_init(firw_t *fir_win, uint32_t taps) {
+    int i;
+    for (i=0;i<taps;i++) {
+        fir_win->win_coef[i] = (double)0.0;
+    }
+    fir_win->num_taps = taps;
+}
+
+
+double math_sinx(double x) {
+    if (x>-1.0E-5 && x < 1.0E-5) return (1.0);
+    return sin(x)/x;
+}
+
+void fir_sinc_lp(fir_t *fir, double omega_c) {
+    int i;
+    double arg=0.0;
+    //should set 2fc?!
+    printf("omega_c=%f\n",omega_c);
+    for (i=0;i<fir->num_taps;i++) {
+        arg = (double)i-(double)(fir->num_taps-1)/2.0;
+        fir->fir_coef[i] = omega_c * math_sinx(omega_c*arg*M_PI);
+    }
+}
+
+void fir_sinc_hp(fir_t *fir, double omega_c) {
+    int i;
+    double arg=0.0;
+    int even = fir->num_taps%2 ? 0: 1;
+    
+    //should set 2fc?!
+    printf("omega_c=%f\n",omega_c);
+    if (even) {
+        for (i=0;i<fir->num_taps;i++) {
+            arg = (double)i-(double)(fir->num_taps-1)/2.0;
+            if (arg == 0.0) {
+                fir->fir_coef[i] = 0.0;
+            } else {
+                //from IOWA
+                fir->fir_coef[i] = cos(omega_c*arg*M_PI)/M_PI/arg + cos(arg*M_PI);
+            }
+        }
+    } else {
+        for (i=0;i<fir->num_taps;i++) {
+            arg = (double)i-(double)(fir->num_taps-1)/2.0;
+            fir->fir_coef[i] = math_sinx(arg*M_PI)-omega_c * math_sinx(omega_c*arg*M_PI);
+        }
+    }
+}
+
+void fir_sinc_bp(fir_t *fir, double omega_c1, double omega_c2) {
+    int i;
+    double arg=0.0;
+    //should set 2fc?!
+    printf("omega_c1=%f\n",omega_c1);
+    printf("omega_c2=%f\n",omega_c2);
+    for (i=0;i<fir->num_taps;i++) {
+        arg = (double)i-(double)(fir->num_taps-1)/2.0;
+        if (arg==0.0) {
+            fir->fir_coef[i] = 0.0;
+        } else {
+            //fir->fir_coef[i] = math_sinx(arg*M_PI) - omega_c2 * math_sinx(omega_c2*arg*M_PI) - omega_c1 * math_sinx(omega_c1*arg*M_PI);
+            fir->fir_coef[i] = (cos(omega_c1*arg*M_PI) - cos(omega_c2*arg*M_PI))/M_PI/arg;
+        }
+    }
+}
+
+void fir_sinc_bs(fir_t *fir, double omega_c1, double omega_c2) {
+    int i;
+    double arg=0.0;
+    //should set 2fc?!
+    printf("omega_c1=%f\n",omega_c1);
+    printf("omega_c2=%f\n",omega_c2);
+    for (i=0;i<fir->num_taps;i++) {
+        arg = (double)i-(double)(fir->num_taps-1)/2.0;
+        if (arg==0.0) {
+            fir->fir_coef[i] = 0.0;
+        } else {
+            //fir->fir_coef[i] = math_sinx(arg*M_PI) - omega_c2 * math_sinx(omega_c2*arg*M_PI) - omega_c1 * math_sinx(omega_c1*arg*M_PI);
+            fir->fir_coef[i] = math_sinx(arg*M_PI)  - omega_c2*math_sinx(omega_c2*arg*M_PI) - omega_c1*math_sinx(omega_c1*arg*M_PI);
+        }
+    }
+}
+
+void fir_convolute(fir_t *fir,firw_t *firw) {
+    int i=0;
+    for (i=0;i<fir->num_taps;i++) {
+        fir->fir_coef[i] = fir->fir_coef[i]*firw->win_coef[i];
+    }
+}
+
+
+void firw_rect(firw_t *fir_win) {
+    int i;
+    int n1 = fir_win->num_taps/2;
+    int even = fir_win->num_taps%2 ? 0: 1;
+    
+    if (even) n1+=1;
+    
+    for (i=0;i<n1;i++) {
+        fir_win->win_coef[i] = 1.0;
+    }
+    
+    for (i=0;i<n1;i++) {
+        fir_win->win_coef[fir_win->num_taps-1-i] =  fir_win->win_coef[i];
+    }
+    
+}
+
+
+void firw_hamming(firw_t *fir_win) {
+    int i;
+    double dN=0;
+    double arg=0;
+    //double p=0;
+    //double arg=0;
+    
+    int n1 = fir_win->num_taps/2;
+    int even = fir_win->num_taps%2 ? 0: 1;
+    if (!even) n1+=1;
+    dN = fir_win->num_taps +1;
+    
+    for (i=0;i<n1;i++) {
+        //arg = (double)i-(double)(fir_win->num_taps-1)/2.0;
+        //fir_win->win_coef[i] =  0.54+(1-0.54)*cos(2*M_PI*arg/n1);
+        
+        //fir_win->win_coef[i] =  0.54+(1-0.54)*cos(2*M_PI*i/n1);
+        arg = (double)i-(double)(fir_win->num_taps-1)/2.0;
+        fir_win->win_coef[i] = 0.54+0.46*cos(2*M_PI*arg/fir_win->num_taps);
+        
+    }
+    //fold
+    for (i=0;i<n1;i++) {
+        //arg = (double)i-(double)(fir_win->num_taps-1)/2.0;
+        //fir_win->win_coef[i] =  0.54+(1-0.54)*cos(2*M_PI*arg/n1);
+        
+        fir_win->win_coef[fir_win->num_taps-1-i] =  fir_win->win_coef[i];
+    }
+    
+}
+
+
+void firw_hanning(firw_t *fir_win) {
+    int i;
+    double dN=0;
+    double arg=0;
+    
+    int n1 = fir_win->num_taps/2;
+    int even = fir_win->num_taps%2 ? 0: 1;
+    if (!even) n1+=1;
+    dN = fir_win->num_taps +1;
+    
+    for (i=0;i<n1;i++) {
+        arg = (double)i-(double)(fir_win->num_taps-1)/2.0;
+        fir_win->win_coef[i] = 0.5+(1-0.5)*cos(2*M_PI*arg/fir_win->num_taps);
+        
+    }
+    //fold
+    for (i=0;i<n1;i++) {
+        fir_win->win_coef[fir_win->num_taps-1-i] =  fir_win->win_coef[i];
+    }
+}
+
+void firw_blackman(firw_t *firw) {
+    int i;
+    double dN=0;
+    double arg=0;
+    
+    int n1 = firw->num_taps/2;
+    int even = firw->num_taps%2 ? 0: 1;
+    if (!even) n1+=1;
+    dN = firw->num_taps +1;
+    
+    for (i=0;i<n1;i++) {
+        arg = (double)i-(double)(firw->num_taps-1)/2.0;
+        /*
+        firw->win_coef[i] = 0.42
+        +0.50*cos(2*M_PI*arg/(firw->num_taps))
+        +0.08*cos(4*M_PI*arg/(firw->num_taps));
+        */
+        firw->win_coef[i] = 0.42
+        +0.50*cos(2*M_PI*arg/(firw->num_taps-1))
+        +0.08*cos(4*M_PI*arg/(firw->num_taps-1));
+        
+    }
+    //fold
+    for (i=0;i<n1;i++) {
+        firw->win_coef[firw->num_taps-1-i] =  firw->win_coef[i];
+    }
+}
+
+void fir_print_matlab(fir_t *fir) {
+    int i;
+    printf("f=[\n");
+    for (i=0;i<fir->num_taps;i++) {
+        printf("%f\n",fir->fir_coef[i]);
+    }
+    printf("];\n");
+}
+
+void firw_print_matlab(firw_t *firw) {
+    int i;
+    printf("w=[\n");
+    for (i=0;i<firw->num_taps;i++) {
+        printf("%f\n",firw->win_coef[i]);
+    }
+    printf("];\n");
+}
+
+
+void fir_print_c(fir_t *fir) {
+    int i;
+    printf("double f=[\n");
+    for (i=0;i<fir->num_taps;i++) {
+        printf("%f,\n",fir->fir_coef[i]);
+    }
+    printf("];\n");
+}
+
diff --git a/FIR/firmath.h b/FIR/firmath.h
new file mode 100644
index 0000000..3540a98
--- /dev/null
+++ b/FIR/firmath.h
@@ -0,0 +1,43 @@
+//
+//  firmath.h
+//  FIR_rect_win
+//
+//  Created by Jacky Jack on 04/07/2021.
+//
+
+#ifndef firmath_h
+#define firmath_h
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <stdint.h>
+#include <math.h>
+
+typedef struct fir_t {
+    uint32_t num_taps;
+    double *fir_coef;
+} fir_t;
+
+typedef struct firw_t {
+    uint32_t num_taps;
+    double *win_coef;
+} firw_t;
+
+void fir_init(fir_t *fir, uint32_t taps);
+void firw_init(firw_t *fir_win, uint32_t taps);
+
+double math_sinx(double x);
+void fir_sinc_lp(fir_t *fir, double fc);
+void fir_sinc_hp(fir_t *fir, double omega_c);
+void fir_sinc_bp(fir_t *fir, double omega_c1, double omega_c2);
+void fir_sinc_bs(fir_t *fir, double omega_c1, double omega_c2);
+void fir_convolute(fir_t *fir,firw_t *fir_win);
+void firw_rect(firw_t *firw);
+void firw_hamming(firw_t *firw);
+void firw_hanning(firw_t *firw);
+void firw_blackman(firw_t *firw);
+void fir_print_matlab(fir_t *fir);
+void firw_print_matlab(firw_t *firw);
+void fir_print_c(fir_t *fir);
+
+#endif /* firmath_h */
diff --git a/WasmAudio.xcodeproj/project.pbxproj b/WasmAudio.xcodeproj/project.pbxproj
index 53e8a8c..4c87b7c 100644
--- a/WasmAudio.xcodeproj/project.pbxproj
+++ b/WasmAudio.xcodeproj/project.pbxproj
@@ -7,7 +7,10 @@
 	objects = {
 
 /* Begin PBXBuildFile section */
+		8D1ACB0726A0278200AAF1EB /* firmath.c in Sources */ = {isa = PBXBuildFile; fileRef = 8D1ACB0626A0278200AAF1EB /* firmath.c */; };
 		8D6E30352694457C007D7ECF /* main.c in Sources */ = {isa = PBXBuildFile; fileRef = 8D6E30342694457C007D7ECF /* main.c */; };
+		8D6E303F269445E3007D7ECF /* SDL2.framework in Frameworks */ = {isa = PBXBuildFile; fileRef = 8D6E303E269445E2007D7ECF /* SDL2.framework */; };
+		8D6E30442694472D007D7ECF /* Makefile in Sources */ = {isa = PBXBuildFile; fileRef = 8D6E30432694472D007D7ECF /* Makefile */; };
 /* End PBXBuildFile section */
 
 /* Begin PBXCopyFilesBuildPhase section */
@@ -23,8 +26,15 @@
 /* End PBXCopyFilesBuildPhase section */
 
 /* Begin PBXFileReference section */
+		8D1ACB0526A0278200AAF1EB /* firmath.h */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.c.h; path = firmath.h; sourceTree = "<group>"; };
+		8D1ACB0626A0278200AAF1EB /* firmath.c */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.c.c; path = firmath.c; sourceTree = "<group>"; };
 		8D6E30312694457C007D7ECF /* WasmAudio */ = {isa = PBXFileReference; explicitFileType = "compiled.mach-o.executable"; includeInIndex = 0; path = WasmAudio; sourceTree = BUILT_PRODUCTS_DIR; };
 		8D6E30342694457C007D7ECF /* main.c */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.c.c; path = main.c; sourceTree = "<group>"; };
+		8D6E303C269445C8007D7ECF /* Library */ = {isa = PBXFileReference; lastKnownFileType = folder; name = Library; path = ../../../../../Library; sourceTree = "<group>"; };
+		8D6E303E269445E2007D7ECF /* SDL2.framework */ = {isa = PBXFileReference; lastKnownFileType = wrapper.framework; name = SDL2.framework; path = ../../../../../Library/Frameworks/SDL2.framework; sourceTree = "<group>"; };
+		8D6E304026944620007D7ECF /* SDL2_ttf.framework */ = {isa = PBXFileReference; lastKnownFileType = wrapper.framework; name = SDL2_ttf.framework; path = ../../../../../Library/Frameworks/SDL2_ttf.framework; sourceTree = "<group>"; };
+		8D6E30432694472D007D7ECF /* Makefile */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.make; path = Makefile; sourceTree = "<group>"; };
+		8D6E304526944876007D7ECF /* index.html */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = text.html; path = index.html; sourceTree = "<group>"; };
 /* End PBXFileReference section */
 
 /* Begin PBXFrameworksBuildPhase section */
@@ -32,17 +42,30 @@
 			isa = PBXFrameworksBuildPhase;
 			buildActionMask = 2147483647;
 			files = (
+				8D6E303F269445E3007D7ECF /* SDL2.framework in Frameworks */,
 			);
 			runOnlyForDeploymentPostprocessing = 0;
 		};
 /* End PBXFrameworksBuildPhase section */
 
 /* Begin PBXGroup section */
+		8D1ACB0426A0276B00AAF1EB /* FIR */ = {
+			isa = PBXGroup;
+			children = (
+				8D1ACB0626A0278200AAF1EB /* firmath.c */,
+				8D1ACB0526A0278200AAF1EB /* firmath.h */,
+			);
+			path = FIR;
+			sourceTree = "<group>";
+		};
 		8D6E30282694457C007D7ECF = {
 			isa = PBXGroup;
 			children = (
+				8D1ACB0426A0276B00AAF1EB /* FIR */,
+				8D6E3042269446EE007D7ECF /* Build */,
 				8D6E30332694457C007D7ECF /* WasmAudio */,
 				8D6E30322694457C007D7ECF /* Products */,
+				8D6E303B269445C8007D7ECF /* Frameworks */,
 			);
 			sourceTree = "<group>";
 		};
@@ -62,6 +85,25 @@
 			path = WasmAudio;
 			sourceTree = "<group>";
 		};
+		8D6E303B269445C8007D7ECF /* Frameworks */ = {
+			isa = PBXGroup;
+			children = (
+				8D6E304026944620007D7ECF /* SDL2_ttf.framework */,
+				8D6E303E269445E2007D7ECF /* SDL2.framework */,
+				8D6E303C269445C8007D7ECF /* Library */,
+			);
+			name = Frameworks;
+			sourceTree = "<group>";
+		};
+		8D6E3042269446EE007D7ECF /* Build */ = {
+			isa = PBXGroup;
+			children = (
+				8D6E304526944876007D7ECF /* index.html */,
+				8D6E30432694472D007D7ECF /* Makefile */,
+			);
+			path = Build;
+			sourceTree = "<group>";
+		};
 /* End PBXGroup section */
 
 /* Begin PBXNativeTarget section */
@@ -118,6 +160,8 @@
 			isa = PBXSourcesBuildPhase;
 			buildActionMask = 2147483647;
 			files = (
+				8D1ACB0726A0278200AAF1EB /* firmath.c in Sources */,
+				8D6E30442694472D007D7ECF /* Makefile in Sources */,
 				8D6E30352694457C007D7ECF /* main.c in Sources */,
 			);
 			runOnlyForDeploymentPostprocessing = 0;
@@ -240,6 +284,10 @@
 			isa = XCBuildConfiguration;
 			buildSettings = {
 				CODE_SIGN_STYLE = Automatic;
+				FRAMEWORK_SEARCH_PATHS = (
+					"$(inherited)",
+					"$(LOCAL_LIBRARY_DIR)/Frameworks",
+				);
 				PRODUCT_NAME = "$(TARGET_NAME)";
 			};
 			name = Debug;
@@ -248,6 +296,10 @@
 			isa = XCBuildConfiguration;
 			buildSettings = {
 				CODE_SIGN_STYLE = Automatic;
+				FRAMEWORK_SEARCH_PATHS = (
+					"$(inherited)",
+					"$(LOCAL_LIBRARY_DIR)/Frameworks",
+				);
 				PRODUCT_NAME = "$(TARGET_NAME)";
 			};
 			name = Release;
diff --git a/WasmAudio/main.c b/WasmAudio/main.c
index b031629..6f1766b 100644
--- a/WasmAudio/main.c
+++ b/WasmAudio/main.c
@@ -5,16 +5,15 @@
 //  Created by Jacky Jack on 06/07/2021.
 //
 
-#include <stdio.h>
-#include <stdio.h>
 #include <stdlib.h>
 #include <stdio.h>
 #include <stdint.h>
-#include <strings.h>
+#include <string.h>
 #include <getopt.h>
 #include <signal.h>
 #include <fcntl.h>
 #include <pthread.h>
+#include <unistd.h>
 
 
 
@@ -22,9 +21,11 @@
 #include <emscripten/emscripten.h>
 #include <SDL/SDL.h>
 #include <SDL/SDL_ttf.h>
+#include <SDL/SDL_audio.h>
 #include <GLES2/gl2.h>
 #else
     #include <SDL2/SDL.h>
+    #include <SDL2/SDL_audio.h>
     #ifdef __APPLE__
     #include <SDL2_ttf/SDL_ttf.h>
     #else
@@ -34,12 +35,392 @@
     //#include <GLES2/gl2.h>
 #endif
 
+#define SCREEN_WIDTH   320
+#define SCREEN_WIDTH2  (SCREEN_WIDTH/2)
+#define SCREEN_HEIGHT  320
+#define SCREEN_HEIGHT2 (SCREEN_HEIGHT/2)
+
+#define BUFSIZE 1536000
+
+//Maximum recording time plus padding
+#define RECORDING_BUFFER_SECONDS  (2)
+//Maximum recording time
+#define MAX_RECORDING_SECONDS (RECORDING_BUFFER_SECONDS+2)
+
+int first_run=1;
+static int quit=0;
+static SDL_Window *window = NULL;
+static SDL_Renderer *renderer = NULL;
+//Audio device IDs
+static SDL_AudioDeviceID recordingDeviceId = 0;
+static SDL_AudioDeviceID playbackDeviceId = 0;
+int audio_rec_buffer_size=-1;
+int audio_rec_buffer_max_size=-1;
+//int audio_play_buffer_size=-1;
+//int audio_play_buffer_max_size=-1;
+static uint8_t audio_rec_buffer_[BUFSIZE];
+static double process_buf[BUFSIZE/4];
+uint8_t *audio_rec_buffer=NULL;
 
+int audio_buf_position=0;
+//uint8_t *audio_play_buffer=NULL;
+int current_state=0;
+
+
+void audio_recording_callback(void *data, uint8_t *insamples, int len)
+{
+    //printf("record len=%d\n",len);
+    if (audio_buf_position<audio_rec_buffer_size) {
+        memcpy( audio_rec_buffer+audio_buf_position, insamples, len);
+        audio_buf_position += len;
+    }
+    //memcpy(insamples, audio_rec_buffer+audio_buf_position, len);
+    
+    printf("rec_pos=%d\n",audio_buf_position);
+}
+
+void audio_playback_callback(void *data, uint8_t *outsamples, int len) {
+    //printf("playback len=%d\n",len);
+    //memcpy( audio_rec_buffer,outsamples, len);
+    if (audio_buf_position<audio_rec_buffer_size) {
+        memcpy( outsamples, audio_rec_buffer+audio_buf_position,len);
+        audio_buf_position += len;
+    }
+    
+}
 
+//The various recording actions we can take
+enum RecordingState
+{
+    SELECTING_DEVICE,
+    STOPPED,
+    RECORDING,
+    RECORDED,
+    PLAYBACK,
+    ERROR
+};
 
+void convert_double_to_f32() {
+    int i;
+    for (i=0;i<audio_rec_buffer_size;i+=4) {
+        float *f_ = (float *)&audio_rec_buffer[i];
+        float f = *f_;
+        process_buf[i/4] = (double)f;
+    }
+}
+
+void convert_f32_to_double() {
+    int i=0;
+    for (i=0;i<audio_rec_buffer_size;i+=4) {
+        double d = process_buf[i/4];
+        float f = (float)d;
+        float *f_ = (float *)audio_rec_buffer;
+        f_[i/4] = (double)f;
+    }
+}
+
+
+uint32_t tick_start, tick_end,tick_1sec;
+
+#if __EMSCRIPTEN__
+void main_tick() {
+#else
+int main_tick() {
+#endif
+    int i,j;
+    int update_fractal=0;
+    uint64_t perf_start, perf_end;
+    
+    perf_start = SDL_GetPerformanceCounter();
+    tick_start = SDL_GetTicks();
+    
+    SDL_Event event;
+    SDL_StartTextInput();
+        while (SDL_PollEvent(&event) != 0)
+        {
+                    
+            switch (event.type)
+            {
+                case SDL_QUIT:
+                {
+                    quit = 1;
+                    break;
+                }
+                case SDL_KEYDOWN:
+                {
+                    switch (event.key.keysym.sym)
+                    {
+
+                    case 21:
+                    case SDLK_r:
+                            //record if stopped
+                            if ((current_state == STOPPED) || (current_state == RECORDED)) {
+                                audio_buf_position = 0;
+                                SDL_PauseAudioDevice(recordingDeviceId, SDL_FALSE);
+                                current_state = RECORDING;
+                                printf("State: RECORDING\n");
+                            }
+                        break;
+                    case 22:
+                    case SDLK_s:
+                            //play if recorded
+                            if (current_state == RECORDED) {
+                                audio_buf_position = 0;
+                                SDL_PauseAudioDevice( playbackDeviceId, SDL_FALSE );
+                                current_state = PLAYBACK;
+                                printf("State: PLAYBACK\n");
+                            } /*else if (current_state == PLAYBACK) {
+                                current_state = STOPPED;
+                            } else if (current_state == STOPPED) {
+                                current_state = PLAYBACK;
+                            }*/
+                        break;
+                    case 20:
+                    case SDLK_q:
+                            //process recorderd buffer with low pass filter
+                            if (current_state == RECORDED) {
+                                convert_f32_to_double();
+                                convert_double_to_f32();
+                            }
+                        break;
+                    default:
+                        printf("Unknown key %d\n",event.key.keysym.sym);
+                        update_fractal = 1;
+                    }
+                    break;
+                }
+            }
+            //printf("Poll event\n");
+            
+        }
+#if __EMSCRIPTEN__
+        if (current_state == RECORDING) {
+            SDL_LockAudioDevice( recordingDeviceId );
+            printf("recording=%d\n",audio_buf_position);
+            if( audio_buf_position > audio_rec_buffer_size )
+            {
+                //Stop recording audio
+                SDL_PauseAudioDevice( recordingDeviceId, SDL_TRUE );
+                current_state = RECORDED;
+                printf("State: RECORDED\n");
+            }
+            
+            SDL_UnlockAudioDevice( recordingDeviceId );
+        } else if (current_state == PLAYBACK) {
+            SDL_LockAudioDevice( playbackDeviceId );
+            //Finished playback
+            if( audio_buf_position > audio_rec_buffer_size )
+            {
+                //Stop playing audio
+                SDL_PauseAudioDevice( playbackDeviceId, SDL_TRUE );
+                current_state = RECORDED;
+                printf("State: RECORDED\n");
+            }
+            //Unlock callback
+            SDL_UnlockAudioDevice( playbackDeviceId );
+        }
+#endif
+        
+
+        //check for first ever run
+        if (first_run == 1)
+        {
+            first_run = 0;
+            update_fractal = 1;
+        }
+
+        if (update_fractal == 1)
+        {
+
+        }
+        
+        #ifndef __EMSCRIPTEN__
+        if (update_fractal == 1)
+        #endif
+        {
+            SDL_GL_SwapWindow( window );
+        }
+        update_fractal=0;
+    
+    tick_end = SDL_GetTicks();
+    if ((tick_end-tick_1sec)>1000) {
+        //perf_end = SDL_GetPerformanceCounter()-perf_start;
+        //tick_end = SDL_GetTicks()-tick_start;
+        //printf("FPS:%f\n",(1.0f/perf_end));
+        printf("FPS:%f\n",1.0f/((tick_end-tick_start)/1000.0f));
+        tick_1sec = tick_end;
+    }
+    
+
+#if !__EMSCRIPTEN__
+    return 0;
+#endif
+}
+
+
+void main_loop()
+{
+    int i,count;
+    tick_1sec = SDL_GetTicks();
+#if __EMSCRIPTEN__
+    emscripten_set_main_loop(main_tick, 25, 1);
+#else
+    while (0 == quit)
+    {
+        main_tick();
+#if !__EMSCRIPTEN__
+        if (current_state == RECORDING) {
+            SDL_LockAudioDevice( recordingDeviceId );
+            printf("recording=%d\n",audio_buf_position);
+            if( audio_buf_position > audio_rec_buffer_size )
+            {
+                //Stop recording audio
+                SDL_PauseAudioDevice( recordingDeviceId, SDL_TRUE );
+                current_state = RECORDED;
+                printf("State: RECORDED\n");
+            }
+            
+            SDL_UnlockAudioDevice( recordingDeviceId );
+        } else if (current_state == PLAYBACK) {
+            SDL_LockAudioDevice( playbackDeviceId );
+            //Finished playback
+            if( audio_buf_position > audio_rec_buffer_size )
+            {
+                //Stop playing audio
+                SDL_PauseAudioDevice( playbackDeviceId, SDL_TRUE );
+                current_state = RECORDED;
+                printf("State: RECORDED\n");
+            }
+            //Unlock callback
+            SDL_UnlockAudioDevice( playbackDeviceId );
+        }
+#endif
+    }
+#endif
+}
 
 int main(int argc, const char * argv[]) {
+    int i,count;
     // insert code here...
-    printf("Hello, World!\n");
+    printf("Hello, World2!\n");
+    //if ( SDL_Init(SDL_INIT_EVERYTHING) < 0 )
+    if ( SDL_Init(SDL_INIT_AUDIO|SDL_INIT_VIDEO) < 0 )
+    {
+        fprintf(stderr, "EXIT:Unable to init SDL: %s\n", SDL_GetError());
+        exit(1);
+    }
+    
+    
+    
+    atexit(SDL_Quit);
+    
+    printf("Prepare SDL2 window\n");
+    SDL_GL_SetAttribute( SDL_GL_CONTEXT_MAJOR_VERSION, 2 );
+    SDL_GL_SetAttribute( SDL_GL_CONTEXT_MINOR_VERSION, 1 );
+    window = SDL_CreateWindow("KOH", SDL_WINDOWPOS_UNDEFINED, SDL_WINDOWPOS_UNDEFINED, SCREEN_WIDTH, SCREEN_HEIGHT, SDL_WINDOW_OPENGL|SDL_WINDOW_SHOWN);
+    renderer = SDL_CreateRenderer(window, -1, SDL_RENDERER_ACCELERATED);
+    SDL_SetRenderDrawColor(renderer, 0xff, 0xaa, 0xaa, 0xaa);
+    SDL_GLContext gl_context = SDL_GL_CreateContext(window);
+    SDL_GL_SetSwapInterval( 0 );
+
+    SDL_GL_SetAttribute(SDL_GL_DOUBLEBUFFER, 1);
+    SDL_GL_SetAttribute(SDL_GL_DEPTH_SIZE, 24);
+    
+    count  = SDL_GetNumAudioDevices(0);
+    printf("Playback devices  %d\n",count);
+    for (i=0;i<count;i++) {
+        printf("Playback audio device %d: %s\n", i, SDL_GetAudioDeviceName(i, 0));
+    }
+    count  = SDL_GetNumAudioDevices(1);
+    printf("Recording devices %d\n",count);
+    for (i=0;i<count;i++) {
+        printf("Recording audio device %d: %s\n", i, SDL_GetAudioDeviceName(i, 1));
+    }
+    
+    //https://github.com/emscripten-core/emscripten/issues/3477
+    //try whatever possible
+    SDL_AudioSpec audio_rec_want, audio_rec_have;
+    SDL_memset(&audio_rec_want, 0, sizeof(audio_rec_want)); /* or SDL_zero(want) */
+    audio_rec_want.freq = 48000;
+    audio_rec_want.format = AUDIO_F32;
+    audio_rec_want.channels = 2;
+    audio_rec_want.samples = 4096;
+    audio_rec_want.callback = audio_recording_callback;
+    recordingDeviceId = SDL_OpenAudioDevice(SDL_GetAudioDeviceName(1, SDL_TRUE ), SDL_TRUE, &audio_rec_want, &audio_rec_have, SDL_AUDIO_ALLOW_FORMAT_CHANGE|SDL_AUDIO_ALLOW_FREQUENCY_CHANGE);
+    
+    if (audio_rec_want.freq != audio_rec_have.freq) {
+        printf("Freq changed %d -> %d\n",audio_rec_want.freq,audio_rec_have.freq);
+    }
+    
+    if (audio_rec_want.format != audio_rec_have.format) {
+        printf("Format changed %d -> %d\n",audio_rec_want.format, audio_rec_have.format);
+    }
+    
+    if (recordingDeviceId == 0) {
+        printf("Failed to open recording device\n");
+    } else {
+        int byte_per_sample = audio_rec_have.channels * ( SDL_AUDIO_BITSIZE( audio_rec_have.format )/8);
+        int byte_per_second = audio_rec_have.freq * byte_per_sample;
+        printf("bytes per second %d\n",byte_per_second);
+        audio_rec_buffer_size = byte_per_second*RECORDING_BUFFER_SECONDS;
+        audio_rec_buffer_max_size = byte_per_second*MAX_RECORDING_SECONDS;
+        //audio_rec_buffer = malloc(audio_rec_buffer_max_size);
+        audio_rec_buffer = &audio_rec_buffer_[0];
+        printf("buffsize_max=%d\n",audio_rec_buffer_max_size);
+        printf("buffsize=%d\n",audio_rec_buffer_size);
+        memset(audio_rec_buffer,0,audio_rec_buffer_max_size);
+    }
+    
+    SDL_AudioSpec audio_play_want, audio_play_have;
+    audio_play_want.freq = 48000;
+    audio_play_want.format = AUDIO_F32;
+    audio_play_want.channels = 2;
+    audio_play_want.samples = 4096;
+    audio_play_want.callback = audio_playback_callback;
+    playbackDeviceId = SDL_OpenAudioDevice(NULL, SDL_FALSE, &audio_play_want, &audio_play_have, SDL_AUDIO_ALLOW_FORMAT_CHANGE|SDL_AUDIO_ALLOW_FREQUENCY_CHANGE);
+    
+    if (audio_play_want.freq != audio_play_have.freq) {
+        printf("Freq changed %d -> %d\n",audio_rec_want.freq,audio_rec_have.freq);
+    }
+    
+    if (audio_play_want.format != audio_play_have.format) {
+        printf("Format changed %d -> %d\n",audio_play_want.format, audio_play_have.format);
+    }
+    current_state = STOPPED;
+    printf("State: STOPED\n");
+    
+    
+    
+    
+    
+    //SDL_PauseAudioDevice(recordingDeviceId,0);
+    //!SDL_LockAudioDevice(recordingDeviceId);
+    //SDL_PauseAudioDevice(recordingDeviceId, 0);
+    //SDL_PauseAudio(0);
+    //SDL_Delay(4000);
+    //!SDL_UnlockAudioDevice(recordingDeviceId);
+    //!SDL_CloseAudio();
+    //SDL_CloseAudioDevice(recordingDeviceId);
+    /*
+    if (SDL_OpenAudio(&audio_want, &audio_have) < 0) {
+        SDL_Log("Failed to open audio: %s", SDL_GetError());
+    } else {
+        if (audio_have.format != audio_want.format) {
+            SDL_Log("We didn't get Float32 audio format.");
+        }
+        SDL_PauseAudio(0);
+        SDL_Delay(5000);
+        SDL_CloseAudio();
+    }
+    */
+    
+    main_loop();
+    
+    SDL_DestroyRenderer(renderer);
+    SDL_DestroyWindow(window);
+    SDL_CloseAudio();//?
+    SDL_VideoQuit();//?
+    SDL_Quit();
+    
     return 0;
 }