Add second order notching filter.

miniaudio.h

@@ -1871,6 +1871,33 @@ ma_result ma_peak2_process_pcm_frames(ma_peak2* pFilter, void* pFramesOut, const
 ma_uint32 ma_peak2_get_latency(ma_peak2* pFilter);
 
 
+/**************************************************************************************************************************************************************
+
+Notching Filter
+
+**************************************************************************************************************************************************************/
+typedef struct
+{
+    ma_format format;
+    ma_uint32 channels;
+    ma_uint32 sampleRate;
+    double q;
+    double frequency;
+} ma_notch2_config;
+
+ma_notch2_config ma_notch2_config_init(ma_format format, ma_uint32 channels, ma_uint32 sampleRate, double q, double frequency);
+
+typedef struct
+{
+    ma_biquad bq;
+} ma_notch2;
+
+ma_result ma_notch2_init(const ma_notch2_config* pConfig, ma_notch2* pFilter);
+ma_result ma_notch2_reinit(const ma_notch2_config* pConfig, ma_notch2* pFilter);
+ma_result ma_notch2_process_pcm_frames(ma_notch2* pFilter, void* pFramesOut, const void* pFramesIn, ma_uint64 frameCount);
+ma_uint32 ma_notch2_get_latency(ma_notch2* pFilter);
+
+
 
 /************************************************************************************************************************************************************
 *************************************************************************************************************************************************************
@@ -30995,6 +31022,131 @@ ma_uint32 ma_peak2_get_latency(ma_peak2* pFilter)
 }
 
 
+/**************************************************************************************************************************************************************
+
+Notching Filter
+
+**************************************************************************************************************************************************************/
+ma_notch2_config ma_notch2_config_init(ma_format format, ma_uint32 channels, ma_uint32 sampleRate, double q, double frequency)
+{
+    ma_notch2_config config;
+
+    MA_ZERO_OBJECT(&config);
+    config.format     = format;
+    config.channels   = channels;
+    config.sampleRate = sampleRate;
+    config.q          = q;
+    config.frequency  = frequency;
+
+    if (config.q == 0) {
+        config.q = 0.707107;
+    }
+
+    return config;
+}
+
+
+static MA_INLINE ma_biquad_config ma_notch2__get_biquad_config(const ma_notch2_config* pConfig)
+{
+    ma_biquad_config bqConfig;
+    double q;
+    double w;
+    double s;
+    double c;
+    double a;
+
+    MA_ASSERT(pConfig != NULL);
+
+    q = pConfig->q;
+    w = 2 * MA_PI_D * pConfig->frequency / pConfig->sampleRate;
+    s = ma_sin(w);
+    c = ma_cos(w);
+    a = s / (2*q);
+
+    bqConfig.b0 =  1;
+    bqConfig.b1 = -2 * c;
+    bqConfig.b2 =  1;
+    bqConfig.a0 =  1 + a;
+    bqConfig.a1 = -2 * c;
+    bqConfig.a2 =  1 - a;
+
+    bqConfig.format   = pConfig->format;
+    bqConfig.channels = pConfig->channels;
+
+    return bqConfig;
+}
+
+ma_result ma_notch2_init(const ma_notch2_config* pConfig, ma_notch2* pFilter)
+{
+    ma_result result;
+    ma_biquad_config bqConfig;
+
+    if (pFilter == NULL) {
+        return MA_INVALID_ARGS;
+    }
+
+    MA_ZERO_OBJECT(pFilter);
+
+    if (pConfig == NULL) {
+        return MA_INVALID_ARGS;
+    }
+
+    bqConfig = ma_notch2__get_biquad_config(pConfig);
+    result = ma_biquad_init(&bqConfig, &pFilter->bq);
+    if (result != MA_SUCCESS) {
+        return result;
+    }
+
+    return MA_SUCCESS;
+}
+
+ma_result ma_notch2_reinit(const ma_notch2_config* pConfig, ma_notch2* pFilter)
+{
+    ma_result result;
+    ma_biquad_config bqConfig;
+
+    if (pFilter == NULL || pConfig == NULL) {
+        return MA_INVALID_ARGS;
+    }
+
+    bqConfig = ma_notch2__get_biquad_config(pConfig);
+    result = ma_biquad_reinit(&bqConfig, &pFilter->bq);
+    if (result != MA_SUCCESS) {
+        return result;
+    }
+
+    return MA_SUCCESS;
+}
+
+static MA_INLINE void ma_notch2_process_pcm_frame_s16(ma_notch2* pFilter, ma_int16* pFrameOut, const ma_int16* pFrameIn)
+{
+    ma_biquad_process_pcm_frame_s16(&pFilter->bq, pFrameOut, pFrameIn);
+}
+
+static MA_INLINE void ma_notch2_process_pcm_frame_f32(ma_notch2* pFilter, float* pFrameOut, const float* pFrameIn)
+{
+    ma_biquad_process_pcm_frame_f32(&pFilter->bq, pFrameOut, pFrameIn);
+}
+
+ma_result ma_notch2_process_pcm_frames(ma_notch2* pFilter, void* pFramesOut, const void* pFramesIn, ma_uint64 frameCount)
+{
+    if (pFilter == NULL) {
+        return MA_INVALID_ARGS;
+    }
+
+    return ma_biquad_process_pcm_frames(&pFilter->bq, pFramesOut, pFramesIn, frameCount);
+}
+
+ma_uint32 ma_notch2_get_latency(ma_notch2* pFilter)
+{
+    if (pFilter == NULL) {
+        return 0;
+    }
+
+    return ma_biquad_get_latency(&pFilter->bq);
+}
+
+
 
 /**************************************************************************************************************************************************************
 

tests/test_filtering/ma_test_filtering.c

@@ -27,6 +27,7 @@ ma_result filtering_init_decoder_and_encoder(const char* pInputFilePath, const c
 #include "ma_test_filtering_hpf.c"
 #include "ma_test_filtering_bpf.c"
 #include "ma_test_filtering_peak.c"
+#include "ma_test_filtering_notch.c"
 
 int main(int argc, char** argv)
 {
@@ -57,12 +58,17 @@ int main(int argc, char** argv)
     if (result != MA_SUCCESS) {
         hasError = MA_TRUE;
     }
-#endif
 
     result = ma_register_test("Peaking EQ Filtering", test_entry__peak);
     if (result != MA_SUCCESS) {
         hasError = MA_TRUE;
     }
+#endif
+
+    result = ma_register_test("Notching Filtering", test_entry__notch);
+    if (result != MA_SUCCESS) {
+        hasError = MA_TRUE;
+    }
 
     for (iTest = 0; iTest < g_Tests.count; iTest += 1) {
         printf("=== BEGIN %s ===\n", g_Tests.pTests[iTest].pName);

tests/test_filtering/ma_test_filtering_notch.c

@@ -0,0 +1,168 @@
+ma_result notch_init_decoder_and_encoder(const char* pInputFilePath, const char* pOutputFilePath, ma_format format, ma_decoder* pDecoder, ma_encoder* pEncoder)
+{
+    return filtering_init_decoder_and_encoder(pInputFilePath, pOutputFilePath, format, 0, 0, pDecoder, pEncoder);
+}
+
+
+ma_result test_notch2__by_format(const char* pInputFilePath, const char* pOutputFilePath, ma_format format)
+{
+    ma_result result;
+    ma_decoder decoder;
+    ma_encoder encoder;
+    ma_notch2_config notchConfig;
+    ma_notch2 notch;
+
+    printf("    %s\n", pOutputFilePath);
+
+    result = notch_init_decoder_and_encoder(pInputFilePath, pOutputFilePath, format, &decoder, &encoder);
+    if (result != MA_SUCCESS) {
+        return result;
+    }
+
+    notchConfig = ma_notch2_config_init(decoder.outputFormat, decoder.outputChannels, decoder.outputSampleRate, 0, 2000);
+    result = ma_notch2_init(&notchConfig, &notch);
+    if (result != MA_SUCCESS) {
+        ma_decoder_uninit(&decoder);
+        ma_encoder_uninit(&encoder);
+        return result;
+    }
+
+    for (;;) {
+        ma_uint8 tempIn[4096];
+        ma_uint8 tempOut[4096];
+        ma_uint64 tempCapIn  = sizeof(tempIn)  / ma_get_bytes_per_frame(decoder.outputFormat, decoder.outputChannels);
+        ma_uint64 tempCapOut = sizeof(tempOut) / ma_get_bytes_per_frame(decoder.outputFormat, decoder.outputChannels);
+        ma_uint64 framesToRead;
+        ma_uint64 framesJustRead;
+
+        framesToRead = ma_min(tempCapIn, tempCapOut);
+        framesJustRead = ma_decoder_read_pcm_frames(&decoder, tempIn, framesToRead);
+
+        /* Filter */
+        ma_notch2_process_pcm_frames(&notch, tempOut, tempIn, framesJustRead);
+
+        /* Write to the WAV file. */
+        ma_encoder_write_pcm_frames(&encoder, tempOut, framesJustRead);
+
+        if (framesJustRead < framesToRead) {
+            break;
+        }
+    }
+
+    ma_encoder_uninit(&encoder);
+    return MA_SUCCESS;
+}
+
+ma_result test_notch2__f32(const char* pInputFilePath)
+{
+    return test_notch2__by_format(pInputFilePath, "output/notch2_f32.wav", ma_format_f32);
+}
+
+ma_result test_notch2__s16(const char* pInputFilePath)
+{
+    return test_notch2__by_format(pInputFilePath, "output/notch2_s16.wav", ma_format_s16);
+}
+
+#if 0
+ma_result test_notch4__by_format(const char* pInputFilePath, const char* pOutputFilePath, ma_format format)
+{
+    ma_result result;
+    ma_decoder decoder;
+    ma_encoder encoder;
+    ma_notch_config notchConfig;
+    ma_notch notch;
+
+    printf("    %s\n", pOutputFilePath);
+
+    result = notch_init_decoder_and_encoder(pInputFilePath, pOutputFilePath, format, &decoder, &encoder);
+    if (result != MA_SUCCESS) {
+        return result;
+    }
+
+    notchConfig = ma_notch_config_init(decoder.outputFormat, decoder.outputChannels, decoder.outputSampleRate, 2000, 4);
+    result = ma_notch_init(&notchConfig, &notch);
+    if (result != MA_SUCCESS) {
+        ma_decoder_uninit(&decoder);
+        ma_encoder_uninit(&encoder);
+        return result;
+    }
+
+    for (;;) {
+        ma_uint8 tempIn[4096];
+        ma_uint8 tempOut[4096];
+        ma_uint64 tempCapIn  = sizeof(tempIn)  / ma_get_bytes_per_frame(decoder.outputFormat, decoder.outputChannels);
+        ma_uint64 tempCapOut = sizeof(tempOut) / ma_get_bytes_per_frame(decoder.outputFormat, decoder.outputChannels);
+        ma_uint64 framesToRead;
+        ma_uint64 framesJustRead;
+
+        framesToRead = ma_min(tempCapIn, tempCapOut);
+        framesJustRead = ma_decoder_read_pcm_frames(&decoder, tempIn, framesToRead);
+
+        /* Filter */
+        ma_notch_process_pcm_frames(&notch, tempOut, tempIn, framesJustRead);
+
+        /* Write to the WAV file. */
+        ma_encoder_write_pcm_frames(&encoder, tempOut, framesJustRead);
+
+        if (framesJustRead < framesToRead) {
+            break;
+        }
+    }
+
+    ma_encoder_uninit(&encoder);
+    return MA_SUCCESS;
+}
+
+ma_result test_notch4__f32(const char* pInputFilePath)
+{
+    return test_notch4__by_format(pInputFilePath, "output/notch4_f32.wav", ma_format_f32);
+}
+
+ma_result test_notch4__s16(const char* pInputFilePath)
+{
+    return test_notch4__by_format(pInputFilePath, "output/notch4_s16.wav", ma_format_s16);
+}
+#endif
+
+int test_entry__notch(int argc, char** argv)
+{
+    ma_result result;
+    ma_bool32 hasError = MA_FALSE;
+    const char* pInputFilePath;
+
+    if (argc < 2) {
+        printf("No input file.\n");
+        return -1;
+    }
+
+    pInputFilePath = argv[1];
+    
+
+    result = test_notch2__f32(pInputFilePath);
+    if (result != MA_SUCCESS) {
+        hasError = MA_TRUE;
+    }
+
+    result = test_notch2__s16(pInputFilePath);
+    if (result != MA_SUCCESS) {
+        hasError = MA_TRUE;
+    }
+
+#if 0
+    result = test_notch4__f32(pInputFilePath);
+    if (result != MA_SUCCESS) {
+        hasError = MA_TRUE;
+    }
+
+    result = test_notch4__s16(pInputFilePath);
+    if (result != MA_SUCCESS) {
+        hasError = MA_TRUE;
+    }
+#endif
+
+    if (hasError) {
+        return -1;
+    } else {
+        return 0;
+    }
+}