プログラムでマイクゲインを増やす

Question

VOIPシナリオでマイクのゲインを上げようとしています。 PortAudioを使用して入力ストリーム（paFloat32型のサンプル）を取得していますが、これらの値にfloatを掛けて出力ストリームに渡しています。 注：VOIPアプリケーションがゲインを適用してマイク入力として使用できる仮想入力デバイス（プログラム：VB-Cable）に自動的にリダイレクトする仮想出力デバイスに渡します。

品質をより良く維持する信号のゲインを向上させるためのより良い方法があるのだろうかと思います。

入力を高精度のフォーマットに変換し、ゲインの乗算をこの形式で実行し、クリッピングを適用して元に戻すことで、このようなゲイン計算を実行する方が良いことを読んだことがあります。 PortAudioのpaFloat32型でこれを行う方法がわかりません。ソースコードにコメントアウトしました。 tinycon, PortAudio

がコンパイル：g++ main.cpp tinycon.cpp -o main -L./ -lcygportaudio-2 -lrt -lm -pthread -std=c++11

コード：

#include "portaudio.h" 
#include <iostream> 
#include <chrono> 
#include <thread> 
#include <mutex> 
#include "tinycon.h" 

#define SAMPLE_RATE  (44100) 
#define FRAMES_PER_BUFFER (441) 
#define DITHER_FLAG   (1) 

#define PA_SAMPLE_TYPE paFloat32 
#define SAMPLE_SIZE (4) 
#define SAMPLE_SILENCE (0) 
#define PRINTF_S_FORMAT "%f" 

/*******************************************************************/ 
double multiplier = 1.0; 
double multiplierStep = 0.1; 
int main(int argc, char **argv); 
int xrun(PaStream *stream, int err, char* sampleBlock); 
void error1(PaStream *stream, char* sampleBlock); 
void error2(PaStream *stream, int err); 
void listDevices(); 

// Use tinycon and a second thread for non blocking input 
class tcon : public tinyConsole 
{ 
public: 
     tcon (std::string s): tinyConsole(s) {;} 

     int hotkeys(char c) 
     { 
       if (c == 's') { 
         if (multiplier >= (0+multiplierStep)) { 
           multiplier -= multiplierStep; 
         } 
         printf("Multiplier: %f\n", multiplier); 
         return 1; 
       } 
       if (c == 'w') { 
         multiplier += multiplierStep; 
         printf("Multiplier: %f\n", multiplier); 
         return 1; 
       } 
       return 0; 
     } 
}; 
int inputThread() { 
     tcon tc (std::string("")); 
     tc.run(); 
} 

void listDevices() { 
     int i, numDevices, defaultDisplayed; 
     const PaDeviceInfo *deviceInfo; 

     Pa_Initialize(); 

     numDevices = Pa_GetDeviceCount(); 

     printf("Number of devices = %d\n", numDevices); 
     int isInputDevice = 0; 
     for(i=0; i<numDevices; i++) 
     { 
       deviceInfo = Pa_GetDeviceInfo(i); 
       int isInputDevice = (deviceInfo->maxInputChannels > 0); 
       printf("%sDeviceID: %d, Name: %s\n", (isInputDevice ? "Input" : "Output"), i, deviceInfo->name); 
     } 
     fprintf (stderr, "Press any key to close\n"); 
     getch(); 
} 

int main (int argc, char **argv) 
{ 
     int c; 
     int inputDeviceId = -1; 
     int outputDeviceId = -1; 
     opterr = 0; 
     const char* helpMessage = 
       "-h : show this help message\n" 
       "-i <int> : select the INPUT DEVICE by id\n" 
       "-o <int> : select the OUPUT DEVICE by id\n" 
       "-m <double> : SIGNAL MULTIPLIER\n" 
       "-s <double> : SIGNAL MULTIPLIER STEP (press w or s while console focused to go up and down by this ammount.\n" 
       "-d : list devices\n"; 

     while ((c = getopt (argc, argv, "i:o:l:m:s:hd")) != -1) { 
       switch (c) { 
         case 'i': 
           inputDeviceId = atoi(optarg); 
           break; 
         case 'o': 
           outputDeviceId = atoi(optarg); 
           break; 
         case 'm': 
           multiplier = atof(optarg); 
           break; 
         case 's': 
           multiplierStep = atof(optarg); 
           break; 
         case 'd': 
           listDevices(); 
           return 0; 
         case '?': 
           if (isprint (optopt)) 
             fprintf (stderr, "Unknown option `-%c'.\n", optopt); 
           else 
             fprintf (stderr, "Unknown option character `\\x%x'.\n", optopt); 
         case 'h': 
           fprintf (stderr, helpMessage); 
           fprintf (stderr, "Press any key to close\n"); 
           getch(); 
           return 1; 
         default: 
         abort(); 
       } 
     } 

     // Start non blocking input thread 
     std::thread nonBlockingInputThread(inputThread); 


    PaStreamParameters inputParameters, outputParameters; 
    PaStream *stream = NULL; 
    PaError err; 
    const PaDeviceInfo* inputInfo; 
    const PaDeviceInfo* outputInfo; 
    char *sampleBlock = NULL; 
    int i; 
    int numBytes; 
    int numChannels; 

    err = Pa_Initialize(); 
    if(err != paNoError) error2(stream, err); 

    inputParameters.device = (inputDeviceId == -1) ? Pa_GetDefaultInputDevice() : inputDeviceId; /* default input device */ 
    inputInfo = Pa_GetDeviceInfo(inputParameters.device); 
    outputParameters.device = (outputDeviceId == -1) ? Pa_GetDefaultOutputDevice() : outputDeviceId; /* default output device */ 
    outputInfo = Pa_GetDeviceInfo(outputParameters.device); 

     numChannels = inputInfo->maxInputChannels < outputInfo->maxOutputChannels 
       ? inputInfo->maxInputChannels : outputInfo->maxOutputChannels; 

    inputParameters.channelCount = numChannels; 
    inputParameters.sampleFormat = PA_SAMPLE_TYPE; 
    inputParameters.suggestedLatency = inputInfo->defaultHighInputLatency ; 
    inputParameters.hostApiSpecificStreamInfo = NULL; 
    printf("Input device # %d.\n", inputParameters.device); 
    printf(" Name: %s\n", inputInfo->name); 


     outputParameters.channelCount = numChannels; 
     outputParameters.sampleFormat = PA_SAMPLE_TYPE; 
     outputParameters.suggestedLatency = outputInfo->defaultHighOutputLatency; 
     outputParameters.hostApiSpecificStreamInfo = NULL; 
    printf("Output device # %d.\n", outputParameters.device); 
    printf(" Name: %s\n", outputInfo->name); 

    /* -- setup -- */ 

    err = Pa_OpenStream(
       &stream, 
       &inputParameters, 
       &outputParameters, 
       SAMPLE_RATE, 
       FRAMES_PER_BUFFER, 
       paClipOff,  /* we won't output out of range samples so don't bother clipping them */ 
       NULL, /* no callback, use blocking API */ 
       NULL); /* no callback, so no callback userData */ 
    if(err != paNoError) error2(stream, err); 

    numBytes = FRAMES_PER_BUFFER * numChannels * SAMPLE_SIZE ; 
    sampleBlock = (char *) malloc(numBytes); 
    if(sampleBlock == NULL) 
    { 
     printf("Could not allocate record array.\n"); 
     error1(stream, sampleBlock); 
    } 

    err = Pa_StartStream(stream); 
    if(err != paNoError) error1(stream, sampleBlock); 


     while (1) { 
     // You may get underruns or overruns if the output is not primed by PortAudio. 
     err = Pa_ReadStream(stream, sampleBlock, FRAMES_PER_BUFFER); 
     if(err) xrun(stream, err, sampleBlock); 

       int blockIndex; 
       float* sampleBlockShort = (float*)sampleBlock; 
       for (blockIndex = 0; blockIndex < FRAMES_PER_BUFFER; blockIndex++) { 
         /* 
         double dSample = (double)sampleBlockShort[blockIndex]; 
         dSample *= multiplier; 
         if (dSample > 32767.0) dSample = 32767.0; 
         if (dSample < -32768.0) dSample = -32768.0; 
         sampleBlockShort[blockIndex] = (short)dSample; 
         */ 
         sampleBlockShort[blockIndex] *= multiplier; 
       } 

       err = Pa_WriteStream(stream, sampleBlock, FRAMES_PER_BUFFER); 
       if(err) xrun(stream, err, sampleBlock); 
    } 
    printf("Wire off.\n"); fflush(stdout); 

    err = Pa_StopStream(stream); 
    if(err != paNoError) error1(stream, sampleBlock); 

    free(sampleBlock); 

    Pa_Terminate(); 
    return 0; 

} 

int xrun(PaStream *stream, int err, char* sampleBlock) { 
    printf("err = %d\n", err); fflush(stdout); 
    if(stream) { 
     Pa_AbortStream(stream); 
     Pa_CloseStream(stream); 
    } 
    free(sampleBlock); 
    Pa_Terminate(); 
    if(err & paInputOverflow) 
     fprintf(stderr, "Input Overflow.\n"); 
    if(err & paOutputUnderflow) 
     fprintf(stderr, "Output Underflow.\n"); 
    return -2; 
} 

void error1(PaStream *stream, char* sampleBlock) { 
    free(sampleBlock); 
    exit(-1); 
} 

void error2(PaStream *stream, int err) { 
    if(stream) { 
     Pa_AbortStream(stream); 
     Pa_CloseStream(stream); 
    } 
    Pa_Terminate(); 
    fprintf(stderr, "An error occured while using the portaudio stream\n"); 
    fprintf(stderr, "Error number: %d\n", err); 
    fprintf(stderr, "Error message: %s\n", Pa_GetErrorText(err)); 
    exit(-1); 
} 

Answer 1

を私はあなたが使用できることを発見し、私はそれを有効にした場合でも、1

依存関係に設定されたゲインとの顕著なノイズの問題がありますこのためのwebrtcライブラリもあります。それは便利なノイズ抑制が付属しています。私はcompression_gain_dbとtarget_level_dbfsが実際に何をしているのか理解していませんが、最も高い値に設定すると最も利益が上がるようです。 @alexanderによって提案されたようにint16で作業することは、私のカスタムソリューションに多くの問題を解決し、ループ全体を修正してバッファ全体を処理する助けとなりました。 webrtcのソリューションと私の両方のソリューションは、以下のサンプルコードでリアルタイムで再生することができます。

以下にコード例が含まれています。

$ ./main.exe -h 
-h : show this help message 
-i <int> : select the INPUT DEVICE by id 
-o <int> : select the OUPUT DEVICE by id 
-c <int [0,90]> : compression_gain_db 
-t <int [0, 31]> : target_level_dbfs 
-g <0 or 1> : toggle webrtc gain control on and off (1 by default) 
-k <0 or 1> : toggle custom gain control on and off (1 by default) 
-f <int [1, maxInt]> : customGainControlFactor 
-q <int [0, 3]> : webrtc noise supression level, high is more suppression 
-e <0 or 1> : toggle webrtc noise suppression on and off (1 by default) 
-d : list devices 

Real time controls: 
compression_gain_db   UP_KEY='a' DOWN_KEY='s' 
target_dbfs_level    UP_KEY='d' DOWN_KEY='f' 
webrtcGainControlEnabled       TOGGLE_KEY='g' 
webrtcNoiseSuppressionLevel UP_KEY='q' DOWN_KEY='w' 
webrtcNoiseSuppressionEnabled      TOGGLE_KEY='e' 
customGainFactor    UP_KEY='h' DOWN_KEY='j' 
customGainFactorEnabled       TOGGLE_KEY='k' 
Press any key to close 

依存性：tinycon, PortAudio, libwebrtc-audio-processing-devel

注：g++ main.cpp tinycon.cpp -o main -L./ -lcygportaudio-2 -lrt -lm -pthread -I/usr/include/webrtc_audio_processing/ -DWEBRTC_WIN -DWEBRTC

main.cppに

#include "portaudio.h" 
#include <iostream> 
#include <limits> 
#include <chrono> 
#include <thread> 
#include <mutex> 
#include "tinycon.h" 

#include "webrtc/modules/audio_processing/include/audio_processing.h" 
#include "webrtc/modules/interface/module_common_types.h" 
#include "webrtc/system_wrappers/include/trace.h" 
using webrtc::AudioProcessing; 
using webrtc::AudioFrame; 
using webrtc::GainControl; 
using webrtc::NoiseSuppression; 

#define SAMPLE_RATE  (32000) 
#define FRAMES_PER_BUFFER (320) 
#define DITHER_FLAG   (0) 

#define PA_SAMPLE_TYPE paInt16 
#define SAMPLE_SIZE (2) 
#define SAMPLE_SILENCE (0) 
#define PRINTF_S_FORMAT "%d" 

/*******************************************************************/ 
int customGainFactor = 1; 
int customGainFactorStep = 1; 
bool customGainControlEnabled = true; 
int compression_gain_db = 1; 
int compression_gain_dbStep = 1; 
int target_level_dbfs = 1; 
int target_level_dbfsStep = 1; 
bool webrtcGainControlEnabled = true; 
bool webrtcNoiseSuppressionEnabled = true; 
int webrtcNoiseSuppressionLevel = 1; 
int main(int argc, char **argv); 
int xrun(PaStream *stream, int err, char* sampleBlock); 
void error1(PaStream *stream, char* sampleBlock); 
void error2(PaStream *stream, int err); 
void listDevices(); 
webrtc::NoiseSuppression::Level webrtcNoiseSuppressionLevelToEnum(int level); 
// Use tinycon and a second thread for non blocking input 
class tcon : public tinyConsole 
{ 
public: 
     tcon (std::string s): tinyConsole(s) {;} 

     int hotkeys(char c) 
     { 
       if (c == 'a') { 
         if (compression_gain_db >= (0+compression_gain_dbStep)) { 
           compression_gain_db -= compression_gain_dbStep; 
         } 
         printf("Compression_gain_db: %d\n", compression_gain_db); 
         return 1; 
       } 
       if (c == 's') { 
         if (compression_gain_db <= (90-compression_gain_dbStep)) { 
           compression_gain_db += compression_gain_dbStep; 
         } 
         printf("Compression_gain_db: %d\n", compression_gain_db); 
         return 1; 
       } 
       if (c == 'd') { 
         if (target_level_dbfs >= (0+target_level_dbfsStep)) { 
           target_level_dbfs -= target_level_dbfsStep; 
         } 
         printf("target_level_dbfs: %d\n", target_level_dbfs); 
         return 1; 
       } 
       if (c == 'f') { 
         if (target_level_dbfs <= (31-target_level_dbfsStep)) { 
           target_level_dbfs += target_level_dbfsStep; 
         } 
         printf("target_level_dbfs: %d\n", target_level_dbfs); 
         return 1; 
       } 
       if (c == 'g') { 
         webrtcGainControlEnabled = !webrtcGainControlEnabled; 
         printf("webrtcGainControlEnabled: %s\n", (webrtcGainControlEnabled) ? "true" : "false"); 
         return 1; 
       } 
       if (c == 'h') { 
         if (customGainFactor >= (1+customGainFactorStep)) { 
           customGainFactor -= customGainFactorStep; 
         } 
         printf("customGainFactor: %d\n", customGainFactor); 
         return 1; 
       } 
       if (c == 'j') { 
         customGainFactor += customGainFactorStep; 
         printf("customGainFactor: %d\n", customGainFactor); 
         return 1; 
       } 
       if (c == 'k') { 
         customGainControlEnabled = !customGainControlEnabled; 
         printf("customGainControlEnabled: %s\n", (customGainControlEnabled) ? "true" : "false"); 
         return 1; 
       } 
       if (c == 'q') { 
         if (webrtcNoiseSuppressionLevel <= (3-1)) { 
           webrtcNoiseSuppressionLevel += 1; 
         } 
         printf("webrtcNoiseSuppressionLevel: %d\n", webrtcNoiseSuppressionLevel); 
         return 1; 
       } 
       if (c == 'w') { 
         if (webrtcNoiseSuppressionLevel >= (0+1)) { 
           webrtcNoiseSuppressionLevel -= 1; 
         } 
         printf("webrtcNoiseSuppressionLevel: %d\n", webrtcNoiseSuppressionLevel); 
         return 1; 
       } 
       if (c == 'e') { 
         webrtcNoiseSuppressionEnabled = !webrtcNoiseSuppressionEnabled; 
         printf("webrtcNoiseSuppressionEnabled: %s\n", (webrtcNoiseSuppressionEnabled) ? "true" : "false"); 
         return 1; 
       } 
       return 0; 
     } 
}; 
int inputThread() { 
     tcon tc (std::string("")); 
     tc.run(); 
} 

void listDevices() { 
     int i, numDevices, defaultDisplayed; 
     const PaDeviceInfo *deviceInfo; 

     Pa_Initialize(); 

     numDevices = Pa_GetDeviceCount(); 

     printf("Number of devices = %d\n", numDevices); 
     int isInputDevice = 0; 
     for(i=0; i<numDevices; i++) 
     { 
       deviceInfo = Pa_GetDeviceInfo(i); 
       int isInputDevice = (deviceInfo->maxInputChannels > 0); 
       printf("%sDeviceID: %d, Name: %s\n", (isInputDevice ? "Input" : "Output"), i, deviceInfo->name); 
     } 
     fprintf (stderr, "Press any key to close\n"); 
     getch(); 
} 

int main (int argc, char **argv) 
{ 
     int c; 
     int inputDeviceId = -1; 
     int outputDeviceId = -1; 
     opterr = 0; 
     const char* helpMessage = 
       "-h : show this help message\n" 
       "-i <int> : select the INPUT DEVICE by id\n" 
       "-o <int> : select the OUPUT DEVICE by id\n" 
       "-c <int [0,90]> : compression_gain_db\n" 
       "-t <int [0, 31]> : target_level_dbfs\n" 
       "-g <0 or 1> : toggle webrtc gain control on and off (1 by default)\n" 
       "-k <0 or 1> : toggle custom gain control on and off (1 by default)\n" 
       "-f <int [1, maxInt]> : customGainControlFactor\n" 
       "-q <int [0, 5]> : webrtc noise supression level, high is more suppression\n" 
       "-e <0 or 1> : toggle webrtc noise suppression on and off (1 by default)\n" 
       "-d : list devices\n" 
       "\n" 
       "Real time controls:\n" 
       "compression_gain_db   UP_KEY='a' DOWN_KEY='s'\n" 
       "target_dbfs_level    UP_KEY='d' DOWN_KEY='f'\n" 
       "webrtcGainControlEnabled       TOGGLE_KEY='g'\n" 
       "webrtcNoiseSuppressionLevel UP_KEY='q' DOWN_KEY='w'\n" 
       "webrtcNoiseSuppressionEnabled      TOGGLE_KEY='e'\n" 
       "customGainFactor    UP_KEY='h' DOWN_KEY='j'\n" 
       "customGainFactorEnabled       TOGGLE_KEY='k'\n"; 

     while ((c = getopt (argc, argv, "i:o:c:t:g:k:f:w:q:hd")) != -1) { 
       switch (c) { 
         case 'i': 
           inputDeviceId = atoi(optarg); 
           break; 
         case 'o': 
           outputDeviceId = atoi(optarg); 
           break; 
         case 'c': 
           compression_gain_db = atoi(optarg); 
           break; 
         case 't': 
           target_level_dbfs = atoi(optarg); 
           break; 
         case 'g': 
           webrtcGainControlEnabled = (atoi(optarg) == 1) ? true : false; 
           break; 
         case 'f': 
           customGainFactor = atoi(optarg); 
           break; 
         case 'k': 
           customGainControlEnabled = (atoi(optarg) == 1) ? true : false; 
           break; 
         case 'w': 
           webrtcNoiseSuppressionLevel = atoi(optarg); 
           break; 
         case 'e': 
           webrtcNoiseSuppressionEnabled = (atoi(optarg) == 1) ? true : false; 
           break; 
         case 'd': 
           listDevices(); 
           return 0; 
         case '?': 
           if (isprint (optopt)) 
             fprintf (stderr, "Unknown option `-%c'.\n", optopt); 
           else 
             fprintf (stderr, "Unknown option character `\\x%x'.\n", optopt); 
         case 'h': 
           fprintf (stderr, helpMessage); 
           fprintf (stderr, "Press any key to close\n"); 
           getch(); 
           return 1; 
         default: 
         abort(); 
       } 
     } 

     // Start non blocking input thread 
     std::thread nonBlockingInputThread(inputThread); 


    PaStreamParameters inputParameters, outputParameters; 
    PaStream *stream = NULL; 
    PaError err; 
    const PaDeviceInfo* inputInfo; 
    const PaDeviceInfo* outputInfo; 
    char *sampleBlock = NULL; 
    int i; 
    int numBytes; 
    int numChannels; 

    err = Pa_Initialize(); 
    if(err != paNoError) error2(stream, err); 

    inputParameters.device = (inputDeviceId == -1) ? Pa_GetDefaultInputDevice() : inputDeviceId; /* default input device */ 
    inputInfo = Pa_GetDeviceInfo(inputParameters.device); 
    outputParameters.device = (outputDeviceId == -1) ? Pa_GetDefaultOutputDevice() : outputDeviceId; /* default output device */ 
    outputInfo = Pa_GetDeviceInfo(outputParameters.device); 

     numChannels = inputInfo->maxInputChannels < outputInfo->maxOutputChannels 
       ? inputInfo->maxInputChannels : outputInfo->maxOutputChannels; 

    inputParameters.channelCount = numChannels; 
    inputParameters.sampleFormat = PA_SAMPLE_TYPE; 
    inputParameters.suggestedLatency = inputInfo->defaultHighInputLatency ; 
    inputParameters.hostApiSpecificStreamInfo = NULL; 
    printf("Input device # %d.\n", inputParameters.device); 
    printf(" Name: %s\n", inputInfo->name); 


     outputParameters.channelCount = numChannels; 
     outputParameters.sampleFormat = PA_SAMPLE_TYPE; 
     outputParameters.suggestedLatency = outputInfo->defaultHighOutputLatency; 
     outputParameters.hostApiSpecificStreamInfo = NULL; 
    printf("Output device # %d.\n", outputParameters.device); 
    printf(" Name: %s\n", outputInfo->name); 

    /* -- setup -- */ 

    err = Pa_OpenStream(
       &stream, 
       &inputParameters, 
       &outputParameters, 
       SAMPLE_RATE, 
       FRAMES_PER_BUFFER, 
       paClipOff,  /* we won't output out of range samples so don't bother clipping them */ 
       NULL, /* no callback, use blocking API */ 
       NULL); /* no callback, so no callback userData */ 
    if(err != paNoError) error2(stream, err); 

    numBytes = FRAMES_PER_BUFFER * numChannels * SAMPLE_SIZE ; 
    sampleBlock = (char *) malloc(numBytes); 
    if(sampleBlock == NULL) 
    { 
     printf("Could not allocate record array.\n"); 
     error1(stream, sampleBlock); 
    } 

     // Configure webrtc::audioprocessing 
     int webrtcErr; 
     AudioProcessing* apm = AudioProcessing::Create(); 

     apm->high_pass_filter()->Enable(true); 

     apm->noise_suppression()->set_level(webrtcNoiseSuppressionLevelToEnum(webrtcNoiseSuppressionLevel)); 
     apm->noise_suppression()->Enable(webrtcNoiseSuppressionEnabled); 

     apm->gain_control()->set_mode(apm->gain_control()->kFixedDigital); 
     apm->gain_control()->set_compression_gain_db(compression_gain_db); 
     apm->gain_control()->set_target_level_dbfs(target_level_dbfs); 
     apm->gain_control()->Enable(webrtcGainControlEnabled); 

    err = Pa_StartStream(stream); 
    if(err != paNoError) error1(stream, sampleBlock); 

     while (1) { 
     // You may get underruns or overruns if the output is not primed by PortAudio. 
     err = Pa_ReadStream(stream, sampleBlock, FRAMES_PER_BUFFER); 
     if(err) xrun(stream, err, sampleBlock); 

       // Run custom gain solution 
       if (customGainControlEnabled) { 
         int blockIndex; 
         short* sampleBlockShort = (short*)sampleBlock; 
         for (blockIndex = 0; blockIndex < FRAMES_PER_BUFFER*numChannels; blockIndex++) { 
             int iSample = (int)sampleBlockShort[blockIndex]; 
             iSample *= customGainFactor; 
             if (iSample > std::numeric_limits<short>::max()) 
             iSample = 
                (iSample > std::numeric_limits<short>::max()) ? std::numeric_limits<short>::max() 
               : (iSample < std::numeric_limits<short>::min()) ? std::numeric_limits<short>::min() 
               : iSample; 
             sampleBlockShort[blockIndex] = (short)iSample; 
         } 
       } 

       // Apply webrtc gain and noise suppression 
       apm->noise_suppression()->set_level(webrtcNoiseSuppressionLevelToEnum(webrtcNoiseSuppressionLevel)); 
       apm->noise_suppression()->Enable(webrtcNoiseSuppressionEnabled); 
       apm->gain_control()->set_compression_gain_db(compression_gain_db); 
       apm->gain_control()->set_target_level_dbfs(target_level_dbfs); 
       apm->gain_control()->Enable(webrtcGainControlEnabled); 

       webrtc::AudioFrame frame; 
       frame.num_channels_ = numChannels; 
       frame.sample_rate_hz_ = SAMPLE_RATE; 
       frame.samples_per_channel_ = FRAMES_PER_BUFFER; 

       memcpy(frame.data_, sampleBlock, numBytes); 
       if ((webrtcErr = apm->ProcessStream(&frame)) < 0) { 
         printf("Error Code: %d\n", webrtcErr); fflush(stdout); 
         return -1; 
       } 
       memcpy(sampleBlock, frame.data_, numBytes); 

       err = Pa_WriteStream(stream, sampleBlock, FRAMES_PER_BUFFER); 
       if(err) xrun(stream, err, sampleBlock); 
    } 
    printf("Wire off.\n"); fflush(stdout); 

    err = Pa_StopStream(stream); 
    if(err != paNoError) error1(stream, sampleBlock); 

    free(sampleBlock); 

    Pa_Terminate(); 
    return 0; 

} 

int xrun(PaStream *stream, int err, char* sampleBlock) { 
    printf("err = %d\n", err); fflush(stdout); 
    if(stream) { 
     Pa_AbortStream(stream); 
     Pa_CloseStream(stream); 
    } 
    free(sampleBlock); 
    Pa_Terminate(); 
    if(err & paInputOverflow) 
     fprintf(stderr, "Input Overflow.\n"); 
    if(err & paOutputUnderflow) 
     fprintf(stderr, "Output Underflow.\n"); 
    return -2; 
} 

void error1(PaStream *stream, char* sampleBlock) { 
    free(sampleBlock); 
    exit(-1); 
} 

void error2(PaStream *stream, int err) { 
    if(stream) { 
     Pa_AbortStream(stream); 
     Pa_CloseStream(stream); 
    } 
    Pa_Terminate(); 
    fprintf(stderr, "An error occured while using the portaudio stream\n"); 
    fprintf(stderr, "Error number: %d\n", err); 
    fprintf(stderr, "Error message: %s\n", Pa_GetErrorText(err)); 
    exit(-1); 
} 

webrtc::NoiseSuppression::Level webrtcNoiseSuppressionLevelToEnum(int level) { 
     switch (level) { 
       case 0 : return webrtc::NoiseSuppression::Level::kLow; 
       case 1 : return webrtc::NoiseSuppression::Level::kModerate; 
       case 2 : return webrtc::NoiseSuppression::Level::kHigh; 
       case 3 : return webrtc::NoiseSuppression::Level::kVeryHigh; 
     } 
} 

：あなたは問題がある場合 here

のコンパイルを参照してくださいlibwebrtcと私は、cygwinの上で働いています