fader

fader在音频处理中是比较基础的处理。通常用于平滑的调节音量，或是音频的渐入和渐出效果。

比较常见的fader有line和cubic线型的fader。

line fader即fader的渐变过程是线性的。cubic的渐变过程是三次曲线。

fader主要有三个参数，attuationDb, type, timeMs.

line fader：

通过当前的音量curVolumDb，计算fader的初始gain值：startGain = dbToGain(curVolumDb)

fader结束音量为curVolumDb + attuationDb,那么fader结束的gain值为：endGain = dbToGain(curVolumDb + curVolumDb)

将fader的开始到结束的时间timeMs转化为sample为单位：timeInSample = timeMs * sampleRate / 1000.

那么line fader的step为：step = (endGain - startGain) / timeInSample.

初始化curSample为0， curGain= startGain.

每处理一个sample(sample * curGain), curSample加1. curGain加step，直至curSample等于timeInSample,整个fader过程结束。

5s内衰减5db

5s时间fader in

cubic fader:

cubic fader的原理为，将0~1划分为多个段（假设为segNum）。计算每个Segment端点的gain值：segGain.

由于有segNum个段，那么0~1被离散为segNum + 1个点，每个点的segGain[n]值为（n/(segNum +1)）^3. n=0,1,2...segNum+1;

将0~1之间的segGain map到startGain ~ endGain之间。

对于0~timeInSample之间的点，我们计算当前的sample处于哪个segment,当curSample是当前segment的第一个点时，将curGain设置成segGain[n].

当前segment按line fader一样的方法计算每个点的gain，每处理一个sample, curGain加step.

5s内衰减5db

 

 5s时间fader in

 

 实现代码如下：

在main函数创建两个thread，readThread, ppThread.

readThread每次读取wav文件256个sample，并每次取出64 sample转化成non-interleave的数据，发送到ppThread中。

定义一个全局的三维数组gPpBuf[chNum][bankNum][sampleNum]，将转化成non-interleave的数据放到数组中，维护rp和wp来记录readThread和ppThread的当前读写的bank位置。

在ppThread中，每次接收到64sample做fader处理。

#include<stdio.h>
#include<stdlib.h>
#include<errno.h>
#include<string.h>
#include<pthread.h>
#include<math.h>
typedef struct{
char chunkId[4];//"RIFF"
unsigned long chunkSize;
char format[4];//"WAVE"
}WAVE_RIFF;
typedef struct{
char chunkId[4];//"fmt"
unsigned long chunkSize;
unsigned short audioFormat;
unsigned short chNum;
unsigned long sampleRate;
unsigned long byteRate;//SampleRate * NumChannels * BitsPerSample/8
unsigned short blockAlign;//NumChannels * BitsPerSample/8
unsigned short bitsPerSample;//8,16,32
}WAVE_FMT;
typedef struct{
char chunkId[4];//"data"
unsigned long chunkSize;//NumSamples * NumChannels * BitsPerSample/8
}WAVE_DATA;
typedef struct
{
    char fileName[256];
    FILE *fp;
    long pos;
    unsigned long totalSampleNum;
    WAVE_RIFF riffChunk;
    WAVE_FMT fmtChunk;
    WAVE_DATA dataChunk;
}WAVE_INFO;

#define READ_SAMPLES 256
#define PP_SAMPLES 64
typedef struct
{
    unsigned short chNum;
    unsigned short bankNum;
    unsigned long samplesPerBank;
    unsigned short bytesPerSample;
    unsigned short bankRp;
    unsigned short bankWp;
    unsigned char ***pData;
    unsigned char fgEos;
}PP_BUF_T;

typedef enum
{
    FADER_TYPE_LINE,
    FADER_TYPE_CUBIC,
}FADER_TYPE_E;
typedef struct
{
    float attuationDb;
    FADER_TYPE_E type;
    unsigned long timeMs;
}FADER_PARAM_T;

typedef struct
{
    FADER_PARAM_T faderParams;
    unsigned long timeInSample;
    float curVolumDb;
    float curGain;
    float startGain;
    float targetGain;
    unsigned long curSample;
    unsigned long sampleRate;
    float *segGain;
    unsigned short segNum;
}FADER_HANDLE_T;
typedef struct
{
    short **pData;
    unsigned short chNum;
    unsigned short samples;
    unsigned short bytesPerSample;
}DATA_INFO_T;
PP_BUF_T gPpBuf;
FADER_HANDLE_T gFaderHandle;
unsigned char fgEnd = 0;
float mapSegGainToRealGain(FADER_HANDLE_T *pFaderHandle, float segGain)
{
    float deltaGain = pFaderHandle->targetGain - pFaderHandle->startGain;
    float realGain = deltaGain * segGain + pFaderHandle->startGain;
    return realGain;
}
void faderPrepareShape(FADER_HANDLE_T *pFaderHandle, unsigned short segNum)
{
    unsigned short segIdx;
    pFaderHandle->segGain = (float *)malloc((segNum + 1) * sizeof(float));
    pFaderHandle->segNum = segNum;
    float tmp;
    if (pFaderHandle->faderParams.type != FADER_TYPE_CUBIC)
         return;
    //0~1 divide into N seg.
    for (segIdx = 0; segIdx < segNum + 1; segIdx++)
    {
        tmp = (float)segIdx / segNum;
        pFaderHandle->segGain[segIdx] = tmp * tmp * tmp;
        pFaderHandle->segGain[segIdx] = mapSegGainToRealGain(pFaderHandle, pFaderHandle->segGain[segIdx]);
    }
}
float dbToGain(float db)
{
    return pow(10, db/20);
}
void faderInit(FADER_HANDLE_T *pFaderHandle, float attuationDb, FADER_TYPE_E type, unsigned long timeMs, unsigned long sampleRate, float curVolumDb)
{
    pFaderHandle->faderParams.attuationDb = attuationDb;
    pFaderHandle->faderParams.type = type;
    pFaderHandle->faderParams.timeMs = timeMs;
    pFaderHandle->timeInSample = timeMs * sampleRate / 1000;
    pFaderHandle->curGain = pFaderHandle->startGain = dbToGain(curVolumDb);
    pFaderHandle->targetGain = dbToGain(curVolumDb + attuationDb);
    pFaderHandle->curSample = 0;
    faderPrepareShape(pFaderHandle, 20);
    printf("faderInit
");
}

void faderCalGain(FADER_HANDLE_T *pFaderHandle)
{
    printf("faderCalcGain
");
    float startGainInCurSeg, endGainInCurSeg, step;
    float deltaGain = pFaderHandle->targetGain - pFaderHandle->startGain;
    unsigned long samplesInSeg = pFaderHandle->timeInSample / pFaderHandle->segNum;
    unsigned short curSeg = (float)pFaderHandle->curSample / samplesInSeg;
    unsigned long startSampleInCurSeg = samplesInSeg * curSeg;
    switch (pFaderHandle->faderParams.type)
    {
        case FADER_TYPE_LINE:
            step = deltaGain / pFaderHandle->timeInSample;
            pFaderHandle->curGain += deltaGain / pFaderHandle->timeInSample;
            //pFaderHandle->curGain = pFaderHandle->startGain + deltaGain * pFaderHandle->curSample / pFaderHandle->timeInSample;
            break;
        case FADER_TYPE_CUBIC:
            startGainInCurSeg = pFaderHandle->segGain[curSeg];
            endGainInCurSeg = pFaderHandle->segGain[curSeg + 1];
            step = (endGainInCurSeg - startGainInCurSeg) / samplesInSeg;
            if (pFaderHandle->curSample == startSampleInCurSeg)
                pFaderHandle->curGain = startGainInCurSeg;
            else
                pFaderHandle->curGain += step;
            break;
    }
    printf("curGain:%f, curSample:%ld, timeInSample:%ld
", pFaderHandle->curGain, pFaderHandle->curSample, pFaderHandle->timeInSample);
}

void fader(FADER_HANDLE_T *pFaderHandle, DATA_INFO_T *pDataInfo)
{
    unsigned short sampleIdx, chIdx;
    for (sampleIdx = 0; sampleIdx < pDataInfo->samples; sampleIdx++)
    {
        if (pFaderHandle->curSample != pFaderHandle->timeInSample)
        {
            faderCalGain(pFaderHandle);
            pFaderHandle->curSample++;
        }
        for (chIdx = 0; chIdx < pDataInfo->chNum; chIdx++)
        {
            pDataInfo->pData[chIdx][sampleIdx] *= pFaderHandle->curGain;
        }
    }
}
void printWaveHeader(WAVE_INFO *pWaveInfo)
{
    printf("fileName:%s
", pWaveInfo->fileName);
    printf("riff chunk:
");
    printf("chunkId:%c%c%c%c
", pWaveInfo->riffChunk.chunkId[0], pWaveInfo->riffChunk.chunkId[1], pWaveInfo->riffChunk.chunkId[2], pWaveInfo->riffChunk.chunkId[3]);
    printf("chunkSize:%ld
", pWaveInfo->riffChunk.chunkSize);
    printf("format:%c%c%c%c
", pWaveInfo->riffChunk.format[0], pWaveInfo->riffChunk.format[1], pWaveInfo->riffChunk.format[2], pWaveInfo->riffChunk.format[3]);
    printf("fmt chunk:
");
    printf("chunkId:%c%c%c
", pWaveInfo->fmtChunk.chunkId[0], pWaveInfo->fmtChunk.chunkId[1], pWaveInfo->fmtChunk.chunkId[2]);
    printf("chunkSize:%ld
", pWaveInfo->fmtChunk.chunkSize);
    printf("audioFormat:%d
", pWaveInfo->fmtChunk.audioFormat);
    printf("chNum:%d
", pWaveInfo->fmtChunk.chNum);
    printf("sampleRate:%ld
", pWaveInfo->fmtChunk.sampleRate);
    printf("byteRate:%ld
", pWaveInfo->fmtChunk.byteRate);
    printf("blockAlign:%d
", pWaveInfo->fmtChunk.blockAlign);
    printf("bitsPerSample:%d
", pWaveInfo->fmtChunk.bitsPerSample);
    printf("data chunk:
");
    printf("chunkId:%c%c%c%c
", pWaveInfo->dataChunk.chunkId[0], pWaveInfo->dataChunk.chunkId[1], pWaveInfo->dataChunk.chunkId[2], pWaveInfo->dataChunk.chunkId[3]);
    printf("chunkSize:%ld
", pWaveInfo->dataChunk.chunkSize);
    
}
void initWaveInfo(WAVE_INFO *pWaveInfo, unsigned short chNum, unsigned long sampleRate, unsigned short bitsPerSample)
{
    //strncpy(pWaveInfo->riffChunk.chunkId, "RIFF", 4);
    pWaveInfo->riffChunk.chunkId[0] = 'R';
    pWaveInfo->riffChunk.chunkId[1] = 'I';
    pWaveInfo->riffChunk.chunkId[2] = 'F';
    pWaveInfo->riffChunk.chunkId[3] = 'F';
    pWaveInfo->riffChunk.chunkSize = 0;
    //strncpy(pWaveInfo->riffChunk.format, "WAVE", 4);
    pWaveInfo->riffChunk.format[0] = 'W';
    pWaveInfo->riffChunk.format[1] = 'A';
    pWaveInfo->riffChunk.format[2] = 'V';
    pWaveInfo->riffChunk.format[3] = 'E';
    //strncpy(pWaveInfo->fmtChunk.chunkId, "fmt", 3);
    pWaveInfo->fmtChunk.chunkId[0] = 'f';
    pWaveInfo->fmtChunk.chunkId[1] = 'm';
    pWaveInfo->fmtChunk.chunkId[2] = 't';
    pWaveInfo->fmtChunk.chunkId[3] = ' ';
    pWaveInfo->fmtChunk.chunkSize = sizeof(WAVE_FMT) - 8;
    pWaveInfo->fmtChunk.audioFormat = 1;
    pWaveInfo->fmtChunk.chNum = chNum;
    pWaveInfo->fmtChunk.sampleRate = sampleRate;
    pWaveInfo->fmtChunk.byteRate = sampleRate * chNum * bitsPerSample / 8;
    pWaveInfo->fmtChunk.blockAlign = chNum * bitsPerSample / 8;
    pWaveInfo->fmtChunk.bitsPerSample = bitsPerSample;
    //strncpy(pWaveInfo->dataChunk.chunkId, "data", 4);
    pWaveInfo->dataChunk.chunkId[0] = 'd';
    pWaveInfo->dataChunk.chunkId[1] = 'a';
    pWaveInfo->dataChunk.chunkId[2] = 't';
    pWaveInfo->dataChunk.chunkId[3] = 'a';
    
    pWaveInfo->dataChunk.chunkSize = 0;
    pWaveInfo->totalSampleNum = 0;
    ///printWaveHeader(pWaveInfo);
}

void rwRiffChunk(WAVE_INFO *pWaveInfo, unsigned char fgRead)
{
    if (fgRead)
    {
        fread((char *)&pWaveInfo->riffChunk.chunkId, 4, 1, pWaveInfo->fp);
        fread((char *)&pWaveInfo->riffChunk.chunkSize, 4, 1, pWaveInfo->fp);
        fread((char *)&pWaveInfo->riffChunk.format, 4, 1, pWaveInfo->fp);
    }
    else
    {
        fwrite((char *)&pWaveInfo->riffChunk.chunkId, 4, 1, pWaveInfo->fp);
        fwrite((char *)&pWaveInfo->riffChunk.chunkSize, 4, 1, pWaveInfo->fp);
        fwrite((char *)&pWaveInfo->riffChunk.format, 4, 1, pWaveInfo->fp);
    }
}
void rwFmtChunk(WAVE_INFO *pWaveInfo, unsigned char fgRead)
{
    if (fgRead)
    {
        fread((char *)&pWaveInfo->fmtChunk.chunkId, 4, 1, pWaveInfo->fp);
        fread((char *)&pWaveInfo->fmtChunk.chunkSize, 4, 1, pWaveInfo->fp);
        fread((char *)&pWaveInfo->fmtChunk.audioFormat, 2, 1, pWaveInfo->fp);
        fread((char *)&pWaveInfo->fmtChunk.chNum, 2, 1, pWaveInfo->fp);
        fread((char *)&pWaveInfo->fmtChunk.sampleRate, 4, 1, pWaveInfo->fp);
        fread((char *)&pWaveInfo->fmtChunk.byteRate, 4, 1, pWaveInfo->fp);
        fread((char *)&pWaveInfo->fmtChunk.blockAlign, 2, 1, pWaveInfo->fp);
        fread((char *)&pWaveInfo->fmtChunk.bitsPerSample, 2, 1, pWaveInfo->fp);
    }
    else
    {
        fwrite((char *)&pWaveInfo->fmtChunk.chunkId, 4, 1, pWaveInfo->fp);
        fwrite((char *)&pWaveInfo->fmtChunk.chunkSize, 4, 1, pWaveInfo->fp);
        fwrite((char *)&pWaveInfo->fmtChunk.audioFormat, 2, 1, pWaveInfo->fp);
        fwrite((char *)&pWaveInfo->fmtChunk.chNum, 2, 1, pWaveInfo->fp);
        fwrite((char *)&pWaveInfo->fmtChunk.sampleRate, 4, 1, pWaveInfo->fp);
        fwrite((char *)&pWaveInfo->fmtChunk.byteRate, 4, 1, pWaveInfo->fp);
        fwrite((char *)&pWaveInfo->fmtChunk.blockAlign, 2, 1, pWaveInfo->fp);
        fwrite((char *)&pWaveInfo->fmtChunk.bitsPerSample, 2, 1, pWaveInfo->fp);
        
    }
}
void rwDataChunk(WAVE_INFO *pWaveInfo, unsigned char fgRead)
{
    if (fgRead)
    {
        fread((char *)&pWaveInfo->dataChunk.chunkId, 4, 1, pWaveInfo->fp);
        fread((char *)&pWaveInfo->dataChunk.chunkSize, 4, 1, pWaveInfo->fp);
    }
    else
    {
        fwrite((char *)&pWaveInfo->dataChunk.chunkId, 4, 1, pWaveInfo->fp);
        fwrite((char *)&pWaveInfo->dataChunk.chunkSize, 4, 1, pWaveInfo->fp);
    }
}

void readWaveHeader(char *fileName, WAVE_INFO *pWaveInfo)
{
    size_t retSize;
    strncpy(pWaveInfo->fileName, fileName, strlen(fileName));
    pWaveInfo->fp = fopen(fileName, "rb");
    if (pWaveInfo->fp == NULL)
    {
        printf("fopen fail, errno:%d
", errno);
        return;
    }
    #if 0
    retSize = fread((char *)&pWaveInfo->riffChunk, sizeof(WAVE_RIFF), 1, pWaveInfo->fp);
    retSize = fread((char *)&pWaveInfo->fmtChunk, sizeof(WAVE_FMT), 1, pWaveInfo->fp);
    retSize = fread((char *)&pWaveInfo->dataChunk, sizeof(WAVE_DATA), 1, pWaveInfo->fp);
    #endif
    rwRiffChunk(pWaveInfo, 1);
    rwFmtChunk(pWaveInfo, 1);
    rwDataChunk(pWaveInfo, 1);
    pWaveInfo->pos = ftell(pWaveInfo->fp);
    pWaveInfo->totalSampleNum = pWaveInfo->dataChunk.chunkSize / (pWaveInfo->fmtChunk.bitsPerSample / 8);
    fclose(pWaveInfo->fp);
    printWaveHeader(pWaveInfo);
}

void initPpBuf(unsigned short chNum, unsigned short bankNum, unsigned long samplesPerBank, unsigned short bytesPerSample)
{
    unsigned short chIdx, bankIdx;
    gPpBuf.chNum = chNum;    
    gPpBuf.bankNum = bankNum;    
    gPpBuf.samplesPerBank = samplesPerBank;
    gPpBuf.bytesPerSample = bytesPerSample;

    gPpBuf.bankRp = gPpBuf.bankWp = 0;
    gPpBuf.fgEos = 0;
    gPpBuf.pData = (unsigned char ***)malloc(chNum * sizeof(unsigned char **));
    for (chIdx = 0; chIdx < chNum; chIdx++)
    {
        gPpBuf.pData[chIdx] = (unsigned char **)malloc(bankNum * sizeof(unsigned char *));
        for (bankIdx =0; bankIdx < bankNum; bankIdx++)
        {
            gPpBuf.pData[chIdx][bankIdx] = (unsigned char *) malloc(samplesPerBank * bytesPerSample * sizeof(unsigned char));
        }
    }
}

int sendData(unsigned char *writeBuffer, unsigned short chNum)
{
    unsigned short sampleIdx, chIdx, byteIdx;
    //printf("sendData, wp:%d, rp:%d
", gPpBuf.bankWp, gPpBuf.bankRp);
    if ((gPpBuf.bankWp + 1 ) % gPpBuf.bankNum == gPpBuf.bankRp)
    {
        //full
        return 1;
    }
    else
    {
        for (sampleIdx = 0; sampleIdx < PP_SAMPLES; sampleIdx++)
        {
            for (chIdx =0; chIdx < chNum; chIdx++)
            {
                for (byteIdx = 0; byteIdx < gPpBuf.bytesPerSample; byteIdx++)
                {
               gPpBuf.pData[chIdx][gPpBuf.bankWp][sampleIdx * gPpBuf.bytesPerSample + byteIdx] = writeBuffer[(chIdx + sampleIdx * chNum) * gPpBuf.bytesPerSample + byteIdx];  
          }
            }
        }
        gPpBuf.bankWp = (gPpBuf.bankWp + 1) % gPpBuf.bankNum;
    }
    return 0;
}

int recvData(unsigned char **readBuffer)
{
    unsigned short chIdx;
    //printf("recvData, wp:%d, rp:%d
", gPpBuf.bankWp, gPpBuf.bankRp);
    if (gPpBuf.bankWp == gPpBuf.bankRp)
    {
        //empty
        return 1;
    }
    else
    {
        for (chIdx = 0; chIdx < gPpBuf.chNum; chIdx++)
        {
            memcpy(&readBuffer[chIdx][0], &gPpBuf.pData[chIdx][gPpBuf.bankRp][0], PP_SAMPLES * gPpBuf.bytesPerSample * sizeof(unsigned char));
        }
        gPpBuf.bankRp = (gPpBuf.bankRp + 1) % gPpBuf.bankNum;
    }
    return 0;
}
void *readThread(void *arg)
{
    char *fileName = (char *)arg;
    size_t retSize;
    WAVE_INFO waveInfo;
    memset(&waveInfo, 0, sizeof(WAVE_INFO));
    unsigned long bytesPerLoop;
    unsigned short loopIdx, loop;
    unsigned long readCount = 0;
    readWaveHeader(fileName, &waveInfo);
    unsigned long readSize = READ_SAMPLES * waveInfo.fmtChunk.chNum * waveInfo.fmtChunk.bitsPerSample / 8;
    printf("readSize:%ld
", readSize);
    unsigned char *readBuffer = (unsigned char *)malloc(readSize * sizeof(unsigned char));
    waveInfo.fp = fopen(fileName, "rb");
    fseek(waveInfo.fp,  waveInfo.pos, SEEK_SET);
    while (1)
    {
        retSize = fread(readBuffer, readSize, 1, waveInfo.fp);
        if (retSize <= 0)
        {
             printf("fread fail,retSize:%d, %s, eof:%d, readCount:%ld
", (int) retSize, strerror(errno), feof(waveInfo.fp), readCount);
             gPpBuf.fgEos = 1;
             break;
        }
        else
        {
             bytesPerLoop = PP_SAMPLES *waveInfo.fmtChunk.chNum * waveInfo.fmtChunk.bitsPerSample / 8;
             loop = readSize / bytesPerLoop;
             loopIdx = 0;
             while (loopIdx < loop)
             {
                 if (0 != sendData(readBuffer + loopIdx * bytesPerLoop, waveInfo.fmtChunk.chNum))
                 {
                     usleep(1000);
                 }
                 else
                 {
                     loopIdx++;
                 }
             }
             readCount++; 
        }
    }
    return NULL;
}
void pp(DATA_INFO_T *pDataInfo)
{
    fader(&gFaderHandle, pDataInfo);
}

void saveOneChInWave(unsigned char *pData, unsigned long size, WAVE_INFO *pWaveInfo)
{
   size_t retSize = 0;
   if (pWaveInfo->fp == NULL)
   {
       pWaveInfo->fp = fopen(pWaveInfo->fileName, "wb");
       #if 0
       retSize = fwrite((char *)&pWaveInfo->riffChunk, sizeof(WAVE_RIFF), 1, pWaveInfo->fp);
       retSize = fwrite((char *)&pWaveInfo->fmtChunk, sizeof(WAVE_FMT), 1, pWaveInfo->fp);
        retSize = fwrite((char *)&pWaveInfo->dataChunk, sizeof(WAVE_DATA), 1, pWaveInfo->fp);
        #endif
        rwRiffChunk(pWaveInfo, 0);
        rwFmtChunk(pWaveInfo, 0);
        rwDataChunk(pWaveInfo, 0);   
    } 
    retSize = fwrite(pData, size, 1, pWaveInfo->fp);
    pWaveInfo->totalSampleNum += (size / pWaveInfo->fmtChunk.chNum / (pWaveInfo->fmtChunk.bitsPerSample / 8));
    pWaveInfo->pos = ftell(pWaveInfo->fp);
}

void updateWaveHeader(WAVE_INFO *pWaveInfo)
{
    size_t retSize;
    pWaveInfo->riffChunk.chunkSize = pWaveInfo->pos - 8;
    pWaveInfo->dataChunk.chunkSize = pWaveInfo->totalSampleNum * pWaveInfo->fmtChunk.chNum * pWaveInfo->fmtChunk.bitsPerSample / 8;
    fseek(pWaveInfo->fp,  0, SEEK_SET);
    #if 0
    retSize = fwrite((char *)&pWaveInfo->riffChunk, sizeof(WAVE_RIFF), 1, pWaveInfo->fp);
    retSize = fwrite((char *)&pWaveInfo->fmtChunk, sizeof(WAVE_FMT), 1, pWaveInfo->fp);
    retSize = fwrite((char *)&pWaveInfo->dataChunk, sizeof(WAVE_DATA), 1, pWaveInfo->fp);
    #endif    
    rwRiffChunk(pWaveInfo, 0);
    rwFmtChunk(pWaveInfo, 0);
    rwDataChunk(pWaveInfo, 0);   
    fclose(pWaveInfo->fp);
    
    printWaveHeader(pWaveInfo);
}
void *ppThread(void *arg)
{
    char *fileName = (char *)arg;
    WAVE_INFO waveInfo;
    memset(&waveInfo, 0, sizeof(waveInfo));
    strncpy(waveInfo.fileName, fileName, strlen(fileName));
    printf("out file:%s
", waveInfo.fileName);
    waveInfo.fp = NULL;
    initWaveInfo(&waveInfo, 1, 48000, 16);
    unsigned char **readBuffer = (unsigned char **)malloc(gPpBuf.chNum * sizeof(unsigned char *));
    unsigned short chIdx;
    for(chIdx = 0; chIdx < gPpBuf.chNum; chIdx++)
    {
        readBuffer[chIdx] = (unsigned char *)malloc(PP_SAMPLES * gPpBuf.bytesPerSample * sizeof(unsigned char));
    }
    while (1)
    {
        if (0 != recvData(readBuffer))
        {
            if (gPpBuf.fgEos)
                break;
            usleep(1000);
        }
        else
        {
            DATA_INFO_T dataInfo;
            dataInfo.chNum = gPpBuf.chNum;
            dataInfo.samples = PP_SAMPLES;
            dataInfo.bytesPerSample = gPpBuf.bytesPerSample;
            dataInfo.pData = (short **)readBuffer;
            pp(&dataInfo);
            saveOneChInWave(readBuffer[0], PP_SAMPLES * gPpBuf.bytesPerSample, &waveInfo);
        }
    }
    updateWaveHeader(&waveInfo);
    fgEnd = 1;
}

int main(int argc, char **argv)
{
#if 0
    WAVE_INFO inputWaveInfo, outputWaveInfo;
    readWaveHeader(argv[1], &inputWaveInfo);
    //initWaveInfo(&outputWaveInfo, 2, 48000, 16);
#endif
    
#if 1
    pthread_t readThreadId, ppThreadId;
    initPpBuf(6, 3, PP_SAMPLES, 2);
    memset(&gFaderHandle, 0, sizeof(FADER_HANDLE_T));
    float curVolumDb = -96;
    float attuationDb = 96;
    FADER_TYPE_E type = FADER_TYPE_LINE;
    unsigned long timeMs = 5000;
    unsigned long sampleRate = 48000;
    faderInit(&gFaderHandle, attuationDb, type, timeMs, sampleRate, curVolumDb);
    pthread_create(&readThreadId, NULL, readThread, argv[1]);
    pthread_create(&ppThreadId, NULL, ppThread, argv[2]);
    while(!fgEnd)
    {
        sleep(1);
    }
#endif
    return 0;
}