html5使用websocket发送(PCM)音频数据到服务器，再转在wav文件

PCM格式

 

 

通过websocket发送音频数据。 

    
    



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通过服务器来接收音频数据。这个时间可以以文件形式保存下来为.pcm就可以了。这里就使用工具来接收

 

 

最后生成pcm文件

 

 

保存好用.用Audacity工具来播放，看是不是正常的音频文件

 

 

播放正常。证明是个pcm的音频文件。得到了pcm（裸数据），我们可以做一个把pcm转成wav文件

 

#include 
#include 

/**
 * Convert PCM16LE raw data to WAVE format
 * @param pcmpath       Input PCM file.
 * @param channels      Channel number of PCM file.
 * @param sample_rate   Sample rate of PCM file.
 * @param wavepath      Output WAVE file.
 */
int simplest_pcm16le_to_wave(const char *pcmpath, int channels, int sample_rate, const char *wavepath)
{

    printf("#########################1111#############################\n");
    typedef struct WAVE_HEADER{
        char    fccID[4];       //内容为""RIFF
        unsigned long dwSize;   //最后填写，WAVE格式音频的大小
        char    fccType[4];     //内容为"WAVE"
    }WAVE_HEADER;

    typedef struct WAVE_FMT{
        char    fccID[4];          //内容为"fmt "
        unsigned long  dwSize;     //内容为WAVE_FMT占的字节数，为16
        unsigned short wFormatTag; //如果为PCM，改值为 1
        unsigned short wChannels;  //通道数，单通道=1，双通道=2
        unsigned long  dwSamplesPerSec;//采用频率
        unsigned long  dwAvgBytesPerSec;/* ==dwSamplesPerSec*wChannels*uiBitsPerSample/8 */
        unsigned short wBlockAlign;//==wChannels*uiBitsPerSample/8
        unsigned short uiBitsPerSample;//每个采样点的bit数，8bits=8, 16bits=16
    }WAVE_FMT;

    typedef struct WAVE_DATA{
        char    fccID[4];       //内容为"data"
        unsigned long dwSize;   //==NumSamples*wChannels*uiBitsPerSample/8
    }WAVE_DATA;

    if(channels==2 || sample_rate==0)
    {
        channels = 2;
        sample_rate = 44100;
    }
    int bits = 16;

    WAVE_HEADER pcmHEADER;
    WAVE_FMT    pcmFMT;
    WAVE_DATA   pcmDATA;

    unsigned short m_pcmData;
    FILE *fp, *fpout;
    printf("#########################2222#############################\n");
    fp = fopen(pcmpath, "rb+");
    if(fp==NULL)
    {
        printf("Open pcm file error.\n");
        return -1;
    }
    fpout = fopen(wavepath, "wb+");
    if(fpout==NULL)
    {
        printf("Create wav file error.\n");
        return -1;
    }
    printf("########################3333##############################\n");
    /* WAVE_HEADER */
    memcpy(pcmHEADER.fccID, "RIFF", strlen("RIFF"));
    memcpy(pcmHEADER.fccType, "WAVE", strlen("WAVE"));
    fseek(fpout, sizeof(WAVE_HEADER), 1);   //1=SEEK_CUR
    /* WAVE_FMT */
    memcpy(pcmFMT.fccID, "fmt ", strlen("fmt "));
    pcmFMT.dwSize = 16;
    pcmFMT.wFormatTag = 1;
    pcmFMT.wChannels = 2;
    pcmFMT.dwSamplesPerSec = sample_rate;
    pcmFMT.uiBitsPerSample = bits;
    /* ==dwSamplesPerSec*wChannels*uiBitsPerSample/8 */
    pcmFMT.dwAvgBytesPerSec = pcmFMT.dwSamplesPerSec*pcmFMT.wChannels*pcmFMT.uiBitsPerSample/8;
    /* ==wChannels*uiBitsPerSample/8 */
    pcmFMT.wBlockAlign = pcmFMT.wChannels*pcmFMT.uiBitsPerSample/8;

    printf("##################4444####################################\n");

    fwrite(&pcmFMT, sizeof(WAVE_FMT), 1, fpout);

    /* WAVE_DATA */
    memcpy(pcmDATA.fccID, "data", strlen("data"));
    pcmDATA.dwSize = 0;
    fseek(fpout, sizeof(WAVE_DATA), SEEK_CUR);
    printf("##################5555####################################\n");
    fread(&m_pcmData, sizeof(unsigned short), 1, fp);
    while(!feof(fp))
    {
        pcmDATA.dwSize += 2;
        fwrite(&m_pcmData, sizeof(unsigned short), 1, fpout);
        fread(&m_pcmData, sizeof(unsigned short), 1, fp);
    }
    printf("##################4444####################################\n");
    /*pcmHEADER.dwSize = 44 + pcmDATA.dwSize;*/
    //修改时间：2018年1月5日
    pcmHEADER.dwSize = 36 + pcmDATA.dwSize;

    rewind(fpout);
    fwrite(&pcmHEADER, sizeof(WAVE_HEADER), 1, fpout);
    fseek(fpout, sizeof(WAVE_FMT), SEEK_CUR);
    fwrite(&pcmDATA, sizeof(WAVE_DATA), 1, fpout);

    fclose(fp);
    fclose(fpout);
    printf("##################6666####################################\n");
    return 0;
}

int main()
{
    simplest_pcm16le_to_wave("E:\\project\\audio\\in.pcm", 2, 44100, "E:\\project\\audio\\out.wav");

    return 0;
}

 

再用Audacity播放out.wav文件，可正常播放。

涉及到音频领域。后面文章，再继讲如何把pcm转在g711a或是aac音频。