EasyPlayerPro Windows播放器进行本地对讲喊话音频采集功能实现

需求

在安防行业应用中，除了在本地看到摄像机的视频和进行音频监听外，还有一个重要的功能，那就是对讲. EasyPlayerPro-win为了减轻二次开发者的工作量，将本地音频采集也进行了集成；

功能特点

• 支持获取本地所有音频输入设备列表;
• 可任意选择任一音频输入设备;
• 可设置采样率和采样精度及位率;
• 可设置编码格式(当前支持G711A,G711U,AAC);

实现流程

1. 采用DirectSound8进行本地音频采集;
2. 将采集到的音频数据写入编码队列;
3. 在编码线程中获取源始音频数据，进行音频编码;
4. 编码完成后，将编码数据回调给上层应用;

    //获取声音采集设备列表
    int     GetAudioCaptureDeviceList(int *num, SOUND_CAPTURE_DEVICE_INFO **pDeviceInfo);


    int     OpenAudioCaptureDevice(int captureDeviceIndex);
    int     GetSupportWaveFormatList(int *num, WAVEFORMATEX **ppWaveFormatEx);
    int     StartCapture(int waveFormatExIndex, DirectSoundCaptureCallback callback, void *userptr);
    int     StopCapture();
    void    CloseAudioCaptureDevice();

    static LPTHREAD_START_ROUTINE __stdcall _lpDirectSoundCaptureThread ( LPVOID _pParam );

代码实现

    //开始采集音频
    int     DirectSoundCapturer::StartCapture(int waveFormatExIndex, DirectSoundCaptureCallback callback, void *userptr)
    {
    if (NULL == pSoundCaptureThread)        return -1;
    if (NULL == pSoundCaptureThread->pSupportWaveFormatEx)      return -1;

    if (waveFormatExIndex< 0 || waveFormatExIndex>=pSoundCaptureThread->supportWaveFormatExCount)   return -2;

    HRESULT hr = S_OK;

    WAVEFORMATEX *_wfxInput = (WAVEFORMATEX*)&pSoundCaptureThread->pSupportWaveFormatEx[waveFormatExIndex];

    memcpy(&pSoundCaptureThread->inWaveFormatEx, _wfxInput, sizeof(WAVEFORMATEX));

    DSCBUFFERDESC   dscbd;
    ZeroMemory( &dscbd, sizeof(DSCBUFFERDESC) );


    pSoundCaptureThread->dwNotifySize  = max( 1024, _wfxInput->nAvgBytesPerSec / 8 );
    pSoundCaptureThread->dwNotifySize -= pSoundCaptureThread->dwNotifySize % _wfxInput->nBlockAlign;
    pSoundCaptureThread->dwCaptureBufferSize = pSoundCaptureThread->dwNotifySize * 16;

    dscbd.dwSize        = sizeof(DSCBUFFERDESC);
    dscbd.dwBufferBytes = pSoundCaptureThread->dwCaptureBufferSize;
    dscbd.lpwfxFormat   = _wfxInput;
    hr = pSoundCaptureThread->lpDirectSoundCapture8->CreateCaptureBuffer( &dscbd, &pSoundCaptureThread->lpDSBCapture, NULL);

    if (FAILED(hr))                                 return -3;
    if (NULL == pSoundCaptureThread->lpDSBCapture)  return -4;

    pSoundCaptureThread->dwNextCaptureOffset = 0;

    hr = pSoundCaptureThread->lpDSBCapture->QueryInterface( IID_IDirectSoundNotify, (PVOID*)&pSoundCaptureThread->lpDSNotify );
    for( INT i = 0; i < 16; i++ ) 
    {
        pSoundCaptureThread->DSBPosNotify[i].dwOffset     = (pSoundCaptureThread->dwNotifySize * i) + pSoundCaptureThread->dwNotifySize - 1;
        pSoundCaptureThread->DSBPosNotify[i].hEventNotify = pSoundCaptureThread->hCaptureNotifyEvent;
    }
    hr = pSoundCaptureThread->lpDSNotify->SetNotificationPositions( 16, pSoundCaptureThread->DSBPosNotify);

    hr = pSoundCaptureThread->lpDSBCapture->Start( DSCBSTART_LOOPING );
    //m_fIsCapture = TRUE;

    if (SUCCEEDED(hr))
    {
        if (NULL == pSoundCaptureThread->hCaptureNotifyThread)
        {
            pSoundCaptureThread->flag = 0x01;
            pSoundCaptureThread->userPtr = this;
            pSoundCaptureThread->captureCallback = callback;
            pSoundCaptureThread->callbackUserPtr = userptr;
            pSoundCaptureThread->hCaptureNotifyThread = CreateThread(NULL, 0, (LPTHREAD_START_ROUTINE)_lpDirectSoundCaptureThread, 
                pSoundCaptureThread, 0, NULL);
            while (pSoundCaptureThread->flag!=0x02 && pSoundCaptureThread->flag!=0x00)  {Sleep(100);}
        }
    }

    return hr;
    }


    //获取源始音频数据
    int DirectSoundCapturer::ProcessCaptureData()
    {
    HRESULT hrRet = 0;
    LONG    lLockSize;

    if (NULL == pSoundCaptureThread)            return -1;
    if (pSoundCaptureThread->flag == 0x03)      return -1;
    if (NULL == pSoundCaptureThread->lpDSBCapture)  return -1;

    do {

        DWORD   dwCapturePos, dwReadPos;
        hrRet = pSoundCaptureThread->lpDSBCapture->GetCurrentPosition( &dwCapturePos, &dwReadPos );

        lLockSize = dwReadPos - pSoundCaptureThread->dwNextCaptureOffset;
        if( lLockSize < 0 ) lLockSize += pSoundCaptureThread->dwCaptureBufferSize;

        // Block align lock size so that we are always write on a boundary
        lLockSize -= (lLockSize % pSoundCaptureThread->dwNotifySize);
        if( lLockSize == 0 ) {
            hrRet = -1;
            break;
        }

        PVOID   pCapturedData[2]   = {NULL, NULL};
        DWORD   dwCaptureLength[2] = {0, 0};

        // Lock the capture buffer down
        hrRet = pSoundCaptureThread->lpDSBCapture->Lock( pSoundCaptureThread->dwNextCaptureOffset,
                                     lLockSize, 
                                     &pCapturedData[0],
                                     &dwCaptureLength[0],
                                     &pCapturedData[1],
                                     &dwCaptureLength[1], 0L );
        if( FAILED( hrRet ) ) {
            hrRet = -2;
            break;
        }

        if (NULL != pSoundCaptureThread->captureCallback)
        {
            pSoundCaptureThread->captureCallback(&pSoundCaptureThread->inWaveFormatEx, pSoundCaptureThread->callbackUserPtr,
                (unsigned char *)pCapturedData[0], (int)dwCaptureLength[0], (unsigned char *)pCapturedData[1], (int)dwCaptureLength[1]);
        }

        pSoundCaptureThread->dwNextCaptureOffset += dwCaptureLength[0];
        pSoundCaptureThread->dwNextCaptureOffset %= pSoundCaptureThread->dwCaptureBufferSize;       // Circular buffer

        if( pCapturedData[1] != NULL ) {
            pSoundCaptureThread->dwNextCaptureOffset += dwCaptureLength[1];
            pSoundCaptureThread->dwNextCaptureOffset %= pSoundCaptureThread->dwCaptureBufferSize; // Circular buffer
        }

        pSoundCaptureThread->lpDSBCapture->Unlock( pCapturedData[0], dwCaptureLength[0],
                               pCapturedData[1], dwCaptureLength[1] );
    } while(0);

    return hrRet;
    }

关于EasyPlayerPro播放器

EasyPlayerPro是一款全功能的流媒体播放器，支持RTSP、RTMP、HTTP、HLS、UDP、RTP、File等多种流媒体协议播放、支持本地文件播放，支持本地抓拍、本地录像、播放旋转、多屏播放、倍数播放等多种功能特性，核心基于ffmpeg，稳定、高效、可靠、可控，支持Windows、Android、iOS三个平台，目前在多家教育、安防、行业型公司，都得到的应用，广受好评！

EasyPlayerPro：https://github.com/EasyDSS/EasyPlayerPro

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