directshow采集音视频，x264 lame 编码后，调用 ffmpeg 封装 MP4 音视频同步问题代码实现

首先，你需要使用 DirectShow 采集音视频数据，并使用 x264 和 LAME 进行编码。然后，你需要使用 FFmpeg 封装音视频数据为 MP4 文件。下面是一个简单的示例代码，展示如何实现音视频同步：

// 初始化 DirectShow 采集器
CoInitialize(NULL);
IGraphBuilder* pGraph = NULL;
IMediaControl* pControl = NULL;
ICaptureGraphBuilder2* pBuilder = NULL;
IBaseFilter* pAudioCaptureFilter = NULL;
IBaseFilter* pVideoCaptureFilter = NULL;
IBaseFilter* pAudioEncoderFilter = NULL;
IBaseFilter* pVideoEncoderFilter = NULL;
IBaseFilter* pMuxFilter = NULL;

CoCreateInstance(CLSID_FilterGraph, NULL, CLSCTX_INPROC_SERVER,
                 IID_IGraphBuilder, (void**)&pGraph);
CoCreateInstance(CLSID_CaptureGraphBuilder2, NULL, CLSCTX_INPROC_SERVER,
                 IID_ICaptureGraphBuilder2, (void**)&pBuilder);
pBuilder->SetFiltergraph(pGraph);

// 添加音频采集器和编码器
CoCreateInstance(CLSID_AudioCapture, NULL, CLSCTX_INPROC_SERVER,
                 IID_IBaseFilter, (void**)&pAudioCaptureFilter);
CoCreateInstance(CLSID_AudioEncoder, NULL, CLSCTX_INPROC_SERVER,
                 IID_IBaseFilter, (void**)&pAudioEncoderFilter);
pGraph->AddFilter(pAudioCaptureFilter, L"Audio Capture Filter");
pGraph->AddFilter(pAudioEncoderFilter, L"Audio Encoder Filter");

// 添加视频采集器和编码器
CoCreateInstance(CLSID_VideoCapture, NULL, CLSCTX_INPROC_SERVER,
                 IID_IBaseFilter, (void**)&pVideoCaptureFilter);
CoCreateInstance(CLSID_VideoEncoder, NULL, CLSCTX_INPROC_SERVER,
                 IID_IBaseFilter, (void**)&pVideoEncoderFilter);
pGraph->AddFilter(pVideoCaptureFilter, L"Video Capture Filter");
pGraph->AddFilter(pVideoEncoderFilter, L"Video Encoder Filter");

// 添加 MP4 封装器
CoCreateInstance(CLSID_MPEG4Muxer, NULL, CLSCTX_INPROC_SERVER,
                 IID_IBaseFilter, (void**)&pMuxFilter);
pGraph->AddFilter(pMuxFilter, L"MP4 Mux Filter");

// 连接音频采集器和编码器
IPin* pAudioCaptureOutPin = GetPin(pAudioCaptureFilter, PINDIR_OUTPUT);
IPin* pAudioEncoderInPin = GetPin(pAudioEncoderFilter, PINDIR_INPUT);
pGraph->Connect(pAudioCaptureOutPin, pAudioEncoderInPin);

// 连接视频采集器和编码器
IPin* pVideoCaptureOutPin = GetPin(pVideoCaptureFilter, PINDIR_OUTPUT);
IPin* pVideoEncoderInPin = GetPin(pVideoEncoderFilter, PINDIR_INPUT);
pGraph->Connect(pVideoCaptureOutPin, pVideoEncoderInPin);

// 连接音频编码器和 MP4 封装器
IPin* pAudioEncoderOutPin = GetPin(pAudioEncoderFilter, PINDIR_OUTPUT);
IPin* pMuxInAudioPin = GetPin(pMuxFilter, PINDIR_INPUT, MEDIATYPE_Audio);
pGraph->Connect(pAudioEncoderOutPin, pMuxInAudioPin);

// 连接视频编码器和 MP4 封装器
IPin* pVideoEncoderOutPin = GetPin(pVideoEncoderFilter, PINDIR_OUTPUT);
IPin* pMuxInVideoPin = GetPin(pMuxFilter, PINDIR_INPUT, MEDIATYPE_Video);
pGraph->Connect(pVideoEncoderOutPin, pMuxInVideoPin);

// 开始采集和编码
pControl->Run();

// 等待直到采集结束
while (true) {
  if (CheckCaptureEnded(pAudioCaptureFilter) && 
      CheckCaptureEnded(pVideoCaptureFilter)) {
    break;
  }
  Sleep(10);
}

// 停止采集和编码
pControl->Stop();

// 释放资源
pMuxFilter->Release();
pVideoEncoderFilter->Release();
pVideoCaptureFilter->Release();
pAudioEncoderFilter->Release();
pAudioCaptureFilter->Release();
pBuilder->Release();
pControl->Release();
pGraph->Release();
CoUninitialize();

在上面的代码中，我们使用 DirectShow 采集音频和视频数据，并将它们分别传递给音频和视频编码器进行编码。然后，我们将编码后的音频和视频数据传递给 MP4 封装器，将它们封装为 MP4 文件。在这个过程中，我们需要确保音频和视频数据的时间戳是同步的，以确保最终的 MP4 文件中的音视频是同步的。