试着在RenderStream添加下这一段 //音频视频同步
    if CaptureGraph.QueryInterface(IID_IAMGraphStreams, pGS) = 0 then
    begin
      pGS.SyncUsingStreamOffset(TRUE);
      pGS := nil;
    end;
    IF multiplexer.QueryInterface(IID_IConfigAviMux,pConfigMux) = 0 then
    begin
      pConfigMux.SetMasterStream(1);
      pConfigMux := nil;
    end;    IF multiplexer.QueryInterface(IID_IConfigInterleaving,pinterleave) = 0 then
    begin
      pinterleave.put_Mode(INTERLEAVE_CAPTURE);
      pinterleave := nil;
    end;    //AudioSourceFilter.QueryInterface(IID_IAMBufferNegotiation, pNeg);
    FindInterface(nil, @MEDIATYPE_Audio, AudioSourceFilter as IBaseFilter, IID_IAMBufferNegotiation, pNeg);
    prop.cbBuffer := 4096;  // 此处为一帧音频数据的大小
    prop.cBuffers := 32;  // 设置缓冲区的帧数
    prop.cbAlign := 16;
    pNeg.SuggestAllocatorProperties(prop);