Question

基本上，我有一个简洁的H.264字节流，采用I和P样本的形式。我可以使用MediaStreamSource和MediaElement播放这些样本，它们可以很好地播放。我还需要将它们保存为MP4文件，以便以后可以使用Media Element或VLC播放。这就是我尝试使用Media Foundation的方式; 我从MFCreateMPEG4MediaSink创建了一个IMFMediaSink;这是我的代码：

IMFMediaType *pMediaType = NULL;
IMFByteStream *pByteStream = NULL;
HRESULT hr = S_OK;
if (SUCCEEDED(hr))
{
    hr = MFCreateMediaType(&pMediaType);
}

pSeqHdr = reinterpret_cast<UINT8 *>(mSamplesQueue.SequenceHeader());
if (SUCCEEDED(hr))
{
    hr = pMediaType->SetBlob(MF_MT_MPEG_SEQUENCE_HEADER, pSeqHdr, 35);
}
UINT32 pcbBlobSize = {0};
hr = pMediaType->GetBlobSize(MF_MT_MPEG_SEQUENCE_HEADER, &pcbBlobSize);

/*if (SUCCEEDED(hr))
{
    hr = pMediaType->SetUINT32(MF_MPEG4SINK_SPSPPS_PASSTHROUGH, TRUE);
}*/
if (SUCCEEDED(hr))
{
    hr = pMediaType->SetGUID(MF_MT_MAJOR_TYPE, MFMediaType_Video);
}
if (SUCCEEDED(hr))
{
    hr = pMediaType->SetGUID(MF_MT_SUBTYPE, VIDEO_INPUT_FORMAT);
}
if (SUCCEEDED(hr))
{
    hr = MFSetAttributeRatio(pMediaType, MF_MT_FRAME_RATE, VIDEO_FPS, 1);
}
if (SUCCEEDED(hr))
{
    hr = pMediaType->SetUINT32(MF_MT_AVG_BITRATE, VIDEO_BIT_RATE);
}
if (SUCCEEDED(hr))
{
    hr = pMediaType->SetUINT32(MF_MT_INTERLACE_MODE, MFVideoInterlace_Progressive);
}
if (SUCCEEDED(hr))
{
    hr = MFSetAttributeSize(pMediaType, MF_MT_FRAME_SIZE, VIDEO_WIDTH, VIDEO_HEIGHT);
}
if (SUCCEEDED(hr))
{
    // Pixel aspect ratio
    hr = MFSetAttributeRatio(pMediaType, MF_MT_PIXEL_ASPECT_RATIO, 1, 1);
}
if (SUCCEEDED(hr))
{
    hr = MFCreateFile(
        MF_ACCESSMODE_READWRITE,
        MF_OPENMODE_DELETE_IF_EXIST,
        MF_FILEFLAGS_NONE,
        L"output1.mp4",
        &pByteStream);
}
if (SUCCEEDED(hr))
{
    hr = MFCreateMPEG4MediaSink(
        pByteStream,
        pMediaType,
        NULL,
        &pMediaSink);
}

然后我使用MFCreateSinkWriterFromMediaSink从此媒体接收器创建IMFSinkWriter;这是我的代码：

if (SUCCEEDED(hr))
{
    hr = MFCreateSinkWriterFromMediaSink(pMediaSink, NULL, &pSinkWriter);
}
// Tell the sink writer to start accepting data.
if (SUCCEEDED(hr))
{
    hr = pSinkWriter->BeginWriting();
}

if (SUCCEEDED(hr))
{
    pSinkWriter->AddRef();
}

然后我用IMFSinkWriter :: WriteSample（0，IMFSample）将每个样本写入接收器编写器;这是我的代码： IMFSample * pSample = NULL; IMFMediaBuffer * pBuffer = NULL;

const DWORD cbBuffer = mSamplesQueue.GetNextSampleSize();
UINT32 isIDR = mSamplesQueue.GetNextSampleIsIDR();
BYTE *pData = NULL;

// Create a new memory buffer.
HRESULT hr = MFCreateMemoryBuffer(cbBuffer, &pBuffer);

// Lock the buffer and copy the video frame to the buffer.
if (SUCCEEDED(hr))
{
    DWORD buffLen = cbBuffer;
    hr = pBuffer->Lock(&pData, &buffLen, 0);
}
if (SUCCEEDED(hr))
{
    hr = mSamplesQueue.Dequeu(&pData);
}
if (pBuffer)
{
    pBuffer->Unlock();
}

// Set the data length of the buffer.
if (SUCCEEDED(hr))
{
    hr = pBuffer->SetCurrentLength(cbBuffer);
}

// Create a media sample and add the buffer to the sample.
if (SUCCEEDED(hr))
{
    hr = MFCreateSample(&pSample);
}
if (SUCCEEDED(hr))
{
    hr = pSample->AddBuffer(pBuffer);
}

// Set the time stamp and the duration.
if (SUCCEEDED(hr))
{
    hr = pSample->SetSampleTime(rtStart);
}
if (SUCCEEDED(hr))
{
    hr = pSample->SetSampleDuration(rtDuration);
}
if (SUCCEEDED(hr))
{
    hr = pSample->SetUINT32(MFSampleExtension_CleanPoint, isIDR);
}
//pSample->
// Send the sample to the Sink Writer.
if (SUCCEEDED(hr))
{
    hr = pSinkWriter->WriteSample(0, pSample);
}

SafeRelease(&pSample);
SafeRelease(&pBuffer);

样本的编写是一个迭代代码，从我拥有的每个样本调用（我正在使用1k I和P样本进行测试）。现在，当我调用IMFSinkWriter :: Finalize（）时，它告诉我“0xc00d4a45：Sink无法创建有效的输出文件，因为未向接收器提供所需的标头。”。它确实创建了一个非常有效的MP4文件（对于我的1k样本，4.6 MB）。 This is the link to the trace from MFTrace. 如果它要求MF_MT_MPEG_SEQUENCE_HEADER，那么我用IMFMediaType :: SetBlob（MF_MT_MPEG_SEQUENCE_HEADER，BYTE []，UINT32）设置它们我用Elecard视频格式分析器检查了文件，标题似乎不完整。我可以帮助找出我缺少的东西，或者是否有更好的/其他方式来做我想要实现的目标？谢谢！

Answer 1

对我来说，问题是MF_MT_MPEG_SEQUENCE_HEADER blob的格式。

与dwSequenceHeader和H.264上的MSDN文档相比，SPS和PPS应该在前面加上起始码（0x00,0x00,0x01）而不是2字节长度字段。

http://msdn.microsoft.com/en-us/library/dd757808%28VS.85%29.aspx

Answer 2

不确定，但不应该：

hr = pMediaType->SetGUID(MF_MT_SUBTYPE, VIDEO_ENCODING_FORMAT);

而不是：

hr = pMediaType->SetGUID(MF_MT_SUBTYPE, VIDEO_INPUT_FORMAT);

使用媒体基础从h.264字节流创建MP4容器（附件B）？

2 个答案: