MediaFoundation: TimeStamp of first frame is not getting correctly set to 0. Instead, it is getting set as 0.0333 (frame duration)

Eswaramoorthy K 0 Reputation points
2024-11-11T10:46:09.8533333+00:00

I'm trying to read two frames, each individually stored in binary files named frame1.bin and frame2.bin, and create an MP4 video file called sample.mp4.

Here's what I'm doing:

I read a frame, associate it with its respective timestamp, and write it to the video file.

CComPtr<IMFMediaBuffer> mediaBuffer(createMediaBuffer(input));

// Create a media sample and add the buffer to the sample.
CComPtr<IMFSample> sample;
MFWRITER_RETURN_ON_ERROR(throwIf(MFCreateSample(&sample)));
MFWRITER_RETURN_ON_ERROR(throwIf(sample->AddBuffer(mediaBuffer)));

// Set the time stamp and the duration.
MFWRITER_RETURN_ON_ERROR(throwIf(sample->SetSampleTime(_frameStart)));
MFWRITER_RETURN_ON_ERROR(throwIf(sample->SetSampleDuration(_frameDuration)));

// Send the sample to the Sink Writer.
MFWRITER_RETURN_ON_ERROR(throwIf(_sinkWriter->WriteSample(_videoStreamIndex, sample)));

// Advance the starting position for the next frame
_frameStart += _frameDuration;

I create and set the properties of sinkWriter as below:

std::wstring wideFile = L"sample.mp4";
CComPtr<IMFMediaType> pMediaTypeOut, pMediaTypeIn;
MFWRITER_RETURN_HRESULT_ON_ERROR(MFCreateSinkWriterFromURL(wideFile.c_str(), NULL, NULL, &_sinkWriter));

// Set the output media type.
MFWRITER_RETURN_HRESULT_ON_ERROR(MFCreateMediaType(&pMediaTypeOut));
MFWRITER_RETURN_HRESULT_ON_ERROR(pMediaTypeOut->SetGUID(MF_MT_MAJOR_TYPE, MFMediaType_Video));
MFWRITER_RETURN_HRESULT_ON_ERROR(pMediaTypeOut->SetGUID(MF_MT_SUBTYPE, MFVideoFormat_H264));

MFWRITER_RETURN_HRESULT_ON_ERROR(pMediaTypeOut->SetUINT32(MF_MT_MPEG2_PROFILE, eAVEncH264VProfile_Main));

// Set the Bit rate.  NOTE this assumes the input data is natively 24 bits per pixel (8 per band, 3 bands)
MFWRITER_RETURN_HRESULT_ON_ERROR(pMediaTypeOut->SetUINT32(MF_MT_AVG_BITRATE, computeH264BitRate(_quality, width, height, _frameRate, 24)));

MFWRITER_RETURN_HRESULT_ON_ERROR(pMediaTypeOut->SetUINT32(MF_MT_INTERLACE_MODE, MFVideoInterlace_Progressive));

MFWRITER_RETURN_HRESULT_ON_ERROR(MFSetAttributeSize(pMediaTypeOut, MF_MT_FRAME_SIZE, width, height));

_frameDuration = static_cast<long long>(std::round((1.0 / _frameRate) * HUNDRED_NANOSECONDS));

// Derive the frame rate from 
UINT32 rateNumerator = 0, rateDenominator = 0;
MFWRITER_RETURN_HRESULT_ON_ERROR(MFAverageTimePerFrameToFrameRate(_frameDuration, &rateNumerator, &rateDenominator));

MFWRITER_RETURN_HRESULT_ON_ERROR(MFSetAttributeRatio(pMediaTypeOut, MF_MT_FRAME_RATE, rateNumerator, rateDenominator));

MFWRITER_RETURN_HRESULT_ON_ERROR(MFSetAttributeRatio(pMediaTypeOut, MF_MT_PIXEL_ASPECT_RATIO, 1, 1));
MFWRITER_RETURN_HRESULT_ON_ERROR(_sinkWriter->AddStream(pMediaTypeOut, &_videoStreamIndex));


// Set the input media type.
MFWRITER_RETURN_HRESULT_ON_ERROR(MFCreateMediaType(&pMediaTypeIn));
MFWRITER_RETURN_HRESULT_ON_ERROR(pMediaTypeIn->SetGUID(MF_MT_MAJOR_TYPE, MFMediaType_Video));
MFWRITER_RETURN_HRESULT_ON_ERROR(pMediaTypeIn->SetGUID(MF_MT_SUBTYPE, MFVideoFormat_YUY2));

MFWRITER_RETURN_HRESULT_ON_ERROR(pMediaTypeIn->SetUINT32(MF_MT_INTERLACE_MODE, MFVideoInterlace_Progressive));
MFWRITER_RETURN_HRESULT_ON_ERROR(MFSetAttributeSize(pMediaTypeIn, MF_MT_FRAME_SIZE, width, height));
MFWRITER_RETURN_HRESULT_ON_ERROR(MFSetAttributeRatio(pMediaTypeIn, MF_MT_FRAME_RATE, rateNumerator, rateDenominator));
MFWRITER_RETURN_HRESULT_ON_ERROR(MFSetAttributeRatio(pMediaTypeIn, MF_MT_PIXEL_ASPECT_RATIO, 1, 1));

MFWRITER_RETURN_HRESULT_ON_ERROR(_sinkWriter->SetInputMediaType(_videoStreamIndex, pMediaTypeIn, NULL));


_frameStart = 0;

// Tell the sink writer to start accepting data.
MFWRITER_RETURN_HRESULT_ON_ERROR(_sinkWriter->BeginWriting());

Issue I am facing:
The timestamp is starting at 0.0333 instead of 0, which seems to correspond to the frame duration value. I printed the _frameStart value before and after associating it with the sample using SetSampleTime, and it printed 0 in both cases, as expected. However, in the generated MP4 file, the timestamp of the first frame is 0.0333 instead of 0. I am unable to determine the cause of this issue.

C++
C++
A high-level, general-purpose programming language, created as an extension of the C programming language, that has object-oriented, generic, and functional features in addition to facilities for low-level memory manipulation.
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