- 1 year ago
Media foundation: Writing G711 PCMU to mp4
To write G711 PCMU audio data to an MP4 file using Media Foundation in C++, you'll need to perform the following steps:
Initialize the Media Foundation framework using
MFStartup
function.Create a media sink for the MP4 file using
MFCreateSinkWriterFromURL
function.Configure the media sink writer with the desired output file format and encoding settings. Set the output media type to
MFAudioFormat_PCM
and configure the audio properties such as sample rate, channel count, and bit depth.Create a media sample using
MFCreateSample
function and allocate a buffer for the audio data usingMFCreateMemoryBuffer
function.Fill the audio buffer with the G711 PCMU audio data.
Set the audio buffer in the media sample using
IMFSample::AddBuffer
method.Set the sample duration, timestamp, and sample attribute in the media sample.
Write the media sample to the media sink writer using
IMFSinkWriter::WriteSample
method.Repeat steps 4 to 8 for each audio sample you want to write.
Finalize and close the media sink writer using
IMFSinkWriter::Finalize
andIMFSinkWriter::Close
methods.Shutdown the Media Foundation framework using
MFShutdown
function.
Here's an example code snippet demonstrating the basic process:
cpp#include <windows.h>
#include <mfapi.h>
#include <mfidl.h>
#include <mfreadwrite.h>
HRESULT WriteG711PCMUtoMP4(const WCHAR* outputFilePath, const BYTE* audioData, DWORD dataSize, DWORD sampleRate, DWORD channelCount, DWORD bitsPerSample) {
HRESULT hr = S_OK;
// Initialize Media Foundation
hr = MFStartup(MF_VERSION);
if (FAILED(hr)) {
return hr;
}
// Create media sink writer for MP4 file
IMFSinkWriter* pSinkWriter = nullptr;
hr = MFCreateSinkWriterFromURL(outputFilePath, nullptr, nullptr, &pSinkWriter);
if (FAILED(hr)) {
MFShutdown();
return hr;
}
// Configure audio output format
IMFMediaType* pMediaTypeOut = nullptr;
hr = MFCreateMediaType(&pMediaTypeOut);
if (SUCCEEDED(hr)) {
hr = pMediaTypeOut->SetGUID(MF_MT_MAJOR_TYPE, MFMediaType_Audio);
if (SUCCEEDED(hr)) {
hr = pMediaTypeOut->SetGUID(MF_MT_SUBTYPE, MFAudioFormat_PCM);
}
if (SUCCEEDED(hr)) {
hr = pMediaTypeOut->SetUINT32(MF_MT_AUDIO_SAMPLES_PER_SECOND, sampleRate);
}
if (SUCCEEDED(hr)) {
hr = pMediaTypeOut->SetUINT32(MF_MT_AUDIO_NUM_CHANNELS, channelCount);
}
if (SUCCEEDED(hr)) {
hr = pMediaTypeOut->SetUINT32(MF_MT_AUDIO_BITS_PER_SAMPLE, bitsPerSample);
}
if (SUCCEEDED(hr)) {
hr = pSinkWriter->AddStream(pMediaTypeOut, nullptr);
}
}
// Start writing process
if (SUCCEEDED(hr)) {
hr = pSinkWriter->BeginWriting();
}
// Create media sample and buffer for audio data
IMFSample* pSample = nullptr;
IMFMediaBuffer* pBuffer = nullptr;
hr = MFCreateSample(&pSample);
if (SUCCEEDED(hr)) {
hr = MFCreateMemoryBuffer(dataSize, &pBuffer);
}
if (SUCCEEDED(hr)) {
hr = pSample->AddBuffer(pBuffer