I have such an implementation
void coAudioPlayerSampleGrabber::test(SoundDataType dataType,
unsigned char const * pData,
int64_t dataLen)
{
HeapSetInformation(NULL, HeapEnableTerminationOnCorruption, NULL, 0);
IMFSourceReader *pReader = NULL;
IMFByteStream * spByteStream = NULL;
HRESULT hr = S_OK;
// Initialize the COM library.
hr = CoInitializeEx(NULL, COINIT_APARTMENTTHREADED | COINIT_DISABLE_OLE1DDE);
// Initialize the Media Foundation platform.
if (SUCCEEDED(hr))
{
hr = MFStartup(MF_VERSION);
}
hr = MFCreateMFByteStreamOnStreamEx((IUnknown*)pData, &spByteStream);
if (FAILED(hr))
{
printf("Error MFCreateMFByteStreamOnStreamEx");
}
IMFAttributes * Atrr = NULL;
hr = MFCreateAttributes(&Atrr, 10);
if (FAILED(hr))
{
printf("Error MFCreateAttributes");
}
hr = Atrr->SetUINT32(MF_READWRITE_ENABLE_HARDWARE_TRANSFORMS, true);
if (FAILED(hr))
{
printf("Error Atrr->SetUINT32(MF_READWRITE_ENABLE_HARDWARE_TRANSFORMS, true)");
}
hr = MFCreateSourceReaderFromByteStream(spByteStream, Atrr, &pReader);
if (FAILED(hr))
{
printf("Error MFCreateSourceReaderFromByteStream");
}
if (FAILED(hr))
{
printf("Error opening input file");
}
IMFMediaType *pAudioType = NULL; // Represents the PCM audio format.
hr = ConfigureAudioStream(dataType, pReader, &pAudioType);
if (FAILED(hr))
{
printf("Error ConfigureAudioStream");
}
IMFSample *pSample = NULL;
IMFMediaBuffer *pBuffer = NULL;
BYTE *pAudioData = NULL;
DWORD cbBuffer = 0;
std::vector<SampleData> samples_vec;
while (true)
{
DWORD dwFlags = 0;
hr = pReader->ReadSample((DWORD)MF_SOURCE_READER_FIRST_AUDIO_STREAM, 0, NULL, &dwFlags, NULL, &pSample);
if (FAILED(hr)) { break; }
if (dwFlags & MF_SOURCE_READERF_CURRENTMEDIATYPECHANGED)
{
printf("Type change - not supported by WAVE file format.\n");
break;
}
if (dwFlags & MF_SOURCE_READERF_ENDOFSTREAM)
{
printf("End of input file.\n");
break;
}
hr = pSample->ConvertToContiguousBuffer(&pBuffer);
if (FAILED(hr)) { break; }
hr = pBuffer->Lock(&pAudioData, NULL, &cbBuffer);
if (FAILED(hr)) { break; }
//Do something with the pAudioData which is an array of unsigned chars of lenth cbBuffer
SampleData tmp;
tmp.pAudioData = new byte[cbBuffer];
memcpy(tmp.pAudioData, pAudioData, cbBuffer);
tmp.cbBuffer = cbBuffer;
samples_vec.push_back(tmp);
// Unlock the buffer.
hr = pBuffer->Unlock();
pAudioData = NULL;
if (FAILED(hr)) { break; }
}
SafeRelease(&pReader);
SafeRelease(&pSample);
SafeRelease(&pBuffer);
SafeRelease(&spByteStream);
SafeRelease(&Atrr);
// Shut down Media Foundation.
MFShutdown();
CoUninitialize();
}
So as you can see I have pointer to data and size this is actually my data I need to decode it. Problem is that here
hr = MFCreateMFByteStreamOnStreamEx((IUnknown*)pData, &spByteStream);
I got an error access violation
and as far as I see this is because I try to convert pData
to IUnknown*
. Question is - How to convert it right?
You can't cut corners like this:
unsigned char const * pData;
...
hr = MFCreateMFByteStreamOnStreamEx((IUnknown*)pData, &spByteStream);
IUnknown
is not yet another fancy alias for a byte. You are supposed to literally supply interface pointer representing stream, as documented.
Media Foundation does offer you means to read from memory bytes. You need to create a create a real stream, IStream
or IRandomAccessStream
or IMFByteStream
per docuemntation. Also supply IMFAttributes
you created with proper attributes to specify data type (which otherwise in the case of a file are derived from extension or MIME type) and then Source Reader API would be able to process memory bytes as source of media file data, and suitable decoder would decode audio into PCM data (similar to this).
Something you can do real quick: CreateStreamOnHGlobal
to create IStream
implementation and copy your bytes into underlying buffer (see docs). Then MFCreateMFByteStreamOnStream
would create a IMFByteStream
wrappr over it, and you can use this wrapper as MFCreateSourceReaderFromByteStream
argument.