/// <summary>
/// Creates a memory buffer of the specified size
/// </summary>
/// <param name="bufferSize">Memory buffer size in bytes</param>
/// <returns>The memory buffer</returns>
public static IMFMediaBuffer CreateMemoryBuffer(int bufferSize)
{
IMFMediaBuffer buffer;
MediaFoundationInterop.MFCreateMemoryBuffer(bufferSize, out buffer);
return(buffer);
}
/// <summary>
/// Initialize the MediaFoundationProvider with specific file.
/// </summary>
public MediaFoundationProvider(string url)
{
MediaFoundationApi.Startup();
if (!File.Exists(url))
{
throw new FileNotFoundException("This file doesn't exist");
}
MediaFoundationInterop.MFCreateSourceResolver(out IMFSourceResolver resolver);
//Creates both IMFMediaSource and IMFByteStream.Uses the stream for 'Read' method and uses the source to collect format information.
resolver.CreateObjectFromURL(url, SourceResolverFlags.MF_RESOLUTION_BYTESTREAM | SourceResolverFlags.MF_RESOLUTION_CONTENT_DOES_NOT_HAVE_TO_MATCH_EXTENSION_OR_MIME_TYPE, null, out _, out object _stream);
IMFByteStream byteStream = _stream as IMFByteStream;
resolver.CreateObjectFromByteStream(byteStream, null, SourceResolverFlags.MF_RESOLUTION_MEDIASOURCE | SourceResolverFlags.MF_RESOLUTION_CONTENT_DOES_NOT_HAVE_TO_MATCH_EXTENSION_OR_MIME_TYPE, null, out _, out object _source);
Marshal.FinalReleaseComObject(resolver);
IMFMediaSource source = _source as IMFMediaSource;
source.CreatePresentationDescriptor(out IMFPresentationDescriptor descriptor);
descriptor.GetStreamDescriptorCount(out uint sdcount);
for (uint i = 0; i < sdcount; i++)
{
descriptor.GetStreamDescriptorByIndex(i, out _, out IMFStreamDescriptor sd);
sd.GetMediaTypeHandler(out IMFMediaTypeHandler typeHandler);
typeHandler.GetMediaTypeByIndex(0, out IMFMediaType mediaType);
mediaType.GetMajorType(out Guid streamtype);
if (streamtype == MediaTypes.MFMediaType_Audio)
{
mediaType.GetUINT32(MediaFoundationAttributes.MF_MT_AUDIO_SAMPLES_PER_SECOND, out int rate);//SampleRate
mediaType.GetUINT32(MediaFoundationAttributes.MF_MT_AUDIO_NUM_CHANNELS, out int channelcount);
int samplesize;
try
{
mediaType.GetUINT32(MediaFoundationAttributes.MF_MT_AUDIO_BITS_PER_SAMPLE, out samplesize);
}
catch (COMException e)
{
if ((uint)e.HResult != 0xC00D36E6)
{
throw e;
}
else
{
samplesize = 8;
}
}
WaveFormat = new WaveFormat(rate, samplesize, channelcount);
}
else
{
continue;
}
}
byteStream.GetLength(out streamlength);
byteStream.SetCurrentPosition(0);
//Moves all the bytes in IMFByteStream to MemoryStream.
MediaFoundationInterop.MFCreateMemoryBuffer(unchecked ((int)streamlength), out IMFMediaBuffer mediabuffer);
mediabuffer.Lock(out IntPtr pbuffer, out int length, out _);
byteStream.Read(pbuffer, length, out _);
byte[] buffer = new byte[length];
Marshal.Copy(pbuffer, buffer, 0, length);
datastream = new MemoryStream(buffer);
}