/// <summary>
/// Encodes a file
/// </summary>
/// <param name="outputFile">Output filename (container type is deduced from the filename)</param>
/// <param name="inputProvider">Input provider (should be PCM, some encoders will also allow IEEE float)</param>
public void Encode(string outputFile, IWaveProvider inputProvider)
{
if (inputProvider.WaveFormat.Encoding != WaveFormatEncoding.Pcm && inputProvider.WaveFormat.Encoding != WaveFormatEncoding.IeeeFloat)
{
throw new ArgumentException("Encode input format must be PCM or IEEE float");
}
var inputMediaType = new MediaType(inputProvider.WaveFormat);
var writer = CreateSinkWriter(outputFile);
try
{
int streamIndex;
writer.AddStream(outputMediaType.MediaFoundationObject, out streamIndex);
// n.b. can get 0xC00D36B4 - MF_E_INVALIDMEDIATYPE here
writer.SetInputMediaType(streamIndex, inputMediaType.MediaFoundationObject, null);
PerformEncode(writer, streamIndex, inputProvider);
}
finally
{
Marshal.ReleaseComObject(writer);
Marshal.ReleaseComObject(inputMediaType.MediaFoundationObject);
}
}
private WaveFormat GetCurrentWaveFormat(IMFSourceReader reader)
{
IMFMediaType uncompressedMediaType;
reader.GetCurrentMediaType(MediaFoundationInterop.MF_SOURCE_READER_FIRST_AUDIO_STREAM, out uncompressedMediaType);
// Two ways to query it, first is to ask for properties (second is to convert into WaveFormatEx using MFCreateWaveFormatExFromMFMediaType)
var outputMediaType = new MediaType(uncompressedMediaType);
Guid actualMajorType = outputMediaType.MajorType;
Debug.Assert(actualMajorType == MediaTypes.MFMediaType_Audio);
Guid audioSubType = outputMediaType.SubType;
int channels = outputMediaType.ChannelCount;
int bits = outputMediaType.BitsPerSample;
int sampleRate = outputMediaType.SampleRate;
return audioSubType == AudioSubtypes.MFAudioFormat_PCM
? new WaveFormat(sampleRate, bits, channels)
: WaveFormat.CreateIeeeFloatWaveFormat(sampleRate, channels);
}
/// <summary>
/// Creates a new encoder that encodes to the specified output media type
/// </summary>
/// <param name="outputMediaType">Desired output media type</param>
public MediaFoundationEncoder(MediaType outputMediaType)
{
if (outputMediaType == null) throw new ArgumentNullException("outputMediaType");
this.outputMediaType = outputMediaType;
}
/// <summary>
/// Creates the reader (overridable by )
/// </summary>
protected virtual IMFSourceReader CreateReader(MediaFoundationReaderSettings settings)
{
IMFSourceReader reader;
MediaFoundationInterop.MFCreateSourceReaderFromURL(file, null, out reader);
reader.SetStreamSelection(MediaFoundationInterop.MF_SOURCE_READER_ALL_STREAMS, false);
reader.SetStreamSelection(MediaFoundationInterop.MF_SOURCE_READER_FIRST_AUDIO_STREAM, true);
// Create a partial media type indicating that we want uncompressed PCM audio
var partialMediaType = new MediaType();
partialMediaType.MajorType = MediaTypes.MFMediaType_Audio;
partialMediaType.SubType = settings.RequestFloatOutput ? AudioSubtypes.MFAudioFormat_Float : AudioSubtypes.MFAudioFormat_PCM;
// set the media type
// can return MF_E_INVALIDMEDIATYPE if not supported
reader.SetCurrentMediaType(MediaFoundationInterop.MF_SOURCE_READER_FIRST_AUDIO_STREAM, IntPtr.Zero, partialMediaType.MediaFoundationObject);
return reader;
}
