private IMFSample ReadFromSource()
{
// we always read a full second
int bytesRead = sourceProvider.Read(sourceBuffer, 0, sourceBuffer.Length);
if (bytesRead == 0)
{
return(null);
}
var mediaBuffer = MediaFoundationApi.CreateMemoryBuffer(bytesRead);
IntPtr pBuffer;
int maxLength, currentLength;
mediaBuffer.Lock(out pBuffer, out maxLength, out currentLength);
Marshal.Copy(sourceBuffer, 0, pBuffer, bytesRead);
mediaBuffer.Unlock();
mediaBuffer.SetCurrentLength(bytesRead);
var sample = MediaFoundationApi.CreateSample();
sample.AddBuffer(mediaBuffer);
// we'll set the time, I don't think it is needed for Resampler, but other MFTs might need it
sample.SetSampleTime(inputPosition);
long duration = BytesToNsPosition(bytesRead, sourceProvider.WaveFormat);
sample.SetSampleDuration(duration);
inputPosition += duration;
Marshal.ReleaseComObject(mediaBuffer);
return(sample);
}
/// <summary>
/// Attempts to read from the transform
/// Some useful info here:
/// http://msdn.microsoft.com/en-gb/library/windows/desktop/aa965264%28v=vs.85%29.aspx#process_data
/// </summary>
/// <returns></returns>
private int ReadFromTransform()
{
var outputDataBuffer = new MFT_OUTPUT_DATA_BUFFER[1];
// we have to create our own for
var sample = MediaFoundationApi.CreateSample();
var pBuffer = MediaFoundationApi.CreateMemoryBuffer(outputBuffer.Length);
sample.AddBuffer(pBuffer);
sample.SetSampleTime(outputPosition); // hopefully this is not needed
outputDataBuffer[0].pSample = sample;
_MFT_PROCESS_OUTPUT_STATUS status;
var hr = transform.ProcessOutput(_MFT_PROCESS_OUTPUT_FLAGS.None,
1, outputDataBuffer, out status);
if (hr == MediaFoundationErrors.MF_E_TRANSFORM_NEED_MORE_INPUT)
{
Marshal.ReleaseComObject(pBuffer);
Marshal.ReleaseComObject(sample);
// nothing to read
return(0);
}
else if (hr != 0)
{
Marshal.ThrowExceptionForHR(hr);
}
IMFMediaBuffer outputMediaBuffer;
outputDataBuffer[0].pSample.ConvertToContiguousBuffer(out outputMediaBuffer);
IntPtr pOutputBuffer;
int outputBufferLength;
int maxSize;
outputMediaBuffer.Lock(out pOutputBuffer, out maxSize, out outputBufferLength);
outputBuffer = BufferHelpers.Ensure(outputBuffer, outputBufferLength);
Marshal.Copy(pOutputBuffer, outputBuffer, 0, outputBufferLength);
outputBufferOffset = 0;
outputBufferCount = outputBufferLength;
outputMediaBuffer.Unlock();
outputPosition += BytesToNsPosition(outputBufferCount, WaveFormat); // hopefully not needed
Marshal.ReleaseComObject(pBuffer);
Marshal.ReleaseComObject(sample);
Marshal.ReleaseComObject(outputMediaBuffer);
return(outputBufferLength);
}
/// <summary>
/// Creates and wraps a new IMFMediaType object based on a WaveFormat
/// </summary>
/// <param name="waveFormat">WaveFormat</param>
public MediaType(WaveFormat waveFormat)
{
mediaType = MediaFoundationApi.CreateMediaTypeFromWaveFormat(waveFormat);
}
/// <summary>
/// Creates and wraps a new IMFMediaType object
/// </summary>
public MediaType()
{
mediaType = MediaFoundationApi.CreateMediaType();
}