private HResult OpenMediaSource(IMFMediaSource pSource)
{
HResult hr = HResult.S_OK;
IMFAttributes pAttributes = null;
hr = MFExtern.MFCreateAttributes(out pAttributes, 2);
if (Succeeded(hr))
{
hr = pAttributes.SetUnknown(MFAttributesClsid.MF_SOURCE_READER_ASYNC_CALLBACK, this);
}
if (Succeeded(hr))
{
IMFSourceReader pReader;
hr = MFExtern.MFCreateSourceReaderFromMediaSource(
pSource,
pAttributes,
out pReader
);
m_pReader = (IMFSourceReaderAsync)pReader;
}
SafeRelease(pAttributes);
return(hr);
}
private void SetFormat(WaveFormat format)
{
source.CreatePresentationDescriptor(out IMFPresentationDescriptor descriptor);
descriptor.GetStreamDescriptorCount(out uint sdcount);
bool hasaudio = false;
for (uint i = 0; i < sdcount; i++)
{
descriptor.GetStreamDescriptorByIndex(i, out _, out IMFStreamDescriptor sd);
descriptor.SelectStream(i);
sd.GetMediaTypeHandler(out IMFMediaTypeHandler typeHandler);
typeHandler.GetMediaTypeByIndex(0, out IMFMediaType mediaType);
mediaType.GetMajorType(out Guid streamtype);
if (streamtype == MediaTypes.MFMediaType_Audio)
{
try
{
mediaType.SetUINT32(MediaFoundationAttributes.MF_MT_AUDIO_SAMPLES_PER_SECOND, format.SampleRate);//SampleRate
mediaType.SetUINT32(MediaFoundationAttributes.MF_MT_AUDIO_NUM_CHANNELS, format.Channels);
mediaType.SetUINT32(MediaFoundationAttributes.MF_MT_AUDIO_BITS_PER_SAMPLE, format.BitsPerSample);
mediaType.SetGUID(MediaFoundationAttributes.MF_MT_SUBTYPE, AudioSubtypes.MFAudioFormat_PCM);
}
catch (COMException)
{
throw new InvalidOperationException("Can't configure the source with specific format.");
}
hasaudio = true;
}
else
{
continue;
}
}
if (!hasaudio)
{
throw new ArgumentException("The device doesn't have audio stream.");
}
this.format = format;
IMFAttributes readerattr = MediaFoundationApi.CreateAttributes(2);
readerattr.SetUnknown(MediaFoundationAttributes.MF_SOURCE_READER_ASYNC_CALLBACK, callback);
MediaFoundationInterop.MFCreateSourceReaderFromMediaSource(source, readerattr, out IMFSourceReader _sourceReader);
sourceReader = _sourceReader as IMFSourceReader2;
}
//-------------------------------------------------------------------
// SetDevice
//
// Set up preview for a specified video capture device.
//-------------------------------------------------------------------
public HResult SetDevice(MFDevice pDevice)
{
HResult hr = HResult.S_OK;
IMFActivate pActivate = pDevice.Activator;
IMFMediaSource pSource = null;
IMFAttributes pAttributes = null;
object o = null;
lock (this)
{
try
{
// Release the current device, if any.
hr = CloseDevice();
if (Succeeded(hr))
{
// Create the media source for the device.
hr = pActivate.ActivateObject(typeof(IMFMediaSource).GUID, out o);
}
if (Succeeded(hr))
{
pSource = (IMFMediaSource)o;
}
// Get Symbolic device link
m_pwszSymbolicLink = pDevice.SymbolicName;
//
// Create the source reader.
//
// Create an attribute store to hold initialization settings.
if (Succeeded(hr))
{
hr = MFExtern.MFCreateAttributes(out pAttributes, 2);
}
if (Succeeded(hr))
{
hr = pAttributes.SetUINT32(MFAttributesClsid.MF_READWRITE_DISABLE_CONVERTERS, 1);
}
if (Succeeded(hr))
{
hr = pAttributes.SetUnknown(MFAttributesClsid.MF_SOURCE_READER_ASYNC_CALLBACK, this);
}
IMFSourceReader pRead = null;
if (Succeeded(hr))
{
hr = MFExtern.MFCreateSourceReaderFromMediaSource(pSource, pAttributes, out pRead);
}
if (Succeeded(hr))
{
m_pReader = (IMFSourceReaderAsync)pRead;
}
if (Succeeded(hr))
{
// Try to find a suitable output type.
for (int i = 0; ; i++)
{
IMFMediaType pType;
hr = m_pReader.GetNativeMediaType((int)MF_SOURCE_READER.FirstVideoStream, i, out pType);
if (Failed(hr))
{
break;
}
try
{
hr = TryMediaType(pType);
if (Succeeded(hr))
{
// Found an output type.
break;
}
}
finally
{
SafeRelease(pType);
}
}
}
if (Succeeded(hr))
{
// Ask for the first sample.
hr = m_pReader.ReadSample((int)MF_SOURCE_READER.FirstVideoStream, 0, IntPtr.Zero, IntPtr.Zero, IntPtr.Zero, IntPtr.Zero);
}
if (Failed(hr))
{
if (pSource != null)
{
pSource.Shutdown();
// NOTE: The source reader shuts down the media source
// by default, but we might not have gotten that far.
}
CloseDevice();
}
}
finally
{
SafeRelease(pSource);
SafeRelease(pAttributes);
}
}
return(hr);
}
public HResult SetUnknown(Guid guidKey, object pUnknown)
{
return(m_Attribs.SetUnknown(guidKey, pUnknown));
}
