/// +=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=+=
/// <summary>
/// Opens prepares the media session and topology and opens the media source
/// and media sink.
///
/// Once the session and topology are setup, a MESessionTopologySet event
/// will be triggered in the callback handler. After that the events there
/// trigger other events and everything rolls along automatically.
/// </summary>
/// <param name="sourceFileName">the source file name</param>
/// <param name="outputFileName">the name of the output file</param>
/// <history>
/// 01 Nov 18 Cynic - Originally Written
/// </history>
public void PrepareSessionAndTopology(string sourceFileName, string outputFileName)
{
HResult hr;
IMFSourceResolver pSourceResolver = null;
IMFTopology pTopology = null;
IMFPresentationDescriptor sourcePresentationDescriptor = null;
int sourceStreamCount = 0;
IMFStreamDescriptor audioStreamDescriptor = null;
bool streamIsSelected = false;
IMFTopologyNode sourceAudioNode = null;
IMFTopologyNode outputSinkNode = null;
IMFMediaType currentAudioMediaType = null;
int audioStreamIndex = -1;
LogMessage("PrepareSessionAndTopology ");
// we sanity check the filenames - the existence of the path and if the file already exists
// should have been checked before this call
if ((sourceFileName == null) || (sourceFileName.Length == 0))
{
throw new Exception("PrepareSessionAndTopology: source file name is invalid. Cannot continue.");
}
if ((outputFileName == null) || (outputFileName.Length == 0))
{
throw new Exception("PrepareSessionAndTopology: output file name is invalid. Cannot continue.");
}
try
{
// reset everything
CloseAllMediaDevices();
// Create the media session.
hr = MFExtern.MFCreateMediaSession(null, out mediaSession);
if (hr != HResult.S_OK)
{
throw new Exception("PrepareSessionAndTopology call to MFExtern.MFCreateMediaSession failed. Err=" + hr.ToString());
}
if (mediaSession == null)
{
throw new Exception("PrepareSessionAndTopology call to MFExtern.MFCreateMediaSession failed. mediaSession == null");
}
// set up our media session call back handler.
mediaSessionAsyncCallbackHandler = new TantaAsyncCallbackHandler();
mediaSessionAsyncCallbackHandler.Initialize();
mediaSessionAsyncCallbackHandler.MediaSession = mediaSession;
mediaSessionAsyncCallbackHandler.MediaSessionAsyncCallBackError = HandleMediaSessionAsyncCallBackErrors;
mediaSessionAsyncCallbackHandler.MediaSessionAsyncCallBackEvent = HandleMediaSessionAsyncCallBackEvent;
// Register the callback handler with the session and tell it that events can
// start. This does not actually trigger an event it just lets the media session
// know that it can now send them if it wishes to do so.
hr = mediaSession.BeginGetEvent(mediaSessionAsyncCallbackHandler, null);
if (hr != HResult.S_OK)
{
throw new Exception("PrepareSessionAndTopology call to mediaSession.BeginGetEvent failed. Err=" + hr.ToString());
}
// Create a new topology. A topology describes a collection of media sources, sinks, and transforms that are
// connected in a certain order. These objects are represented within the topology by topology nodes,
// which expose the IMFTopologyNode interface. A topology describes the path of multimedia data through these nodes.
hr = MFExtern.MFCreateTopology(out pTopology);
if (hr != HResult.S_OK)
{
throw new Exception("PrepareSessionAndTopology call to MFExtern.MFCreateTopology failed. Err=" + hr.ToString());
}
if (pTopology == null)
{
throw new Exception("PrepareSessionAndTopology call to MFExtern.MFCreateTopology failed. pTopology == null");
}
// ####
// #### we now create the media source, this is an audio file
// ####
// use the file name to create the media source for the audio device. Media sources are objects that generate media data.
// For example, the data might come from a video file, a network stream, or a hardware device, such as a camera. Each
// media source contains one or more streams, and each stream delivers data of one type, such as audio or video.
mediaSource = TantaWMFUtils.GetMediaSourceFromFile(sourceFileName);
if (mediaSource == null)
{
throw new Exception("PrepareSessionAndTopology call to mediaSource == null");
}
// A presentation is a set of related media streams that share a common presentation time. We now get a copy of the media
// source's presentation descriptor. Applications can use the presentation descriptor to select streams
// and to get information about the source content.
hr = mediaSource.CreatePresentationDescriptor(out sourcePresentationDescriptor);
if (hr != HResult.S_OK)
{
throw new Exception("PrepareSessionAndTopology call to mediaSource.CreatePresentationDescriptor failed. Err=" + hr.ToString());
}
if (sourcePresentationDescriptor == null)
{
throw new Exception("PrepareSessionAndTopology call to mediaSource.CreatePresentationDescriptor failed. sourcePresentationDescriptor == null");
}
// Now we get the number of stream descriptors in the presentation. A presentation descriptor contains a list of one or more
// stream descriptors. These describe the streams in the presentation. Streams can be either selected or deselected. Only the
// selected streams produce data. Deselected streams are not active and do not produce any data.
hr = sourcePresentationDescriptor.GetStreamDescriptorCount(out sourceStreamCount);
if (hr != HResult.S_OK)
{
throw new Exception("PrepareSessionAndTopology call to sourcePresentationDescriptor.GetStreamDescriptorCount failed. Err=" + hr.ToString());
}
if (sourceStreamCount == 0)
{
throw new Exception("PrepareSessionAndTopology call to sourcePresentationDescriptor.GetStreamDescriptorCount failed. sourceStreamCount == 0");
}
// Look at each stream, there can be more than one stream here
// Usually only one is enabled. This app uses the first "selected"
// stream we come to which has the appropriate media type
for (int i = 0; i < sourceStreamCount; i++)
{
// we require the major type to be audio
Guid guidMajorType = TantaWMFUtils.GetMajorMediaTypeFromPresentationDescriptor(sourcePresentationDescriptor, i);
if (guidMajorType != MFMediaType.Audio)
{
continue;
}
// we also require the stream to be enabled
hr = sourcePresentationDescriptor.GetStreamDescriptorByIndex(i, out streamIsSelected, out audioStreamDescriptor);
if (hr != HResult.S_OK)
{
throw new Exception("PrepareSessionAndTopology call to sourcePresentationDescriptor.GetStreamDescriptorByIndex failed. Err=" + hr.ToString());
}
if (audioStreamDescriptor == null)
{
throw new Exception("PrepareSessionAndTopology call to sourcePresentationDescriptor.GetStreamDescriptorByIndex failed. audioStreamDescriptor == null");
}
// if the stream is selected, leave now we will release the audioStream descriptor later
if (streamIsSelected == true)
{
audioStreamIndex = i; // record this
break;
}
// release the one we are not using
if (audioStreamDescriptor != null)
{
Marshal.ReleaseComObject(audioStreamDescriptor);
audioStreamDescriptor = null;
}
audioStreamIndex = -1;
}
// by the time we get here we should have a audioStreamDescriptor if
// we do not, then we cannot proceed
if (audioStreamDescriptor == null)
{
throw new Exception("PrepareSessionAndTopology call to sourcePresentationDescriptor.GetStreamDescriptorByIndex failed. audioStreamDescriptor == null");
}
if (audioStreamIndex < 0)
{
throw new Exception("PrepareSessionAndTopology call to sourcePresentationDescriptor.GetStreamDescriptorByIndex failed. audioStreamIndex < 0");
}
// ####
// #### we now create the media sink, we need the type from the stream to do
// #### this which is why we wait until now to set it up
// ####
currentAudioMediaType = TantaWMFUtils.GetCurrentMediaTypeFromStreamDescriptor(audioStreamDescriptor);
if (currentAudioMediaType == null)
{
throw new Exception("PrepareSessionAndTopology call to currentAudioMediaType == null");
}
mediaSink = OpenMediaFileSink(outputFileName);
if (mediaSink == null)
{
throw new Exception("PrepareSessionAndTopology call to mediaSink == null");
}
// ####
// #### we now make up a topology branch for the audio stream
// ####
// Create a source node for this stream.
sourceAudioNode = TantaWMFUtils.CreateSourceNodeForStream(mediaSource, sourcePresentationDescriptor, audioStreamDescriptor);
if (sourceAudioNode == null)
{
throw new Exception("PrepareSessionAndTopology call to CreateSourceNodeForStream failed. pSourceNode == null");
}
// Create the output node - this is a file sink in this case.
outputSinkNode = TantaWMFUtils.CreateSinkNodeForStream(mediaSink);
if (outputSinkNode == null)
{
throw new Exception("PrepareSessionAndTopology call to CreateOutputNodeForStream failed. outputSinkNode == null");
}
// Add the nodes to the topology. First the source
hr = pTopology.AddNode(sourceAudioNode);
if (hr != HResult.S_OK)
{
throw new Exception("PrepareSessionAndTopology call to pTopology.AddNode(sourceAudioNode) failed. Err=" + hr.ToString());
}
// then add the output
hr = pTopology.AddNode(outputSinkNode);
if (hr != HResult.S_OK)
{
throw new Exception("PrepareSessionAndTopology call to pTopology.AddNode(outputSinkNode) failed. Err=" + hr.ToString());
}
// Connect the output stream from the source node to the input stream of the output node. The parameters are:
// dwOutputIndex - Zero-based index of the output stream on this node.
// *pDownstreamNode - Pointer to the IMFTopologyNode interface of the node to connect to.
// dwInputIndexOnDownstreamNode - Zero-based index of the input stream on the other node.
hr = sourceAudioNode.ConnectOutput(0, outputSinkNode, 0);
if (hr != HResult.S_OK)
{
throw new Exception("PrepareSessionAndTopology call to pSourceNode.ConnectOutput failed. Err=" + hr.ToString());
}
// Set the topology on the media session.
// If SetTopology succeeds, the media session will queue an
// MESessionTopologySet event.
hr = mediaSession.SetTopology(0, pTopology);
MFError.ThrowExceptionForHR(hr);
// Release the topology
if (pTopology != null)
{
Marshal.ReleaseComObject(pTopology);
}
}
catch (Exception ex)
{
LogMessage("Error: " + ex.Message);
OISMessageBox(ex.Message);
}
finally
{
// Clean up
if (pSourceResolver != null)
{
Marshal.ReleaseComObject(pSourceResolver);
}
if (sourcePresentationDescriptor != null)
{
Marshal.ReleaseComObject(sourcePresentationDescriptor);
}
if (audioStreamDescriptor != null)
{
Marshal.ReleaseComObject(audioStreamDescriptor);
}
if (sourceAudioNode != null)
{
Marshal.ReleaseComObject(sourceAudioNode);
}
if (outputSinkNode != null)
{
Marshal.ReleaseComObject(outputSinkNode);
}
if (currentAudioMediaType != null)
{
Marshal.ReleaseComObject(currentAudioMediaType);
}
}
}