Multiple input MFT in Microsoft Media Foundation

2
votes

I'm struggling with mixing two audio streams into single output stream. MFNode has an AudioMixerMFT but TopoEdit crashes when I try to build a topology like this & execute it:

enter image description here

Note: I tried TopoEdit that comes with Windows SDK 7.1 & also the one with few fixes by the author of "Developing Microsoft® Media Foundation Applications"

I thought it could be some issue with TopoEdit so I built the Topology in code (by modifying the code from Ch#9 of "Developing Microsoft® Media Foundation Applications") but it still failed with 'E_UNEXPECTED Catastrophic failure' on mediaEvent->GetStatus(&hrStatus) inside HRESULT CPlayer::ProcessEvent(CComPtr<IMFMediaEvent>& mediaEvent) on Session Start event.

Now at this point I thought it could be some issue with AudioMixerMFT so I wrote a Custom MFT with 2 inputs that acts like a simple pass-through (Only sends 1st input & ignores 2nd one). And I built a topology in TopoEdit like and it worked:

enter image description here

But when I connected 'Audio 2.wav' to MFT, it crashed. Now I tried to use this custom MFT in my own code & it worked again with single input but failed with 'E_UNEXPECTED Catastrophic failure' when applied two inputs.

Not sure what could be the problem, I started to doubt if multiple input MFT is supported, I came across a post http://social.msdn.microsoft.com/Forums/windowsdesktop/en-US/21596e11-c4e2-480a-b28f-9e2f5fa8820d/mutlinput-and-multioutput (yes it is quite old) that says it is not supported.

Is there anyone out there who was able to run AudioMixerMFT from MFNode successfully? Any alternates to Microsoft Media Foundation? or Any hint would be appreciated. Thanks

1
c++ms-media-foundation
Dual input MFTs and DMOs can work. DirectShow is the alternate option to MF. Dual input DMO will not work in DirectShow out of the box, but a custom DirectShow filter is capable of doing the job. - Roman R.
Thanks @RomanR. Could you please point me to some sample dual input MFT, if you know of any. And btw any guess on what could be wrong, an issue with TopoEdit or MFTs? - Zeeshan Ali
No sample code handy, sorry. You should be able to see connection issues on debugger (your MFT returning error codes in SetOutputType or othrewise before the error takes place). Most likely the problem is on your MFT, but question lacks details to guess it. Typically, dual input components are tricky to implement because they have to sync the streams, but you don't yet reach this point. - Roman R.

1 Answers

1
votes

MFNode is my open source project.

If you read the MFNode's documentation, you will see that TopoEdit does not handle more than one inputstream in a MFT. And yes TopoEdit crashes. You can fix the bug in TopoEdit source code. It is just a null pointer that TopoEdit does not checked. But unfortunatly, it does not solve the problem. TopoEdit is not able to call ProcessInput twice on the two input streams, before calling ProcessOutput.

You have to provide a custom media session to make it work (implement IMFMediaSession).

In a next update of MFNode Project, i will provide a player to use all the MFNode, and especially the MFNode Audio Mixer.

EDIT: in tededit.cpp, TopoEdit crashes at CTedEditorVisualObjectEventHandler::NotifyObjectDeleted :

... CTedTopologyNode* pNode = m_pEditor->FindNode(pConn->GetOutputNodeID()); ...

pNode can be null pointer and TopoEdit does not check.

EDIT

I've updated my project. Check MFNodePlayer. I use a custom MediaSession to handle the wave mixer topology.

It works well but it is not perfect because of two things. If you stop the topo and then replay, it fails (because i must stop all source, and perhaps reset the time clock and bytestream). Second, there is a function wich handles IMFTransform in a recursive way. It is hard to debug.

I will fix later.

PS : Special thanks to "Developing Microsoft Media Foundation Applications" book. It helps me a lot to create a custom MediaSession.