how to mux video and audio into matroska (.mkv) format:
Get the program Graphedit. Make sure you have the directshow package installed (see first post). Have your encoded audio and video ready and start up graphedit. Go to Graph>Insert Filters>DirectShow Filters>Matroska Muxer and double click. A box saying "Matroska Muxer" will pop up in the background. Then go up to File Writer and double click. Pick a place to save whateveryouwanttonameit.mkv and hit save. The file writer will appear in the main window as well. Close the Filters window. Click on the Output pin of the matroska muxer and drag it down to the in of the file writer. The two should connect.
Now go to File>Render Media File. Open your video, and it will automatically connect to the first input pin of the matroska muxer. Do the same with your audio file.
The graph should now look something like this.
Now hit the little play button on the top and wait for it to finish. That's it, your file is ready.
For more information on matroska go to www.matroska.org


