DivX Player supports MKV files using AAC audio. If you received an error message about AC3 audio, you can visit this FAQ If you received a message that you need a direct show filter, then your MKV audio is not supported. You can convert your audio into a supported format using the method below:
Download and install MediaInfo:http://downloads.sourceforge.net/mediainfo/MediaInfo_GUI_0.7.8_Windows_i386.exe
Drag and drop your video file into media info. Look at the "first video stream" and write down the FPS (frames per second) of your video.
Download and install MKV toolnix:
Then download MKV extract:
Unzip the file, and place the 4 files into C:\\Program Files\\MKVtoolnix
Download the free version of switch sound file converter:
go to C:\\Program Files\\MKVtoolnix and open MKVextractGUI.exe
drag your MKV file on to it. Select the video track, audio track, and your preferred output location and push the "extract button".
Open up Switch Sound File Converter.
Drag the exported audio file into this application. Choose your output folder, set the output format to .aac, and hit "convert".
go to C:\\Program Files\\MKVtoolnix and open mmg.exe
Drag and drop the video track you extracted and your new audio track into the application.
Select the video track and click on the "format specific options" tab. Put in the FPS that you wrote down at the start of this tutorial into the FPS input box.
Set the file name and output location. Make sure the extension of the file is '.mkv'. If it is .mks or .mka, change it to .mkv. Press the "start muxing" button.
Your new file is now ready to play in DivX Player.