[Originally Posted by Ledgem]
Winamp is perfectly capable of playing .mkv and .ogm, actually. By default, it's set to reject those filetypes. Here's how to enable support for it:

(Note that these instructions are for the Winamp 5 series; it may also work on Winamp versions 2 and 3, but I'm creating this guidelines based off of Winamp 5)
1. Access the Winamp Preferences (shortcut Ctrl+P)
2. Click on Plugins > Input. You should see a list of "Input plug-ins"; find "Nullsoft Directshow Decoder v#.## [in_dshow.dll]" and select it.
3. Click Configure. A box of file associations should appear. By default you should see these associations: MPG;MPEG;M2V;AVI;ASF;WMV
Simply add OGM and MKV to that list. Your new files association list should look like this:
MPG;MPEG;M2V;AVI;ASF;WMV;OGM;MKV

Hit OK, and exit the preferences. Winamp will no longer reject OGM and MKV files.

I haven't tried using Winamp to play h.264 encodes. Theoretically, if you have h.264 support on another player through something universal (such as CCCP) then you should be able to have playback of h.264 encodes in Winamp too.

+++

I've seen the problem before in Winamp except no matter what container VSFilter would not load (OGM or MKV). The "solution" I found was turning on autoloading VSFilter in Haali's Media Splitter settings.

[http://forum.doom9.org/archive/index.php/t-106539.html]