Winamp no doubt is one of the most used music players but unfortunately it doesn’t play some file formats like .MKV, .MP4, .RMVB, and .MOV. Here’s a tutorial to make WInamp play such files. Here’s how you do it:
First of all you need to make sure you have installed most of the necessary codec files. If you aren’t sure about it then I advise you to install the K-Lite Codec Pack. Also download and install QuickTime Alternative for playing quicktime videos.

Now start Winamp and go to Preferences> Plug-ins > Input and Select Nullsoft DirectShow Decoder in the right hand side and click “Configure” below.

By default, the DirectShow configuration for Winamp should look like above.

Extend the list by adding “;MP4;MKV;MOV;RMVB” (without the quotes). This option enables Winamp to play .MKV, .MP4, .RMVB and .MOV files using DirectShow filters. Once done click ‘OK’
That’s it, you should be able to play MKV, .MP4, .RMVB, .MOV Files in your favorite Winamp.
[via-tmsnetwork]
I am able to play my MKV files in winamp thanks to your post here. But I am unable to activate subtitles in winamp. In VLC media player I can right click the image and a subtitles option is in the menu. I went into the Video formating for the Direct show on Winamp using Alt+3 and found the key bindings. It says to use ‘S’ to toggle the subtitles but that isn’t working for me. Do you have any suggestions?
Thank you very much!
Before that,i even did’t know the
Nullsoft DirectShow Decoder can work it like that !
To Austin:
I kept hitting S to toggle the subtitles, and nothing happened. When I did this on my winamp, there were two little icons at the bottom of my screen in the taskbar. One was reddish and one was whiteish. The white one is where i could right click and select the subtitles that I would in VLC player. I did not notice the icons at first and it sadly took me a few hours to figure out what they were! It seemed to work fine but I don’t know if I was just lucky
cool tip thanks
but i would recommend to use FFdshow instead of installing codec packs
I always use to play all my favorite video mkv,mp4, rmvb and avi format in winamp in vista for 13 months now with no problem. Now im test install windows 7 (build 7100), format video mkv and mp4 cannot play correctly, i check video properties in winamp the filter use is microsoft DTV-DVD which located “msmpeg2adec.dll & msmpeg2vdc.dll”. I think my problem is conflict filter. I try to move that *.dll files to another folder, my winamp can play mkv and mp4 without any problem, but cannot play DVD anymore. Instead that i moved that *.dll files back to the original location to play dvds. I know windows 7 still under unreliable state yet. Any solution for avoid move the *.dll files? Thx in advance.