What codecs does Matroska support?

[Wakaku]

Hello, I just want to ask what codecs are officially supported by the Matroska format to be safely contained. My goal is to remux all my videos of different formats into the MKV container, yet I found out myself that MKVToolNix could not allow some formats like WMV, but FFmpeg has no problems. My workaround is to first remux those formats using FFmpeg then remux again with MKVToolNix, as the resulting MKV files are smaller with MKVToolNix than FFmpeg.

I really favor Matroska over other containers. For example, its header and XML tags, smaller files, faster playback and seeking, embedding covers, images and other files, etc.

If anybody could create a list here or point me to an appropriate site or somewhere I would be grateful.

If not possible, kindly answer if the following codecs are safe to be contained within MKV or if it would be problematic in the future:
1. WMV, WMA
2. RealVideo, any related audio like Cooker (from RMVB)

Thanks in advance for any help.

[ndjamena]

https://www.matroska.org/technical/specs/codecid/index.html

That's not complete though. Real Video is listed, I'm pretty sure all WMV formats fall under V_MS/VFW/FOURCC, it's just that MKVMerge doesn't support the actual container, FFMPEG does but once it's in an MKV MKVToolNix should be fine with them (VC-1 is a Microsoft V_MS/VFW/FOURCC codec too, so all video taken from WMV should work identically to that Blu Ray codec with MKVToolNix).

[Marsia Mariner]

ndjamena is right, MKVmerge does not support the ASF container. Possibly because of Micro$oft themselves:

http://www.advogato.org/article/101.html

The few times I created Matroska files containing WMV and WMA, I used GraphStudio + Gabest's Matroska Muxer for generating intermediate MKV and MKA files, and only then I could use MKVmerge for the final remux.