Now that we have specified an optimum order for all top level elements, we can look at the existing muxers to see which produce good and bad data.
mkvmerge produce good files. It's using the second part of the Meta Seek to define each Cluster entry. But it is putting Attachments at the front, which is not necesseraly good for streamed files (to avoid skipping over or reading a lot of unnecessary data like fonts).
FFmpeg both produce good files. It's using the second part of the Meta Seek to define each Cluster entry. Since it doesn't support Tags, Chapters and Attachments, it doesn't fail to place them in the optimum space...
Files created with the DivX Converter (libDivXMediaFormat 3.4.1.0004) has numerous issues:
When the same 6 MB file is remuxed with mvkmerge, it's 53 KB smaller. And it doesn't take in account the 4 KB of padding that mkvmerge is using for tag/chapters editing at the beginning of the file.
This article will be updated as we analyze more files or muxers are tuned to produce better files. This article was last updated on 2010-04-30