Racism? In MY Media Player? It’s More Likely Than You Think
Normally I am fairly lazy when it comes to muxing anything I encode, I have some shellscripts that do everything I need. After my CPU fiasco the other day, I have been rather edgy about what I do on my system, so a bunch of things I normally have open are being closed while I encode, with the encode being run in a screen session in case X dies on it due to RAM abuse or something. One thing I did was stop using my muxing script as well, although I don’t really see why anymore, I figure I had a reason at some stage. Yesterday, I used MKVMergeGUI (mmg) to mux an encode, and today, another. Because my script normally sets some things forcibly, it didn’t occur for me to double check it in mmg. This was when I found out the horrible truth: Several popular media player are racist against certain mimetypes.
Is there even a word for mimetype discrimination? I can’t think of one, but I’m sure Darkhold will if I cared to ask. Now, anyone who has experience with muxing fonts for soft subtitle styling will know that you have to be picky with what mimetype mkvmerge or whichever other muxer you choose to use writes in for each font. The works-for-everything mimetype is application/x-truetype-font, however by default, opentype fonts get written in as application/vnd.ms-opentype and some others get even stranger. From what my brief testing showed, MediaPlayer Classic – Home Cinema (MPC-HC) works correctly regardless. ZoomPlayer and MPlayer seem to break on that but are fine with the general application/x-font or application/x-truetype-font. VLC breaks on everything besides application/x-truetype-font, and it seems gstreamer based splitters/players will fallback to the font file extension to get it right, which is interesting as normally gstreamer Does It Wrong(tm).
I did find however that mplayer is able to link back into the system fonts if it cannot find what it needs. This made testing a bit annoying but once I had spoken to Greg, the lead libass developer, everyone became clear. So in summary, always mux your fonts as application/x-font to ensure it works correctly on all good players, even if they are discriminatory against your native mimetypes. Chances are I am the only one who would ever forget this anyway, but it’s always good to point things out to people who don’t know.
Bonus Points: Find my discriminatory comment in this post.
Comments
Leave a Reply