[FFmpeg-devel] [Preview] MPEG-4 Subtitle support

[Philip Langdale]

Hi all,

I've been meaning to push my WIP to github for a while, and Clément
asked if I could, so here it is:

https://github.com/philipl/FFmpeg/tree/mov_text

Note a couple of things:

1) The hack to insert 'stop' packets for subtitles is very much a hack.
I know how to do it properly, as described in the commit description - I
just need to actually do it.

2) Obviously, the encoder and decoder are heavily based on the existing
SRT encoder and decoder. I will be stripping these down and removing
all the html styling bits when I can.

3) I don't intend to add support for proper timed text styling in the
initial pass. I haven't found a player that reads them, so it's
impossible to test, and to actually implement style encoding without
going insane, I'd need to make avio usable from avcodec - meaning
moving it to avutil and going through all the ABI breakage hassle that
would follow.

I've tested subtitle playback in mplayer and on an ipad so far.

--phil