[MPlayer-dev-eng] Re: [PATCH] SSA/ASS subtitles support

[陆然]

Hi,

On Wednesday 05 July 2006 23:53, Evgeniy Stepanov wrote:
> You won't be able to get multicolored subtitles this way. It is better to
> write your own function using ass_read_subdata as an example.

No problem, It's could be a start point ;)


> Not exactly. New system adds events to ass_track as they are found in the
> stream and keeps them forever. The old system only keeps the latest event,
> which is clearly not enough with ssa.
>
> You can't extract _all_ subtitles in a file until it is completely demuxed.
> So you should allocate an ass_track for each mp4 subtitle track, and update
> it with subs coming from the demuxer. In matroska/ssa case it is
> implemented in ass_process_chunk() and ass_process_line().

So it's the limit of the container? Then MP4 is special I think, In MP4 the 
every track is completely indexed, in fact MPlayer already generated all the 
infomation needed to generate every subtitle (start time, offset in the 
file...). Audio & video track is well indexed too, thus when 
demux_fill_buffer is called, it simply fill the requied audio/video track, 
subtitle track will not be demuxed "by the way". That's why I prefer get 
subtitles in the open process. If there is too many subtitles the delay might 
be noticable in this approach though.

-- 
Best Regards,
LR