[FFmpeg-devel] [PATCH] Bluray Subtitle Support, v7 (Updated patch to v12)

[Reimar Döffinger]

On Wed, Aug 26, 2009 at 06:36:01PM +0200, Michael Niedermayer wrote:
> On Wed, Aug 26, 2009 at 01:34:45PM +0200, Reimar D?ffinger wrote:
> > No, you need this patch, but Michael will have to comment on what is the
> > right approach (it disables empty packets for timestamp encoding for
> > subtitles, which causes the massive size increase):
> 
> "the right approuch" is what is written in the spec in question about
> the specific subtitle format
> 
> if subtitles are placed in more than a single packet a timebase and likely
> dummy 0 packets are needed in avi. But as said the question is how should
> the correct avi file look like ...

There should be a subtitle packet approximately correctly interleaved,
and no empty subtitle packets.
In avi, the subtitle contains the display time as absolute values,
so the pts value it gets on demuxing is not relevant (this part is admittedly
ugly and might cause some issues when remuxing, editing or whatever -
but essentially that's out of our hands).
For official files, we get the message "[avi @ 0x2231a60]scale/rate is
0/0 which is invalid.", so scale and rate are set to 0 (though even if
we do that, we sure should not set the internal time_base to 0/0 as the
current code tries to do, that opens a far to big can of worms!).
Note that I think this would cause some serious issues for
non-interleaved files, but I'd just consider interleaved files with
XSUB subtitles invalid (I don't think they are valid actually).