[MPlayer-dev-eng] [PATCH] libass: fix parsing of tracks extracted from containers

[Uoti Urpala]

On Thu, 2008-09-11 at 00:31 +0200, Aurelien Jacobs wrote:
> Evgeniy Stepanov wrote:
> > I like this patch in general. If the demuxer is that intelligent, ReadOrder is 
> > not needed at all.
> 
> Good.
> I guess I will just apply it when I switch to lavf matroska demuxer by
> default again.

I'm not sure whether you read my reply your patch yet; there were at
least two things wrong with it.

> Hum... I have nothing against ReadOrder ! The only problem with ReadOrder
> is that it don't fit in spec compliant ASS, so I wasn't able to put it
> in. And as it's pretty much useless, that's not really a problem.

If you read the latest discussion even Michael seems to have accepted
that your "spec compliant" format may not be an optimal one.

> > If a container does not support packet durations, it's muxer can rebuild 
> > .ass format or whatever.
> 
> So virtually every muxer would need to rebuild .ass format (or anything
> containing display_duration) except matroska.
> On the other hand, when using standard .ass as an interchange format
> between muxers/demuxers/decoders, only matroska has to do some specific
> handling.

Currently the Matroska format can be muxed unmodified into at least one
container. Any other format can be muxed into zero. Even if the other
containers do not use the Matroska format that doesn't mean they'd all
use whatever other format you pick. So there's no guarantee that any
other format would result in less rebuilding, and at the moment it would
certainly result in more. A format that keeps the values in demuxer
packet fields without duplicating them in bitstream is better for
program architecture.