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

[Uoti Urpala]

On Mon, 2008-09-15 at 16:52 +0300, Ivan Kalvachev wrote:
> So the stuff I don't understand.
> 
> 1. Is "Block's timecode" the only PTS that this packet have?

Yes.

> 2. Why do we want the demuxer to mess with the string (aka, data, aka payload) instead of just passing it. In other words, why do we dump useful data?

I'm not 100% sure what you mean with this question. Do you mean why
Aurelien wants to convert the format from the one normally used by
Matroska? I think he wants to "standardize" on his own version of the
format and hopes to use a single internal format which doesn't need
conversions to/from containers that use his version (though currently no
container does and there's little evidence they would in the future).

> 3. If "Block's timecode" is stored in AVPacket.pts and "Block's duration" is stored in AVPacket.convergence_duration, doesn't that mean we have everything we need for muxing?

Aurelien's use of convergence_duration was mistaken and he should have
used another field (probably waited for a patch adding display_duration
to be applied); but yes, all the information should be available in the
packet fields, and having it in the bitstream is completely redundant
for an internal format.