[MPlayer-dev-eng] [PATCH] prefer lavf demuxer for Matroska files over the native one

[Uoti Urpala]

On Wed, 2008-03-19 at 19:13 +0300, Evgeniy Stepanov wrote:
> On Tuesday 18 March 2008 21:13:33 Uoti Urpala wrote:
> > How much have you tested it? The lavf demuxer has been tested much less
> > by users. Is there anything the lavf demuxer would do objectively better
> > than demux_mkv? IMO demux_mkv is one of the well working demuxers and
> > there's no hurry to switch away from it unless lavf supports more
> > features or has at least been thoroughly tested to work at least as
> > well.
> >
> > I quickly tested the lavf demuxer and the first file already showed a
> > missing subtitle at the start. There's also the common demux_lavf
> > problem that relative seeks that would go before the start of file fail
> > instead of seeking to the start. IMO demux_mkv is still the better
> > alternative.
> 
> It can switch to nosound :) Plus, it is one less demuxer to maintain in the 
> future.

We can worry about maintenance when demux_mkv will require significant
amounts of it.

> Sure, it does not justify breaking playback of some files. I checked it with 
> several files and did not notice any lost subtitles. I'd like to see a 
> sample.

A quick look under debugger shows that the problem is incorrect
timestamps. The first 3 subtitle packets from demux_lavf have
pts = 0.18, endpts =  6.90
pts = 6.90, endpts = 13.62
pts = 0.18, endpts =  6.90
where the second should be the same as the other 2.

I tried making a partial file as a sample, then noticed that it doesn't
play at all with -demuxer lavf...

Creating a sample for THAT problem should be easy to do yourself, any
partial file should do.