[MPlayer-dev-eng] Blu-ray m2ts PGS subtitle port from ffmpeg: call for developers

[Uoti Urpala]

On Fri, 2010-05-21 at 16:18 -0300, Dâniel Fraga wrote:
> On Fri, 21 May 2010 20:48:46 +0300
> Uoti Urpala <uoti.urpala at pp1.inet.fi> wrote:
> 
> > The FFmpeg code is not complete. It's missing important parts needed at
> > least to parse timing information (IIRC ffplay shows the subtitles with
> > completely arbitrary end times that have nothing to do with the correct
> > timing information). So using the current FFmpeg decoder is not enough
> > to parse the subtitle packets.
> > 
> > In addition to decoding the subtitles, a rendering implementation is
> > also needed. The test code I wrote earlier supports vo_vdpau only (since
> > that was the easiest to implement rendering for). That code would need
> > some changes before I could publish it even for testing purposes.
> 
> 	I undertand Uoti.
> 
> 	And what about Xine's code? It shows correctly PGS subtitles.
> Would it be useful to implement (port) what's missing on ffmpeg or
> mplayer? I mean, at least the hard work, since of course it would not
> be possible to just use the same code Xine uses (or even VLC's code).

I haven't looked at what Xine does. I did briefly look at VLC; at least
back then VLC did not have proper PGS support either, it just blindly
used nonsense values from FFmpeg. OTOH MPC-HC has a probably more
functional implementation.

I'm haven't verified whether additional parsing of the PGS packets is
necessary in addition to current FFmpeg code. It may be enough to ignore
the timing values from FFmpeg and use outside logic based on packet
timestamps.