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

[Michael Niedermayer]

On Sun, Sep 14, 2008 at 02:56:58PM +0300, Ivan Kalvachev wrote:
> On 9/10/08, Michael Niedermayer <michaelni at gmx.at> wrote:
> > On Wed, Sep 10, 2008 at 03:26:55PM +0300, Ivan Kalvachev wrote:
> >> On 9/10/08, Michael Niedermayer <michaelni at gmx.at> wrote:
> >> > On Sun, Sep 07, 2008 at 06:23:11PM +0300, Uoti Urpala wrote:
> > [...]
> >> >> think your proposal to move all timing information to the codec level
> >> >> to
> >> >> avoid the container limitations is problematic. It is the opposite of
> >> >> what is done with audio and video. Audio has an implicit duration based
> >> >
> >> > mpeg2 video does have a duration field in its bitstream, quite well
> >> > known
> >> > for things like telecine.
> >>
> >> Soft telecine is implemented by the combined use of repeat_first_field
> >> and top_field_first in progressive picture. It only increase the
> >> duration(1/fps) by 50%.
> >> There is no way to specify duration.
> >
> > first, what you say is not correct (read the spec).
> 
> Be so kind to correct me and to tell me what and where exactly should I read.
> I did read the documentation before sending the mail, and
> I am quite familiar with the way DVB subtitles work.

the mpeg2 spec.
quote:
------
If  progressive_sequence  is  equal  to  ‘1’,  this  flag,   combined   with
repeat_first_field, indicates  how  many  times  (one,  two  or  three)  the
reconstructed frame is output by the decoding process.
              ^^^^^
------
You are only wrong in a fine detail but still, mpeg2 can repeat a frame 3
times not just 1.5 ...


> 
> > second a duration field limted to 1 and 1.5 is still a duration field.
> 
> Duration field of 1-1.5 *1/fps is useless for subtitles.

true, its still a duration field though

[...]
-- 
Michael     GnuPG fingerprint: 9FF2128B147EF6730BADF133611EC787040B0FAB

Its not that you shouldnt use gotos but rather that you should write
readable code and code with gotos often but not always is less readable
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