[FFmpeg-devel] [RFC] Many formats return wrong position => seeking problems

[Michael Niedermayer]

On Sat, Mar 07, 2009 at 05:28:41PM +0100, Ivan Schreter wrote:
> Reimar D?ffinger wrote:
> > On Sat, Mar 07, 2009 at 03:43:12PM +0100, Ivan Schreter wrote:
> >   
> >> I'm writing some low-level support for new seeking API. In principle, it 
> >> works OK now, but many format demuxers in lavf are broken in the sense 
> >> that they don't return correct packet positions. This is mandatory for 
> >> new seeking API and for corrections to current seeking API as well.
> >>     
> >
> > Can you please define what "correct position" means? That would make it
> > easier to know which are broken and how to fix them (or alternatively
> > flame you if the requirements are too restrictive ;-) ).
> >   
> Well, quite easy:
> 
> av_read_frame() returns an AVPacket, containing file position in member 
> pos. If I reposition the file pointer to this position in the file, I 
> expect next av_read_frame() to return exactly the same packet (also with 
> same DTS/PTS, single exception being undefined DTS/PTS after repositioning).

in that sense most formats do not have a position, as they will never work
once you touch the file pointer, their demuxers rather need various parts
of their internal state updated
and code that does this exists and works.


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

Those who are too smart to engage in politics are punished by being
governed by those who are dumber. -- Plato 
-------------- next part --------------
A non-text attachment was scrubbed...
Name: not available
Type: application/pgp-signature
Size: 189 bytes
Desc: Digital signature
URL: <http://lists.mplayerhq.hu/pipermail/ffmpeg-devel/attachments/20090307/a95c6992/attachment.pgp>