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

Ivan Schreter schreter
Sat Mar 7 15:43:12 CET 2009


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.

I already corrected MPEG-TS and posted a patch for rmdec, which is 
probably still insufficient. But I cannot possibly fix all of the 
formats, as I don't have necessary knowledge of them nor time to get the 
knowledge about them.

Therefore, I decided to leave this to maintainers of respective formats 
(or some 3rd party developers interested in having correct seeking for 
format X) and to introduce a new flag AVFMT_HAS_CORRECT_POS or something 
like that, which tells the seeking code to use the new code for formats 
already having correct positions (e.g., MPEG-TS).

After all format handlers are corrected, we can throw this flag away 
again. Also, only after all format handlers are corrected, there is a 
possibility to have new seeking API at all.

Any objections to this new flag and/or better suggestions?



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