[FFmpeg-devel] ogg seeking status

Reimar Döffinger Reimar.Doeffinger at gmx.de
Tue Feb 7 21:28:23 CET 2012


On Mon, Feb 06, 2012 at 04:36:37PM -0500, Don Moir wrote:
> Good to see you are persistent reimar, I figured you and others
> might be getting tired of this by now.
> 
> >On Mon, Feb 06, 2012 at 12:14:09PM -0500, Don Moir wrote:
> >>o - the reimar patch to ogg_read_timestamp does provide somewhat
> >>accurate keyframe seeking - problem is it doesn't get close
> >>enough - not sure if this is a failure of the algorithm or not
> >>but I do know that much closer keyframes are available - I was
> >>not able to improve on it. Since you still don't have the index
> >>entries, future seeks will tend to have the same "not close
> >>enough" problem and this can effect exact timestamp seeking
> >>quite abit. If you don't care about exact timestamp seeking then
> >>I suppose it works well enough, but expect it to be off
> >>sometimes quite abit.
> >
> >Can you provide a sample?
> 
> This file is kind of large but shows a couple things. Probably best
> tested in MPlayer for you. I can also provide more samples.
> 
> 1) with your ogg_read_timestamp patch in and on startup, click
> around the 6 - 7 minute mark and it should jump back to the 3 - 4
> minute mark

MPlayer seeks at least within 10 seconds of any position in the 6
- 7 minute area.
However the audio time stamps for a while reset to 0 before going
back to proper values, so that might cause some issues.
I have not yet tests FFmpeg/ffplay, but it seems to me that the
seek function in principle seems to work fine.


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