[Libav-user] any way to interrupt avcodec_decode_video2 ?

Carl Eugen Hoyos cehoyos at ag.or.at
Wed Jan 1 21:01:25 CET 2014

Don Moir <donmoir at ...> writes:

> >> A simple seek to zero is quick, but if I have to wait on 
> >> avcodec_decode_video2 to return, then its slower and can 
> >> be quite slow.
> > 
> > Yes, this is exactly what CODEC_FLAG2_SHOW_ALL is for.

> CODEC_FLAG2_SHOW_ALL ///< Show all frames before the first 
> keyframe
> So show garbage? What does that have to do with how fast 
> avcodec_decode_video2 returns?

>From a purely technical point-of-view, one could probably 
argue that CODEC_FLAG2_SHOW_ALL only affects how fast 
avcodec_decode_video2() returns.

Once you have verified this solves the performance problem 
you see (remember that as explained on irc, nobody understands 
your reports), you can worry about the "garbage": Either it 
is possible to call the decode function as often as necessary 
(I am not sure) or it will be trivial to add such a return 
flag compared to the callback you suggest.

I agree with you that multi-threading may not help in your 
use case because of its large overhead.

Carl Eugen

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