[FFmpeg-devel] About guess_correct_pts / AVFrame.best_effort_timestamp

Martin Storsjö martin
Wed Feb 16 19:38:18 CET 2011

On Wed, 16 Feb 2011, John Cox wrote:

> >I'm not sure if any such formats exist though, I'm just trying to make 
> >sure my knowledge of the subject is right.
> >
> >As far as I understand, DTS'es shouldn't be reordered? The definition I 
> >saw is that whatever comes out from an ideal, instanteous decoder, when 
> >fed with a packet at time DTS, should be displayed at that particular 
> >time.
> No.  At least not of you are using DTS in the sense it is defined in H.222.  An
> "instantaneous decoder" is one that takes no time processing a frame.  A frame
> may be delayed or reordered by such a decoder.  If you put a frame in at time
> DTS you would expect it to come out at time PTS.  In the decode pipeline DTS
> has no useful meaning after the decode stage.

Yes, I think I expressed myself incorrectly, I'm not too well-versed with 
the exact terminology.

The packet that made the instantaneous decoder output the delayed frame, 
the DTS of that frame would be equal to the PTS of the frame that was 
output, is that right?

// Martin

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