[FFmpeg-devel] [RFC] Error concealment for B-frames/fixing issue 824

[Michael Niedermayer]

On Tue, May 05, 2009 at 02:08:33PM -0700, Baptiste Coudurier wrote:
> Baptiste Coudurier wrote:
> > On Fri, Apr 10, 2009 at 06:50:08PM -0700, Baptiste Coudurier wrote:
> >> Hi Reimar,
> >>
> >> On 4/9/2009 3:13 PM, Reimar D?ffinger wrote:
> >>> On Thu, Apr 09, 2009 at 10:52:32PM +0200, Michael Niedermayer wrote:
> >>>> there are 2 very seperate things
> >>>> 1. errors
> >>>> 2. b frames without reference frames after seeking
> >>>>
> >>>> normal users dont want to see randomly trashed frames after seeking
> >>>> in undamged files
> >>> I think I agree... Is there a counter somewhere that could be used to
> >>> find out which frame in the GOP we are at?
> >> Yes temp_ref in pic structure.
> >>
> >>> Some options I can think of:
> >>> 1) change code to not skip a B-frame if it is the second frame in a closed GOP
> >>> 2) only skip B-frames if they directly follow the first I-frame of a non-closed GOP
> >>> 3) (without really knowing what "broken link" means) only skip B-frames if "broken
> >>> link" is set
> >> From what I understand, broken link explicitly state that the 2 next b
> >> frames cannot be decoded because the stream was cut at the preceding I
> >> frame, therefore the original reference I frame is no more available.
> >>
> >> And I think your strategy should be ok :)
> > 
> > Here is another attempt.
> > 
> > It will decodes them only is closed gop is set.
> > I got a sample with open gop and B frames before the I frame, it
> > works, also, decoding them anyway does not crash when dummy picture is
> > allocated some block are gray.
> > 
> > Patch attached.
> > 
> 
> New patch attached, more correct.

looks ok

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

The misfortune of the wise is better than the prosperity of the fool.
-- Epicurus
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