[Ffmpeg-devel] Apple h264 compatibility

Måns Rullgård mru
Sun Jun 19 20:29:59 CEST 2005


Jeff Clagg <snacky at ikaruga.co.uk> writes:

> On Sun, Jun 19, 2005 at 07:41:34PM +0200, M?ns Rullg?rd wrote:
>
>> Mplayer with frame dropping doesn't work with H.264.  It appears that
>> it discards B frames without decoding them, in the belief that they
>> are not used as reference frames.  This used to be the case with older
>> codecs, but H.264 allows B frames as reference frames.  Try without
>> frame dropping.  If there are still decoding errors, there's a bug or
>> an unimplemented feature.
>
> My (possibly ignorant) impression was that the problem is caused by
> libavcodec not setting avctx->hurry_up to a sane default value for h264.

AVCodecContext.hurry_up is an input parameter, to be set by the
application.  The only sane default is to decode everything.

> Interestingly, while mplayer does NOT have framedropping on by default,
> adding -noframedrop to the command line fixes the problem.

Then it was apparently dropping something anyway.  Check if some
configuration file has enabled it.

-- 
M?ns Rullg?rd
mru at inprovide.com





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