[Ffmpeg-devel] problem decoding frames when first frame is B
Mon Apr 23 20:58:05 CEST 2007
>>>>> Open GOP makes some sense when
>>>>> random access is impossible, such as broadcast, which is where it
>>>>> is primarily found. DVD uses closed
Open gop always make sense.
>>> So it is not possible to decode the first two frames? Is this true
>>> even with the latest svn version of ffmpeg?
It can't be decoded if the broken link flag is set to 1 in the gop
header. I wouldn't trust a broken link flag anyway, and I would bet
anyway that they aren't decodable
>> The first frame produced when the decoder is switched on must be
>> possible to decode somehow. If you jump into the stream at a later
>> point you'll always have a couple of initial B-frames with one
>> reference before your starting point. Not even FFmpeg can invent this
>> missing data. The decoder copes with it just fine though, so there's
>> no big deal.
I think it rather seek to the following intra.
> I am building a frame accurate video decoder using ffmpeg and I need to be
> able to decode those frames.
I don't think you can.
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