[Ffmpeg-devel] problem decoding frames when first frame is B

rkmr.em at gmail.com rkmr.em
Fri Apr 20 20:53:50 CEST 2007


On 4/20/07, M?ns Rullg?rd <mans at mansr.com> wrote:
>
> "rkmr.em at gmail.com" <rkmr.em at gmail.com> writes:
> > I have a valid MPEG-2 video stream in which the first two frames are
> > B-frames. ffmpeg is not able to decode those two frames:
> >
> >                        avcodec_decode_video( m_vDec, m_decodedPicture,
> > &got_picture, (uint8_t*) samplePtr, sampleLength );
> >
> > got_picture is 0 for the first two frames. Is this a know problem?
>
> Upload a sample, please.


can you tell how to do this? it is a 49MB file.


Do you mean that the first frame is a B-frame with only intra coded
> blocks, or that the first frames in display order are B-frames
> predicted against a following (display order) I-frame, which is the
> first coded frame?


the display order is like this:
BBIBBP..
I am not sure how it is actually coded.




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