[FFmpeg-devel] Command-line parameters usedtoo latefor has_codec_parameters()

Luca Abeni lucabe72
Fri Jan 16 14:40:23 CET 2009

Hi Alexandre,

>> According to the documentation in avcodec.h, in decoding pix_fmt is set by
>> libavcodec so no, I do not think it is possible (and I think setting pix_fmt
>> before reading any frame would not make much sense).
> Even if I pre-set it to the same value that I know is in the bitstream ?
> Then, ffmpeg is unable to avoid the read-in-memory of a full GOP at the 
> beginning ?

I might be wrong here (and I hope people will correct me if I am wrong), but
I think pix_fmt is set as soon as the H.263 codec is initialised (by calling
ff_h263_decode_init(). So, you do not really need a whole GOP (a whole GOP
will be needed, I think, for setting width and height, but you can set them
in rtp_parse_open()). But I do not know if it is possible to decode a stream
if you did not receive the first frame of the GOP (I mean: if you do not
decode the I frame, you cannot decode the P frames depending on it, right?).
But I am not sure about this...


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