[MPlayer-dev-eng] Distinction between I and P frames
stefan.gehrer at freescale.com
Mon Jul 18 15:52:35 CEST 2005
Marek ... wrote:
>I-frame should be in evry 4. frame,
Where is this information from? A QuickTime setting?
>P.S.: Payload of RTP packet of h.263 video (first 10 bytes):
>04 00 80 02 08 01 26 e8 e8 e8
>P-frames (but i think that these are I-frames - because of reason above):
>04 00 81 26 0a 07 03 38 78 a8
>04 00 80 c2 0a 01 00 e1 08 0f
>04 00 81 02 0a 03 00 66 f0 f6
>04 00 81 16 0a 03 00 64 7d ff
From a quick check I would have the same interpretation of the headers
picture_coding_type indicates I-frame only in the first, P-frame in the
Having intra macroblocks is allowed in P-frames too, so maybe the
refresh you see
is caused by P-frames full of intra macroblocks or at least stripes of intra
macroblocks, which is a common method of reducing error drift too.
If it is done this way, there is no way to know "how much intra" one
just by parsing the headers, you can only know it after decoding the
P.S.: this seems a little off-topic for this list.
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