[Ffmpeg-devel] 3G Video phone encoder behaviour (discussion)
Sat Nov 4 08:46:56 CET 2006
As I'm sure you are aware of a 3G mobile phone (during
a video call) have one 64 kbits channel on the CS side
and for all the terminals I have seen they adopt the
1) During call setup you send an I-frame.
2) All of the consecutive frames are P-frames. They never
send an I-frame again, unless requested (from other terminal
or maybe loss of radio-link - aka VFU Video Fast Update).
3) The encoder cycles the MB:s as INTRA in different
patterns for the P-frames. Some as a scan line from left
to right, other from up to down, other in a more random
So, now to my question. I have tried to look through the source
code in ffmpeg to see if this encoder behaviour is implemented
and can be switched on. It does not look like it but I have
just "skimmed" the source and did not really grasp all.
Is this possible to do ? If not is this something you have
discussed of supporting or am I on my own in this case ;-)
Thanks a million,
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