[M4IF Technotes] B-frame in simple profile

[Herbert Thoma]

Liang Cheng schrieb:
> 
> Hi,
> Can anyone of you tell me why there is no B-frame in
> mpeg4 simple profile? 

May be, because B-frames are not simple enough? :-)
> How long is the mp4 suggested
> maximum refresh period.

I am not aware of a suggested maximum refresh period
in MPEG-4 Video.
> H.263 takes about 132 frames
> before the next I-frame.

H.263 does not require an I-frame every 132 frames.
H.263 reqires that every macroblock is coded as
INTRA macroblock at least every 132 frames. You
don't need to send any I-frame after the first
frame.
Best Regards,
 Herbert.
> Thanks,
> Liang
> 
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-- 
Herbert Thoma
FhG-IIS A, Studio Department
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