[M4IF Technotes] B-frame in simple profile

[Christoph Lampert]

On Mon, 11 Nov 2002, Liang Cheng wrote:
> Hi,
> Can anyone of you tell me why there is no B-frame in
> mpeg4 simple profile?  How long is the mp4 suggested
> maximum refresh period.  H.263 takes about 132 frames
> before the next I-frame.

No _macroblock_ is allowed to be coded using a predicted
mode (inter,inter4v,gmc,...) more than 131 times in a row. 
Christoph
-- 
Christoph H. Lampert chl   math,uni-bonn,de | Diese Signature wurde maschi-     
Beringstr. 6, Zi. 15, 53115 Bonn, Germany | nell erstellt und bedarf
Tel. (0228) 73-4708  Fax. +49 228 73-7916 | keiner Unterschrift. AZ 27B-6