[M4IF Technotes] hi

[Jani Huoponen]

Dear Sudhakar,
> Dear all,
> 
> Can somebody help me with the answers for the following.
> 
> 1. Which method of Quantization is used in MPEG-4 video 
> simple profile?

Type 2.
> Are both methods of Quantizations used in MPEG-4 Video simple profile?

No. Type 1 (quantization matrices) is not used in Simple profile.
> 2. Is fixed interval synchronization supported in simple 
> profile? Is it
> compulsory to use the method? Is there any mentioning about it in
> syntax?(This method requires that VOP start codes and 
> resynchronization
> markers appear only at legal fixed interval locations in the 
> bitstream)

If you mean that should encoded VOPs have a fixed time interval between them
then the answer is yes. Simple profile supports this. See section 6.3.3. in
the 14496-2 standard, the field called "fixed_vop_rate" explains how this
works. It is not a compulsory method, i.e., VOPs can have variable time
intervals between them.
BR, Jani
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Jani Huoponen
Engineering Manager, System Design
Hantro Products Oy
Nahkatehtaankatu 2, 90100 Oulu, Finland
+358-40-5272676
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