[Mp4-tech][video] help me about mb_in_video_packet

[Herbert Thoma]

Matthew schrieb:
> Hi, Dear all
>  
>  
>  
> In the MPEG-4 video syntax, "data_partitioned_i_vop"
>  
> There is a element "*mb_in_video_packet*", I don't know where this
> element can be obtained,
>  
> Is it in the system syntax or I can't compute it through other syntax
> elelments.

In "data_partitioned_i_vop" you have a
do {
read MB header and DC coeffs
} while (next_bits != dc_marker)
The value of mb_in_video_packet is the number of macroblocks in this
video packet which means the number of times you executed the do while
loop.
So in principle something like
mb_in_video_packet = 0
do {
read MB header and DC coeffs
mb_in_video_packet++
} while (next_bits != dc_marker)
should work.
Kind regards,
 Herbert.
> Thanks
>  
> Matthew
> 
> 
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-- 
Herbert Thoma
Head of Video Group
Multimedia Realtime Systems Department
Fraunhofer IIS
Am Wolfsmantel 33, 91058 Erlangen, Germany
Phone: +49-9131-776-323
Fax:   +49-9131-776-399
email: tma iis.fhg.de
www: http://www.iis.fhg.de/