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[OpenDivX] I want to implement a 2 pass vbr encoder



Hi,

I have a lot of spare time and would like to implement a 2 pass VBR encoding 
algorithm in encore. In order to do that I'm reading this:

http://www.research.ibm.com/journal/rd/434/westerink.html

This document describes an implementation of a 2 pass MPEG-2 vbr encoder. For 
that it first does a first CBR pass, gathering statistics, processes them in 
order to obtain control parameters for the second pass. Then during the second 
pass there is a bitrate control process that takes into account the prediction 
error.

I also grabbed the encore sources and I'm looking into rc_q2.c and rc_q2.h.

I have noticed that the bitrate modelling algorithm in the encore sources is 
not a CBR algorithm but rather an ABR algorithm (Average Bit Rate). In order to 
implement a 2 pass encoder I need to first implement a true CBR rate control, a 
strong one like in MPEG-1 or MPEG-2.

I will go and grab rate control sources for MPEG-1 and MPEG-2 CBR and implement 
them into encore. Then I will implement the statistics processing and VBR 
control process.

I begin in this video compression field but I have a lot of time and I have C 
programming skills on Unix.

Where can I find good documentation about MoMuSys MPEG-4 implementation and 
MPEG-4 standard? Could Adam Li, the author of rc_q2.c help me a little by 
explaining me how it works so that I don't begin at 0.


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