[MEncoder-users] CBR XVID

[Tamas Selmeci]

Hello!

I'd like to create a constant bitrate Xvid video. CBR means the bitrate 
must not exceed 1800-2000 kbps neither in a 1 second period. (Let us not 
speak about the quality degradation) Here's the current mencoder command 
line I use:

nice -n 19 mencoder input.avi -o output.avi -idx -ofps 25 -ovc xvid 
-xvidencopts bitrate=1800:nointerlacing:max_key_interval=50:quant_type=mpeg

In average, the bitrate is really not higher than 1800 kbps. What I 
would additionally need is a "max_bitrate" switch, which is not 
available for -ovc xvid. My problem is that the bitrate can get much 
higher than 1800 kbps for a period of time in case of action in the 
movie. I'd definitely like to inhibit the encoder to create sections 
with bitrates higher than 1800-2000 kbps.

Do you have any idea how I could achieve this? Xvid, 25 fps, 1800 kbps 
are constraints. Shall I use:
- fixed_quant: what is it?
- rc_reaction_delay_factor?
- rc_averaging_period?
- rc_buffer? What kind of value does it expect? Frames? Bytes?

Any hints appreciated.

Thanks,
-- 
Selmeci, Tamas
http://www.open-st.eu