Bitrate Modulation in DivX 5.03

[RathO]

Im not quite sure to understand how we can decide of the Bitrate Modulation in DivX 5.03 setting.

What does it give to slide to Low or High-Motion?

Is it true that if we leave to constant quality, we'll have the same quality regardless the number of passes?

PS Just to be sure of the multi-pass settings, we have to do the 1st pass only by setting: Multi-pass, 1st pass, then we do the next passes using Multipass, Nth pass and ask to update the divx.log file?

[cordraconis]

I believe that with "High motion modulation" the codec will give more bits to the high-motion scenes, and less to the low-motion scenes. It will do this anyway after lets say 10 passes, but if you use the "modulation", then it'll give more bits *faster*, so you'll have the same result after lets say 5 passes. Something like a N2O injection in your engine: Your top-speed will still be the same, only you'll get there a lot faster !!! :D

Read my posts in the "DivX 5.0.3 Released"-thread, regarding the use of the Curve Modulation. I believe this is a faster-than-Npas setting, to reach the optimal distribution earlier... Here is part of my post again:

"Also, I think that the Curve-modulation (hi/lo motion) is more meant to *reduce the number of passes* to reach optimal results. In theory, if you do a lot of passes, then the bitrate distribution should be optimal, regardless of the amount of High/Low-motion scenes. If you leave it to "Constant quality", and do a high number of passes, the result should be always the same. "

Since this is more a "Testing" thread, I recommend doing the same series of frames over and over again (like I did), but each time save the .log file. If you have enough .log files, then it should be possible to put all of them in a 3D-graph in Excell (if you are more familiar with this kind of things :D ). Then people can start discuss the Screenshots of the distribution of the bitrate, quantisizers etc... This "visual approach" should be easier to discuss the effects of the various settings.