[x264-devel] Preset parameter for x264

[Loren Merritt]

On Wed, 29 Aug 2007, Son Minh Tran wrote:

> Concerning the condition of the comparison, I wonder how one can provide
> the setting of x264 in order to obtain the "High Quality" / "High Speed"
> compression. It is a complex question isn't it? We have a combination of
> a lot of parameters thanks to the flexibility of x264, then how can we
> choose the right/suboptimal combination in order to achieve the
> target, and especially to in order to submit to a competition, where
> other models of H264 can choose some settings totally difference?

Optimizing for real quality is tricky. But for a comparison that mostly 
considers objective metrics, it's easy, and just takes lots of cpu time. 
Just try all possible combinations of settings on a variety of content. Or 
if you want to spend some extra human time to save a lot of cpu time, 
elimintate a few of the insane options, and apply an iterative search on 
the remainder.
The different h264 implementations don't really affect anything. MSU 
provides a cpu quota and a bitrate quota to be used for each encode, I 
provide settings that maximize metrics within that quota, and all the 
other encoders optimize with the same constraints.
If one implementation has a feature that another doesn't, there's no 
unfairness. Just one is better than the other.

--Loren Merritt