This is how I do it:
--preset medium --rd 5
versus
--preset medium
To compare encodes I use a script like:
Code:
a=FFVideoSource() # original before encoding
b=FFVideoSource() # encoded
c=subtract(a,b)
c=c.lumalevels(133,149)
interleave(a,b,c)
return last
function LumaLevels(clip source, int "black", int "white", float "sat")
{
black=default(black,16) # PCLevels
white=default(white,235) # PCLevels
sat =default(sat,1)
Cont = 255/float(white-black)
Bright = -int(float((black-16)*Cont+16.5))
Tweak(source,bright=Bright, cont=Cont, coring=false, sat=sat)
}
This helps me to identify where in the frame there are differences. I can then decide whether I care about those differences.
For my own encodes I'm currently using:
--crf 20 --preset medium --output-depth 10 --rd 6
--crf 24 --preset medium --output-depth 10 --bframes 2 --rd 6
--crf 28 --preset medium --output-depth 10 --bframes 2 --rd 6
I think medium with --rd 6 is better than slow and it's the same encode speed or a little faster than slow. Slow uses --rd 4. Medium uses --rd 3. So --rd 6 is a significant difference for the medium preset.
Yes, I know that --rd 6 is currently the same as 5 - when 6 arrives, I'm ready!
I decided to focus on --rd due to:
http://forum.doom9.org/showpost.php?...postcount=4237