[MPlayer-DOCS] encoding-guide: outdated description of x264enc options?

Guillaume POIRIER poirierg at gmail.com
Sat Jan 6 20:02:03 CET 2007


Hi,

On 1/6/07, Andrew Savchenko <Bircoph at list.ru> wrote:
> It seems that description of x264 encoding options is slightly
> outdated. Into paragraph "Options which primarily affect speed and
> quality" in description of the subq opion anyone can see:
> ----------
> subq=6 is the slowest, highest quality mode.
> ----------
>
> But in the manual:
> ----------
> 6    Enables  rate-distortion optimization of macroblock types in
> I- and P-frames.
> 7    Enables rate-distortion optimization of motion  vectors  and
> intra modes. (best)
> ----------
> So, subq=7 seems to be the highest quality mode. Probably it sould
> be describded instead of subq=6. Or its quality gain is negligible
> in comparision with speed loss and it is considered as
> unrecommended?

>From my experience, subq=7 can improve PSNR between 0,01dB and 0,02dB,
and slows down encoding by about 33% compared to subq=6.
Because this introduces a significant slowdown without a significant
improvement in quality, I wouldn't recommend using it unless you're
after every bit of quality improvement.

Andrew do you plan to update this section, or would you prefer let me do it?

Guillaume
-- 
An association of men who will not quarrel with one another is a thing
which has never yet existed, from the greatest confederacy of nations
down to a town meeting or a vestry.
 -- Thomas Jefferson
(when interviewed about MPlayer ML flamewars)
http://www.brainyquote.com/quotes/quotes/t/thomasjeff157207.html



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