[MEncoder-users] "High Quality" H.264 at low bit rates ;)

Gunter Ohrner G.Ohrner at post.rwth-aachen.de
Tue Mar 4 11:50:58 CET 2008


Grozdan Nikolov (openSUSE Linux) wrote:
>>nointerlaced:subq=7:partitions=all:8x8dct:me=umh:frameref=5:bframes=3:b_pyr
>>amid:weight_b:me_prepass:psnr:ssim

> partitions=all is basically useless and only slows down the encoding by
> activating the p4x4 partions which in reality provides less than 0.2% in
> compression but slows down encoding a lot. So better use
> partitions=p8x8,b8x8,i8x8,i4x4

Yes, I read about that, but I wanted to check what the best result I could
get - ignoring encoding speed - would look like, and afterwards tune the
parameters to achieve a usuable speed with an accepatble quality tradeoff.

> also if you're using b-frames then enable brdo and bime options and set
> direct_pred=auto ... enable trellis=1 and cabac too

Ok, I did (I thought cabac was on by default?). With these changes, I now
get SSIM 0.9752217 @ 2000 kbps and SSIM 0.9566152 @ 1000 kbps - thus
slightly better, though nothing revolutionary.

I'll probably have to settle at 3000 kbps for this clip... :-/

Thanks anyway for your quick help!

Greetings,

  Gunter




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