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

[Gunter Ohrner]

Grozdan Nikolov (openSUSE Linux) wrote:
>> What PSNR and SSIM results should I be able to expect with 2 MBit?
>> Can anyone of you provide some values to compare?

> PSNR/SSIM highly depends on the source/bitrate/resolution so you can't
> compare a source that easily with two or more different sources

Ok.

> @ cropped standard resolution and bitrate of 1020 kbps, i usually get SSIM
> between 0.976 and 0.986 but again this highly depends on the source and
> the x264 settings you use

For my test clip 720x544 @ 2000kbps (cropped to avoid black borders) I get,
using a current libx264 including all three patches you suggested, SSIM
0.9745643. (3-pass encoding)

mencoder parameters were

nointerlaced:subq=7:partitions=all:8x8dct:me=umh:frameref=5:bframes=3:b_pyramid:weight_b:me_prepass:psnr:ssim

So this still seems to be somewhat low in comparison, doesn't it? I needed
3000kbps to push SSIM > 0.98. At 3000kbps, the video looks "acceptable" for
me. With 1000kbps I merely get 0.9559612...

Is there anything obviously wrong with my settings? I verify I'm not doing
something obviously wrong I also tested the h264enc script which produces
comparable results, however - at least it does not achieve significantly
better quality.

Greetings,

  Gunter