[x265] Re; Re: information about --hevc-aq follow up

[nalla shanaha]

To clarify, in the options used for the --hevc-aq tests, 240p, 360p,
480p test results were generated from the same (1080p) source video. I
did not test for 720p because it takes a long time for that to encode.

So, if the test video was the Solo movie trailier, called solo.mkv,
then for --hevc-aq

ffmpeg -i solo.mkv -s 424x240 -c:v hevc -crf 28 -preset:v faster
-x265-params 'log-level=none:hevc-aq=1' -an -y output.mkv

and --no-hevc-aq

ffmpeg -i solo.mkv -s 424x240 -c:v hevc -crf 28 -preset:v faster
-x265-params 'log-level=none:hevc-aq=0' -an output.mkv

,and so on for 360p ( -s 640x360) and 480p ( -s 854x480). All source
videos were 1080p.

I verified that the --hevc-aq was actually being enabled(/disabled)
using mediainfo. Of course, the pixellation in --hevc-aq output is a
dead giveaway, so one does not really need to use mediainfo.

I must also mention that though the bit rate for the default settings
(--no-hevc-aq,crf=28,preset=medium) for 3.0 is higher by about 10-15%
, the visual quality is definitely better. Again, I cant quantify
this. But it is always possible to get better visual quality by
sacrificing bitrate.