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Old 30th January 2019, 23:22   #6683  |  Link
katzenjoghurt
Registered User
 
Join Date: Feb 2007
Posts: 128
The frustrated encoder

Oh my.
Am I the only one having such a hard time encoding scenes with red light / red backgrounds?

E.g. if a character turns on a red light, his face would turn suddenly totally blocky.
Blue light is fine, green light also seems to be a bit bad, but red light is the devil.
Looks like x265 (also x264 I think) detects the scene as super-dark and reduces
the bitrate like crazy.

I doubt that it's just a display thing as I can see the problem on my Dell display,
my Benq display and my Samsung TV.

By now I fix it by scanning every source for red scenes before encoding and setting
zones like crazy via --zones startframe,endframe,b=1.5/startframe,endfr....
Super-tedious.

I was shocked again today after I checked my encoding of Disney's Aladdin...
Red sand with black dots -> blurred to unshaded flat areas.
Red stone wall backgrounds -> bluuuurr.

Looks like I need to double or triple the bitrate manually in these scenes just to keep
the subjectively visible detail level compared to the non-reddish scenes.

AQ3 won't help all too much either. The overall bitrate would get just too high if
I want to retain the details that way. *sigh*

Last edited by katzenjoghurt; 30th January 2019 at 23:26.
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