#3794: SWSCALE: Quantization Errors in Y Studio Range
------------------------------------+-----------------------------------
Reporter: troy_s | Owner: (none)
Type: defect | Status: closed
Priority: normal | Component: swscale
Version: git-master | Resolution: invalid
Keywords: range | Blocked By:
Blocking: | Reproduced by developer: 0
Analyzed by developer: 0 |
------------------------------------+-----------------------------------
Comment (by Balling):
Replying to [comment:15 Balling]:
> You can't be serious right now...
>
> The gradient in RGB has 256 gradations, while gradient in YCbCr limited
only can have 235-16+1. Seriously??? I mean, this is just wow. Of course
you will lose some grays in --> YCbCr!
>
> That is why SMPTE RP 219 defines everything for Y! And does not have
Full range at all!
>
> Also if you looked accurately into the SMPTE RP 219 standard, you would
find out that part of your ramp is 100% white (235, 128, 128) there and
part is black or +Q. For Arib they just define the form of ramp, the SAME
way SMPTE 219 does. It is 1440 pixels long, and 205 is black (or +Q) and
205 are 100% white. See how it should have been done.
https://www.youtube.com/watch?v=PqvEy5JLll4
--
Ticket URL: <https://trac.ffmpeg.org/ticket/3794#comment:16>
FFmpeg <https://ffmpeg.org>
FFmpeg issue tracker
_______________________________________________
FFmpeg-trac mailing list
FFmpeg-trac@avcodec.org
https://ffmpeg.org/mailman/listinfo/ffmpeg-trac
To unsubscribe, visit link above, or email
ffmpeg-trac-requ...@ffmpeg.org with subject "unsubscribe".
