[FFmpeg-trac] #11182(swscale:closed): yuvtestsrc and yuv444p->rgba->yuv444p conversion result in huge difference

[FFmpeg]

#11182: yuvtestsrc and yuv444p->rgba->yuv444p conversion result in huge difference
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             Reporter:  Andrew-R     |                    Owner:  (none)
                 Type:  defect       |                   Status:  closed
             Priority:  normal       |                Component:  swscale
              Version:  unspecified  |               Resolution:  invalid
             Keywords:  colorspace   |               Blocked By:
  color_primaries                    |
             Blocking:               |  Reproduced by developer:  0
Analyzed by developer:  0            |
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Comment (by Balling):

 >"The very White could never be the very White"

 Yes. Even during Photo CD era this was well understood, now HDR white is
 not paper white. https://en.wikipedia.org/wiki/Photo_CD

 An oddity of this encoding scheme is that it allows Photo CD images to
 represent colors which are above 100% (up to 140.2%), "whiter than
 white".[31] At the time of Photo CD's introduction, this allowed the
 display of images on the analog televisions of the day to show brighter,
 more vivid colors than would otherwise be the case. This was acceptable as
 the analog televisions of the day were designed to be driven beyond their
 100% level without abruptly clipping


 >The display may accept raw YUV alike, while the application does not
 necessarily provide.

 The display has its own color science. It does not directly accept YUV.
 Modern LG C9 TV is full linux machine, rather powerful.


 PS C:\Users\ZAQU> ssh root at 192.168.1.72

 root at 192.168.1.72's password: (well, standard password here is alpine)
 NEVER EVER OVERWRITE SYSTEM PARTITIONS LIKE KERNEL, ROOTFS, TVSERVICE.
 Your TV will be bricked, guaranteed! See https://rootmy.tv/warning for
 more info.

  /!\ Your system is using a default password.
  /!\ Insert SSH public key into /home/root/.ssh/authorized_keys and
 perform a reboot to remove this warning.

 root at LGwebOSTV:~# uname -a
 Linux LGwebOSTV 4.4.84-169.gld4tv.4 #1 SMP PREEMPT Wed Feb 28 14:01:22 KST
 2024 aarch64 GNU/Linux
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Ticket URL: <https://trac.ffmpeg.org/ticket/11182#comment:17>
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