[FFmpeg-trac] #3801(undetermined:reopened): SWSCALE: Incorrect Values (+-1) in Full Range Conversion RGB to YCbCr

[FFmpeg]

#3801: SWSCALE: Incorrect Values (+-1) in Full Range Conversion RGB to YCbCr
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             Reporter:  troy_s       |                    Owner:  (none)
                 Type:  defect       |                   Status:  reopened
             Priority:  normal       |                Component:
                                     |  undetermined
              Version:  unspecified  |               Resolution:
             Keywords:  range        |               Blocked By:
             Blocking:               |  Reproduced by developer:  0
Analyzed by developer:  0            |
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Comment (by Balling):

 Well, you know what. First of all, you must have specified that the file
 should be opened with ffplay -video_size 1920x1080 -pixel_format yuvj444p
 -f rawvideo -i ARIB_STD-B28_YCbCr_full.yuv -vf scale=in_color_matrix=bt709

 Second of all, it uses range full YCbCr values, as can be checked using

 ffplay -video_size 1920x1080 -pixel_format yuv444p -f rawvideo -i
 ARIB_STD-B28_YCbCr_full.yuv (see black that is 0 in Y).
 Here it does not matter '''yuvj444p or yuv444p''' we are using, BTW!

 That is why "contain one stripe that sources at -2%" will be just not
 included for full range.

 But ARIB B28 never specified full range YCbCr format... Just like SMPTE RP
 219. Also looks like the 100 red and blue are not actually 100% or it is
 just a bug somewhere... They are RGB 254, not 255.
-- 
Ticket URL: <https://trac.ffmpeg.org/ticket/3801#comment:6>
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