[FFmpeg-trac] #2407(swscale:new): Conversion from yuv to RGB leads to broken gradients and colors.

[FFmpeg]

#2407: Conversion from yuv to RGB leads to broken gradients and colors.
---------------------------------+----------------------------------
             Reporter:  sun      |                     Type:  defect
               Status:  new      |                 Priority:  normal
            Component:  swscale  |                  Version:  1.2
             Keywords:           |               Blocked By:
             Blocking:           |  Reproduced by developer:  0
Analyzed by developer:  0        |
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 Summary of the bug:
 If you convert a yuv source to RGB, the image is gets broken up. There
 appears a slight overall color tint as well as a little change in
 brightness and depending on the input pixel format heavy banding.

 How to reproduce:
 {{{
 ffmpeg -i dnxhd.mov -vcodec libx264 -b:v 100000k -vf format=rgb24
 dnxhdconv.mov

 ffmpeg version 1.2
 built on Mar 25 2013 21:47:38 with gcc 4.7 (Ubuntu/Linaro 4.7.2-2ubuntu1)
 }}}

 Download the example file from here:
 http://www.mediafire.com/?3hk4w4v425d7rwb

 Use the command and look at the relatively dark, flat sufaces.
 You can make a countercheck by using:

 {{{
 ffmpeg -i dnxhd.mov -vcodec libx264 -b:v 100000k -vf format=bgr24
 dnxhdconv.mov
 }}}

 Which will not show the problem, so it's not a mathematical issue of
 rounding values during conversion, but a unique issue of the rgb24
 conversion.

 This is a dnxd 10-bit file. I have also tested 8 bit limited- and 8 bit
 fullscale videos and the problem shows up there too, but not that strong.

 I will post full terminal output as soon as I get my complete system
 running. It's broken at the moment.

-- 
Ticket URL: <https://ffmpeg.org/trac/ffmpeg/ticket/2407>
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