[FFmpeg-trac] #3794(swscale:new): SWSCALE: Quantization Errors in Y Studio Range

FFmpeg trac at avcodec.org
Wed Jul 23 10:28:48 CEST 2014


#3794: SWSCALE: Quantization Errors in Y Studio Range
------------------------------------+-----------------------------------
             Reporter:  troy_s      |                    Owner:
                 Type:  defect      |                   Status:  new
             Priority:  normal      |                Component:  swscale
              Version:  git-master  |               Resolution:
             Keywords:              |               Blocked By:
             Blocking:              |  Reproduced by developer:  0
Analyzed by developer:  0           |
------------------------------------+-----------------------------------
Changes (by cehoyos):

 * keywords:  709 Y luma =>


Comment:

 There is something that I don't understand about this ticket (which in
 reality doesn't matter since I won't be fixing the issue):
 Your command line outputs a raw yuv file. If there is something wrong with
 this file, I would expect you to write "the third pixel from the left has
 input value x:y:z, FFmpeg outputs a:b:c instead of the expected y:u:v" or
 "all pixels are 2% too bright" or "the dynamics are all off as in...".
 Instead you attached rgb24 images: How can they be used to check yuv
 values?

 This is apart from the fact that I wonder if pal8 as an input format
 (instead of rgb24 and/or bgr24) may have its own subtle issues.
 (This reminds me that there is ticket #979 about different output values
 depending on the input being rgb24 or bgr24.)

--
Ticket URL: <https://trac.ffmpeg.org/ticket/3794#comment:3>
FFmpeg <https://ffmpeg.org>
FFmpeg issue tracker


More information about the FFmpeg-trac mailing list