[FFmpeg-trac] #10882(undetermined:new): swscale wastefully scales luma during yuv420p -> yuv422p

[FFmpeg]

#10882: swscale wastefully scales luma during yuv420p -> yuv422p
-------------------------------------+-------------------------------------
             Reporter:  Kieran       |                     Type:  defect
  Kunhya                             |
               Status:  new          |                 Priority:  normal
            Component:               |                  Version:
  undetermined                       |  unspecified
             Keywords:               |               Blocked By:
             Blocking:               |  Reproduced by developer:  0
Analyzed by developer:  0            |
-------------------------------------+-------------------------------------
 Run any conversion from yuv420p to yuv422p.

 Swscale appears to run hscale and vscale on the unscaled luma plane as
 follows:

 dst[x] = (src[x] * (2^n)) >> n;

 This uses a lot of CPU for no benefit.
-- 
Ticket URL: <https://trac.ffmpeg.org/ticket/10882>
FFmpeg <https://ffmpeg.org>
FFmpeg issue tracker