[FFmpeg-trac] #9538(undetermined:new): eq filter does not maintain transparency

[FFmpeg]

#9538: eq filter does not maintain transparency
--------------------------------------+----------------------------------
             Reporter:  Jozef Chutka  |                     Type:  defect
               Status:  new           |                 Priority:  normal
            Component:  undetermined  |                  Version:  4.4.1
             Keywords:  eq            |               Blocked By:
             Blocking:                |  Reproduced by developer:  0
Analyzed by developer:  0             |
--------------------------------------+----------------------------------
 Using `eq` filter, the transparency information is lost and black pixles
 are rendered instead.

 How to reproduce:
 {{{
 ffmpeg -filter_complex
 "color=color=green:size=1280x720[v];movie=input/rainbow.png,format=argb,eq=saturation=1,[v]overlay"
 -frames:v 1 output/out-eq.png -y
 }}}

 Notice, there is a small cut in the middle of rainbow.png. When using `eq`
 filter this part gets rendered as black instead of the proper background
 color.

 Removing the `eq` from the chain, it does the job properly
 {{{
 ffmpeg -filter_complex
 "color=color=green:size=1280x720[v];movie=input/rainbow.png,format=argb,[v]overlay"
 -frames:v 1 output/out.png -y
 }}}

 The issue exists with 4.4.1 and also latest builds.
-- 
Ticket URL: <https://trac.ffmpeg.org/ticket/9538>
FFmpeg <https://ffmpeg.org>
FFmpeg issue tracker