[FFmpeg-trac] #4805(undetermined:new): swscale does not process pixels when only color-matrix differs between input and output
FFmpeg
trac at avcodec.org
Wed Aug 26 14:18:23 CEST 2015
#4805: swscale does not process pixels when only color-matrix differs between
input and output
-------------------------------------+-------------------------------------
Reporter: rmk | Owner:
Type: enhancement | Status: new
Priority: normal | Component:
Version: unspecified | undetermined
Keywords: | Resolution:
Blocking: | Blocked By:
Analyzed by developer: 0 | Reproduced by developer: 0
-------------------------------------+-------------------------------------
Comment (by rmk):
Replying to [comment:2 heleppkes]:
> We have the colormatrix filter for this kind of conversions.
>
> -vf colormatrix=src=bt709:dst=bt601
I know but
- it's GPL (in my case that means I cannot use it),
- it's very limited as far as pixel format is concerned, compared to
swscale
- it's more limited as far as color space support is concerned, compared
to swscale
- it seems like a good idea to only do the maintenance for coefficients
etc. in one place and since the swscale api contract (as well as the
vf_scale options) seems well-suited for the task, it is probably
surprising for users to find that the functionality is not in that place
(although there might be reasons as far as code complexity is concerned,
that I don't know, not really knowing the impl code)
I can only guess that the reason the colormatrix filter is there, was that
someone else ran into this limitation, maybe knew the colormatrix support
from ffmbc and decided to rather port than tackle the more complex task of
making swscale support it (which is completely legitimate, of course).
--
Ticket URL: <https://trac.ffmpeg.org/ticket/4805#comment:4>
FFmpeg <https://ffmpeg.org>
FFmpeg issue tracker
More information about the FFmpeg-trac
mailing list