[FFmpeg-devel] [PATCH 13/22] fftools/ffmpeg_filter: stop disregarding user-specified pixel format

[Michael Niedermayer]

On Fri, Jul 07, 2023 at 11:48:38AM +0200, Anton Khirnov wrote:
> When the user explicitly specifies a pixel format that is not supported
> by the encoder, ffmpeg CLI will currently use some heuristics to pick
> another supported format. This is wrong and the correct action here is
> to fail.
> 
> Surprisingly, a number of FATE tests are affected by this and actually
> use a different pixel format than is specified in the makefiles.
> ---
>  fftools/ffmpeg_filter.c                       | 36 ++-----------------
>  tests/fate/fits.mak                           |  6 ++--
>  tests/fate/lavf-video.mak                     |  2 +-
>  tests/fate/vcodec.mak                         |  4 +--
>  .../{fitsdec-gbrap16le => fitsdec-gbrap16be}  |  4 +--
>  .../fate/{fitsdec-gbrp16 => fitsdec-gbrp16be} |  4 +--
>  tests/ref/lavf/gif                            |  2 +-
>  7 files changed, 13 insertions(+), 45 deletions(-)
>  rename tests/ref/fate/{fitsdec-gbrap16le => fitsdec-gbrap16be} (79%)
>  rename tests/ref/fate/{fitsdec-gbrp16 => fitsdec-gbrp16be} (79%)

This also seems to break the user interface and seems to violates what is documented:
(unless iam too tired and mix something up here)

@item -pix_fmt[:@var{stream_specifier}] @var{format} (@emph{input/output,per-stream})
Set pixel format. Use @code{-pix_fmts} to show all the supported
pixel formats.
If the selected pixel format can not be selected, ffmpeg will print a
warning and select the best pixel format supported by the encoder.
If @var{pix_fmt} is prefixed by a @code{+}, ffmpeg will exit with an error
if the requested pixel format can not be selected, and automatic conversions
inside filtergraphs are disabled.
If @var{pix_fmt} is a single @code{+}, ffmpeg selects the same pixel format
as the input (or graph output) and automatic conversions are disabled.



[...]
-- 
Michael     GnuPG fingerprint: 9FF2128B147EF6730BADF133611EC787040B0FAB

Take away the freedom of one citizen and you will be jailed, take away
the freedom of all citizens and you will be congratulated by your peers
in Parliament.
-------------- next part --------------
A non-text attachment was scrubbed...
Name: signature.asc
Type: application/pgp-signature
Size: 195 bytes
Desc: not available
URL: <https://ffmpeg.org/pipermail/ffmpeg-devel/attachments/20230709/79cd64c5/attachment.sig>