[FFmpeg-devel] [PATCH v2 1/1] avfilter/vf_vpp_qsv: apply 3D LUT from file.

[Chen Yufei]

On Wed, Jan 24, 2024 at 7:39 PM Anton Khirnov <anton at khirnov.net> wrote:
>
> Quoting Chen Yufei (2024-01-20 16:14:29)
> > Usage: "vpp_qsv=lut3d_file=<path to file>"
>
> Passing file paths to a filter and having the filter load the file is
> not recommended, it is generally preferable to have an
> AV_OPT_TYPE_BINARY option, with IO performed by the caller.
>
> E.g. in ffmpeg CLI you can do
>  -filter vpp_qsv=/lut3d=<file>
> to load the option value from a file.

I searched for code using `AV_OPT_TYPE_BINARY`.
`vf_libplacebo.c` gives me a good example.

The LUT parsing code is took from `libavfilter/vf_lut3d.c`.
It's mainly text processing which calls functions on `FILE*`.
Using `AV_OPT_TYPE_BINARY` would require many changes in LUT paring
code, and also need to change the command line option of `vf_lut3d`.
So I'd keep the lut file option as is.

If there are no other review messages. I'll send patch v3 this weekend.

The planed change is to
check runtime version >= 2.11 if `lut3d_file` option is set,
return `AVERROR(ENOTSUP)` and print error message if version is too low.

-- 
Best regards,
Chen Yufei