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

[Chen Yufei]

On Mon, Jan 29, 2024 at 11:29 AM Zhao Zhili <quinkblack at foxmail.com> wrote:
>
> >
> > If someone can show me code in FFmpeg that parses loaded data as text,
> > I can follow
> > that and send a new patch. This is to avoid doing things the wrong
> > way, as I'm a newcomer
> > and don't know if there's existing code to do this.
>
> Check read_binary() in ffmpeg_filter.c for loading data from file and setting AV_OPT_TYPE_BINARY
> option value.
>
> Check pix_fmts option in buffersink.c for the consumer side of AV_OPT_TYPE_BINARY.
>
> static const AVOption buffersink_options[] = {
>     { "pix_fmts", "set the supported pixel formats", OFFSET(pixel_fmts), AV_OPT_TYPE_BINARY, .flags = FLAGS },
>

Thanks for giving directions. I find `FFTextReader` in
libavformat/subtitles.h and can follow that to create a
struct `FF3DLUTReader` to do text processing.

But there's one problem I don't know how to solve. When using
`AV_OPT_TYPE_BINARY`, the original file name
is not available in the filter code, only the loaded data and length
is available.

Take a look at `ff_lut3d_init`, it relies on file name extension to
detect LUT file type and call different parse functions.
If we add another option to specify LUT file type, then vf_lut3d's
command line option would require change.

-- 
Best regards,
Chen Yufei