[FFmpeg-devel] [PATCH] [libdav1d.c]: Add options for spatial layers.

[Andreas Rheinhardt]

Thierry Foucu:
> Disable by default to output all the layers, to match libaomdec wrapper.
> Add option to select the operating point for the spatial layers.
> Update the documentation with the new options.
> ---
>  doc/decoders.texi     | 6 ++++++
>  libavcodec/libdav1d.c | 8 ++++++++
>  2 files changed, 14 insertions(+)
> 
> diff --git a/doc/decoders.texi b/doc/decoders.texi
> index 676e062e72..86c899b5be 100644
> --- a/doc/decoders.texi
> +++ b/doc/decoders.texi
> @@ -71,6 +71,12 @@ Set amount of tile threads to use during decoding. The default value is 0 (autod
>  Apply film grain to the decoded video if present in the bitstream. Defaults to the
>  internal default of the library.
>  
> + at item oppoint
> +Select an operating point of a scalable AV1 bitstream (0 - 32)

Should be 0 - 31.
> +
> + at item alllayer
> +Output all spatial layers of a scalable AV1 bitstream. The default value is false.
> +
>  @end table
>  
>  @section libdavs2
> diff --git a/libavcodec/libdav1d.c b/libavcodec/libdav1d.c
> index cf4b178f1d..ea4ef641bf 100644
> --- a/libavcodec/libdav1d.c
> +++ b/libavcodec/libdav1d.c
> @@ -40,6 +40,8 @@ typedef struct Libdav1dContext {
>      int tile_threads;
>      int frame_threads;
>      int apply_grain;
> +    int operating_point;
> +    int all_layers;
>  } Libdav1dContext;
>  
>  static const enum AVPixelFormat pix_fmt[][3] = {
> @@ -134,6 +136,10 @@ static av_cold int libdav1d_init(AVCodecContext *c)
>      if (dav1d->apply_grain >= 0)
>          s.apply_grain = dav1d->apply_grain;
>  
> +    s.all_layers = dav1d->all_layers;
> +    if (dav1d->operating_point >= 0)
> +        s.operating_point = dav1d->operating_point;
> +
>      s.n_tile_threads = dav1d->tile_threads
>                       ? dav1d->tile_threads
>                       : FFMIN(floor(sqrt(threads)), DAV1D_MAX_TILE_THREADS);
> @@ -378,6 +384,8 @@ static const AVOption libdav1d_options[] = {
>      { "tilethreads", "Tile threads", OFFSET(tile_threads), AV_OPT_TYPE_INT, { .i64 = 0 }, 0, DAV1D_MAX_TILE_THREADS, VD },
>      { "framethreads", "Frame threads", OFFSET(frame_threads), AV_OPT_TYPE_INT, { .i64 = 0 }, 0, DAV1D_MAX_FRAME_THREADS, VD },
>      { "filmgrain", "Apply Film Grain", OFFSET(apply_grain), AV_OPT_TYPE_BOOL, { .i64 = -1 }, -1, 1, VD },
> +    { "oppoint",  "Select an operating point of the scalable bitstream", OFFSET(operating_point), AV_OPT_TYPE_INT, { .i64 = -1 }, 0, 31, VD },

If I am not mistaken, it is not possible (you get an error message and
the default value is not set) to have a default value outside of the
range of allowed values. That is because write_number() which performs
the range checks in libavutil/opt.c is also called to write the
default values. Would be nice if you could make having a default value
outside of the range of allowed values work.

I can't comment on the rest of the patch, being entirely unfamiliar
with dav1d.

- Andreas