[FFmpeg-devel] [PATCH v2 2/2] avfilter/vf_thumbnail: switch to query_func2

[Niklas Haas]

On Fri, 20 Jun 2025 16:13:34 +0200 Niklas Haas <ffmpeg at haasn.xyz> wrote:
> From: Niklas Haas <git at haasn.dev>
>
> Instead of enumerating a static list of planar formats to support, walk
> through the format list and enable all supported formats.
>
> As of writing, this generates the following format list:
> - gbrap
> - gbrap10le
> - gbrap12le
> - gbrap14le
> - gbrap16le
> - gbrp
> - gbrp10le
> - gbrp12le
> - gbrp14le
> - gbrp16le
> - gbrp9le
> - gray
> - gray10le
> - gray12le
> - gray14le
> - gray16le
> - gray9le
> - ya16le
> - ya8
> - yuv410p
> - yuv411p
> - yuv420p
> - yuv420p10le
> - yuv420p12le
> - yuv420p14le
> - yuv420p16le
> - yuv420p9le
> - yuv422p
> - yuv422p10le
> - yuv422p12le
> - yuv422p14le
> - yuv422p16le
> - yuv422p9le
> - yuv440p
> - yuv440p10le
> - yuv440p12le
> - yuv444p
> - yuv444p10le
> - yuv444p12le
> - yuv444p14le
> - yuv444p16le
> - yuv444p9le
> - yuva420p
> - yuva420p10le
> - yuva420p16le
> - yuva420p9le
> - yuva422p
> - yuva422p10le
> - yuva422p12le
> - yuva422p16le
> - yuva422p9le
> - yuva444p
> - yuva444p10le
> - yuva444p12le
> - yuva444p16le
> - yuva444p9le
> - yuvj411p
> - yuvj420p
> - yuvj422p
> - yuvj440p
> - yuvj444p
> ---
>  libavfilter/vf_thumbnail.c | 43 +++++++++++++++++++++++++++++---------
>  1 file changed, 33 insertions(+), 10 deletions(-)
>
> diff --git a/libavfilter/vf_thumbnail.c b/libavfilter/vf_thumbnail.c
> index 55a0598e50..6f7a0ba766 100644
> --- a/libavfilter/vf_thumbnail.c
> +++ b/libavfilter/vf_thumbnail.c
> @@ -32,6 +32,7 @@
>  #include "libavutil/pixdesc.h"
>  #include "avfilter.h"
>  #include "filters.h"
> +#include "formats.h"
>
>  #define HIST_SIZE (3*256)
>
> @@ -305,23 +306,45 @@ static int config_props(AVFilterLink *inlink)
>      return 0;
>  }
>
> -static const enum AVPixelFormat pix_fmts[] = {
> +static const enum AVPixelFormat packed_rgb_fmts[] = {
>      AV_PIX_FMT_RGB24, AV_PIX_FMT_BGR24,
>      AV_PIX_FMT_RGBA,  AV_PIX_FMT_BGRA,
>      AV_PIX_FMT_RGB0,  AV_PIX_FMT_BGR0,
>      AV_PIX_FMT_ABGR,  AV_PIX_FMT_ARGB,
>      AV_PIX_FMT_0BGR,  AV_PIX_FMT_0RGB,
> -    AV_PIX_FMT_YUV410P, AV_PIX_FMT_YUV411P,
> -    AV_PIX_FMT_YUV420P, AV_PIX_FMT_YUV422P,
> -    AV_PIX_FMT_YUV440P, AV_PIX_FMT_YUV444P,
> -    AV_PIX_FMT_YUVJ420P, AV_PIX_FMT_YUVJ422P,
> -    AV_PIX_FMT_YUVJ440P, AV_PIX_FMT_YUVJ444P,
> -    AV_PIX_FMT_YUVJ411P,
> -    AV_PIX_FMT_YUVA420P, AV_PIX_FMT_YUVA422P, AV_PIX_FMT_YUVA444P,
> -    AV_PIX_FMT_GBRP, AV_PIX_FMT_GBRAP,
>      AV_PIX_FMT_NONE
>  };
>
> +static int query_formats(const AVFilterContext *ctx,
> +                         AVFilterFormatsConfig **cfg_in,
> +                         AVFilterFormatsConfig **cfg_out)
> +{
> +    const AVPixFmtDescriptor *desc = NULL;
> +    AVFilterFormats *formats;
> +
> +    formats = ff_make_format_list(packed_rgb_fmts);
> +    if (!formats)
> +        return AVERROR(ENOMEM);
> +
> +
> +    while ((desc = av_pix_fmt_desc_next(desc))) {
> +        int color_comps = desc->nb_components - !!(desc->flags & AV_PIX_FMT_FLAG_ALPHA);
> +        if ((color_comps == 1 || (desc->flags & AV_PIX_FMT_FLAG_PLANAR)) &&
> +            !(desc->flags & (AV_PIX_FMT_FLAG_FLOAT | AV_PIX_FMT_FLAG_BITSTREAM)) &&
> +            (desc->comp[0].depth <= 8 || HAVE_BIGENDIAN == !!(desc->flags & AV_PIX_FMT_FLAG_BE)) &&
> +            (desc->nb_components < 3 || desc->comp[1].plane != desc->comp[2].plane) &&
> +            desc->comp[0].depth <= 16)
> +        {
> +            printf("Adding format %s\n", desc->name);

Oops, removed this left-over printf locally.

> +            int ret = ff_add_format(&formats, av_pix_fmt_desc_get_id(desc));
> +            if (ret < 0)
> +                return ret;
> +        }
> +    }
> +
> +    return ff_set_common_formats2(ctx, cfg_in, cfg_out, formats);
> +}
> +
>  static const AVFilterPad thumbnail_inputs[] = {
>      {
>          .name         = "default",
> @@ -350,5 +373,5 @@ const FFFilter ff_vf_thumbnail = {
>      .uninit        = uninit,
>      FILTER_INPUTS(thumbnail_inputs),
>      FILTER_OUTPUTS(thumbnail_outputs),
> -    FILTER_PIXFMTS_ARRAY(pix_fmts),
> +    FILTER_QUERY_FUNC2(query_formats),
>  };
> --
> 2.49.0
>