[FFmpeg-devel] [PATCH] avfilter/vf_tonemap: add slice threading

[Vittorio Giovara]

On Tue, Apr 30, 2019 at 6:07 AM Paul B Mahol <onemda at gmail.com> wrote:

> Signed-off-by: Paul B Mahol <onemda at gmail.com>
> ---
>  libavfilter/vf_tonemap.c | 39 ++++++++++++++++++++++++++++++++++-----
>  1 file changed, 34 insertions(+), 5 deletions(-)
>
> diff --git a/libavfilter/vf_tonemap.c b/libavfilter/vf_tonemap.c
> index efd4af5466..d1728c8513 100644
> --- a/libavfilter/vf_tonemap.c
> +++ b/libavfilter/vf_tonemap.c
> @@ -191,10 +191,36 @@ static void tonemap(TonemapContext *s, AVFrame *out,
> const AVFrame *in,
>      *b_out *= sig / sig_orig;
>  }
>
> +typedef struct ThreadData {
> +    AVFrame *in, *out;
> +    const AVPixFmtDescriptor *desc;
> +    double peak;
> +} ThreadData;
> +
> +static int tonemap_slice(AVFilterContext *ctx, void *arg, int jobnr, int
> nb_jobs)
> +{
> +    TonemapContext *s = ctx->priv;
> +    ThreadData *td = arg;
> +    AVFrame *in = td->in;
> +    AVFrame *out = td->out;
> +    const AVPixFmtDescriptor *desc = td->desc;
> +    const int slice_start = (in->height * jobnr) / nb_jobs;
> +    const int slice_end = (in->height * (jobnr+1)) / nb_jobs;
> +    double peak = td->peak;
> +
> +    for (int y = slice_start; y < slice_end; y++)
> +        for (int x = 0; x < out->width; x++)
> +            tonemap(s, out, in, desc, x, y, peak);
> +
> +    return 0;
> +}
> +
>  static int filter_frame(AVFilterLink *link, AVFrame *in)
>  {
> -    TonemapContext *s = link->dst->priv;
> -    AVFilterLink *outlink = link->dst->outputs[0];
> +    AVFilterContext *ctx = link->dst;
> +    TonemapContext *s = ctx->priv;
> +    AVFilterLink *outlink = ctx->outputs[0];
> +    ThreadData td;
>      AVFrame *out;
>      const AVPixFmtDescriptor *desc = av_pix_fmt_desc_get(link->format);
>      const AVPixFmtDescriptor *odesc =
> av_pix_fmt_desc_get(outlink->format);
> @@ -245,9 +271,11 @@ static int filter_frame(AVFilterLink *link, AVFrame
> *in)
>      }
>
>      /* do the tone map */
> -    for (y = 0; y < out->height; y++)
> -        for (x = 0; x < out->width; x++)
> -            tonemap(s, out, in, desc, x, y, peak);
> +    td.out = out;
> +    td.in = in;
> +    td.desc = desc;
> +    td.peak = peak;
> +    ctx->internal->execute(ctx, tonemap_slice, &td, NULL,
> FFMIN(in->height, ff_filter_get_nb_threads(ctx)));
>

why this FFMIN()?

     /* copy/generate alpha if needed */
>      if (desc->flags & AV_PIX_FMT_FLAG_ALPHA && odesc->flags &
> AV_PIX_FMT_FLAG_ALPHA) {
> @@ -315,4 +343,5 @@ AVFilter ff_vf_tonemap = {
>      .priv_class      = &tonemap_class,
>      .inputs          = tonemap_inputs,
>      .outputs         = tonemap_outputs,
> +    .flags           = AVFILTER_FLAG_SLICE_THREADS,
>  };
> --
>

lgtm
-- 
Vittorio