[FFmpeg-devel] [PATCH] vfilter: Speed up vf_mutiply with inlining

[Ronald S. Bultje]

Hi,

On Fri, Apr 14, 2023 at 5:08 PM Suraj Shirvankar <surajshirvankar at gmail.com>
wrote:

> Add inline to provide a slight speed up fo vf_multiply
>
> Signed-off-by: Suraj Shirvankar <surajshirvankar at gmail.com>
> ---
>  libavfilter/vf_multiply.c | 9 ++++-----
>  1 file changed, 4 insertions(+), 5 deletions(-)
>
> diff --git a/libavfilter/vf_multiply.c b/libavfilter/vf_multiply.c
> index 979b885eb1..b9ff92d8e1 100644
> --- a/libavfilter/vf_multiply.c
> +++ b/libavfilter/vf_multiply.c
> @@ -72,9 +72,8 @@ static int config_input(AVFilterLink *inlink)
>      return 0;
>  }
>
> -static void multiply(const uint8_t *ssrc, const uint8_t *rref, uint8_t
> *ddst,
> -                     float scale, float offset, int w)
> -{
> +static inline void multiply(const uint8_t *ssrc, const uint8_t *rref,
> +                            uint8_t *ddst, float scale, float offset, int
> w) {
>      const float *src = (const float *)ssrc;
>      const float *ref = (const float *)rref;
>      float *dst = (float *)ddst;
>

Please provide performance measurements to justify the change. Wouldn't it
be better to write SIMD?


> @@ -86,8 +85,8 @@ static void multiply(const uint8_t *ssrc, const uint8_t
> *rref, uint8_t *ddst,
>      }
>  }
>
> -static int multiply_slice(AVFilterContext *ctx, void *arg, int jobnr, int
> nb_jobs)
> -{
> +static inline int multiply_slice(AVFilterContext *ctx, void *arg, int
> jobnr,
> +                                 int nb_jobs) {
>      MultiplyContext *s = ctx->priv;
>      const float offset = s->offset;
>      const float scale = s->scale;
>

This does nothing, since the function pointer is passed to
ff_filter_execute().

Ronald