[FFmpeg-devel] [PATCH 08/11] avfilter/avf_showvolume: use log10 instead of log()/M_LN10

[Paul B Mahol]

On 10/29/15, Ganesh Ajjanagadde <gajjanagadde at gmail.com> wrote:
> This is likely more precise and conveys the intent better.
>
> Signed-off-by: Ganesh Ajjanagadde <gajjanagadde at gmail.com>
> ---
>  libavfilter/avf_showvolume.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/libavfilter/avf_showvolume.c b/libavfilter/avf_showvolume.c
> index 95b5388..395375a 100644
> --- a/libavfilter/avf_showvolume.c
> +++ b/libavfilter/avf_showvolume.c
> @@ -197,7 +197,7 @@ static int filter_frame(AVFilterLink *inlink, AVFrame
> *insamples)
>              max = FFMAX(max, src[i]);
>
>          max = av_clipf(max, 0, 1);
> -        values[VAR_VOLUME] = 20.0 * log(max) / M_LN10;
> +        values[VAR_VOLUME] = 20.0 * log10(max);
>          values[VAR_CHANNEL] = c;
>          color = av_expr_eval(s->c_expr, values, NULL);
>
> --
> 2.6.2

Have you checked which one is faster?
I really have no opinion on this but gain is neglible.