[FFmpeg-devel] [PATCH 25/25] avfilter/af_headphone: Don't check for clipping in separate loop

[Paul B Mahol]

On Tue, Sep 08, 2020 at 11:18:56PM +0200, Andreas Rheinhardt wrote:
> Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt at gmail.com>
> ---
> More patches will be coming later.
> 
>  libavfilter/af_headphone.c | 10 ++--------
>  1 file changed, 2 insertions(+), 8 deletions(-)
> 
> diff --git a/libavfilter/af_headphone.c b/libavfilter/af_headphone.c
> index 03ef88c4a4..edf8e773d7 100644
> --- a/libavfilter/af_headphone.c
> +++ b/libavfilter/af_headphone.c
> @@ -281,6 +281,8 @@ static int headphone_fast_convolute(AVFilterContext *ctx, void *arg, int jobnr,
>  
>      for (j = 0; j < in->nb_samples; j++) {
>          dst[2 * j] += fft_acc[j].re * fft_scale;
> +        if (fabsf(dst[2 * j]) > 1)
> +            n_clippings[0]++;
>      }
>  
>      for (j = 0; j < ir_len - 1; j++) {
> @@ -289,14 +291,6 @@ static int headphone_fast_convolute(AVFilterContext *ctx, void *arg, int jobnr,
>          *(ringbuffer + write_pos) += fft_acc[in->nb_samples + j].re * fft_scale;
>      }
>  
> -    for (i = 0; i < out->nb_samples; i++) {
> -        if (fabsf(dst[0]) > 1) {
> -            n_clippings[0]++;
> -        }
> -
> -        dst += 2;
> -    }
> -
>      *write = wr;

This patch is wrong and uneeded.
See, this filter use slice threading, and thus if multiple threads are used in multichannel audio
it will report incorrect results.