From d39fae08866efebbfdf25951fbaff4df9d26e6b3 Mon Sep 17 00:00:00 2001 From: Paul B Mahol Date: Fri, 5 Oct 2018 00:15:26 +0200 Subject: [PATCH] avfilter/avf_showspectrum: fix scaling in zoom mode --- libavfilter/avf_showspectrum.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) diff --git a/libavfilter/avf_showspectrum.c b/libavfilter/avf_showspectrum.c index 38d0a9d768..a750b9a3f1 100644 --- a/libavfilter/avf_showspectrum.c +++ b/libavfilter/avf_showspectrum.c @@ -340,12 +340,12 @@ static int run_channel_fft(AVFilterContext *ctx, void *arg, int jobnr, int nb_jo FFTComplex *h = s->fft_scratch[ch]; int L = s->buf_size; int N = s->win_size; - int M = s->win_size; + int M = s->win_size / 2; - phi = 2.0 * M_PI * (s->stop - s->start) / (double)inlink->sample_rate / (s->win_size - 1); + phi = 2.0 * M_PI * (s->stop - s->start) / (double)inlink->sample_rate / (M - 1); theta = 2.0 * M_PI * s->start / (double)inlink->sample_rate; - for (int n = 0; n < s->win_size; n++) { + for (int n = 0; n < M; n++) { h[n].re = cos(n * n / 2.0 * phi); h[n].im = sin(n * n / 2.0 * phi); }