run_channel_fft   321 libavfilter/avf_showspatial.c         ctx->internal->execute(ctx, run_channel_fft, fin, NULL, 2);
run_channel_fft  1454 libavfilter/avf_showspectrum.c         ctx->internal->execute(ctx, run_channel_fft, fin, NULL, s->nb_display_channels);
run_channel_fft  1653 libavfilter/avf_showspectrum.c             ctx->internal->execute(ctx, run_channel_fft, fin, NULL, s->nb_display_channels);