ffmpeg | branch: master | Niklas Haas <g...@haasn.dev> | Fri Jun 13 16:54:27 2025 +0200| [229393d8dc8fff295a4ff9ab34957dd24edd5fd7] | committer: Niklas Haas
avfilter/f_ebur128: move true peak calculation out of main loop Easier to read, less convoluted, and ~30% faster. Most importantly, this avoids repeating the redundant recalculation of the true peak on every single sample, by moving the FIND_PEAK() loop out of the main loop. (Note that FIND_PEAK() does not depend on the current sample index at all, so there is no reason for it to ever be recomputed here) > http://git.videolan.org/gitweb.cgi/ffmpeg.git/?a=commit;h=229393d8dc8fff295a4ff9ab34957dd24edd5fd7 --- libavfilter/f_ebur128.c | 23 ++++++++++++++--------- 1 file changed, 14 insertions(+), 9 deletions(-) diff --git a/libavfilter/f_ebur128.c b/libavfilter/f_ebur128.c index 2e1eedd855..23092b597f 100644 --- a/libavfilter/f_ebur128.c +++ b/libavfilter/f_ebur128.c @@ -668,16 +668,22 @@ static int filter_frame(AVFilterLink *inlink, AVFrame *insamples) (const uint8_t **)insamples->data, nb_samples); if (ret < 0) return ret; - for (ch = 0; ch < nb_channels; ch++) - ebur128->true_peaks_per_frame[ch] = 0.0; - for (idx_insample = 0; idx_insample < ret; idx_insample++) { - for (ch = 0; ch < nb_channels; ch++) { - ebur128->true_peaks[ch] = FFMAX(ebur128->true_peaks[ch], fabs(*swr_samples)); - ebur128->true_peaks_per_frame[ch] = FFMAX(ebur128->true_peaks_per_frame[ch], - fabs(*swr_samples)); - swr_samples++; + + double maxpeak = 0.0; + for (int ch = 0; ch < nb_channels; ch++) { + double tp = ebur128->true_peaks[ch]; + double tppf = 0.0; + for (int i = 0; i < ret; i++) { + const double sample = fabs(swr_samples[i * nb_channels]); + tp = FFMAX(tp, sample); + tppf = FFMAX(tppf, sample); } + maxpeak = FFMAX(maxpeak, tp); + ebur128->true_peaks[ch] = tp; + ebur128->true_peaks_per_frame[ch] = tppf; } + + ebur128->true_peak = DBFS(maxpeak); } #endif @@ -720,7 +726,6 @@ static int filter_frame(AVFilterLink *inlink, AVFrame *insamples) } FIND_PEAK(ebur128->sample_peak, ebur128->sample_peaks, SAMPLES); - FIND_PEAK(ebur128->true_peak, ebur128->true_peaks, TRUE); /* For integrated loudness, gating blocks are 400ms long with 75% * overlap (see BS.1770-2 p5), so a re-computation is needed each 100ms _______________________________________________ ffmpeg-cvslog mailing list ffmpeg-cvslog@ffmpeg.org https://ffmpeg.org/mailman/listinfo/ffmpeg-cvslog To unsubscribe, visit link above, or email ffmpeg-cvslog-requ...@ffmpeg.org with subject "unsubscribe".
