From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from ffbox0-bg.ffmpeg.org (ffbox0-bg.ffmpeg.org [79.124.17.100]) by master.gitmailbox.com (Postfix) with ESMTPS id 1C44C4EE7A for ; Fri, 13 Jun 2025 16:40:08 +0000 (UTC) Received: from [127.0.1.1] (localhost [127.0.0.1]) by ffbox0-bg.ffmpeg.org (Postfix) with ESMTP id 1A3B768CA75; Fri, 13 Jun 2025 19:38:24 +0300 (EEST) Received: from haasn.dev (haasn.dev [78.46.187.166]) by ffbox0-bg.ffmpeg.org (Postfix) with ESMTP id 9685068C8D0 for ; Fri, 13 Jun 2025 19:38:07 +0300 (EEST) Received: from haasn.dev (unknown [10.30.1.1]) by haasn.dev (Postfix) with UTF8SMTP id 01E0742B93; Fri, 13 Jun 2025 18:38:02 +0200 (CEST) From: Niklas Haas To: ffmpeg-devel@ffmpeg.org Date: Fri, 13 Jun 2025 18:37:52 +0200 Message-ID: <20250613163801.197737-9-ffmpeg@haasn.xyz> X-Mailer: git-send-email 2.49.0 In-Reply-To: <20250613163801.197737-1-ffmpeg@haasn.xyz> References: <20250613163801.197737-1-ffmpeg@haasn.xyz> MIME-Version: 1.0 Subject: [FFmpeg-devel] [PATCH v2 09/13] avfilter/f_ebur128: move true peak calculation out of main loop X-BeenThere: ffmpeg-devel@ffmpeg.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: FFmpeg development discussions and patches List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Reply-To: FFmpeg development discussions and patches Cc: Niklas Haas Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Errors-To: ffmpeg-devel-bounces@ffmpeg.org Sender: "ffmpeg-devel" Archived-At: List-Archive: List-Post: From: Niklas Haas 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) --- 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 -- 2.49.0 _______________________________________________ ffmpeg-devel mailing list ffmpeg-devel@ffmpeg.org https://ffmpeg.org/mailman/listinfo/ffmpeg-devel To unsubscribe, visit link above, or email ffmpeg-devel-request@ffmpeg.org with subject "unsubscribe".