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 184794B16F for ; Thu, 21 Aug 2025 12:56:28 +0000 (UTC) Received: from [127.0.1.1] (localhost [127.0.0.1]) by ffbox0-bg.ffmpeg.org (Postfix) with ESMTP id AD46068D780; Thu, 21 Aug 2025 15:56:24 +0300 (EEST) Received: from c1ad6a1ecdc3 (code.ffmpeg.org [188.245.149.3]) by ffbox0-bg.ffmpeg.org (Postfix) with ESMTPS id 4FD6A68D766 for ; Thu, 21 Aug 2025 15:56:23 +0300 (EEST) MIME-Version: 1.0 To: ffmpeg-devel@ffmpeg.org Subject: [FFmpeg-devel] =?utf-8?q?=5BPATCH=5D_avfilter/setpts=3A_also_pre?= =?utf-8?q?serve_duration_when_not_stripping_fps_=28PR_=2320304=29?= 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: , From: Niklas Haas via ffmpeg-devel 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" Message-Id: <20250821125624.AD46068D780@ffbox0-bg.ffmpeg.org> Date: Thu, 21 Aug 2025 15:56:24 +0300 (EEST) Archived-At: List-Archive: List-Post: PR #20304 opened by Niklas Haas (haasn) URL: https://code.ffmpeg.org/FFmpeg/FFmpeg/pulls/20304 Patch URL: https://code.ffmpeg.org/FFmpeg/FFmpeg/pulls/20304.patch It makes sense to treat the presence of a frame duration and the presence of frame rate metadata identically - because both convey effectively the same amount of information. In f121d95 and fa110c3 respectively, this information was stripped by default, originally to work-around bugs when changing the PTS information of a stream being fed to some encoders. (See https://trac.ffmpeg.org/ticket/10886) Later, commit 959b799c restored the ability to preserve the frame rate medatata via the `strip_fps` option, but this option did not extend to also include the frame duration. This commit resolves the scenario by making `frame_rate` and `duration` handled in a consistent manner, so that the frame rate information is generally preserved unless explicitly stripped by the user. While it does regress the exact invocation presented in the trac ticket unless using `strip_fps=yes`, I consider this an acceptable trade-off, especially in light of the fact that the `fps` filter also exists and is arguably the better tool for the task at hand. >From 8e0de5d811b1828d588844a88cea35440cce0008 Mon Sep 17 00:00:00 2001 From: Niklas Haas Date: Thu, 21 Aug 2025 14:46:52 +0200 Subject: [PATCH] avfilter/setpts: also preserve duration when not stripping fps It makes sense to treat the presence of a frame duration and the presence of frame rate metadata identically - because both convey effectively the same amount of information. In f121d95 and fa110c3 respectively, this information was stripped by default, originally to work-around bugs when changing the PTS information of a stream being fed to some encoders. (See https://trac.ffmpeg.org/ticket/10886) Later, commit 959b799c restored the ability to preserve the frame rate medatata via the `strip_fps` option, but this option did not extend to also include the frame duration. This commit resolves the scenario by making `frame_rate` and `duration` handled in a consistent manner, so that the frame rate information is generally preserved unless explicitly stripped by the user. While it does regress the exact invocation presented in the trac ticket unless using `strip_fps=yes`, I consider this an acceptable trade-off, especially in light of the fact that the `fps` filter also exists and is arguably the better tool for the task at hand. --- doc/filters.texi | 6 +++--- libavfilter/setpts.c | 3 ++- 2 files changed, 5 insertions(+), 4 deletions(-) diff --git a/doc/filters.texi b/doc/filters.texi index 2818bd28b0..e84d7d5554 100644 --- a/doc/filters.texi +++ b/doc/filters.texi @@ -31911,9 +31911,9 @@ This filter accepts the following options: The expression which is evaluated for each frame to construct its timestamp. @item strip_fps (@emph{video only}) -Boolean option which determines if the original framerate metadata is unset. -If set to true, be advised that a sane frame rate should be explicitly -specified if output is sent to a constant frame rate muxer. +Boolean option which determines if the original framerate and frame duration +metadata is unset. If set to true, be advised that a sane frame rate should be +explicitly specified if output is sent to a constant frame rate muxer. Default is @code{false}. @end table diff --git a/libavfilter/setpts.c b/libavfilter/setpts.c index 0565533ed2..b49a0cb64f 100644 --- a/libavfilter/setpts.c +++ b/libavfilter/setpts.c @@ -199,7 +199,8 @@ static int filter_frame(AVFilterLink *inlink, AVFrame *frame) d = eval_pts(setpts, inlink, frame, frame->pts); frame->pts = D2TS(d); - frame->duration = 0; + if (setpts->strip_fps) + frame->duration = 0; av_log(inlink->dst, AV_LOG_TRACE, "N:%"PRId64" PTS:%s T:%f", -- 2.49.1 _______________________________________________ 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".