From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from ffbox0-bg.mplayerhq.hu (ffbox0-bg.ffmpeg.org [79.124.17.100]) by master.gitmailbox.com (Postfix) with ESMTP id 4BF4F42469 for ; Sat, 18 Dec 2021 15:41:36 +0000 (UTC) Received: from [127.0.1.1] (localhost [127.0.0.1]) by ffbox0-bg.mplayerhq.hu (Postfix) with ESMTP id 89ADB68AF33; Sat, 18 Dec 2021 17:41:34 +0200 (EET) Received: from canta.com.ar (mail.canta.com.ar [162.217.64.29]) by ffbox0-bg.mplayerhq.hu (Postfix) with ESMTPS id EE2DC68AE9D for ; Sat, 18 Dec 2021 17:41:27 +0200 (EET) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=canta.com.ar; s=mail; h=Content-Type:In-Reply-To:MIME-Version:Date: Message-ID:From:Subject:References:To:Sender:Reply-To:Cc: Content-Transfer-Encoding:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Id: List-Help:List-Unsubscribe:List-Subscribe:List-Post:List-Owner:List-Archive; bh=hXvr7grAH6kUByE2Uk3HfKo2v5X9Y2BU5A48X0+OFm4=; b=LcuMunh2NTy4D4UQpZUEigZmX /XjXjIbs3bVneAR8g9NtvAcaNXTf5BbABeSMcuxisZPA5hS3i3mPoRiLeZkXudEKNu6X/ehm0OWNB tj59j6fpp4/ibD9rT3nSKh+saGHJZCAMQrbba3xCsbt9qZZuZgLZIlx+BWX9Duhj24dd0=; Received: from [181.47.151.158] (helo=[192.168.0.100]) by canta.com.ar with esmtpsa (TLSv1.2:ECDHE-RSA-AES128-GCM-SHA256:128) (Exim 4.92.3) (envelope-from ) id 1mybpt-0000xH-QR for ffmpeg-devel@ffmpeg.org; Sat, 18 Dec 2021 12:41:26 -0300 To: ffmpeg-devel@ffmpeg.org References: From: =?UTF-8?Q?Daniel_Cantar=c3=adn?= Message-ID: <85334378-9a7c-780a-4c44-fe42c9dcf255@canta.com.ar> Date: Sat, 18 Dec 2021 12:41:18 -0300 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:78.0) Gecko/20100101 Thunderbird/78.14.0 MIME-Version: 1.0 In-Reply-To: Content-Language: en-US X-Content-Filtered-By: Mailman/MimeDel 2.1.29 Subject: Re: [FFmpeg-devel] Politics 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 Content-Transfer-Encoding: 7bit Content-Type: text/plain; charset="us-ascii"; Format="flowed" Errors-To: ffmpeg-devel-bounces@ffmpeg.org Sender: "ffmpeg-devel" Archived-At: List-Archive: List-Post: > I also am not accepting a hardcoded timebase of microseconds. > Rounding really matters for subtitles, since presenting them > a frame early or late is unacceptable That's simply not true. I don't accept or deny a hardcoded microseconds timebase; that's beyond my knowledge to judge. What I say is not true is the other sentence: "presenting them a frame early or late is unnaceptable". That's a gross exaggeration, and should not be a blocker. In my country everyone uses subtitles since decades ago, and people cares about timing only when there's seconds of desync. Yeah, seconds in plural: a single second most likely would be accepted. We're talking about dozens of frames here. Of course, I wouldn't say "innacurate is right". But I wouln't also block other people's work using unreal standards. Now, DRIFTING would be a different beast, and microseconds leaks should be a serious issue for 24/7 streams. I don't see people debating such problem, and "a sigle frame off" is a wrong angle for talking milliseconds precision and rounding. Also, I did some tests with softworkz code, and timings seems working fine with production inputs. I saw several people here talking about complex graphs with different timebases, and changes between subtitle formats. I believe the debate would be much less abstract if somebody could kindly put some example here we could all test for ourselves. I understand nobody could have a full idea of all possible scenarios: that would be unfair to ask for. But I believe people with observations about possible breaking use cases would have such use cases more likely available in mind and could share them with us. I DID actually find problems with timings in softworkz code. But those problems were anything like the things debated here. You see, I've tried to use setpts and asetpts in my graphs, yet there's no ssetpts. Other filters had the same problem. Also, there are live-streaming muxers and codecs that does not support subtitles. See this, for example: https://github.com/FFmpeg/FFmpeg/blob/master/libavformat/hls.c#L506 Or this: https://github.com/FFmpeg/FFmpeg/blob/master/libavformat/dashenc.c#L1066 But I believe those issues can be handled isolated once there's subtitle filtering implemented, so I don't consider them part of this debate per se. _______________________________________________ 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".