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 7097440F83 for ; Sun, 9 Apr 2023 17:53:09 +0000 (UTC) Received: from [127.0.1.1] (localhost [127.0.0.1]) by ffbox0-bg.mplayerhq.hu (Postfix) with ESMTP id C774968BCE7; Sun, 9 Apr 2023 20:53:05 +0300 (EEST) Received: from iq.passwd.hu (iq.passwd.hu [217.27.212.140]) by ffbox0-bg.mplayerhq.hu (Postfix) with ESMTP id 755AA68BB52 for ; Sun, 9 Apr 2023 20:52:59 +0300 (EEST) Received: from localhost (localhost [127.0.0.1]) by iq.passwd.hu (Postfix) with ESMTP id 5828EE70EC for ; Sun, 9 Apr 2023 19:52:15 +0200 (CEST) X-Virus-Scanned: amavisd-new at passwd.hu Received: from iq.passwd.hu ([127.0.0.1]) by localhost (iq.passwd.hu [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id RSe_CE5g0KhK for ; Sun, 9 Apr 2023 19:52:13 +0200 (CEST) Received: from iq (iq [217.27.212.140]) by iq.passwd.hu (Postfix) with ESMTPS id 03D2FE60BF for ; Sun, 9 Apr 2023 19:52:13 +0200 (CEST) Date: Sun, 9 Apr 2023 19:52:12 +0200 (CEST) From: Marton Balint To: FFmpeg development discussions and patches In-Reply-To: <20230409172004.GD1164690@pb2> Message-ID: References: <20230408183724.12479-1-cus@passwd.hu> <20230408211411.GC4538@pb2> <9258ec2c-6635-1edc-f695-1cc2629c6ac8@passwd.hu> <20230409172004.GD1164690@pb2> MIME-Version: 1.0 Subject: Re: [FFmpeg-devel] [PATCH] avformat/mov: remove hack breaking creation time parsing 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: On Sun, 9 Apr 2023, Michael Niedermayer wrote: > On Sun, Apr 09, 2023 at 03:49:33PM +0200, Marton Balint wrote: >> >> >> On Sat, 8 Apr 2023, Michael Niedermayer wrote: >> >>> On Sat, Apr 08, 2023 at 08:37:24PM +0200, Marton Balint wrote: >>>> Commit 23eeffcd48a15e73fb2649b712870b6d101c5471 added a hack to support invalid >>>> files where the creation date was encoded as a classic unix timestamp. This >>>> broke however valid files having creation dates before the unix epoch. >>>> >>>> Signed-off-by: Marton Balint >>>> --- >>>> libavformat/mov.c | 3 +-- >>>> 1 file changed, 1 insertion(+), 2 deletions(-) >>> >>> This results in: >>> @@ -1,11 +1,11 @@ >>> - creation_time : 2012-06-20T20:58:31.000000Z >>> - creation_time : 2012-06-20T20:58:31.000000Z >>> - creation_time : 2012-06-20T20:58:31.000000Z >>> + creation_time : 1946-06-20T20:58:31.000000Z >>> + creation_time : 1946-06-20T20:58:31.000000Z >>> + creation_time : 1946-06-20T20:58:31.000000Z >>> >>> Are you sure that 1946 is the correct creation date and not 2012 ? >> >> If you are referring to the file in ticket #1471, yes, 1946 is consistent >> with what mediainfo shows for creation time. Obviously 1946 was not the >> intended creation time, but that does not warrant us to break files where >> 1946 is the *intended* creation time. Proper way to fix the original issue >> would be to detect the device and software version which produces the >> invalid files, and only apply the hack there. But I don't think that is >> doable here, the file does not seem to contain any device or software >> information. > > what do you mean by intended creation time? > the file format did not exist in 1946. and all the codecs also didnt exist > so when you encounter a file that says its from that time it must be crafted > later and backdated or that bug. > we know the bug is a real thing > do you want to support crafted and backdatred files? if so can you explain > the usecase for that ? http://ffmpeg.org/pipermail/ffmpeg-user/2023-April/056265.html Alternatives I can think of: 1) A -unix_time switch what Anton proposed 2) doing strict compliant parsing only if mdat version is 1 so creation time is 64bit. And change our muxer to write mdat version 1 by default, so ffmpeg will be able to read back what it has written... Regards, Marton _______________________________________________ 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".