Quoting Vittorio Giovara (2021-03-30 18:55:27) > Hello, > I was debugging an issue with a video file containing an invalid > display matrix, probably produced by a non conforming software. > > The content of the matrix is: > 00000000: 0 65536 0 > 00000001: -1 0 0 > 00000002: 0 0 1073741824 > > The -1 (stored as 4294967295) was probably a 1 shifted 32 times instead > of 16. The problem is that this value is bypassing the validation check > in the code below, and the resulting computed SAR value becomes 1:65536. > > This change interprets extremely low entries as invalid and makes sure > to skip them in the SAR computation. This passes fate, but I haven't been > able to test this extensively. > Please see the attached patch, any feedback or better solution is welcome. > -- > Vittorio > > From 54ec72276cbb6f2536e73ff81b7d49a736ec1900 Mon Sep 17 00:00:00 2001 > From: Vittorio Giovara <vittorio.giov...@gmail.com> > Date: Tue, 30 Mar 2021 16:47:39 +0200 > Subject: [PATCH] mov: Skip computing SAR from invalid display matrix elements > > ---
I'm wondering if that code should set sample_aspect_ratio at all. There are two other bits of code in mov.c that may set sample_aspect_ratio, and it's not clear whether it applies _in addition_ to the display matrix or not. -- Anton Khirnov _______________________________________________ ffmpeg-devel mailing list ffmpeg-devel@ffmpeg.org https://ffmpeg.org/mailman/listinfo/ffmpeg-devel To unsubscribe, visit link above, or email ffmpeg-devel-requ...@ffmpeg.org with subject "unsubscribe".
