2018-04-15 16:42 GMT+02:00, Marton Balint <c...@passwd.hu>: > > > On Sun, 15 Apr 2018, Timo Teräs wrote: > >> Calculate DAR with assumed SAR 1:1 when SAR is undefined. Same >> assumption is done in ffplay to create the play window. Usually >> DAR is more useful metadata than SAR when e.g. choosing which >> media of multiple versions to use to fit the display. >> >> Normally undefined SAR means 1:1. E.g. in mov/mp4 files there's >> 'pasp' atom to explicitly define SAR. If that is not specified, >> the video codec's SAR should be used. Should it be also undefined, >> the SAR should be assumed to be 1:1. It makes sense to not change >> SAR in the demux info, so ffmpeg can make copies with matching >> atom structure and codec extra data. So the simplest way to >> report DAR is assume SAR 1:1 when undefined. >> >> Signed-off-by: Timo Teräs <timo.te...@iki.fi> >> --- >> This applies on top of the previous DAR/SAR reporting fix: >> https://ffmpeg.org/pipermail/ffmpeg-devel/2018-April/228141.html >> >> For more details behind this patch, see: >> https://ffmpeg.org/pipermail/ffmpeg-devel/2018-April/228146.html >> >> This seemed to be the most simple and logical fix. Alternatively, >> we could add a new 'effective_display_aspect_ratio' or add a flag >> to enable this assumption if the existing functionality should be >> kept unchanged. I felt this would be the most sensible thing to do. >> I am happy this if there's a more desirable approach to the issue. >> >> Hopefully this and the DAR/SAR reporting fix can be applied before >> next release tag. Thanks for considering! > > I don't think it's good idea to generally assume 1:1 display_aspect_ratio > for every undefined sample aspect ratio.
I don't think that this is what the patch does (and it would definitely be wrong and not what FFplay does), I don't know if the patch is a good idea though. Carl Eugen _______________________________________________ ffmpeg-devel mailing list ffmpeg-devel@ffmpeg.org http://ffmpeg.org/mailman/listinfo/ffmpeg-devel
