On 25/05/18 07:57, Tobias Rapp wrote: > On 25.05.2018 07:58, Xiang, Haihao wrote: >> On Thu, 2018-05-24 at 11:15 +0100, Mark Thompson wrote: >>> >>> For example: >>> >>> ffmpeg -i bt709_input.mkv -vf colorspace=bt2020 bt2020_output.mkv >>> >>> will have the output file marked as BT.709 after this patch, where >>> previously >>> it was "unspecified". (Explicitly setting -color_primaries/-color_trc/- >>> colorspace on the output works in both cases.) >> >> I agree with you it's not worse than before as we don't get the expected >> result >> in both cases. > > Not quite: When a file says "I don't know this property value" you have a > chance to lookup the value somewhere else or use a default. When it says "I > know the value" and gives a wrong value, you completely loose trust.
Right, that is a compelling argument. I agree with you, so I definitely won't apply the patch in this form. > So in my opinion this patch should not be applied, as it possibly makes > ffmpeg generate files with wrong information where it just had no information > before. The correct approach would be to set the encoder properties from > output frame data and only write a header once the encoders have been > initialized completely. Passing the information through libavfilter should be equivalent, but yeah. Thanks, - Mark _______________________________________________ ffmpeg-devel mailing list ffmpeg-devel@ffmpeg.org http://ffmpeg.org/mailman/listinfo/ffmpeg-devel
