tis 2024-01-30 klockan 10:47 +0100 skrev Tomas Härdin: > fre 2024-01-26 klockan 10:12 -0800 skrev Pierre-Anthony Lemieux: > > On Fri, Jan 26, 2024 at 10:02 AM Cédric Le Barz > > <cleb...@ektacom.com> > > wrote: > > > > > > Set aspect ratio for jpeg2000 images. > > > > "The image area on the reference grid is defined by its upper left > > hand reference grid point at location (XOsiz, YOsiz), and its lower > > right hand reference grid point at location (Xsiz – 1, Ysiz – 1)" > > (15444-1, 8.2) > > > > AFAIK setting the MXF aspect ratio item to the ratio of the image > > pixel dimensions only works if (a) the pixel aspect ratio is 1 and > > (b) > > the video is not interlaced -- see 6.2.1.2 and Annex H at > > https://pub.smpte.org/doc/st2067-21/20221124-pub/. > > You also need to know the display rectangle. If for example VBI lines > are present then these might also need be cropped, in addition to the > cropping done at the J2K level. Sometimes container and essence > disagree on what SAR is, which affects the DAR. Which value is the > correct one typically depends on business logic > > A demuxer is the wrong place to put logic like this
Wups, missed that this is a muxer patch, not a demuxer one. Anyway, this patch is very wrong. DAR is a container level thing. We shouldn't take it from the essence unless there is overwhelming reason to do so. My point about VBI still stands, in modified form: if VBI lines are present then this patch would write a bogus DAR Much of the logic currently in mxfenc.c should probably live somewhere higher up since MOV also supports some of these things /Tomas _______________________________________________ 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".
