On Mon, Dec 10, 2018 at 13:19:57 +0100, Carl Eugen Hoyos wrote: > > units (1 byte) Units for the X and Y densities. > > units = 0: no units, X and Y specify the pixel aspect ratio > > units = 1: X and Y are dots per inch > > units = 2: X and Y are dots per cm > > Xdensity (2 bytes) Horizontal pixel density > > Ydensity (2 bytes) Vertical pixel density > The "density" (unless they intentionally reversed the meaning of the > word) is always the inverse of the aspect ratio.
That's what I was wondering as well. > Did they reverse the meaning in your opinion? > Does it make sense to argue that if the unit is "0", the meaning of the > density changes? That was my interpretation. It's a density, if units != 0, otherwise the aspect ratio. (Would a density not correspond to the SAR? I.e. not make sense with square pixels?) I was wondering what other implementations do? jpglib, *Magick. Reference images? I didn't find anything quickly, but one may need to check closer. Cheers, Moritz _______________________________________________ ffmpeg-devel mailing list ffmpeg-devel@ffmpeg.org http://ffmpeg.org/mailman/listinfo/ffmpeg-devel
