Hi, I would like to propose a change to the documentation for the overlay filter. The overlay filter does not detect pixel aspect ratio. This causes improper display resolution when overlaying smaller images on a larger image. A common example of this would be overlaying an SD source on an HD one. The documentation does not mention the fact that overlay ignores pixel aspect ratio because it is a pixel by pixel operation. It would be nice to remind people that they need to overlay pictures with the same pixel aspect ratio or perform a scaling operation. One common example of this would be overlaying SD video on a HD background. I tried to make a patch, but I couldn't find the right file.
It would be nice to add something like this at the end of the 9.83 section just prior to section 9.83.1 in what becomes ffmpeg-filters.html. Please let me know if I need to submit this in some other form. Please note that overlay is a pixel per pixel operation so a scaling operation will be required to properly combine sources with different source aspect ratios such as SD and HD video. _______________________________________________ ffmpeg-devel mailing list ffmpeg-devel@ffmpeg.org http://ffmpeg.org/mailman/listinfo/ffmpeg-devel
