[FFmpeg-devel] Overlay documentation does not mention pixel aspect ratio.
michael at niedermayer.cc
Mon Nov 9 22:59:26 CET 2015
On Sun, Nov 08, 2015 at 02:44:02PM -0800, Zach Swena wrote:
> 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.
a git patch for doc/filters.texi would be ideal
> 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 at ffmpeg.org
Michael GnuPG fingerprint: 9FF2128B147EF6730BADF133611EC787040B0FAB
What does censorship reveal? It reveals fear. -- Julian Assange
-------------- next part --------------
A non-text attachment was scrubbed...
Size: 181 bytes
Desc: Digital signature
More information about the ffmpeg-devel