How to place a video at a specific location on top a larger static background image using ffmpeg?

Question

I have installed a current build of ffmpeg in order to gain access to the -filter_complex option in hopes to be able to use a video as an overlay over a static background image that's larger than the video.

Initially I'm simply trying to get the overlay of the video over the static background image to work with the following command (which does not work):

ffmpeg -loop 1 -i background.png -i overlay.mov -filter_complex overlay -shortest -y output.mov

The output.mov only has a single frame composed of the background.png file with no video overlay.

How can I make this work and additionally add a specific coordinate location for the video atop the background?

BONUS: with a singular command, is it also possible to resize the overlay video to a larger size while placing it atop the bg image?

Answer 1

That command works fine for me (using 0.11.1.git-56ae592 built on Jul 19 2012 or N-42914-gf5a5b43 built on Jul 26 2012); the problem is elsewhere. What version of FFmpeg are you using? (There are current builds for a number of versions.) Are there any messages in the output suggesting that something's not working?

To answer your other questions:

• You can set the coordinates of the overlay filter to x=100, y=50 (from top-left) like so:

  ... -filter_complex overlay=100:50 ...
  

• Resizing the background overlay can be done using the scale filter:

  ... -filter_complex "[0] scale=1280:960 [bg]; [bg][1] overlay" ...
  

  ... -filter_complex "[1] scale=1280:960 [over]; [0][over] overlay" ...
  

• As an addendum, you shouldn't need -filter_complex to do this, something like:

  ffmpeg -i over.mov -vf "movie=background.png [bg]; [bg][in] overlay" out.mp4
  

  should also work. I say "should" because that command actually segfaults with the versions of FFmpeg I tested on, but the command syntax can handle what you want to do without -filter_complex.