Applying Image Overlay to Video

Overlaying an image atop a video is a good way to add content to an informative video, or a means to apply a watermark.

In it's simplest form, the command takes the form of:
- specifying two input files, a video file and an image file
- image scaling size
- image overlay location

$ cat go

#!/bin/bash

VidFile=/tmp/foo.mp4
ImgFile=/tmp/image.png
OutVidFile=/tmp/output.mp4

ffmpeg -y -i ${VidFile} -i ${ImgFile} -filter_complex "[1] scale=w=100:h=100 [tmp]; [0][tmp] overlay=x=10:y=10" -an ${OutVidFile}
mplayer ${OutVidFile}

If you want to have the overlay fade in/out the command is slightly more complex, the filter requires a fade in timestamp and a fade out timestamp.  The following command has the image fade in at 5 seconds, and begins fading out at the 10 second mark:

$ cat go

#!/bin/bash

VidFile=/tmp/foo.mp4
ImgFile=/tmp/image.png
OutVidFile=/tmp/output.mp4

ffmpeg -y -i ${VidFile} -loop 1 -i ${ImgFile} -filter_complex "[1:v]fade=t=in:st=5:d=1,fade=t=out:st=10:d=1[over];[0:v][over]overlay=x=10:y=10" -t 20 -an ${OutVidFile}

mplayer ${OutVidFile}

The end result: