How to add images to video at specific timestamps for a short time? I would like to create a blank video and add images (occupying the entire screen) throughout the video for a very short amount of time (a frame or a second). 

I found a command to create the blank video:


  ffmpeg -t 7200 -s 640x480 -f rawvideo -pix_fmt rgb24 -r 25 -i /dev/zero empty.mpeg


Now let's say I have an image. I want to insert the image into the video at the 8th second (or some other arbitrary second), and I want it to remain there only briefly. 

How can I do this?
Use the color, scale2ref, and overlay filters. Include the enable option with an expression.

ffmpeg -f lavfi -i color=c=black:s=640x480:d=7200 -i iamge.png -filter_complex "[1][0]scale2ref=oh*mdar:ih[fg][bg];[bg][fg]overlay=(W-w)/2:(H-h)/2:enable='eq(t,8)'[v]" -map "[v]" output