[FFmpeg-user] how to use alpha channel to make transparent effect

[qw]

Hi
I use the below command to place one image on one video:ffmpeg -i ./file1.mp4 -i ./file2.jpg -filter_complex overlay ./file3.mp4

But there is no transparent effect in resulting file, i.e. file3.mp4. What is the command to use alpha channel to make transparent effect?


Thanks!


B.R.


Andrew