This is my code that adds am image to videos, ruing via PHP:
exec('ffmpeg -i input.mp4 -i logo.png -filter_complex
"[0:v][1:v] overlay=10:10" -pix_fmt yuv420p -c:a copy output.mp4');
It works well but the problem is, the image is scaled down or up, up on the video resolution. For example in the following images the logo width is 50px but videos resolution are different:
and this one
How can I prevent the image from scaling down/up ?