Q:

How to put water mark in the bottom right using -filter_complex with padding FFmpeg

Currently this watermark is showing at the top right of the screen, i'd ideally like the bottom right.
overlay=x=(main_w-overlay_w)-30:y=(main_h-overlay_h)/(main_h-overlay_h)+30

A:

Bottom right:
overlay=main_w-overlay_w:main_h-overlay_h

with the short option names:
overlay=W-w:H-h

With 5 pixels of padding:
overlay=main_w-overlay_w-5:main_h-overlay_h-5

with the short option names:
overlay=W-w-5:H-h-5

Example of a complete command:
ffmpeg -i main.mp4 -i image.png -filter_complex "overlay=W-w-5:H-h-5" -c:a copy output.mp4

See overlay filter documentation for more info.

