This script will check if the video file has a 4:3 aspect ratio (box) and if so, it will change it to 16:9 (wide).
It also supports auto aspect ratio change for URLs/Streams running with youtube-dl/yt-dlp on mpv.
Its intended purpose is for videos or libraries with old 4:3 aspect ratio content. Instead of having black bars on the sides or manually changing the aspect ratio every time, it will stretch it to 16:9 aspect ratio automatically.
Works well with a mixed aspect ratio playlist. It will only change the aspect ratio of 4:3 videos, leaving the rest to their default aspect ratio.
Simply place boxtowide.lua in the corresponding mpv scripts location of your operating system:
- Windows:
%APPDATA%\mpv\scripts\orC:\users\USERNAME\AppData\Roaming\mpv\scripts\ - Linux:
~/.config/mpv/scripts/or/home/USERNAME/.config/mpv/scripts/ - Mac:
~/.config/mpv/scripts/or/Users/USERNAME/.config/mpv/scripts/
The script doesn't write or alter configuration files, so removing the boxtowide.lua script from the mpv scripts folder is all that is needed to uninstall/disable.
This script adds parameters to mpv, such as --video-aspect-override to -1 (default) to accurately check and change aspect ratio if needed. If you have something in mpv.conf, scripts or in commandline that changes --video-aspect-override or --video-params/aspect, it will be affected.
You'll still be able to manually change the aspect ratio afterwards during playback. For example if you have a keybind set within input.conf to cycle through aspect ratio values like:
CTRL+a cycle-values video-aspect-override "16:9" "16:10" "4:3" "2.35:1"
A screenshot of mpv running a 4:3 aspect ratio video that has been changed automatically to 16:9 aspect ratio on Windows 10.
