Often you have video sources that use a variety of aspect ratios:
4x3 shows
16x9 shows letterboxed (with top/bottom black bars)
16x9 anamorphic shows (vertically stretched with no black bars) labelled as 4x3 (usually encoded from a STB)
16x9 anamorphic shows labelled with a 16x9 AR (usually DVD's, or Digital TV captures)
4x3 non-square pixel AVIs (eg 720x480)
16x9 non-square pixel AVIs (eg 720x480)
In Sage this often means switching aspect ratio depending on which channel/source the show was recorded from, with each aspect ratio set up to resize the video to the correct proportions.
This plugin allows these Aspect Ratio settings to be stored per:
show title
channel
capture device
or any combination of these, so that when the show is played back, the aspect ratio is switched automatically