Adding a ton of clips to a grid takes a lot of time, and is boring. You have to get the grid looking good, everything lined up… yuck.
So I made a couple of scrips to make it suck less.

For this I found a long video clip (around 2 hours long) and popped it into my AE project.
I trimmed the new comp down to 6 minutes (about as much as I can handle in one sitting).
I decided that 16:9 good enough resolution is around 800×450 for any single video.
This makes my master video 3200×1350 big enough for 12 clips (4 columns & 3 rows).
My video wall only needs 10, so good enough for me.

Screen Shot 2016-03-18 at 2.38.56 PM

First I convert my 2+ hour video into a pre-comp (I just think it is easier to work with pre-comps).
To that pre-comp I added a Time Remap – because I don’t want all the videos to look the same.
Here is the code I added to re-time the videos:

Next I adjust the position of the pre-comps on the main comp with a little code in the “Position” value:

That is it. Duplicate that layer until you get sick.

Screen Shot 2016-03-18 at 2.37.30 PM

I came in later and added a NODE to adjust the number of Columns and Rows – In case I want to clean up that If/ELSE (it is really bugging me – this should be 2 lines of code not this knot of christmas lights — disgusting), and more importantly I added a slider to globally control the time for each video to start (this was stupidly helpful).

Screen Shot 2016-03-18 at 2.38.14 PM