[Xinlai Ni]

you may want to use the clamp() method:

clamp(value, limit1, limit2)
Return type: Number or Array.

Argument type: value, limit1, and limit2 are Numbers or Arrays.

The value of each component of value is constrained to fall between the values of the corresponding values of limit1 and limit2.

Xinlai Ni
Software Engineer, Google Inc.

[Xinlai Ni]

valueAtTime can be used for any property without ‘this’

Xinlai Ni
Software Engineer, Google Inc.

[Xinlai Ni]

https://forums.creativecow.net/thread/2/966958#966960

Xinlai Ni
Software Engineer, Google Inc.

[Xinlai Ni]

First of all, Photoshop template expects the file name to be something like: rendered[#####].psd, so the rendering program can fill in the sequence index – even if you only render 1 frame. So if you change your last line to
renderItem.outputModules[1].file = new File(retPathObj.fullName + '/' + theComp.name + '_' + i.toString() + '-[#####].psd')
It should work, except it adds 00000 to every output frame.
By the way, you can greatly simplify your code by using the renderItem.skipFrames attribute – if you set renderItem.skipFrames = 1, every other frame will be rendered, if 2, every 3rd frame is rendered. So discarding your loop, you’ll have something like:
var renderItem = app.project.renderQueue.items.add(theComp);
renderItem.timeSpanStart = 0;
renderItem.timeSpanDuration = theComp.duration;
renderItem.skipFrames = 5; // render every 6th frame
renderItem.outputModules[1].applyTemplate("Photoshop");
renderItem.outputModules[1].file = new File(retPathObj.fullName + '/' + theComp.name + '-[#####].psd')

This way, you only have 1 render item which outputs all sampled frames for you.

Xinlai Ni
Software Engineer, Google Inc.

[Xinlai Ni]

How about the whole bunch of effects under color correction? like Hue/saturation,…

Xinlai Ni
Software Engineer, Google Inc.

[Xinlai Ni]

Try Color Correction or Tint effect

Xinlai Ni
Software Engineer, Google Inc.

[Xinlai Ni]

Many websites have sound effects sorted by categories, you can probably search by the any key word (e.g., whoosh). Many have free samples available (with lower bitrate and mono) and charge you some $ for high-quality stereo ones.
Google is your good friend 🙂

Xinlai Ni
Software Engineer, Google Inc.

[Xinlai Ni]

Maybe I missed your point, but why do you want a random function to choose one out of four choices and keep it forever? Why not just pick one manually and assign it and not change it throughout the time?

Xinlai Ni
Software Engineer, Google Inc.

[Xinlai Ni]

positionExpression is of File type, yet used as string.
Why not hard-code your expression in the same jsx as this script? File I/O can be expensive.

Xinlai Ni
Software Engineer, Google Inc.

[Xinlai Ni]

Did you have quicktime installed?

Xinlai Ni
Software Engineer, Google Inc.