There are a few different ways you can create a progress bar depending on how you want it to look.
If you just want a solid bar overlayed on to your video then you can use the HTML asset and animate it’s width. I created an example here:
You can set the video width and duration and it will animate a bar. The example is in Node.js but should be easy to port to other languages if needed.
Here is an example output:
You could probably adapt this to set the position of a graphic using offsets if you wanted to move something across the screen.
Another way would be to pre-render an animation in After Effects (or similar tool), export the video at the width and height you need and then you can import that video in to your edit. This will only work if the length of your video is always the same however and you know this in advance.
Thanks @lucas.spielberg The code is helpful, seems to be working, although the progress bar isn’t quite smooth. This is the best solution so far though, didn’t think of this being a possibility before, and might solve some other problems as well.
I wonder, though, what impact this sort of solution has on credits (cost) and rendering time, as it looks like it produces 256 extra clips just to create the process bar.
To clarify, in our videos we might need 5-10 progress bars per video, which would mean 1280 - 2560 extra clips.