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Video Fail

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TL;DR

This was an idea for an open source alternative video chat software that ultimately failed. After having spent weeks experiencing awful video calls, I thought to myself "how hard can this be?". I learned it's quite tough.

Restrictions & Implementation

I've set myself the following restrictions:

We also set ourselves the following implementation details:

Approach

I used the Java library from sarxos as it worked just out of the box. The library is pretty complete and works reliably across multiple platforms. This unfortunately required the addition of SLF4J for logging and Bridj to provide Java bindings. I used this to implement a camera wrapper that abstracted away the details, such that I could just get a BufferedImage whenever I wanted one.

Next I implemented a basic GUI - this turned out to be the best way of debugging the compression of the images. It was relatively simple to have a basic UI display scaled images to an AWT window.

Initially I implemented JavaFastPFOR for compressing the output of the image data. Whilst it can compress relatively ordered integers pretty well, it was awful at compressing unordered integers. I tried to really limit the amount of data, compressing from RGB (3 bytes) to RBB (1 byte in 3:3:2) - still to no avail and much image quality loss. Unfortunately sending the delta of the image data didn't work either.

I then looked at simply using the ImageIO compression utilities offered in standard Java. This was slower, but massively reduced the size of the data - turns out JPEGs are pretty good at compressing image data. Whilst the size per image was approximately ~2kB (~16kb), this is well over our budget of ~30kb/s. We've expended our budget in just two images.

Conclusion

It didn't work. Turns out that winging your way through it won't beat current best methods. Some ideas to try in the future:

Hopefully when I get some free time in the future I can chase this up again.