Progress Report: Migrating to Ren'Py 8.1 and the AVIF Image Format

Hey y'all, Scott heeeeere. 

No, not really. I just typed "Hey y'all" and then the voice of Scott the Woz completed the sentence in my brain, so I had to follow through. 

So Ren'Py 8.1 has now officially dropped and I'm hard at work on my end replacing the existing webp format files in Sileo with crispy new avif files created from lossless sources wherever possible. Unfortunately I don't have lossless files for every single image, but I do for most. Even for those that I don't, I usually have high quality jpegs that are several MB in size which will still serve to produce a much nicer file than what is already in the game. I'm avoiding converting the existing webp files wherever possible, though there is the odd image where this is necessary (IE: a case where a lossless file containing changes over the one I actually have has gone missing). I've also expedited the process for the gallery thumbnails and just converted those as that would likely take days to recreate from the PSDs. The good news is the files converted from webp don't degrade any and are still notably smaller than they were, but the files we're converting from source look significantly better than the existing files while also being significantly smaller in size, so that's obviously the preference!

If you want an idea of just how significant of an improvement the move to avif is, here's a little side by side. Open this fullscreen and look closely at the details.

Left is WEBP (167kb). Right is AVIF (108kb). 

Not only is the avif notably sharper and more detailed, but significantly smaller to boot! An unfortunate side effect of the upgrade to Ren'Py 8.1 is that the Ren'Py component of Sileo has increased in file size by 15MB~ or so, but even having only replaced the backgrounds so far (as well as having converted the gallery thumbnails), we're already down 6MB in file size over 0.54.1. So we've saved roughly a little over 20MB on just the backgrounds and thumbnails alone using higher quality or equivalent files! That's the definition of a win win situation. 

Now this is a fairly time consuming process, it's gonna take a few more days at least to get everything swapped over, but rest assured the next update will not only offer an increase in visual fidelity but also a notably reduced file size! 

In other news, I've tested out the browser functionality in Ren'Py 8.1 and can confirm that video playback is working perfectly! This means the next Sileo update will feature working animated sequences in the browser based version, effectively bringing that version up to parity with the downloadable versions. Performance seems really good too, though I've only tested on high end devices so far. 

As for the migration to Ren'Py 8.1, so far the only thing that needed to be fixed was the update checker which, ironically, hasn't been working in current and previous updates for a little while and I just never noticed. I fixed it, but then had to fix it again for Python 3! It's all up and running now though and so far I haven't found any other compatibility issues with the migration. So far so good! 

Anyway, that's all for now. I'll likely report back in once the move to AVIF is completed and gush over the significantly reduced filesize of the game. See you then!