My app stores and transports lots of groups of similar PNGs. These aren't compressed well by official algorithms like .lzfse, .lz4, .lzbitmap... not even bz2, but I realized that they are well-suited for compression by video codecs since they're highly similar to one another.
I ran an experiment where I compressed a dozen images into an HEVCWithAlpha .mov via AVAssetWriter, and the compression ratio was fantastic, but when I retrieved the PNGs via AVAssetImageGenerator there were lots of artifacts which simply wasn't acceptable. Maybe I'm doing something wrong, or maybe I'm chasing something that doesn't exist.
Is there a way to use video compression like a specialized archive to store and retrieve PNGs losslessly while retaining alpha? I have no intention of using the videos except as condensed storage.
Any suggestions on how to reduce storage size of many large PNGs are also welcome. I also tried using HEVC instead of PNG via the new UIImage.hevcData(), but the decompression/processing times were just insane (5000%+ increase), on top of there being fatal errors when using async.