APG is a new image format intended to be a stopgap, lightweight alternative to AVIF until a proper/stable/mature/turnkey AVIF library with BMFF and alpha channel support exists. It is a barebones format, only capable of wrapping a single AV1 encoded image along with an optional ICC profile.
I chose the name as a nod to Fabrice Bellard's BPG format, which appears to be a lightweight alternative to HEIF for encoding single images with HEVC. This library is attempting to the same thing, only with AV1.
I pronounce it AY-peg, which rhymes with JPEG.
It isn't quite ready for primetime now, so I'd avoid it unless you're just curious about testing basic AV1 image compression. It currently encodes all images in YUV444 12-bit (with an adjustable 1-100 quality level), and doesn't support alpha. If you're discovering this library right now and a turnkey, feature complete AVIF library out there exists since I wrote this README, you should probably use that instead.
You need CMake and nasm.
Released under the Boost Software License (Version 1.0). It depends on AOM's AV1 library, which has its own (similarly permissive) license.