[LeoPanthera]

FLAC is always lossless, but has a variable compression ratio so you can trade compression for speed.

Using the command line "flac" tool, "flac -0" is the fastest, "flac -8" is the slowest, but produces the smallest files.

In my experience, 0-2 all produce roughly equivalent sized files, as do 4-8.

[makapuf]

I tried passing stereo wavs in 2 x 16bits (4bytes) as rgba for qoi but I haven't been very successful.

[adgjlsfhk1]

That's not surprising. QOI is heavily optimized for images which tend to be relatively continuous, while audio tends to oscillate a ton.

[cycomanic]

It might work to fourier transform first (although likely will kill performance)

[adgjlsfhk1]

fixed size FFT (eg length 64) can be made scary fast.