>"Time-domain codecs (such as ADPCM) need significantly higher bitrates for this quality. Subband codecs, such as MP2, have much worse quality at comparable bitrates, and more “modern” transform codecs, such as MP3, usually need at least an 80–100 MHz CPU. For this GBA demo, no existing codec would fit the bill.

So Aikku93 not only wrote a decoder in ARM assembly, but also created a whole new codec: The Ultra Low Complexity Codec (ULC).

ULC is a transform codec and somewhat similar to MP3. ULC transforms slices of PCM data into the frequency domain. Like MP3, it uses the Modified Discrete Cosine Transform (MDCT) to do so. But unlike MP3, it does not split the signal into multiple bands (ULC's MDCT is “full-band”). Where MP3 uses classic entropy encoding (Huffman specifically), ULC does… not. Instead, transformed coefficients are stored with a very simple nibble-based syntax.

In short: ULC is what MP3 could have been. The same core idea, but without the cruft around it."

Nice!

This would make a great audio compressor / decompressor to run on older computers, on older operating systems, on older more resource-constrained hardware (not just the N64) !

Anyway, really nice!

Related:

https://en.wikipedia.org/wiki/Modified_discrete_cosine_trans...