This is Fabian Giesen (ryg) — one of the most respected voices in low-level graphics and compression on the open web — writing about a genuinely obscure corner of GPU texture compression. If you don't already follow his blog, this single post is reason enough to start.

The puzzle: ASTC (Adaptive Scalable Texture Compression) is the modern standard for compressed textures on mobile and increasingly desktop GPUs. Buried inside its bitstream is something called Integer Sequence Encoding (ISE) — a scheme for packing sequences of small integers whose ranges aren't powers of two (think trits and quints: base-3 and base-5 digits packed alongside ordinary bits). Almost no other codec, compression format, or hardware spec reaches for this technique. So why ASTC?

Why this matters to a technical audience:

• It's a rare honest engineering post-mortem of a format design choice. Most spec documents tell you what the format does. Giesen's posts consistently explain why, including the dead ends and constraints — bit-budget pressure, decoder gate-count, the awkward fact that quantization levels often want to be 3, 5, 6, or 12 rather than nice powers of two.
• ISE itself is beautiful. The trit/quint packing trick (5 trits in 8 bits, 3 quints in 7 bits) is one of those small marvels of information theory that feels like it should be more widely used — and the post likely explores exactly why it isn't.
• It connects hardware constraints to math. Texture decompression happens in fixed-function silicon on every fragment fetch. Every gate matters. ISE is a case study in how a software-feeling abstraction (variable-radix encoding) survives the trip into hardware only when the numbers line up just right.
• Audience overlap. Graphics programmers, codec authors, and compiler folks all have something to learn here — but nobody outside that intersection knows ASTC's internals well enough to evaluate the question, which is probably exactly why it has 1 point.

If you've ever wondered why production formats look weird up close — why BC7 has so many modes, why JPEG's quantization tables are what they are, why H.264 has a CABAC — this is the same kind of deep-dive, by someone who actually has the receipts.