Richard Geldreich's Blog

Co-owner of Binomial LLC, working on GPU texture interchange. Open source developer, Open Geospatial Consortium member, graphics programmer, former video game developer. Worked previously at SpaceX (Starlink), Valve, Ensemble Studios (Microsoft), DICE Canada.

Tuesday, January 18, 2022

Lagrangian RDO PNG

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Turns out PNG is very amendable to RDO optimization approaches, but few have really tried. This is something I've been wanting to try fo...

Wednesday, January 12, 2022

Fast AVX2 PNG writer

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281-346 megapixels/sec. when using fixed filters: https://github.com/veluca93/fpnge

Monday, January 10, 2022

LZ_XOR on canterbury corpus

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LZ_XOR 128KB dictionary, AVX2, BMI1, mid-level CPU parsing, Ice Lake CPU (Core i7 1065G7 @ 1.3GHz, Dell Laptop). Only the XOR bytes are entr...

Saturday, January 8, 2022

One nice property of highly constrained length limited prefix codes

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I realized earlier that I don't need AVX2 for really fast Huffman ( really length limited prefix ) decoding. Using a 6-bit max Huffman c...

Friday, January 7, 2022

LZ_XOR on enwik8

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First results of LZ_XOR on enwik8 (a common 100MB test file of Wikipedia data, higher ratio is smaller file): lzham_codec_devel: 74.93% .20...

Thursday, January 6, 2022

Other LZ_XOR variants

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Other LZ instruction set variants that can utilize XOR: 1. ROLZ_XOR: Reduced-Offset LZ (or here ) that uses XOR partial matches. Simplifies...

LZ_XOR

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If LZ compression is compilation , what other instructions are useful to add? I've spent the last several years, off and on, trying to f...

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About Me

Rich Geldreich: Seattle, WA, United States; Back in the day I worked for several years at Digital Illusions on things like the first shipping deferred shaded game ("Shrek" - 2001), software renderers, and game AI. Then, after working for Microsoft at Ensemble Studios for 5 years as engine lead on Halo Wars, I took a year off to create "crunch", an advanced DXTc texture compression library. I then worked 5 years at Valve, where I contributed to Portal 2, Dota 2, CS:GO, and the Linux versions of Valve's Source1 games. I was one of the original developers on the Steam Linux team, where I worked with a (somewhat enigmatic) multi-billionare on proving that OpenGL could still hold its own vs. Direct3D. I also started the vogl (Valve's OpenGL debugger) project from scratch, which I worked on for over a year. In my spare time I work on various open source lossless and texture compression projects: crunch, LZHAM, miniz, jpeg-compressor, and picojpeg.

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