Wuffs’ PNG image decoder

Post by nigeltao » Thu, Apr 08, 2021, 1:30 PM UTC

bschwindHN wrote: post #140

nigeltao wrote: post #139

Earlier quoted context omitted.

> I'm curious if it is at all competitive with the Wuffs decoder You could try adapting https://github.com/google/wuffs/tree/main/script/bench-rust-... > https://github.com/bschwind/png-decoder Note that statements like: let bytes_per_scanline = ((header.width * header.bit_depth as u32 * header.color_type.sample_multiplier()) + 7) / 8; can silently overflow a u32 if width is 0x800_0000, bit_depth is 8 and sample_mult…

> You could try adapting ... Do you accept PRs for the Rust benchmarks? My code is nowhere near competitive to the Wuffs implementation, but it would be a fun goal to work towards. > Note that statements like ... can silently overflow a u32 Thank you for catching that, I'll go through the entire codebase and try to fix those up. That's a part of Rust that always makes me feel uneasy - the compiler will tell you if yo…

Post by rurban » Sat, Apr 10, 2021, 5:41 AM UTC

nigeltao wrote: post #137

rurban wrote: post #60

Looks good, but has somewhat widely false claims: > SMHasher is a test and benchmark suite for a variety of hash function implementations. It can provide data for claims like “our new Foo hash function is faster than the widely used Bar, Baz and Qux hash functions”. However, when comparing Foo to CRC-32, be aware that a SIMD-accelerated CRC-32 implementation can be 47x faster than SMHasher’s simple CRC-32 implementat…

> smhasher implements both Ah, I'm based on aappleby/smasher, which is what the original location ( http://code.google.com/p/smhasher ) redirects to. I didn't realize that you have a more active fork. > not just 47x faster, but 5000x faster It's 47x faster: https://github.com/rurban/smhasher/issues/189