SamandClaude Fable 5.1
9baf42d900
The notes and comments say what is true of the 1.12.1 client and cite the byte address; the record numbers, the dates and the private repository's file paths go. Co-Authored-By: Claude Fable 5.1 <noreply@anthropic.com>
2.4 KiB
benilla's kira fork — what differs from upstream, and how to check
Upstream: tesselode/kira, MIT OR Apache-2.0, version
0.12.1 — the version the workspace lock resolves to. Wired in through [patch.crates-io] in
the workspace root, the way lua-src is. The crate is copied from the cargo registry as
published (src/, Cargo.toml, README.md) plus the two licence files from the repository;
upstream files are CRLF and are left so, except the one file patched.
Why a fork exists at all
The mixer runs on benilla's own audio render thread (sound/output), and with a raid buffing
itself — a dozen live voices, most of them spatial — that thread cost ~1.5 ms of every 60 Hz
frame on an M2 Air (a sampled profile with a dozen spatial voices playing, Track::process
two thirds of it). Upstream's sub-track process spatializes every
frame: two vector normalizes, a length, the attenuation curve and a dB→amplitude powf per
frame per spatial track, then two more powfs per frame for the volume tween and the fade. At
48 kHz × 12 tracks that is ~1.7 M powfs a second plus the vector math, for gains that change
imperceptibly across a 10 ms chunk. FMOD 3 — the mixer the real client delegates to — updates
pan and attenuation per mixer update, not per sample.
The one patch — src/track/sub.rs
Track::process evaluates the spatial gains (attenuation, left/right ear gain, the mono fold)
and the volume × fade amplitude at the chunk's two ends and interpolates them linearly across
the chunk. SpatialData::spatial_gains is spatialize factored into a value; spatialize
itself is kept, unused, so the factoring can be diffed against it. A chunk is the output
device's buffer — 512 frames, ~10.7 ms, sound/output::DEVICE_BUFFER_FRAMES.
What changes audibly: nothing a listener can name. A source crossing an ear's axis within one chunk pans linearly in gain over 10 ms instead of following the dot product per sample; a volume tween ramps linearly in amplitude across each chunk instead of in decibels. Both are below the granularity the reference itself updates at.
How to check
git diff --no-index <registry>/kira-0.12.1/src/track/sub.rs third_party/kira/src/track/sub.rs
(after sed 's/\r$//' on the upstream copy) shows the patch and nothing else; every other file
is byte-identical to the registry crate. The mixer's own tests (cargo test -p benilla-app sound::) run against the fork.