03edb17180
The profile schema accepted `[compressor] enabled = false` (and the
`transparent` and `bypass-all` profiles set it) but the flag was
parsed and dropped — `build_compressor_config()` never threaded
it through to `CompressorConfig`, and `Compressor::process_frame`
had no enable branch. Result: the "compressor and AGC bypassed"
claim in `transparent.toml`'s description was a lie; the
compressor ran on every sample regardless of the profile knob.
Surfaced by Codex's review of the project.
Changes
- `headroom_dsp::CompressorConfig` gains `pub enabled: bool`
(default true). `Compressor::process_frame` early-returns
`(left, right)` and resets `last_gr_db = 0.0` when disabled,
so bus meters / `gain_reduction_db()` report the truthful
"compressor off" state instead of the stale last value.
- `headroom_core::profile::Profile::build_compressor_config`
threads `self.compressor.enabled` into the materialised
`CompressorConfig`. Live profile reload picks this up
automatically — the next `set_config` push from
`setting.set` / `profile.use` flips the audio thread.
- Regression unit test `disabled_compressor_passes_signal_through_unchanged`:
drive a -6 dBFS sine that would compress hard with enabled +
aggressive thresholds, assert output equals input exactly and
GR is zero.
What this does NOT change
- **Limiter has no `enabled` flag** and intentionally remains
always-on. It is the daemon's hard contract (the -0.1 dBTP
ceiling on the processed route, advertised in the README and
in PLAN §3). Users who don't want limiting should route
bypass; the `bypass-all.toml` profile's own comment confirms
the limiter is "still configured as a fail-safe in case a
stream lands on the processed sink anyway."
Verified
186 tests pass (+1 for the disable path); clippy clean at
-D warnings --all-targets.
Live A/B against `pw-cat /tmp/sine` (-6 dBFS sine into
processed): default profile compresses at -4.5 dB GR;
`headroom profile use transparent` flips to 0.00 dB GR
exactly on the next meter tick.
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| .. | ||
| benches | ||
| src | ||
| Cargo.toml | ||
| README.md | ||
headroom-dsp
DSP kernels for Headroom. Pure Rust, no dependencies.
Limiter— feed-forward true-peak brickwall with configurable oversampling (1/2/4/8×), lookahead, hold, and release.Compressor— log-domain feed-forward with peak or RMS detector, soft knee, attack/release, and optional auto-makeup.AttackRelease— exponential envelope follower (peak / inverse-gain modes).DelayLine,SlidingMaxBuffer,PolyphaseUpsampler,PolyphaseDownsampler— supporting building blocks.
All processors are allocation-free in their process_* methods.
Construction allocates; do not construct in the audio thread.
License
MPL-2.0.