Downward expander with configurable ratio, hysteresis, and sidechain. More...
#include "../Core/DspMath.h"#include "../Core/AudioSpec.h"#include "../Core/AudioBuffer.h"#include "../Core/DenormalGuard.h"#include "../Core/StateBlob.h"#include <algorithm>#include <array>#include <atomic>#include <cmath>#include <cstddef>#include <cstdint>#include <numbers>#include <vector>
Go to the source code of this file.
Classes | |
| class | dspark::Expander< T > |
| Downward expander with ratio control, hysteresis, and sidechain. More... | |
Namespaces | |
| namespace | dspark |
| Main namespace for the DSPark framework. | |
Detailed Description
Downward expander with configurable ratio, hysteresis, and sidechain.
A generalization of the noise gate: instead of fully closing (infinite ratio), the expander applies a configurable ratio below the threshold. Includes an integrated envelope detector to prevent low-frequency intermodulation distortion, a true-stereo sidechain high-pass filter, and an external sidechain input (processBlock(audio, sidechain) keys the detector from the sidechain signal; a sidechain shorter than the audio block falls back to the internal key so the caller's buffer is never over-read).
Threading model:
- prepare() / reset() / getState() / setState(): setup or UI threads only, never concurrently with processBlock().
- All parameter setters are RT-safe atomic publications from any thread; the audio thread picks them up at the next block.
- getGateState() / getCurrentGainDb() are approximate cross-thread metering reads (unsynchronized).
- processBlock() before prepare() is a pass-through (it used to hard-mute: the smoothing coefficients were still zero, freezing the gain at 0).
Channels beyond the 16-channel detector cap still receive the (scalar) expander gain; only the per-channel sidechain HPF state is capped.
Dependencies: DspMath.h, AudioSpec.h, AudioBuffer.h, DenormalGuard.h, StateBlob.h.
Definition in file Expander.h.
