# Unisill

> Glue compressor: RMS sensing that blends feed-forward and feedback detection, a soft knee and a release that speeds up on transient material and relaxes on sustained material.

- Engine id: `org.sournd.dynamics.unisill`
- Category: Dynamics
- Licence: paid: £2.99 an effect or £4.99 a synth, once (owned for good, with updates), or included in the Everything plan (£14.99 a month)
- Version: 1.0.0
- Latency: 0 samples
- Tail: 2 s
- Sidechain input: no
- Channels: mono or stereo
- Audio demo: https://sournd.com/static/preview/demos/unisill.mp3 (a drum loop, default settings)

## Parameters

The id is the C ABI parameter id and the JUCE parameter id (as a decimal string).

| Id | Key | Name | Min | Max | Default | Unit | Taper |
|---|---|---|---|---|---|---|---|
| 0 | `threshold_db` | Threshold | -60 | 0 | -18 | dB | linear |
| 1 | `ratio` | Ratio | 1 | 100 | 3 | x | log |
| 2 | `attack_ms` | Attack | 0.1 | 1500 | 10 | ms | log |
| 3 | `release_ms` | Release | 5 | 2000 | 250 | ms | log |
| 4 | `knee_db` | Knee | 0 | 24 | 8 | dB | linear |
| 5 | `feedback_pct` | Feedback blend | 0 | 100 | 35 | % | linear |
| 6 | `auto_release_pct` | Auto release | 0 | 100 | 50 | % | linear |
| 7 | `makeup_db` | Makeup | 0 | 24 | 0 | dB | linear |
| 8 | `mix` | Mix | 0 | 100 | 100 | % | linear |
| 9 | `sidechain_hpf_hz` | Sidechain high-pass | 20 | 500 | 60 | Hz | log |

## Use it in JUCE

CMake ([quick start](/docs/juce/index.md)):

```cmake
juce_add_module(path/to/sournd_engine)
target_include_directories(MyPlugin PRIVATE path/to/include)
target_link_libraries(MyPlugin PRIVATE sournd_engine path/to/libsournd_cabi.a)
```

C++:

```cpp
#include <sournd_engine/sournd_engine.h>

sournd::SourndEngine engine { "org.sournd.dynamics.unisill" };
juce::AudioProcessorValueTreeState parameters { *this, nullptr, "Parameters",
    sournd::SourndEngineParameters::createLayout (engine) };
sournd::SourndEngineParameters bridge { engine, parameters };

// prepareToPlay
engine.prepare ({ sampleRate, (juce::uint32) maximumBlock, 2 });
bridge.prepare (sampleRate);
setLatencySamples ((int) engine.latency());

// processBlock
bridge.apply ((uint32_t) buffer.getNumSamples());
juce::dsp::AudioBlock<float> block { buffer };
engine.process (juce::dsp::ProcessContextReplacing<float> { block });

// get/setStateInformation: hold getCallbackLock() around saveState / loadState,
// so state work never overlaps processBlock (full example: /docs/juce/)
```

Plain C:

```c
sournd_engine *e = NULL;
if (sournd_engine_create("org.sournd.dynamics.unisill", &e) == SOURND_OK) {
    sournd_engine_prepare(e, 48000.0, 512);
    sournd_engine_set_param(e, 0, -18); /* Threshold */
    sournd_engine_process(e, in, out, 2, frames);
    sournd_engine_destroy(e);
}
```

## How it is made

Original sOURnd design blending general techniques: log-domain gain computer with quadratic soft knee, one-pole RMS detection, feed-forward/feedback detector blend, crest-factor program-dependent release.

## Ask your AI

Paste this into your coding assistant:

```text
Add the sournd engine org.sournd.dynamics.unisill to my JUCE plugin. Follow https://sournd.com/docs/juce/index.md
and the engine reference at https://sournd.com/engines/unisill/index.md. Expose every parameter through APVTS.
```