Compressor

Compressor operator properties for Script Engine. Smooths out the dynamic range of an audio signal — loud parts are reduced so quiet parts don't get drowned out. Built on FFmpeg's compander filter, with the standard broadcast controls (input gain, threshold, ratio, attack/release, knee, makeup, mix) plus advanced detector mode, channel link, and detection type. Includes a clip indicator and a one-click reset. The dedicated Compressor V2 offers richer real-time metering and look-ahead.

Property	Type	Access	Description
`InputGainDb`	`float`	`get/set`	Pre-compression gain, in decibels. [min=-24, max=24, default=0]. 0 leaves the signal unchanged. Negative values reduce the input level; positive values boost it before the compressor processes it.
`ThresholdDb`	`float`	`get/set`	Level above which the compressor starts working, in decibels relative to full scale. [min=-48, max=0, default=-9]. Audio louder than this gets reduced by `Ratio`; audio quieter than this is left unchanged. Lower (more negative) values catch more of the signal.
`Ratio`	`float`	`get/set`	How strongly audio above the threshold is reduced. [min=1, max=20, default=4]. Expressed as N:1. 1:1 is no compression; 4:1 is a typical broadcast setting; 10:1 or higher behaves like a limiter.
`Attack`	`float`	`get/set`	How quickly the compressor reacts when the signal exceeds the threshold, in milliseconds. [min=1, max=200, default=5]. Short values catch fast transients but can sound "squashed". Longer values let initial peaks through before gain reduction kicks in.
`Release`	`float`	`get/set`	How quickly the compressor stops working after the signal drops below the threshold, in milliseconds. [min=5, max=5000, default=200]. Short values let the compressor recover quickly; long values keep the gain reduction smooth across phrases.
`Knee`	`float`	`get/set`	Soft-knee width around the threshold. [min=1, max=8, default=2.8]. Controls how gradually the compressor engages near the threshold. Low values give a hard, punchy onset; high values give a soft, gentle engagement.
`Mix`	`float`	`get/set`	Wet/dry mix between the compressed and original signals, as a percentage. [min=0, max=100, default=100]. 100 outputs only the compressed signal; 0 outputs only the original; values in between blend the two — known as parallel compression, useful for keeping the dynamics of the original while still tightening peaks.
`MakeupGainDb`	`float`	`get/set`	Extra gain applied after compression to compensate for the level reduction. [min=0, max=24, default=0]. Compression always lowers the overall level; makeup gain brings the perceived loudness back up.
`CompressorMode`	`CompressorMode`	`get/set`	`CompressorMode` — whether the compressor reduces volume above the threshold (`Downward`) or raises volume below the threshold (`Upward`). `Downward` is the standard mode — loud parts above the threshold get pulled down. `Upward` does the opposite, lifting quieter parts below the threshold up so soft details stand out.
`Link`	`CompressorLink`	`get/set`	How left and right channels are linked when the compressor decides how much to reduce. Pick a linking mode based on whether the channels should be processed together (preserving stereo image but reacting to the loudest of the two) or independently.
`CompressorDetection`	`CompressorDetection`	`get/set`	How the compressor measures the input level — peak vs. RMS. Peak detection reacts to instantaneous peaks (more aggressive on transients). RMS reacts to the smoothed loudness (more transparent on voices and music).
`SignalOverLoad`	`bool`	`get`	True when the compressor's output signal has clipped (read-only). Lights up when the combined effect of compression and `MakeupGainDb` pushes the signal above full scale. Auto-resets after 2 seconds.
`PeakValueDbString`	`string`	`get`	Highest level reached during the most recent overload, in decibels (read-only). Updated whenever `SignalOverLoad` trips, and auto-resets after 2 seconds.
`ResetCommand`	`Command`	`get`	Reset all settings to their broadcast-style defaults.
`SamplesRendered`	`int`	`get`	Total number of audio samples processed by the compressor (read-only, debug).

Inherits from: AbstractAudioOperator, AbstractOperator, AbstractAudioMetering.

See also: Compressor in Operators — user-facing introduction, screenshots, and section summaries.