Component: Compressor (DSP Operators)
| Author | Matrix Ltd |
| Version | 1.2 |
| Category | DSP Operators |
Compressor component
Reduces the dynamic range of a signal by turning down levels above a threshold, with adjustable ratio, attack, release and makeup gain.
Detailed description
No detailed description exists yet for this component
Examples
No additional examples
Macro reference
Compress
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Compress |
| Collects a single value from the input buffer, applies the compressor and passes the result to the output buffer. | |
 - VOID
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Return |
CompressArray
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CompressArray |
| Passes an entire buffer through the compressor and outputs the compressed version of the buffer at the other end. | |
| - VOID
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Return |
ControlCompressor
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ControlCompressor |
| Enables or disables the compressor, enabled by default. When disabled samples pass through unchanged. | |
 - BOOL
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State |
| 0=Disable, 1=Enable | |
| - VOID
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Return |
GetEnvelope
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GetEnvelope |
| Float and 32-bit buffer types only. Returns the detected signal level, measured from the signal centre. | |
 - FLOAT
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Return |
GetEnvelopeInt
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GetEnvelopeInt |
| 8/16-bit integer buffer types only. Returns the detected signal level, measured from the signal centre. | |
 - LONG
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Return |
GetGain
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GetGain |
| Float and 32-bit buffer types only. Returns the gain applied on the last sample, excluding makeup gain. 1.0 = no gain reduction, 0.5 = halved. | |
| - FLOAT
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Return |
GetGainQ8
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GetGainQ8 |
| 8/16-bit integer buffer types only. Returns the gain applied on the last sample in 1/256 steps, excluding makeup gain. 256 = no gain reduction, 128 = halved. | |
 - UINT
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Return |
Reset
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Reset |
| Clears the envelope follower so the compressor starts again from no gain reduction. | |
| - VOID
|
Return |
SetAttackShift
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SetAttackShift |
| 8/16-bit integer buffer types only. Sets how quickly the compressor responds to a rising signal. The time constant is 2 ^ Shift samples. | |
 - BYTE
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Shift |
| 0 = instant, 1 = 2 samples, 2 = 4 samples ... 15 = 32768 samples | |
| - VOID
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Return |
SetAttackTime
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SetAttackTime |
| Float and 32-bit buffer types only. Sets how quickly the compressor responds to a signal rising above the threshold. | |
| - FLOAT
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Time_ms |
| Attack time constant in milliseconds, 0 = instant | |
| - VOID
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Return |
SetMakeupGain
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SetMakeupGain |
| Float and 32-bit buffer types only. Sets the gain applied after compression to restore the overall signal level. | |
| - FLOAT
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Multiplier |
| Linear gain multiplier, 1.0 = no change | |
| - VOID
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Return |
SetMakeupGainQ8
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SetMakeupGainQ8 |
| 8/16-bit integer buffer types only. Sets the gain applied after compression in 1/256 steps, e.g. 256 = x1, 384 = x1.5, 512 = x2. | |
| - UINT
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Gain |
| Makeup gain x 256, 0 to 8192 (x32) | |
| - VOID
|
Return |
SetRatio
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SetRatio |
| Float and 32-bit buffer types only. Sets the compression ratio, e.g. 4.0 for 4:1. A level 4dB above the threshold comes out 1dB above it. Large ratios act as a limiter. | |
| - FLOAT
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Ratio |
| Compression ratio, 1.0 or greater. 1.0 = no compression | |
| - VOID
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Return |
SetRatioShift
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SetRatioShift |
| 8/16-bit integer buffer types only. Sets the compression ratio as a power of two: 0 = 1:1, 1 = 2:1, 2 = 4:1, 3 = 8:1, 4 = 16:1, 5 = 32:1, 24 = limiter. | |
| - BYTE
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Shift |
| Ratio = 2 ^ Shift, 0 to 5 or 24 for a limiter | |
| - VOID
|
Return |
SetReleaseShift
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SetReleaseShift |
| 8/16-bit integer buffer types only. Sets how quickly the compressor recovers once the signal falls. The time constant is 2 ^ Shift samples. | |
| - BYTE
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Shift |
| 0 = instant, 1 = 2 samples, 2 = 4 samples ... 15 = 32768 samples | |
| - VOID
|
Return |
SetReleaseTime
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SetReleaseTime |
| Float and 32-bit buffer types only. Sets how quickly the compressor recovers once the signal falls. | |
| - FLOAT
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Time_ms |
| Release time constant in milliseconds, 0 = instant | |
| - VOID
|
Return |
SetThreshold
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SetThreshold |
| Float and 32-bit buffer types only. Sets the level, measured from the signal centre, above which compression is applied. | |
| - FLOAT
|
Level |
| Threshold level in buffer units, must be greater than zero | |
| - VOID
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Return |
SetThresholdInt
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SetThresholdInt |
| 8/16-bit integer buffer types only. Sets the level, measured from the signal centre, above which compression is applied. | |
| - LONG
|
Level |
| Threshold level in buffer units, 1 to 65535 | |
| - VOID
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Return |
Property reference
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Properties |
|
Connect To |
| DSP component with output buffer to collect our data from. | |
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Buffer Size |
| Number of individual elements the buffer can store, default 1. | |
|
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Buffer Type |
| Sets the buffer data type. Automatically matches the type of the input buffer. | |
|
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Direction |
| Sets the data direction flow of the component | |
|
Compressor |
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Processing |
| Set automatically from the buffer type. 8 and 16-bit integer buffers use fixed point maths with no floating point library, ideal for 8-bit devices. 32-bit integer and float buffers use floating point maths. | |
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Signal Centre |
| Value representing a zero signal. Levels are measured as the distance from this value. Use 0 for signed buffers, or the mid point for unsigned data, e.g. 512 for a 10-bit ADC or 128 for 8-bit data. | |
|
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Threshold |
| Level, measured from the signal centre, above which compression starts. 1 to 65535. Uses the same units as the buffer data. | |
|
|
Ratio |
| Amount of compression applied above the threshold. Fixed point mode works on the linear signal level: the part of the level above the threshold is divided by the ratio. Limiter holds the level at the threshold. | |
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Attack Shift |
| Attack time constant as a power of two number of samples, 0 to 15. 0 = instant, 1 = 2 samples, 2 = 4 samples, 3 = 8 samples ... Shifts are used in place of multiplies to keep the maths fast on 8-bit devices. | |
|
Attack Time (ms) |
| Attack time constant resulting from the attack shift at the specified sample rate. | |
|
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Release Shift |
| Release time constant as a power of two number of samples, 0 to 15. 0 = instant, 1 = 2 samples, 2 = 4 samples, 3 = 8 samples ... | |
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Release Time (ms) |
| Release time constant resulting from the release shift at the specified sample rate. | |
|
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Makeup Gain |
| Linear gain multiplier applied after compression to restore the overall level. 1 = no change. In fixed point mode this is converted to a 1/256 step value when compiled, maximum 32. | |
|
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Sample Rate (Hz) |
| Rate at which samples are passed through the compressor. Used to convert between attack and release times and samples. | |
Component Source Code
Please click here to download the component source project: FC_Comp_Source_DSP_Compressor.fcfx
Please click here to view the component source code (Beta): FC_Comp_Source_DSP_Compressor.fcfx