MuteSyncFract32

Overview

Fixed-point smoothed mute with synchronous requests

Discussion

Smoothly change the gain of all input channels to 0 (mute) or 1 (unmute). You have full control over the time that it takes to mute and unmute. Gain values applied are available on an optional second output pin.

Set the .asyncCommand or .syncCommand variable to 1 (UNMUTE) to change gain smoothly to 0 after unmuteTime ms. Set to 2 (MUTE) to change gain to 1 after muteTime ms. When asyncCommand is set, the set function returns immediately. When changing syncCommand, the set function returns only after the target has been reached.

The module uses a raised cosine window for muting and unmuting. For memory efficiency the module uses a complex recursion to computethe gain profile for the raised cosine.

Module Pack

Advanced

ClassID

classID = 1298

Type Definition

typedef struct _ModuleMuteSyncFract32
{
ModuleInstanceDescriptor instance;            // Common Audio Weaver module instance structure
INT32 isMuted;                                // Boolean for target gain: 1 means silence
INT32 asyncCommand;                           // Start changing the gain without waiting for completion: 1=unmute, 2=mute
INT32 syncCommand;                            // Change the gain and return only when finished: 1=unmute, 2=mute
FLOAT32 muteTime;                             // Muting time in msec
FLOAT32 unmuteTime;                           // Unmuting time in msec
INT32 compatSync;                             // When true, isMuted compatibility is synchronous
INT32 muteState;                              // Current muting action: 0=not set, 1=unmuted, 2=muted, 3=unmute changing, 4=mute changing
fract32 currentGain;                          // Gain being applied to start of next sample block
fract32 muteRotateI;                          // Imaginary part of multiplier to rotate phasor while muting
INT32 syncState;                              // Active synchronous target state
INT32 muteSamples;                            // Muting time in samples
INT32 unmuteSamples;                          // Unmuting time in samples
fract32 muteRotateR;                          // Real part of multiplier to rotate phasor while muting
fract32 unmuteRotateR;                        // Real part of multiplier to rotate phasor while unmuting
fract32 unmuteRotateI;                        // Imaginary part of multiplier to rotate phasor while unmuting
fract32 phasorR;                              // Real part of complex phasor used to compute cosine
fract32 phasorI;                              // Imaginary part of complex phasor used to compute cosine
INT32 sampleTime;                             // Counts samples  since the start of the active mute or unmute operation
} ModuleMuteSyncFract32Class;

Variables

Properties

Name	Type	Usage	isHidden	Default Value	Range
isMuted	int	state	0	0	0:1
asyncCommand	int	state	0	0	0:2
syncCommand	int	state	0	0	0:2
muteTime	float	parameter	0	5	1:1000
unmuteTime	float	parameter	0	50	1:1000
compatSync	int	state	0	1	Unrestricted
muteState	int	state	0	1	0:4
currentGain	fract32	derived	0	0	Unrestricted
muteRotateI	fract32	derived	0	0.01309	Unrestricted
syncState	int	derived	1	1	Unrestricted
muteSamples	int	derived	1	240	Unrestricted
unmuteSamples	int	derived	1	2400	Unrestricted
muteRotateR	fract32	derived	1	0.99991	Unrestricted
unmuteRotateR	fract32	derived	1	1	Unrestricted
unmuteRotateI	fract32	derived	1	0.001309	Unrestricted
phasorR	fract32	state	1	0	Unrestricted
phasorI	fract32	state	1	0	Unrestricted
sampleTime	int	state	1	0	Unrestricted

Pins

Input Pins


Name	in
Description	audio input
Data type	fract32
Channel range	Unrestricted
Block size range	Unrestricted
Sample rate range	Unrestricted
Complex support	Real

Output Pins


Name	out
Description	audio output
Data Type	fract32

Matlab Usage

File Name: mute_sync_fract32_module.m 
 M = mute_sync_fract32_module(NAME, DEFSYNC, GAINPIN) 
 Create an extended fixed-point smoothed mute module that supports a 
 group of synchronous variables for which the set returns only when the 
 resquested mute or unmute operation has completed. Muting and muting 
 smoothing is performed using raised cosine windows as in MuteUnmute so 
 that the gain reaches 0 or 1 after the specified time constant. 
 Arguments: 
       NAME        The name of the module 
       DEFSYNC     Turns synchronous muting on/off (default = 1 = ON) 
       GAINPIN     Indicator for adding a gain output pin  
                   (default = 0 = OFF) 
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