Overview

Phase invert module

Discussion

This module inverts the phase of a signal. Inverting the phase is simply multiplying by -1. When the second argument NUMPINS is 1, then the phase invert control is applied to each individual channel. Otherwise the phase invert control is applied to each individual input pin as a whole. The array .isInverted is used for phase invert control. The array length is updated by the prebuild function.

The module uses a first order smoother to seamlessly switch between +1 and -1. The speed of the smoothing operation is set by the .smoothingTime variable. The module's set function translates the smoothingTime to an internal smoothingCoeff. When the module is built it starts out in a converged state.

By default, the inspector for the module has the control checkboxes organized in a vertical stack. By setting the optional third argument TRANSPOSE = 1 turns the control into a horizontal stack.

Type Definition

typedef struct _ModuleInvertN
{
    ModuleInstanceDescriptor instance;            // Common Audio Weaver module instance structure
    INT32 numControls;                            // Number of individual invert controls
    FLOAT32 smoothingTime;                        // Time constant of the smoothing process
    FLOAT32 smoothingCoeff;                       // Smoothing coefficient.
    INT32* isInverted;                            // Boolean that specifies whether the signal is inverted (=1) or not (=0). One per each pin.
    FLOAT32* currentGain;                         // Instantaneous gain applied by the module. This is also the starting gain of the module.
    FLOAT32* gain;                                // Target gain.
} ModuleInvertNClass;

Variables

Properties

Name	Type	Usage	isHidden	Default value	Range	Units
numControls	int	const	0	1	Unrestricted
smoothingTime	float	parameter	0	10	0:1000	msec
smoothingCoeff	float	derived	1	0.002081	Unrestricted
isInverted	int*	parameter	0	[1 x 1]	0:1
currentGain	float*	state	1	[1 x 1]	-1:1	linear
gain	float*	derived	1	[1 x 1]	-1:1	linear

Pins

Input Pins

Name: in1

Description: audio input

Data type: float

Channel range: Unrestricted

Block size range: Unrestricted

Sample rate range: Unrestricted

Complex support: Real

Output Pins

Name: out1

Description: audio output

Data type: float

MATLAB Usage

File Name: invertn_module.m

 M=invertn_module(NAME, NUMPINS, NUMCHANNELS, TRANSPOSE)
 Creates a module which inverts the phase of a signal (that is, sets the
 gain equal to -1). The change happens smoothly with a specified 
 smoothing time.
 Arguments:
    NAME - name of the module.
    NUMPINS - optional argument that specifies the number of input pins.
       When NUMPINS is 1, the invert control apply to each individual
       channel within the input pin.
       When NUMPINS is more than 1, the invert control apply to
       those input pins.
    NUMCHANNELS - optional argument that specifies the initial number
       of channels in the wire.  When the system is built, the number
       of channels is derived by pin propagation.  This value is only
       for the initial behavior before the system is built.  By default,
       NUMCHANNELS = 2.
    TRANSPOSE - an optional argument which controls how the inspector
       for the module is drawn.  By default, if there are N channels
       then the inspector control is a vertical stack of N checkboxes.
       (TRANSPOSE = 0 by default).  If TRANSPOSE = 1, then the inspector
       is drawn as a horizontal array of N checkboxes.
 AudioWeaverModule [This tag makes it appear under awe_help]