Overview

Computes long term statistics per channel

Discussion

This module is a multichannel version of the RunningStatisics module. The module keeps track of the statistics of the input data. The state variable value holds the statistic result seen thus far since the module start processing. A separate statistic is computed for each input channel.

The statisticsType variable configures which type of computation the block does: 0=Maximum, 1=Minimum, 2=Maximum Absolute Value, Sum=3, Mean=4, RMS=5, StdDev=6, Var=7, AvgEnergy=8.

An optional constructor argument OUTPUTVALUE specifies whether the computed statistic should be output on an output pin. By default, OUTPUTVALUE=0 and the statistic is only stored internally in instantaneousValue. The .reset variable is used to clear history and restart the calculation. The variable .reset is set to 1 when the module is first constructed.

By default, the sample rate of the output pin equals SRin / blocksize. There are some times when this computes the wrong sample rate and you can overwrite the output sample rate using the SAMPLERATE argument.

Type Definition

typedef struct _ModuleRunningStatisticsN
{
    ModuleInstanceDescriptor instance;            // Common Audio Weaver module instance structure
    INT32 statisticsType;                         // Type of statistics needed.
    INT32 numBlocksProcessed;                     // Counter for the number of blocks processed.
    INT32 reset;                                  // Used to identify the first block which is processed.
    FLOAT32* value;                               // Instantaneous output value.
    FLOAT32* mean;                                // State variable for mean.
    FLOAT32* avgEnergy;                           // State variable for average energy.
} ModuleRunningStatisticsNClass;

Variables

Properties

Name	Type	Usage	isHidden	Default value	Range	Units
statisticsType	int	parameter	0	0	0:8
numBlocksProcessed	int	state	0	0	Unrestricted
reset	int	state	0	1	Unrestricted
value	float*	state	0	[1 x 1]	Unrestricted
mean	float*	state	0	[1 x 1]	Unrestricted
avgEnergy	float*	state	0	[1 x 1]	Unrestricted

Pins

Input Pins

Name: in

Description: Audio input

Data type: float

Channel range: Unrestricted

Block size range: Unrestricted

Sample rate range: Unrestricted

Complex support: Real

Output Pins

Name: out

Description: Audio input

Data type: float

Scratch Pins

Channel count: 1

Block size: 32

Sample rate: 48000

MATLAB Usage

File Name: running_statisticsn_module.m

 M = running_statisticsn_module(NAME, OUTPUTVALUE, SAMPLERATE)
 This is a multichannel version of the running_statistics_module.m.
 It computes a per channel statistic of the wire data and the
 statistic is tracked from system startup.  The module stores the
 compute statistic in an N element internal array.  The module can
 also output on an N channel control wire.
 Arguments:
    NAME - name of the module.
    OUTPUTVALUE - Boolean value which specifies whether the module has
         an output pin. If OUTPUTVALUE=0 (the default), then
         the module has no output pin. If OUTPUTVALUE=1, then
         the module has a multichannel control pin (block size = 1).
    SAMPLERATE - optional argument which specifies the output sample rate
         of the module.  By default, this is empty and the output sample
         rate is computed as inputSampleRate / blockSize.  In some cases,
         this sample rate is wrong and you can override it with this
         argument.