Overview

Computes sample statistics over multichannel signals

Discussion

This module calculates the sample statistics of the input signal on a sample-by-sample basis. The input pin can have an arbitray number of interleaved channels and the sample statistics calculation occurs over all channels. The output pin has only a single channel and a blockSize equal to that of input.

For each channel, the module calculates the type of statistics depending on the variable statisticsType selection. The available options are: 0=maximum, 1=minimum, 2=maximum absolute value, and 3=minimum absolute value, 4=mean, 5=RMS, 6=standard deviation, 7=variance, 8=average energy, 9=sum, 10=sum of squares. This includes all channels and the entire block.

If the argument OUTPUTINDEX is checked, then a 2nd output pin will be created. The 2nd output is the corresponding index value of the output operation. The index starts at 0. So an output value of 0 corresponds to the 1st channel. The optional 2nd output pin is single channel, int, with the same block size as the input.

The module also exposes the computed signal as a state variable.

Type Definition

typedef struct _ModuleSampleStatistics
{
    ModuleInstanceDescriptor instance;            // Common Audio Weaver module instance structure
    INT32 statisticsType;                         // Type of statistics calculated: 0=maximum, 1=minimum, 2=maximum absolute value, 3=minimum absolute value.
} ModuleSampleStatisticsClass;

Variables

Properties

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: Sample statistics output

Data type: float

Name: index

Description: Index value

Data type: int

MATLAB Usage

File Name: sample_statistics_module.m

 M=sample_statistics_module(NAME, OUTPUTINDEX)
 This module calculates the statistics on sample-by-sample basis of an 
 arbitrary number of interleaved channels. The type of statistics calculated 
 is determined by the statisticsType parameter.
 
 Arguments:
    NAME - name of the module.
    OUTPUTINDEX - boolean value which specifies whether the module will
    have an optional 2nd output which outputs the channel index value of 
    the sample value is outputed. By default, OUTPUTINDEX = 0, which means
    no 2nd output channel will be created. The 2nd output will be of the 
    data type int. The index starts at 0. So an output value of 0 means
    channel 1 of the input.