BlockStatistics

Overview

Computes statistics of a block of samples

Discussion

This module calculates the Block Statistics of the input signal on a block-by-block basis. The input pin can have an arbitrary number of interleaved channels and the Block Statistics calculation occurs over all channels. The output pin has a single channel and a blockSize of 1.

statisticsType	Description
0	maximum
1	minimum
2	maximum absolute value
3	mean
4	RMS
5	standard deviation
6	variance
7	average energy
8	sum
9	sum of squares

The statistic is computed on a block-by-block basis and stored in the instantaneousValue variable. The module is stateless and the statistic is recomputed for each block.

An optional constructor argument OUTPUTVALUE specifies whether the computed statistic should be output on an output pin.

OUTPUTVALUE=0 (default) - the statistic is only stored internally in instantaneousValue.
OUTPUTVALUE=1 then the value of the statistic is output of the first output pin as a floating-point value.
OUTPUTVALUE=2 then the module has two output pins. The first output pin is the statistic value and the second output pin is the index at which the value occurs. * Using OUTPUTVALUE=2 only makes sense when statisticType=0 (max), 1 (min), or 2 (maxAbs).

Module Pack

Advanced

ClassID

classID = 1227

Type Definition

typedef struct _ModuleBlockStatistics
{
ModuleInstanceDescriptor instance;            // Common Audio Weaver module instance structure
INT32 statisticsType;                         // Type of statistics calculated.
FLOAT32 instantaneousValue;                   // Instantaneous output value.
} ModuleBlockStatisticsClass;

Variables

Properties

Name	Type	Usage	isHidden	Default Value	Range	Units
statisticsType	int	parameter	0	0	0:9
instantaneousValue	float	state	0	0	-10:10

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	Value
Data Type	float


Name	index
Description	Index
Data Type	int

Matlab Usage

File Name: block_statistics_module.m 
 M=block_statistics_module(NAME, OUTPUTVALUE, SAMPLERATE) 
 This module calculates statistics of the input signal on a block-by- 
 block basis. The type of statistics calculated is determined by 
 the statisticsType parameter. The computed value is stored in the 
 internal state variable instantaneousValue.   

 Arguments: 
    NAME - name of the module. 
    OUTPUTVALUE - Integer value which specifies whether the module has 
         an output pin. If OUTPUTVALUE=0, then the module has no output  
         pin. If OUTPUTVALUE=1  (the default), then the instantaneousValue  
         variable is output as a single sample on the first output pin. 
         If OUTPUTVALUE=2 then the module has a second output pin 
         containing the index at which the value occurred.  Outputting the 
         index only makes sense for Max, Min, and MaxAbs statistics.  In 
         all other cases, index = -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.%