Db20Approx

Overview

Converts from linear units to decibels using a fast approximation

Discussion

Converts from linear units to decibels (db20) using a polynomial approximation. The function uses a 3rd order polynomial and the maximum error over the entire input range is 0.003 dB.

Module Pack

Standard

ClassID

classID = 73

Type Definition

typedef struct _ModuleDb20Approx
{
ModuleInstanceDescriptor instance;            // Common Audio Weaver module instance structure
} ModuleDb20ApproxClass;

Pins

Input Pins


Name	in
Description	Input signal
Data type	float
Channel range	Unrestricted
Block size range	Unrestricted
Sample rate range	Unrestricted
Complex support	Real

Output Pins


Name	out
Description	Output signal
Data Type	float

Matlab Usage

File Name: db20_approx_module.m 
 M=db20_approx_module(NAME) 
 Creates an Audio Weaver module that computes the function 20*log10(abs(x)) 
 using a polynomial approximation. This converts from linear units to decibels. 
 The approximation is accurate to 7.984884e-003 dB. 
    NAME - name of the module.