Overview
Subband smoothing across frequency bins
Discussion
This module performs smoothing across frequency bins. Smoothing is done by averaging multiple bins to the left and right of a particular frequency sample. The smoothing only operates on real data. To smooth complex data it must first be decomposed into real and imaginary components.
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The module is designed to work with the wola_analysis_subsystem.m and the sample rate specified equals the decimated subband sample rate.
Type Definition
| Code Block |
|---|
typedef struct _ModuleSbSmooth
{
ModuleInstanceDescriptor instance; // Common Audio Weaver module instance structure
INT32 type; // Determines which type of smoothing is applied: Linear=0, Logarithmic=1, Custom=2
FLOAT32 startFreq; // Starting frequency for the smoothing operation
FLOAT32 width; // Amount of smoothing
INT32* startIndex; // Starting index for the averaging process.
INT32* endIndex; // Ending index for the averaging process.
FLOAT32* oneOverN; // Precomputed 1/N for averaging.
FLOAT32* cumSum; // Cumulative sum of values from the start of the buffer.
} ModuleSbSmoothClass; |
Variables
Properties
Name | Type | Usage | isHidden | Default value | Range | Units |
type | int | parameter | 0 | 1 | 0:2 | |
startFreq | float | parameter | 0 | 0 | 0:3072000 | Hz |
width | float | parameter | 0 | 0.1667 | 0:2400 | |
startIndex | int* | derived | 1 | [257 x 1] | Unrestricted | |
endIndex | int* | derived | 1 | [257 x 1] | Unrestricted | |
oneOverN | float* | derived | 1 | [257 x 1] | Unrestricted | |
cumSum | float* | state | 1 | [258 x 1] | Unrestricted |
Pins
Input Pins
Name: in
Description: audio input
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Sample rate range: Unrestricted
Complex support: Real
Output Pins
Name: out
Description: audio output
Data type: float
MATLAB Usage
File Name: sb_smooth_module.m
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