Overview

Peak and RMS meter module

Discussion

This modules provides a flexible level meter that can operate in several modules. The module has a single multichannel input and separately meters each channel. The meter can be configured to conform to IEC 60280-10 (peak meters) and IEC 60280-17 (VU Meter) specifications. The meterType parameter is used to configure the module as follows.

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In meterTypes 0 to 3, the peak attack and release are performed on a sample-by-sample basis in the envelope follower. In meterTypes 16 to 19, the peak absolute value for the entire input block is found and this one value is passed through the envelope follower.

Type Definition

typedef struct _ModuleMeterFract32
{
    ModuleInstanceDescriptor instance;            // Common Audio Weaver module instance structure
    INT32 meterType;                              // Operating module of the meter. Selects between peak and RMS calculations. See the discussion section for more details
    FLOAT32 attackTime;                           // Attack time of the meter. Specifies how quickly the meter value rises
    FLOAT32 releaseTime;                          // Release time of the meter. Specifies how quickly the meter decays
    fract32 attackCoeffFract32;                   // Internal coefficient that realizes the attack time
    fract32 releaseCoeffFract32;                  // Internal coefficient that realizes the release time
    fract32* value;                               // Array of meter output values, one per channel
} ModuleMeterFract32Class;

Variables

Properties

Pins

Input Pins

Name: in

Description: audio input

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Sample rate range: Unrestricted

Complex support: Real

Scratch Pins

Channel count: 1

Block size: 32

Sample rate: 48000

MATLAB Usage

File Name: meter_fract32_module.m

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