@ohanapediatrics/react-volume-meter

react-volume-meter

A volume meter react component

Installation

npm install react-volume-meter

Example

Run npx styleguidist server, then navigate to http://localhost:6060 to see some examples.

Overview

This component animates a volume meter through an HTML5 canvas element. It takes a Web Audio node as input, creates an AnalyserNode, and computes the volume, which it then displays through the canvas element.

Props

audioContext

An instance of either window.audioContext or window.webkitAudioContext, depending on your browser. If you use the Web Audio API elsewhere on the page, be sure to pass the instance of AudioContext to this component, since you should generally only have one instantiation per page.

src

Optional, although the animation won't start properly without it. A Web Audio Node object that implements the connect method. For example, you can call audioContext.createMediaStreamSource(stream) to create a node from the stream object returned by a navigator.getUserMedia recording.

width

The width of the canvas in pixels. The canvas adjusts its animation automatically but is designed to look best when its width:height ratio is 3:2.

height

The height of the canvas in pixels. The canvas adjusts its animation automatically but is designed to look best when its width:height ratio is 3:2.

maxVolume

Optional. The maximum volume level for the volume meter. Its theoretical maximum is 255 but chances are you'll never get that high in normal use. When the volume exceeds the maxVolume level, the final bar of the meter turns red. Defaults to 50, which seems to work well for microphone recordings of normal human speech.

style

Optional. Style of the canvas element.

blocks

The number of blocks to include on the meter. The width of each block scales according to the width of the meter. Defaults to 5

shape

The shape of the meter - either VM_FLAT for a flat meter or VM_STEPPED for a stepped meter. Defaults to VM_STEPPED