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https://github.com/alexanderwallin/super-tiny-wave-decoder

📻 A super tiny WAVE parser and decoder, without any dependencies or unnecessary abstraction layers
https://github.com/alexanderwallin/super-tiny-wave-decoder

audio decoder tiny wave

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📻 A super tiny WAVE parser and decoder, without any dependencies or unnecessary abstraction layers

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# super-tiny-wave-decoder



[![npm version](https://badge.fury.io/js/super-tiny-wave-decoder.svg)](https://badge.fury.io/js/super-tiny-wave-decoder)



A super tiny WAVE parser and decoder, without any dependencies or unnecessary abstraction layers.



Most of the logic was directly ported from parts of [aurora.js](https://github.com/audiocogs/aurora.js), so lots of ❤️ from here to there!



**Note:** This is terribly similar to [`wav-decoder`](https://github.com/mohayonao/wav-decoder), which I found after making this. There are some minor differences in the API, but if you're fine with the one in `wav-decoder`, you should probably use that one.



## Why?



Sometimes I just want to decode WAVE audio. Sometimes I even just want to parse a WAVE header. All libraries I have found have either too much other stuff I don't need, too abstraced APIs (I don't need it to make the HTTP request for me) or is specifically targeted towards either Node or the web browser.



This library is just a utility that parses WAVE headers and decodes WAVE audio. Nothing more, nothing less.



## Installation



```sh

npm install --save super-tiny-wave-decoder

```



## Usage



```js

import { getWaveHeader, decodeWaveData } from 'super-tiny-wave-decoder'



// Read a wave file somehow

const waveContents = readAudioFileAsAnArrayBufferSomehow('sound.wav')

const waveData = new Uint8Array(waveContents)



// Get WAVE header

const header = getWaveHeader(waveData)



// Get a chunk of 4096 bytes starting after the header and

// decode that chunk

const audioDataChunk = waveData.slice(44, 44 + 4096)

const decodedAudio = decodeWaveData(audioDataChunk, header)



// decodedAudio is now a Float32Array ready to be used as an

// audio buffer

```



## API



### Functions







getAsDataView(data) ⇒ DataView





Wraps and returns a typed array or ArrayBuffer in a DataView






getString(data, offset, bytes, encoding) ⇒ String





Returns a string read from some data.


This code is directly ported and rewritten from aurora.js's stream.coffee.

I have no idea how it works! Might use a library for this if it doesn't

work properly.






getWaveHeader(data) ⇒ Object





Parses a chunk of wave data and tries to extract all wave header

info from it.


You can see an overview of the WAVE header format here:

http://www.topherlee.com/software/pcm-tut-wavformat.html






getWaveDuration(header) ⇒ Number





Returns the duration of some wave audio given its header info






decodeWaveData(header, data) ⇒ Float32Array





Decodes a chunk of wave audio data










### getAsDataView(data) ⇒ DataView

Wraps and returns a typed array or ArrayBuffer in a DataView



**Returns**: DataView - A DataView wrapping the passed data  

**Throws**:



- TypeError The passed data needs to be of a supported type



**Params**



- `data`: Mixed - A DataView, ArrayBuffer, TypedArray or node Buffer






### getString(data, offset, bytes, encoding) ⇒ String

Returns a string read from some data.



This code is directly ported and rewritten from aurora.js's stream.coffee.

I have no idea how it works! Might use a library for this if it doesn't

work properly.



**Returns**: String - A string  

**Link**: https://github.com/audiocogs/aurora.js/blob/master/src/core/stream.coffee#L303  

**Params**



- `data`: Mixed - A DataView, ArrayBuffer, TypedArray or node Buffer

- `offset`: Number - An offset in bytes to start read the string from

- `bytes`: Number - The number of bytes to read

- `encoding`: String - The encoding to parse the text as






### getWaveHeader(data) ⇒ Object

Parses a chunk of wave data and tries to extract all wave header

info from it.



You can see an overview of the WAVE header format here:

http://www.topherlee.com/software/pcm-tut-wavformat.html



**Returns**: Object - An object containing the WAVE header info  

**Throws**:



- Error The passed data needs to be at least 44 bytes long

- Error The passed data needs to match the WAVE header spec



**Params**



- `data`: Mixed - A DataView, ArrayBuffer, TypedArray or node Buffer containing WAVE audio data, more specifically the beginning of a WAVE audio file






### getWaveDuration(header) ⇒ Number

Returns the duration of some wave audio given its header info



**Returns**: Number - The duration of the WAVE audio in seconds  

**Params**



- `header`: Object - A WAVE header object






### decodeWaveData(header, data) ⇒ Float32Array

Decodes a chunk of wave audio data



**Returns**: Float32Array - A Float32Array containing decoded audio  

**Throws**:



- Error The bit depth passed in header must be 8, 16, 24, 32 or 64



**Params**



- `header`: Object - A WAVE header object

- `data`: Mixed - A DataView, ArrayBuffer, TypedArray or node Buffer containing WAVE audio data



## Contributing



Do `npm run` to see what's available, and don't be shy sending a pull request!