wavefile

Copyright (c) 2017-2019 Rafael da Silva Rocha.
https://github.com/rochars/wavefile

wavefile

Create, read and write wav files according to the specs.

• MIT licensed
• Use it in the browser (IE10+)
• Use it in Node.js
• Use it as a command line tool
• Handle files up to 2GB
• Zero dependencies

With wavefile you can:

• Create wav files
• Read wav files
• Change the bit depth of the audio
• Change the sample rate of the audio
• Read and write RIFF tags
• Set and delete cue points and their labels
• Create regions in wav files
• Encode/decode files as ADPCM, A-Law and μ-Law
• Turn RIFF files to RIFX and RIFX to RIFF
• Create or edit BWF metadata ("bext" chunk)

And more.

Install

npm install wavefile

To use it from the command line, install it globally:

npm install wavefile -g

Use

Node

const wavefile = require('wavefile');
let wav = new wavefile.WaveFile();

or

const WaveFile = require('wavefile').WaveFile;
let wav = new WaveFile();

or

import { WaveFile } from 'wavefile';
let wav = new WaveFile();

Browser

Use the wavefile.js file in the dist folder:

<script src="wavefile.js"></script>
<script>
  var wav = new wavefile.WaveFile();
</script>

Or load it from the jsDelivr CDN:

<script src="https://cdn.jsdelivr.net/npm/wavefile"></script>

Or load it from unpkg:

<script src="https://unpkg.com/wavefile"></script>

Browser compatibility

IE10+. Should work in all modern browsers.

Cross-browser tests powered by
<a href="https://www.browserstack.com"><img src="https://rochars.github.io/wavefile/docs/Browserstack-logo@2x.png" width="150px"/></a>

Command line use

To see the available options:

wavefile --help

Node.js Example

const WaveFile = require('wavefile').WaveFile;

// Load a wav file buffer as a WaveFile object
let wav = new WaveFile(buffer);

// Check some of the file properties
console.log(wav.container);
console.log(wav.chunkSize);
console.log(wav.fmt.chunkId);

// Call toBuffer() to get the bytes of the file.
// You can write the output straight to disk:
let wavBuffer = wav.toBuffer();

// Call toDataURI() to get the file as a DataURI:
let wavDataURI = wav.toDataURI();

Table of Contents

• Install
• Use
• Operation Manual
  • Create wave files from scratch
  • Read wave files
  • Add RIFF tags to files
  • Add cue points to files
  • Create regions in files
  • RIFX
  • IMA-ADPCM
  • A-Law
  • mu-Law
  • Change the bit depth
  • Change the sample rate
  • Add BWF metadata
  • RF64
  • XML Chunks
  • The samples
  • Command line
• API
  • The WaveFile methods:
  • The WaveFile properties
    • Cue points
    • Sample loops
    • LIST chunk
• Contributing to wavefile
• References
• Legal

Operation Manual

Create wave files from scratch

Use the fromScratch(numChannels, sampleRate, bitDepth, samples) method.

Mono:

let wav = new WaveFile();

// Create a mono wave file, 44.1 kHz, 32-bit and 4 samples
wav.fromScratch(1, 44100, '32', [0, -2147483, 2147483, 4]);
fs.writeFileSync(path, wav.toBuffer());

Stereo:

Samples can be informed interleaved or de-interleaved. If they are de-interleaved, WaveFile will interleave them. In this example they are de-interleaved.

// Stereo, 48 kHz, 8-bit, de-interleaved samples
// WaveFile interleave the samples automatically
wav.fromScratch(2, 48000, '8', [
    [0, 2, 4, 3],
    [0, 1, 4, 3]
]);
fs.writeFileSync(path, wav.toBuffer());

Possible values for the bit depth are:
"4" - 4-bit IMA-ADPCM
"8" - 8-bit
"8a" - 8-bit A-Law
"8m" - 8-bit mu-Law
"16" - 16-bit
"24" - 24-bit
"32" - 32-bit
"32f" - 32-bit floating point
"64" - 64-bit floating point

You can also use any bit depth between "8" and "53", like "11", "12", "17", "20" and so on.

A word on bit depth

Resolutions other than 4-bit, 8-bit, 16-bit, 24-bit, 32-bit (integer), 32-bit (fp) and 64-bit (fp) are implemented as WAVE_FORMAT_EXTENSIBLE and may not be supported by some players.

Read wave files

const WaveFile = require('wavefile').WaveFile;
wav = new WaveFile();
// Read a wav file from a buffer
wav.fromBuffer(buffer);
// Read a wav file from a base64 string
wav.fromBase64(base64);
// Read a wav file from a data URI
wav.fromDataURI(dataURI);

Add RIFF tags to files

You can create (or overwrite) tags on files with the WaveFile.setTag() method.

// Write the ICMT tag with some comments to the file
wav.setTag("ICMT", "some comments");

To get the value of a tag (if it exists), use WaveFile.getTag():

console.log(wav.getTag("ICMT"));
// some comments

You can delete a tag with WaveFile.deleteTag():

wav.deleteTag("ICMT");

Add cue points to files

You can create cue points using the WaveFile.setCuePoint() method. The method takes a object with the cue point data and creates a cue point in the corresponding position of the file. The only required attribute of the object is position, a number representing the position of the point in milliseconds:

// to create a cue point
wav.setCuePoint({position: 1500});

You can also create cue points with labels by defining a label attribute:

// to create a cue point with a label
wav.setCuePoint({position: 1500, label: 'some label'});

To delete a cue point use WaveFile.deleteCuePoint() informing the index of the point. Points are ordered according to their position. The first point is indexed as 1.

wav.deleteCuePoint(1);

Mind that creating or deleting cue points will change the index of other points if they exist.

To list all the cue points in a file, in the order they appear:

let cuePoints = wav.listCuePoints();

This method will return a list with cue points ordered as they appear in the file.

[
  {
    position: 500, // the position in milliseconds
    label: 'cue marker 1',
    end: 1500, // the end position in milliseconds
    dwName: 1,
    dwPosition: 0,
    fccChunk: 'data',
    dwChunkStart: 0,
    dwBlockStart: 0,
    dwSampleOffset: 22050, // the position as a sample offset
    dwSampleLength: 3646827, // the region length as a sample count
    dwPurposeID: 544106354,
    dwCountry: 0,
    dwLanguage: 0,
    dwDialect: 0,
    dwCodePage: 0,
  },
  //...
];

Create regions in files

You can create regions using the WaveFile.setCuePoint() method. Regions are cue points with extra data.

If you define a not null end attribute in the object describing the cue point, the point will be created as a region. The end attribute should be the end of the region, in milliseconds, counting from the start of the file, and always greater than the position of the point:

// to create a region with a label:
wav.setCuePoint({position: 1500, end: 2500, label: 'some label'});

You can also define the following optional properties when creating a region:

• dwPurposeID
• dwCountry
• dwLanguage
• dwDialect
• dwCodePage

RIFX

wavefile can handle existing RIFX files and create RIFX files from scratch. Files created from scratch will default to RIFF; to create a file as RIFX you must define the container:

wav.fromScratch(1, 48000, '16', [0, 1, -3278, 327], {"container": "RIFX"});

RIFX to RIFF and RIFF to RIFX:

// Turn a RIFF file to a RIFX file
wav.toRIFX();

// Turn a RIFX file to a RIFF file
wav.toRIFF();

IMA-ADPCM

16-bit 8000 Hz mono wave files can be compressed as IMA-ADPCM:

// Encode a 16-bit wave file as 4-bit IMA-ADPCM:
wav.toIMAADPCM();

IMA-ADPCM files compressed with wavefile will have a block align of 256 bytes.

If the audio is not 16-bit it will be converted to 16-bit before compressing. Compressing audio with sample rate different from 8000 Hz or more than one channel is not supported and will thro