audio-type

audio-type

Detect the audio type of a ArrayBuffer/Uint8Array

Install

$ npm i audio-type

Usage

Node.js

import readChunk from 'read-chunk'; // npm install read-chunk
import audioType from 'audio-type';
var buffer = readChunk.sync('meow.wav', 0, 64);

audioType(buffer);
//=> wav

Browser

import audioType from './audio-type.js'

var xhr = new XMLHttpRequest();
xhr.open('GET', 'meow.flac');
xhr.responseType = 'arraybuffer';

xhr.onload = function () {
	audioType(this.response);
	//=> flac
};

xhr.send();

API

audioType(buffer)

Returns one of the keys below, or undefined if the format isn't recognized.

Key	Format	Magic	Offset
wav	WAVE	RIFF…WAVE	0, 8
aiff	AIFF/AIFC	FORM…AIFF/AIFC	0, 8
mp3	MPEG audio	MPEG sync (0xFF Ex) or TAG (ID3v1 trailer)	0
aac	AAC (ADTS)	0xFFF sync, layer 00	0
flac	FLAC, native or in Ogg	fLaC, or OggS…\x7FFLAC	0, or 0 and 28
tta	True Audio	TTA1	0
m4a	MPEG-4 audio	ftyp or M4A	4 or 0
opus	Opus (in Ogg)	OggS…OpusHead	0, 28
oga	Ogg	OggS	0
qoa	Quite OK Audio	qoaf	0
mid	MIDI	MThd	0
caf	Core Audio Format	caff	0
wma	ASF/WMA	ASF header GUID	0
amr	AMR	#!AMR	0
wv	WavPack	wvpk	0
mpc	Musepack	MP+ (SV7) or MPCK (SV8)	0
ape	Monkey's Audio	MAC	0
dsf	DSD Stream File	DSD	0
dff	DSDIFF	FRM8…DSD	0, 12
eac3	E-AC-3 (Dolby Digital Plus)	0x0B77 sync, bsid 11–16	0
ac3	AC-3 (Dolby Digital)	0x0B77 sync, bsid ≤ 8	0
dts	DTS	0x7FFE8001 (or its bit-reordered variants)	0
it	Impulse Tracker	IMPM	0
s3m	Scream Tracker 3	SCRM	44
xm	Extended Module	Extended Module:	0
mod	ProTracker & friends	M.K., M!K!, xCHN, xxCH, FLTx, TDZx, CD81, OKTA	1080
mkv	Matroska	EBML header, DocType matroska	0
webm	WebM	EBML header, DocType webm	0
avi	AVI	RIFF…AVI	0, 8

Note: OpenMPT's .mptm format is IT-derived and reuses the IMPM magic verbatim — it is indistinguishable from .it by magic bytes alone and also detects as it.

buffer

Type: buffer (Node.js), arrayBuffer, uint8array

The first 64 bytes are enough for every format except mod, whose tag sits at offset 1080 (past the sample header table) — pass at least the first 1084 bytes if you need to detect trackers.

ID3v2 tags

mp3, flac, tta and aac files may carry a leading ID3v2 tag. audioType() skips it and inspects what follows: mp3 is only returned once a real MPEG sync is found after the tag — unless the tag's declared size runs past the end of the buffer you gave it, in which case mp3 is assumed (the overwhelming majority of ID3v2-tagged audio in the wild is MP3, and a truncated probe buffer — the common case — can't prove otherwise). dsf's optional ID3v2 tag lives at the end of the file, not the start, so it never enters into this.

License

MIT • ॐ