node-fdkaac

Fraunhofer FDK AAC is a high-quality open-source AAC encoder. For all AAC and M4A encoding needs, a Node.js wrapper of the full fdkaac command line frontend (by nu774) based on libfdk-aac encoder.

The encoder reads linear PCM audio in either WAV, raw PCM or CAF format and encodes it into an M4A or an AAC file.

Requirements

• Linux or MacOS (Windows is NOT support by this package)
• libfdk-aac, fdkaac and ffmpeg installed (instructions see below)
• node 12.20.* or newer

Installation

You can install it with npm:

$ npm install --save node-fdkaac

If you have not installed libfdk-aac, fdkaac and ffmpeg yet, you find a bash script to compile the source code as install.sh in this package.

install.sh requirements:

• automake
• libtool
• git

Run on Debian

$ sudo apt-get install automake libtool git ffmpeg
$ chmod +x install.sh
$ sudo ./install.sh

Run on MacOS with brew

$ brew install automake libtool git ffmpeg
$ chmod +x install.sh
$ sudo ./install.sh

Example

Encode from file to file

const Fdkaac = require("node-fdkaac").Fdkaac;

const encoder = new Fdkaac({
    output: "./audio-files/demo.m4a",
    bitrate: 192,
}).setFile("./audio-files/demo.wav");

encoder
    .encode()
    .then(() => {
        // Encoding finished
    })
    .catch((error) => {
        // Something went wrong
    });

Encode from file to buffer

const Fdkaac = require("node-fdkaac").Fdkaac;

const encoder = new Fdkaac({
    output: "buffer",
    bitrate: 192,
}).setFile("./audio-files/demo.wav");

encoder
    .encode()
    .then(() => {
        // Encoding finished
        const buffer = encoder.getBuffer();
    })
    .catch((error) => {
        // Something went wrong
    });

Encode from buffer to file

[...]

const Fdkaac = require("node-fdkaac").Fdkaac;

const encoder = new Fdkaac({
    "output": "./audio-files/demo.m4a",
    "bitrate": 192
}).setBuffer(audioFileBuffer);

encoder.encode()
    .then(() => {
        // Encoding finished
    })
    .catch((error) => {
        // Something went wrong
    });

Encode from buffer to buffer

[...]

const Fdkaac = require("node-fdkaac").Fdkaac;

const encoder = new Fdkaac({
    "output": "buffer",
    "bitrate": 192
}).setBuffer(audioFileBuffer);

encoder.encode()
    .then(() => {
        // Encoding finished
        const buffer = encoder.getBuffer();
    })
    .catch((error) => {
        // Something went wrong
    });

Get status of encoder as object

const Fdkaac = require("node-fdkaac").Fdkaac;

const encoder = new Fdkaac({
    output: "buffer",
    bitrate: 192,
}).setFile("./audio-files/demo.wav");

encoder
    .encode()
    .then(() => {
        // Encoding finished
    })
    .catch((error) => {
        // Something went wrong
    });

const status = encoder.getStatus();

Get status of encoder as EventEmitter

const Fdkaac = require("node-fdkaac").Fdkaac;

const encoder = new Fdkaac({
    output: "buffer",
    bitrate: 192,
}).setFile("./audio-files/demo.wav");

const emitter = encoder.getEmitter();

emitter.on("progress", ([progress, eta]) => {
    // On progress of encoding; in percent and estimated time of arrival as 00:00
});

emitter.on("finish", () => {
    // On finish
});

emitter.on("error", (error) => {
    // On error
});

encoder
    .encode()
    .then(() => {
        // Encoding finished
    })
    .catch((error) => {
        // Something went wrong
    });

Decode from file to file

const Fdkaac = require("node-fdkaac").Fdkaac;

const decoder = new Fdkaac({
    output: "./audio-files/demo.wav",
}).setFile("./audio-files/demo.m4a");

decoder
    .decode()
    .then(() => {
        // Decoding finished
    })
    .catch((error) => {
        // Something went wrong
    });

Decode from file to buffer

const Fdkaac = require("node-fdkaac").Fdkaac;

const decoder = new Lame({
    output: "buffer",
}).setFile("./audio-files/demo.m4a");

decoder
    .decode()
    .then(() => {
        // Decoding finished
        const buffer = decoder.getBuffer();
    })
    .catch((error) => {
        // Something went wrong
    });

Decode from buffer to file

[...]

const Fdkaac = require("node-fdkaac").Fdkaac;

const decoder = new Lame({
    "output": "./audio-files/demo.wav"
}).setBuffer(m4aInputBuffer);

decoder.decode()
    .then(() => {
        // Decoding finished
    })
    .catch((error) => {
        // Something went wrong
    });

Decode from buffer to buffer

[...]

const Fdkaac = require("node-fdkaac").Fdkaac;

const decoder = new Lame({
    "output": "buffer"
}).setBuffer(mp4aInputBuffer);

decoder.decode()
    .then(() => {
        // Decoding finished
        const buffer = decoder.getBuffer();
    })
    .catch((error) => {
        // Something went wrong
    });

All options

Option	Description	Values	Default
output	Output filename	Path
profile	Target profile (MPEG4 audio object type, AOT)	2 (MPEG-4 AAC LC), 5 (MPEG-4 HE-AAC; SBR), 23 (MPEG-4 AAC LD), 29 (MPEG-4 HE-AAC v2; SBR+PS), 39 (MPEG-4 AAC ELD)	2
bitrate	Target bitrate (for CBR)	Number	undefined
bitrate-mode	Bitrate configuration mode. Available VBR quality value depends on other parameters such as profile, sample rate, or number of channels.	0 (CBR), 1-5 (VBR; higher value => higher bitrate)	0
bandwidth	Frequency bandwidth (lowpass cut-off frequency) in Hz. Available on AAC LC only.	Number	undefined
afterburner	Configure afterburner mode. When enabled, quality is increased at the expense of additional computational workload.	0 (Off), 1 (On)	1
lowdelay-sbr	Configure SBR activity on AAC ELD.	-1 (Use ELD SBR auto configuration, 0 (Disable SBR on ELD), 1 (Enable SBR on ELD)	0
sbr-ratio	Controls activation of downsampled SBR.	0 (Use lib default), 1 (Use downsampled SBR; default for ELD+SBR), 2 (Use dual-rate SBR; default for HE-AAC)	0
transport-format	Transport format. Tagging and gapless playback is only available on M4A.	0 (M4A), 1 (ADIF), 2 (ADTS), 6 (LATM MCP=1), 7 (LATM MCP=0), 10 (LOAS/LATM; LATM within LOAS)	0
adts-crc-check	Add CRC protection on ADTS header.	Boolean	false
header-period	StreamMuxConfig/PCE repetition period in the transport layer.	Number	undefined
gapless-mode	Method to declare amount of encoder delay (and padding) in M4A container. These values are mandatory for proper gapless playback on player side.	0 (iTunSMPB), 1 (ISO standard; edts and sgpd), 2 (Both)	0
include-sbr-delay	When specified, count SBR decoder delay in encoder delay.	Boolean	false
ignorelength	Ignore length field of data chunk in input WAV file.	Boolean	false
moov-before-mdat	Place moov box before mdat box in M4A container. This option might be important for some hardware players, that are known to refuse moov box placed after mdat box.	Boolean	false
raw	Regard input as raw PCM.	Boolean	false
raw-channels	Specify number of channels of raw input	Number	2
raw-rate	Specify sample rate of raw input.	Number	44100
raw-format	Specify sample format of raw input (details see nu774/fdkaac).	String	S16L
meta	Meta data for M4A container.	Object	undefined

Meta options

Option	Description	Values	Default
title	Set title tag.	String	undefined
artist	Set artist tag.	String	undefined
album	Set album tag.	String	undefined
genre	Set genre tag.	String	undefined
date	Set date tag.	String	undefined
composer	Set composer tag.	String	undefined
grouping	Set grouping tag.	String	undefined
comment	Set comment tag.	String	undefined
album-artist	Set album artist tag.	String	undefined
track	Set track tag, with or without number of total tracks.	Number[/Total]	undefined
disk	Set disk tag, with or without number of total discs.	Number[/Total]	undefined
tempo	Set tempo (BPM) tag.	Number	undefined
tag	Set iTunes predefined tag with explicit fourcc key and value. See iTunesMetadata for known predefined keys.	<fcc>:<value>	undefined
long-tag	Set arbitrary tag as iTunes custom metadata. Stored in com.apple.iTunes field.	<fcc>:<value>	undefined

Option description text from fdkaac by nu774. Based on fdkaac commit 4682fe4 from Jan 16, 2017.