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.