Node-MPV 2

A wrapper, that allows you, to comfortably use mpv player with NodeJs. It offers an API for the most relevant functionalities and is highly flexible. The module keeps an instance of MPV running in the background (using MVP's --idle) and communicates over MPV's JSON IPC (Inter-Process Communication) API.

However, it doesn't stop there, it also provides direct access to the IPC socket itself. Thus this module is not limited to the methods it provides, but can used with the full extent of what MPV has to offer, even if some command is not supported by Node-MPV.

Works on UNIX and Windows.

This module requires mpv to be installed on your system to work. For streaming playback from sources such as YouTube and SoundCloud youtube-dl is required.

Support me

Open-source software and this module is and should always be free. I have put countless hours of my free time into creating this NPM module, if you feel like donating the equivalent of a coffee as a token of gratitude, I'd appreciate that. Of course, it's perfectly fine if you choose not to as well.

Node-MPV 1

If you are looking for source code of the original Version 1 of this package, you can find it here. Furthermore, you can install the latest 1.x.x version using

npm install node-mpv@"^1.x.x"

This will install and update to the latest 1.x.x version, but never to anything >= 2.x.x. With this, you will automatically get bug fixes for version 1, without having to worry about any API breaking changes. Keep in mind, that I most likely won't add any new features to Version 1, but only provide bug fixes. Also, you should consider switching to Version 2, there even is a handy migration guide.

Migration to Node-MPV 2

If you're already using Node-MPV 1 please refer to this Migration Guide to see how to migrate your application to Node-MPV 2.

Table of Contents

• Node-MPV 2 - Support me
  • Node-MPV 1
  • Migration to Node-MPV 2
• Table of Contents
• Install
  • Dependencies
    • macOS
    • Linux (Ubuntu/Debian)
    • Windows
• Usage
  • Promises
  • Hooking into a Running Instance of MPV
• API
  • Starting & Stopping
  • Load Content
  • Controlling MPV
  • Information
  • Playlists
  • Audio
  • Video
  • Subtitles
  • Properties
  • Observing
• Events
  • Note
• Error Handling
• Example
• Known Issues
  • Old MPV Version on Debian
  • IPC Command
  • Bug with observing playlist-count in MPV Player 0.17.0
  • MPV Player 0.18.1
  • MPV Hanging or Crashing
• Changelog

Install

As of now, Version 2 is still in beta, but has been used by many people over the last 2 years. It's very very close to a stable version.

npm install node-mpv@beta

Dependencies

At least mpv is required, but youtube-dl is recommended as well. youtube-dl is only required if you want to stream videos or music from YouTube, SoundCloud or other websites supported by youtube-dl. See here for a list of supported websites.

macOS

brew install mpv youtube-dl

Linux (Ubuntu/Debian)

sudo apt-get install mpv youtube-dl

Windows

Go to the respective websites mpv and youtube-dl and follow the install instructions.

Usage

Every single method of Node-MPV returns a Promise, more on that later. The following example assumes, that it is put within an async function. For an example using the old .then() way, look a little further below

// where you import your packages
const mpvAPI = require('node-mpv');
// where you want to initialise the API
const mpv = new mpvAPI();

// somewhere within an async context
// starts MPV
try{
  await mpv.start()
  // loads a file
  await mpv.load('your/favorite/song.mp3');
  // file is playing
  // sets volume to 70%
  await mpv.volume(70);
}
catch (error) {
  // handle errors here
  console.log(error);
}

You can optionally pass a JSON object with options to the constructor. Possible options, along with their default values are the following

{
    "audio_only": false,
    "auto_restart": true,
    "binary": null,
    "debug": false,
    "ipcCommand": null,   
    "socket": "/tmp/node-mpv.sock", // UNIX
    "socket": "\\\\.\\pipe\\mpvserver", // Windows
    "time_update": 1,
    "verbose": false,
}

• audio_only will add the --no-video and --no-audio-display argument and start mpv in audio only mode
• auto_restart - if set to true, MPV is restarted when it has crashed
• binary will use the provided path to a mpv binary instead of using the one found in $PATH
• debug prints error messages
• ipc_command sets the ipc command to start the ipc socket. Possible options are --input-unix-socket and --input-ipc-server. This is usually not needed since Node-MPV is able to determine the correct command on its own
• socket specifies the socket mpv opens. Node-MPV will first check, if there's already an mpv instance running on that socket and hook into it
• time_update the time interval in seconds, how often mpv should report the current time position, when playing a song or video
• verbose will print various information on the console

You can also provide an optional second argument, an Array containing mpv command line options. A list of available arguments can be found in the documentation

const mpv = new mpvAPI({
  "verbose": true,
  "audio_only": true
},
[
  "--fullscreen",
  "--fps=60"
])

await mpv.start()
// Code controlling mpv

mpv is then easily controllable via simple function calls.

await mpv.loadFile("/path/to/your/favorite/song.mp3");

await mpv.volume(70);

Events are used to detect changes.

mpv.on('status', (status) => {
  console.log(status);
});

mpv.on('stopped', () => {
  console.log("Gimme more music");
});

Promises

If, for some reason, you don't want to use the async/await syntax, you can use Promises the old fashioned way. Every single method of Node-MPV returns a Promise. This means you will have to create a promise chain to control the player. The promise will be resolved if everything went fine and possibly returns some information and it will be rejected with a proper error message if something went wrong.

mpv.start()
.then(() => {
    return mpv.load('/path/to/video.mkv');
})
.then(() => {
    return mpv.getDuration();
})
.then((duration) => {
    console.log(duration);
    return mpv.getProperty('someProperty');
})
.then((property) => {
    console.log(property);
})
// catches all possible errors from above
.catch((error) => {
    // Maybe the mpv player could not be started
    // Maybe the video file does not exist or couldn't be loaded
    // Maybe someProperty is not a valid property
    console.log(error);
})

Starting from Node 8.0.0 Async/Await is fully supported. If you're within an async function you can use await for better readability and code structure. The promise code from above becomes this

someAsyncFunction = asnyc () => {
    try{
    	await mpv.start();
    	await mpv.load('path/to/video.mkv');
    	console.log(await mpv.getDuration());
    	console.log(await mpv.getProperty('someProperty'));
    }
    catch (error) {
    	// Maybe the mpv player could not be started
    	// Maybe the video file does not exist or couldn't be loaded
    	// Maybe someProperty is not a valid property
    	console.log(error);
    }
}

Hooking into a Running Instance of MPV

Using the options you can specify the IPC socket, that should be created to handle the communication between MPV and this module. If there is already an instance of MPV running, that has been started with --idle and --input-ipc-server=</tmp/somesocket.sock>, you can hook into that instance by specifying socket=</tmp/somesocket.sock>. In this case, Node-MPV will not create its own instance of MPV but use the already running one.

However, it is not possible to enable auto_restart or any error handling for an external MPV instance. That has to be handled by that instance itself.

Since it is not possible to determine if an MPV instance, that has been started externally, has crashed or was properly quit, both events crashed and quit will be emitted if hooking into an existing instance. See the Events section for more.

API

Starting & Stopping

• start (mpv_args=[])

  Starts the MPV process in the background. Has to be called before the player can be used.

  • mpv_args List of arguments for the MPV player, the same as when calling the constructor. Possible arguments can be found in the documentation.

  return - a promise that resolves when MPV is started and is rejected if an error occurs

  mpv.start()
  .then(() => {
   // The player can be used here
  });

• quit ()

  Quits MPV. The process in the background is terminated and all socket connection is closed. MPV can be restarted using start ()

• isRunning () - boolean

  Returns whether MPV is running or not. This method is an exception, it does not return a Promise

Load Content

• load (content, mode="replace", options)

  Will load the content (either a file, a url or any supported protocol) and start playing it. This behaviour can be changed using the mode option.

  • mode
  • replace(default) replace the current title and play it immediately
  • append appends the file to the playlist
  • append-play appends the file to the playlist. If the playlist is empty this file will be played
  • options (optional) an array that can be used to pass additional options to MPV

  There is another append function in the playlist section, which can be used to append either files or streams.

  return - a promise that resolves if everything went fine and the file or stream is playing (or appended when mode was set to append) and is rejected with an error message when something went wrong

Controlling MPV

• play ()

  Starts playback when in the pause state

• stop ()

  Stops the playback entirely

• pause ()

  Pauses playback

• resume ()

  Resumes from the pause state

• togglePause ()

  Toggles the pause state

• mute (set)

  Mutes or unmutes the player. The mute state can either be toggled or set explicitly

  • set (optional) If not set, the mute state is toggled. If set to true the player is muted, if set to false the player is unmuted, regardless of the current state

• volume (volumeLevel)

  Sets volume to volumeLevel. Allowed values are between 0-100. All values below or above will just set the volume to 0 or 100 respectively

• adjustVolume (value)

  Adjusts the volume with the specified value. If this results in the volume going below 0 or above 100 it will be set to 0 or 100 respectively

• seek (seconds, mode="relative")

  Will search/jump within the current track. Depending on mode, it is searched onwards from the current position, or jumped to the set position, given by seconds

  • mode
  • relative (default) Searches x seconds from the current track position
  • absolute Jumps to the position at x seconds in the current track

  return - a promise that is resolved once the track is being played again or rejected if something went wrong

• goToPosition (seconds)

  Jumps to the position specified by seconds. Going beyond the boundaries of a title results in playback stopping

• loop (times)

  • times (optional) can be any number > 0, inf or no. Will loop of a fixed number of times (number), infinitely (inf) or will stop looping (no)

  If times is not set, this will toggle the mute status between not looping and infinitely looping. If times is set, it will loop the track as often as the passed value.

Information

• isMuted ()

  Tells if MPV is muted

• isPaused ()

  Tells if MPV is paused

• isSeekable ()

  Tells if the currently playing title is seekable or not. Streams that are not fully loaded might not be seekable. The same goes for radio streams for example.

• getDuration ()

  Returns the duration (as a promise) of the currently playing title if available. For example for radio streams this will not be known.

• getTimePosition ()

  Returns the current timeposition (as a promise) for the currently playing title

• getPercentPosition ()

  Returns the current timeposition as a percentage value (as a promise) for the currently playing title

• getTimeRemaining ()

  Returns the remaining time (as a promise) for the currently playing title, if possible

• getMetadata ()

  Returns the available metadata {as a promise) for the currently playing title. The promise returns a JSON Object

  There are some helper functions for quick access to some metadata, they all return promises as usual.

• getArtist ()

• getTitle ()

• getAlbum ()

• getYear ()

• getFilename (mode="full")

  • full (default) the full path or url
  • stripped the path stripped to the file or the end of the url

  Returns the filename (or url) of the currently playing track (as a promise).

Playlists

• loadPlaylist (playlist, mode="replace")

  Loads a playlist file. mode can be one of the two following

  • replace (default) Replaces the old playlist with the new one
  • append Appends the new playlist to the active one

  This function does not work with YouTube or SoundCloud playlists. Use loadFile or loadStream instead

  return - a promise, that is resolved when everything went fine or rejected when an error occurs. For example, if the playlist file cannot be found or the first song in the playlist cannot be played

• append (file, mode="append")

  Appends file (which can also be an url) to the playlist.

  • mode
  • append (default) Append the title
  • append-play When the playlist is empty the title will be started
  • options (optional) an array that can be used to pass additional options to mpv

  return - a promise that resolves if everything went fine and the file or stream is playing (when mode was set to append-play) or was appended (when mode was set to append) and is rejected with an error message when something went wrong.

  It is not necessarily required to check the promise when using append (default). Checking whether the file can be played or not is done when it is played, not when it's appended.

• next (mode="weak")

  Skips the current title. mode can be one of the following two

  • weak (default) If the current title is the last one in the playlist it is not skipped
  • force The title is skipped (even if it was the last one) and playback is stopped

  return - a promise that resolves to true when the track was skipped and false otherwise. Throws an error message if the file is not playable.

• prev (mode="weak")

  Skips the current title. mode can be one of the following two

  • weak (default) If the title is the first one in the playlist it is not stopped
  • force The title is skipped (even if it was the first one) and playback is stopped

  return - a promise that resolves to true when the track was skipped and false otherwise. Throws an error message if the file is not playable.

• jump (position)

  Jumps to the position in the playlist given by position. It's zero-based, meaning that the first spot in the playlist is 0.

  return - a promise that resolves to true when the player jumped in the playlist and false if the desired position is not possible because it is not within the playlist size.

  Throws an error message if the file is not playable.

• clearPlaylist ()

  Clears the playlist

• playlistRemove (index)

  Removes the title at index from the playlist. If index is set to "current" the current title is removed and playback stops

• playlistMove (index1, index2)

  Moves the title at index1 to the position at index2

• shuffle ()

  Shuffles the playlist into a random order

• getPlaylistSize ()

  Returns a promise that resolves to the playlist size

• getPlaylistPosition ()

  Returns a promise that resolves to the current playlist position. The position is 0-based, which means, that positon 1 is 0 and so on.

• getPlaylistPosition1 ()

  Just like getPlaylistPosition() but 1-based, so the first position is 1 and so on.

• loopPlaylist (times)

  • times (optional) can be any number > 0, inf or no. Will loop of a fixed number of times (number), infinitely (inf) or will stop looping (no)

  If times is not set, this will toggle the mute status between not looping and infinitely looping the playlist. If times is set, it will loop the playlist as often as the passed value.

Audio

• addAudioTrack (file, flag, title, lang)

  Adds an audio file to the video that is loaded.

  • file The audio file to load
  • flag (optional) Can be one of "select" (default), "auto" or "cached"
  • title (optional) The name for the audio track in the UI
  • lang (optional) the language of the audio track

  flag has the following effects

  • select - the added audio track is selected immediately
  • auto - the audio track is not selected
  • cached - select the audio track, but if an audio track file with the same name is already loaded, the new file is not added and the old one is selected instead

• removeAudioTrack ()

  Removes the audio track specified by id. Works only for external audio tracks

• selectAudioTrack (id)

  Selects the audio track associated with id

• cycleAudioTracks ()

  Cycles through the audio tracks

• adjustAudioTiming (seconds)

  Shifts the audio timing by seconds

• speed (scale)

  Controls the playback speed by scale which can take any value between 0.01 and 100

  If the --auto-pitch-correction flag is used (default), this will not pitch the audio and uses a scale tempo audio filter

Video

• fullscreen ()

  Goes into fullscreen mode

• leaveFullscreen ()

  Leaves fullscreen mode

• toggleFullscreen ()

  Toggles between fullscreen and windowed mode

• screenshot (file, option)

  Takes a screenshot and saves it to file. options is one of the following

  • subtitles (default) Takes a screenshot including the subtitles
  • video Only the image, no subtitles
  • window The scaled MPV window

• rotateVideo (degrees)

  Rotates the video clockwise. degree can only be multiples of 90 and the rotation is absolute, not relative

• zoomVideo (factor)

  Zooms into the video. 0 does not zoom at all, 1 zooms double and so on

• brightness (value)

  Sets the brightness to value. Allowed values are between -100 and 100

• contrast (value)

  Sets the contrast to value. Allowed values are between -100 and 100

• saturation (value)

  Sets the saturation to value. Allowed values are between -100 and 100

• gamma (value)

  Sets the gamma to value. Allowed values are between -100 and 100

• hue (value)

  Sets the hue to value. Allowed values are between -100 and 100

Subtitles

• addSubtitles (file, flag, title, lang)

  Adds a subtitle file to the video that is loaded.

  • file The subtitle file to load
  • flag (optional) Can be one of "select" (default), "auto" or "cached"
  • title (optional) The name for the subtitle file in the UI
  • lang (optional) The language of the subtitle

  flag has the following effects

  • select - the added subtitle is selected immediately
  • auto - the subtitle is not selected
  • cached - select the subtitle, but if a subtitle file with the same name is already loaded, the new file is not added and the old one is selected instead

• removeSubtitles (id)

  Removes the subtitle file specified by id. Works only for external subtitles

• selectSubtitles (id)

  Selects the subtitle associated with id

• cycleSubtitles ()

  Cycles through all available subtitles

• toggleSubtitleVisibility ()

  Toggles between hidden and visible subtitles

• showSubtitles ()

  Shows the subtitles

• hideSubtitles ()

  Hides the subtitles

• adjustSubtitleTiming (seconds)

  Shifts the subtitle timing by seconds

• subtitleSeek (lines)

  Jumps as many lines of subtitles as defined by lines. Can be negative. This will also seek in the video.

• subtitleScale (scale)

  Adjust the scale of the subtitles

• displayASS (assMessage, duration, position=7)

  Displays ass-formated subtitles. A good documentation about ass can be found here.

  • assMessage the subitle text along with the ass-tags
  • duration the time the subtitle should be displayed in miliseconds
  • position where the subtitles are displayed. It works like a numpad (5 being center and so on). The default is 7 - the top left corner

  This method will add ${osd-ass-cc/0} (along with the position tag) in front of your message, to enable ass formating and parameter expansion.

  You cannot show two different subtitles at the same time, the newer one will overwrite the previous one. This is a limitation of mpv.

  Unfortunately beforehand defined ass styles do not work, you have to style your subtitles using ass-tags

  player.displayASS('{\\fsp10}Hey I'm a letter spaced subtitle in the center of the screen', 5000, 5);

Properties

These methods can be used to alter properties or send arbitrary commands to the running MPV player. Information about what commands and properties are available can be found in the list of commands and list of properties sections of the MPV documentation.

The most common commands are already covered by this module. However, this part enables you to send any command you want over the IPC socket. Using this, you aren't limited to the methods defined by this module.

• setProperty (property, value)

  Sets the specified property to the specified value

• setMultipleProperties (properties)

  Calls setProperty for every property specified in the arguments JSON object. For example

  setMultipleProperties({
    "volume": 70,
    "fullscreen": true
  });

• getProperty (property)

  Gets information about the specified property.

  return - a promise that resolves to the property value

• addProperty (property, value)

  Increase the property by the specified value. Needless to say, this can only be used on numerical properties. Negative values are possible

• multiplyProperty (property, value)

  Multiply the specified property by value

• cycleProperty (property)

  Cycles the values of an arbitrary property

• command (command, args)

  Sends the command to the MPV player with the arguments specified in args The JSON command

  {"command": ["loadfile", "audioSong.mp3"]}

  becomes a function call

  command("loadfile",["audioSong.mp3"]

• commandJSON (command)

  Sends a command, specified by a JSON object to mpv. Please refer to the documentation for the protocol.

  let command = {
      'command': [
          'loadfile',
          'audioSong.mp3'      
      ]
  };
  mpvPlayer.commandJSON(command);

• freeCommand (command)

  This will send an arbitrary command to the MPV player. It must follow the specification of the Json IPC protocol. Its syntax can be found in the documentation.

  A trailing "\n" will be added to the command.

Observing

Node-MPV allows you to observe any property the mpv API offers you, by simply using the observeProperty function.

• observeProperty (property)

  This will observe property, which means, that a status event is emitted, whenever this property changes

• unobserveProperty (property)

  No further status event will be emitted for property

Events

The Node-MPV module provides various events to notify about changes of the MPV player's state.

• crashed

  Whenever MPV has crashed or the process was killed. If the auto_restart option is set to true (default), MPV is restarted again right away.

  Use this event to for example reload your playlist, videos, etc when the player crashed

• getrequest <id, data> - deprecated

  Delivers the reply to a function call to the getRequest method

• seek

  Whenever a seek() or goToPosition() is called, or some external source searches, this event is emitted providing a timeposition object with the following information

  {
  "start": <timeposition before seeking>,
  "end": <timeposition after seeking>
  }

  In case the seek can not be finished, for example, because the file is changed while seeking, this event is not emitted. It is only emitted when the seeking has successfully finished.

• started

  Whenever MPV starts playing a song or video

• stopped

  Whenever the playback has stopped

• paused

  Whenever MPV was paused

• resumed

  Whenever MPV was resumed

• status <status object>

  Whenever the status of one of the observed properties changes, this event will be emitted providing the change to that property in the form of

  {
    "property": <propertyname>,
    "value": <propertyvalue>
  }

  By default, the following properties are observed

  • mute
  • pause
  • duration
  • volume
  • filename
  • path
  • media-title
  • playlist-pos
  • playlist-count
  • loop

  If the player is running in video mode the following properties are present as well.

  • fullscreen
  • sub-visibility

• timeposition <seconds>

  When a song or video is currently playing and the playback is not paused, this event will emit the current position in seconds.

  When creating the MPV instance you can set a parameter, how often this event should occur. Default is every second

• quit

  When MPV player was quit by the user on purpose, this event is emitted. It is not emitted, when the quit() method was used.

  Use this to detect if the user has closed the player.

Note

• filename When playing a local file this contains the filename. When playing for example a YouTube stream, this will only contain the trailing url

• path Provides the absolute path to the file or the full url of a stream

• media-title If available in the file this will contain the title. When streaming from YouTube this will be set to the video's name

  This object can expanded through the observeProperty method making it possible to watch any state you desire, given it is provided by mpv

Error Handling

Because the JSON IPC API of MPV does not provide any useful error messages, except for it worked or it didn't work, I created an error object, that should help you to figure out what went wrong, and hint you into the right direction for fixing the issue.

If there is an error with a method of this library, it will throw an exception (reject the promise) with an error object, that looks like the following.

{
    'errcode': Error Code
    'verbose': Verbal version of the Error Code
    'method': Method that raised the error
    'arguments': List of arguments the method was called with
    'errmessage': More specific error message
    'options': JSON object with valid options for the method if possible
    'stackTrace': The error stack trace
}

The following Error Codes are available

• 0 Unable to load file or stream
• 1 Invalid argument
• 2 Binary not found
• 3 ipcCommand invalid
• 4 Unable to bind IPC socket
• 5 Timeout
• 6 MPV is already running
• 7 Could not send IPC message
• 8 MPV is not running
• 9 Unsupported protocol

Example

const mpvAPI = require('node-mpv');
const mpv = new mpvAPI();

// Start the player
mpv.start()
.then(() => {
	// This will load and start the song
	return mpv.load('/path/to/your/favorite/song.mp3')
})
.then(() => {
	// Set the volume to 50%
	return mpv.volume(50);
})
// this catches every arror from above
.catch((error) => {
	console.log(error);
});

// This will bind this function to the stopped event
mpv.on('stopped', () => {
    console.log("Your favorite song just finished, let's start it again!");
    mpv.loadFile('/path/to/your/favorite/song.mp3');
});

Known Issues

Old MPV Version on Debian

Debian took their stable policy a little to far and MPV is still on version 0.6.0. Unfortunately the IPC functionality was only introduced with version 0.7.0. Thus this module will not work with the Debian packaged MPV. The dependencies to build MPV are also too old on Debian. Luckily there is this project, that helps you to build the dependencies and MPV afterwards. Using this you can easily get the latest stable MPV Player on Debian.

IPC Command

The command-line argument to start the IPC socket has changed in MPV version 0.17.0 from --input-unix-socket to --input-ipc-server. This module uses regular expressions to find the version number from the mpv --version output. If MPV was compiled from source, the version number is stated as UNKNOWN and this module will assume, that you use the latest version and use the new command.

If you use self compiled version stating UNKNOWN as the version number below mpv version 0.17.0 you have to use the ipc_command option with '--input-unix-socket'.

To check this enter the following in your command shell

mpv --version

Bug with observing playlist-count in MPV Player 0.17.0

In mpv version 0.17.0, the playlist-count property is not updated on playlistRemove and append.

I filed an Issue and this is fixed with 0.17.1

MPV Player 0.18.1

MPV Player version 0.18.1 has some issues that the player crashes sometimes when sending commands through the ipc socket. If you're using version 0.18.1 try to use a newer (or older) version.

To check your version number enter the following in your command shell

mpv --version

MPV Hanging or Crashing

If your JS code is correct but you are still experiencing crashes, a good place to start debugging is by disabling the default config and/or plugins.

mpvPlayer = new mpv({
 ...
},
[
 "--no-config",
 "--load-scripts=no"
]);

For example, autoload.lua is known to cause problems when loading files in quick succession from a folder with many files.

Changelog

See changelog for more information or API breaking changes