ycace / webrtc-stats

Helps you collect stats for peer connections

WebRTCStats

WebRTCStats is the most complete utility belt that helps with everything related to getting and parsing the stats for WebRTC PeerConnections.

The main advantage of WebRTCStats is that it parses and groups the stats from PeerConnections and offers them in a easy to read way

On top of that, it offers the timeline which is a list of all the events fired while setting up a PeerConnection. Optionally, you can also wrap getUserMedia to get a better picture.

WebRTCStats extends EventEmitter and uses the same event system to communicate with the rest of the app.

Migrating from v3

To see the changes that appeared in V4 see the changelog

Install

npm install @peermetrics/webrtc-stats

Usage

Loading the module

WebRTC Stats can be loaded as an ES6 module, node module or directly in the browser.

After loading, the library needs to be initialized. See Options for all the initialize options

import {WebRTCStats} from '@peermetrics/webrtc-stats'

let webrtcStats = new WebRTCStats({
    getStatsInterval: 5000
})

Add event listeners for stats:

webrtcStats.on('stats', (ev) => {
    console.log('stats', ev)
})

Use addPeer to add peers to the list of monitored peers:

let pc1 = new RTCPeerConnection({...})
webrtcStats.addPeer({
    pc: pc1,
    peerId: '1' // any string that helps you identify this peer,
	remote: false // optional, override the global remote flag
})

Now every 5000 ms WebRTCStats will fire the stats event which will come with the object:

{
    event: 'stats',
    tag: 'stats',
    peerId: '1',
    timestamp: 'Sun Mar 22 2020 18:02:02', // a timestamp when this was fired
    data: {...}, // an object created after parsing the stats
    rawStats: RTCStatsReport, // the actual RTCStatsReport results from `getStats()`
    statsObject: {}, // an object created from RTCStatsReport that uses the `id` for each report as a key
    filteredStats: {}, // same as statsObject but with some report types filtered out (eg: `codec`, `certificate`)
}

Options

The module accepts the following options when initialized:

let stats = new WebRTCStats({
    // the interval in ms of how often we should get stats
    getStatsInterval: 5000, // Default: 1000

    // if we should include the original RTCStatsReport map when firing the `stats` event
    rawStats: false, // Default: false

    // include an object that resulted from transforming RTCStatsReport into an oject (`report.id` as the key)
    statsObject: true, // Default: false
    
    // if we should filter out some stats
    filteredStats: false, // Default: false

    // If the data object should contain a remote attribute that will contain stats for the remote peer, from `remote-inbound-rtp`, etc
    remote: true, // Default: true

    // If we should wrap the `geUserMedia` calls so we can gather events when the methods is called or success/error
    wrapGetUserMedia: false, // Default: false
    
    // If we should log messages
    debug: false, // Default: false
    
    // What kind of level of logs the lib should display. Values: 'none', 'error', 'warn', 'info', 'debug'
    logLevel: 'warn' // Default: 'none'
})

API

.addPeer(options)

Adds a peer to the watch list. options

• pc: the RTCPeerConnection instance
• peerId: String a unique Id to identify this peer Monitoring of a peer will automatically end when the connection is closed.

.removePeer(peerId)

Stop listening for events/stats for this peer

.getTimeline([filter])

Return the array of events from the timeline up to that point. If the optional filter string is present it will filter out events. Possible values: peer, connection, track, stats, getUserMedia

Events

The module uses EventEmitter to emit events. You can listen to them using .on()

stats.on('eventName', (ev) => {
})

ev will have the following structure:

{
    // The event name. Usually the method called (addTrack, createAnswer)
    event: '',
    // The tag for this event. `stats`, `sdp`, `getUserMedia`, etc
    tag: '',
    // The id for the peer that fired this event
    peerId: '',
    // A timestamp for when the event happened
    timestamp: '',
    // Data for each event type
    data: {},
    
    // The following attrs appear at certain times
    // The error that appeared in the method we were watching
    error: {},
    // These appear on the `stats` event
    rawStats: {},
    statsObject: {},
    filteredStats: {}
}

List of fired events

The tags for the events fired by WebRTCStats are:

• timeline: this will fire when something has been added to the timeline. This event is a duplicate of the following events
• stats: fired for each peer when we've collected stats for it
• getUserMedia: when getUserMedia is called initially
• peer: when a peer was added
• track: a track event: addTrack, removeTrack, mute, unmute, overconstrained
• connection: any event related to connection
• datachannel: any datachannel event

License

MIT

Sponsorship

Platform testing is generously offered by BrowserStack