This module encapsulates code responsible for managing local media and room config. This includes creation of new tracks, stopping existing tracks and preparation of room config before connecting to server.
1. Wrapper function
createControls() code
Wrapper function which keeps controls inside the closure.
const createControls = function(config) {
2. Create controls object
Create controls object which will hold all the html handles. Also initialize tables for displaying local tracks configuration.
const controls = { entrance: { url: document.getElementById("url"), roomName: document.getElementById("roomName"), roomPin: document.getElementById("roomPin"), nickName: document.getElementById("nickName"), enter: document.getElementById("startButton") }, addVideoTrack: { source: document.getElementById("addVideoTrackSource"), width: document.getElementById("addVideoTrackWidth"), height: document.getElementById("addVideoTrackHeight"), codec: document.getElementById("addVideoTrackCodec") }, addAudioTrack: { source: document.getElementById("addAudioTrackSource"), channels: document.getElementById("addAudioTrackChannels") }, addVideoEncoding: { rid: document.getElementById("addVideoTrackEncodingRid"), active: document.getElementById("addVideoTrackEncodingActive"), maxBitrate: document.getElementById("addVideoTrackEncodingMaxBitrate"), resolutionScale: document.getElementById("addVideoTrackEncodingResolutionScale") }, tables: { video: $('#videoTracksTable').DataTable({ "sDom": 't', "columns": [ { "className": 'details-control', "orderable": false, "data": null, "defaultContent": '' }, {"data": "source"}, {"data": "width"}, {"data": "height"}, {"data": "codec"}, {"data": "action"} ] }), audio: $('#audioTracksTable').DataTable({ "sDom": 't', "columns": [ {"data": "source"}, {"data": "channels"}, {"data": "action"} ] }), encodings: $('#videoTrackEncodingsTable').DataTable({ "sDom": 't', "columns": [ {"data": "rid"}, {"data": "active"}, {"data": "maxBitrate"}, {"data": "resolutionScale"}, {"data": "action"} ] }) } }
3. Fill entrance modal window fields
Populate entrance modal with provided config
//apply room config controls.entrance.url.value = config.room.url; controls.entrance.roomName.value = config.room.name; controls.entrance.roomPin.value = config.room.pin; controls.entrance.nickName.value = config.room.nickName;
4. Add new audio tracks to controls
addAudioTrackRow() code
Function that will add new audio tracks to controls and notify main script.
const addAudioTrackRow = function(track) { getMedia([track]).then(function(stream){ let button = '<button id="' + stream.id + '-button" class="btn btn-primary">Delete</button>'; const row = controls.tables.audio.row.add({ source: track.source, channels: track.channels, action: button, stream: stream }).node(); controls.tables.audio.draw(); $('#' + stream.id + "-button").on('click', function(){ //terminate stream console.log("terminate stream " + stream.id); let track = stream.getAudioTracks()[0]; track.stop(); track.dispatchEvent(new Event("ended")); }); stream.getTracks()[0].onended = function() { controls.tables.audio.row(row).remove().draw(); } trackCallback({ stream: stream, encodings: track.encodings }); }); }
Request local media from the WebRTC API
getMedia([track]).then(function(stream){
Add track to the audio tracks table
let button = '<button id="' + stream.id + '-button" class="btn btn-primary">Delete</button>'; const row = controls.tables.audio.row.add({ source: track.source, channels: track.channels, action: button, stream: stream }).node(); controls.tables.audio.draw();
Subscribe to "click" event. Once "Delete" button is clicked stop the track and dispatch "ended" event
$('#' + stream.id + "-button").on('click', function(){ //terminate stream console.log("terminate stream " + stream.id); let track = stream.getAudioTracks()[0]; track.stop(); track.dispatchEvent(new Event("ended")); });
Subscribe to track's "ended" event and clean the table once track is ended
stream.getTracks()[0].onended = function() { controls.tables.audio.row(row).remove().draw(); }
Notify main script we have a new local track
trackCallback({ stream: stream, encodings: track.encodings });
5. Add new video tracks to controls
addVideoTrackRow() code
Function that will add new video tracks to controls and notify main script. This is the same as addAudioTrackRow function except it adds video.
const addVideoTrackRow = function(track) { getMedia([track]).then(function(stream){ let button = '<button id="' + stream.id + '-button" class="btn btn-primary">Delete</button>'; const row = controls.tables.video.row.add({ source: track.source, width: track.width, height: track.height, codec: track.codec, action: button, stream: stream, encodings: track.encodings }).node(); controls.tables.video.draw(); $('#' + stream.id + "-button").on('click', function(){ //terminate stream console.log("terminate stream " + stream.id); let track = stream.getVideoTracks()[0]; track.stop(); track.dispatchEvent(new Event("ended")); }); stream.getTracks()[0].addEventListener("ended", function() { controls.tables.video.row(row).remove().draw(); }); trackCallback({ stream: stream, encodings: track.encodings }); }); }
6. Format video encodings
format() code
Helper function to format video encodings so we can display them in the table nicely
const format = function(d) { if (!d.encodings) { return; } let details = '<table cellpadding="5" cellspacing="0" border="0" style="padding-left:50px;">'; d.encodings.forEach(function(encoding){ details += '<tr>'; for (const [key, value] of Object.entries(encoding)) { details += '<td>'+ key + '</td>'+ '<td>'+ value + '</td>'; } details += '</tr>'; }); details +='</table>'; return details; }
7. Add handler to display/hide track details
Add open and close handler for video tracks details
// Add event listener for opening and closing details $('#videoTracksTableBody').on('click', 'td.details-control', function () { let tr = $(this).closest('tr'); let row = controls.tables.video.row(tr); if (row.child.isShown()) { // This row is already open - close it row.child.hide(); tr.removeClass('shown'); } else { // Open this row row.child(format(row.data())).show(); tr.addClass('shown'); } });
8. Add audio tracks to the table
Add all configured audio tracks to the table
config.media.audio.tracks.forEach(function(track){ addAudioTrackRow(track); })
9. Add video tracks to the table
Add all configured video tracks to the table
config.media.video.tracks.forEach(function(track){ addVideoTrackRow(track); })
10. Mute forms
muteForm() code
Define helper function for muting forms
const muteForm = function(form) { for (const [key, value] of Object.entries(form)) { value.disabled = true; } }
11. Unmute forms
unmuteForm() code
Define helper function for unmuting forms
const unmuteForm = function(form) { for (const [key, value] of Object.entries(form)) { value.disabled = false; } }
12. Mute entrance modal window inputs
muteInput() code
Define function that mutes entrance inputs
const muteInput = function() { muteForm(controls.entrance); }
13. Create room configuration object
roomConfig() code
Define function that will assemble room config
const roomConfig = function() { return { url: controls.entrance.url.value, roomName: controls.entrance.roomName.value, pin: controls.entrance.roomPin.value, nickname: controls.entrance.nickName.value } }
14. Get local video tracks
getVideoStreams() code
Define function that will return all available local video tracks
const getVideoStreams = function() { let streams = []; controls.tables.video.rows().every(function(rowIdx, tableLoop, rowLoop) { let data = this.data(); streams.push({ stream: data.stream, encodings: data.encodings }); }); return streams; }
15. Get local audio tracks
getAudioStreams() code
Define function that will return all available local audio tracks
const getAudioStreams = function() { let streams = []; controls.tables.audio.rows().every(function(rowIdx, tableLoop, rowLoop) { let data = this.data(); streams.push({ stream: data.stream, encodings: [] }); }); return streams; }
16. Handler to add video track to the table
Subscribe to "click" event of add video track button. This function will parse input and add new track to the table
document.getElementById("addVideoTrack").addEventListener("click", function(e){ let encodings = []; controls.tables.encodings.rows().every(function() { let encoding = this.data(); encodings.push({ rid: encoding.rid, active: encoding.active, maxBitrate: encoding.maxBitrate, scaleResolutionDownBy: encoding.resolutionScale }) }); let track = { source: controls.addVideoTrack.source.value, width: controls.addVideoTrack.width.value, height: controls.addVideoTrack.height.value, codec: controls.addVideoTrack.codec.value, encodings: encodings } addVideoTrackRow(track); });
17. Handler to remove encoding from the table
Add ability to remove encodings from the encodings table
$("#videoTrackEncodingsTable").on("click", ".remove", function(){ controls.tables.encodings.row($(this).parents('tr')).remove().draw(); });
18. Handler to add encoding to the table
Subscribe to "click" event of add encoding button. This function will parse input and add a new encoding to the encodings table
document.getElementById("addVideoTrackEncoding").addEventListener("click", function(){ let button = '<button class="btn btn-primary remove">Delete</button>'; controls.tables.encodings.row.add({ rid: controls.addVideoEncoding.rid.value, active: controls.addVideoEncoding.active.value, maxBitrate: controls.addVideoEncoding.maxBitrate.value, resolutionScale: controls.addVideoEncoding.resolutionScale.value, action: button }).draw(); });
19. Handler to add audio track to the table
Subscribe to "click" event of add audio track button. This function will parse input and add new track to the table
document.getElementById("addAudioTrack").addEventListener("click", function(e){ let encodings = []; let track = { source: controls.addAudioTrack.source.value, channels: controls.addAudioTrack.channels.value, encodings: encodings } addAudioTrackRow(track); });
20. Pass callback function to new tracks
Define function that will help to pass the callback function for the new tracks
const onTrack = function(callback) { trackCallback = callback; }
21. Export functions
Export functions for the script
return { muteInput: muteInput, roomConfig: roomConfig, getAudioStreams: getAudioStreams, getVideoStreams: getVideoStreams, onTrack: onTrack }
22. Get media streams from WebRTC API
getMedia() code
Requests local media streams from the WebRTC API.
const getMedia = async function(tracks) { //convert to constraints let screen = false; const constraints= {}; tracks.forEach(function(track){ if (track.source === "mic") { //audio constraints.audio = {}; constraints.audio.stereo = track.channels !== 1 } else if (track.source === "camera") { constraints.video = { width: track.width, height: track.height }; } else if (track.source === "screen") { constraints.video = { width: track.width, height: track.height }; screen = true; } }); //get access to a/v let stream; if (screen) { stream = await navigator.mediaDevices.getDisplayMedia(constraints); } else { stream = await navigator.mediaDevices.getUserMedia(constraints); } return stream; }