Overview

The example shows how to convert stream published on WCS server to HLS and play it in browser using VideoJS library. HLS stream cut starts automatically when strea is requested by HLS URL, for example `https://test1.flashphoner.com:8445/test/test.m3u8` on the screenshot below.

The example allows to choose VideoJS version to play. VideoJS 8 supports Low Latency HLS if server allows to play this format

Since build 2.0.244, the example supports the following parameters:

version - VideoJS version to use: videojs7 or videojs8
src - stream full HLS URL to play, should be encoded with URI, for example https%3A%2F%2Ftest1.flashphoner.com%3A8445%2Ftest%2Ftest.m3u8
autoplay - automatically play the HLS URL, in this case all the input fields and buttons are hidden: false (by default) or true

The player URL example with parameters as displayed on the screenshot above (the link is available in Permalink field)

https://test1.flashphoner.com:8444/client2/examples/demo/streaming/hls-player/hls-player.html?version=videojs7&src=https%3A%2F%2Ftest1.flashphoner.com%3A8445%2Ftest%2Ftest.m3u8

The player URL example with autoplay enabled

https://test1.flashphoner.com:8444/client2/examples/demo/streaming/hls-player/hls-player.html?version=videojs7&src=https%3A%2F%2Ftest1.flashphoner.com%3A8445%2Ftest%2Ftest.m3u8&autoplay=true

In this case the stream should be played automatically with audio muted. A viewer should use a loud slider in the player interface to unmute audio.

The code of the example

The source code can be accessed on server by the following path:

/usr/local/FlashphonerWebCallServer/client2/examples/demo/streaming/hls-player

hls-player.css - player page styles file
hls-player.html - player page
hls-player.js - player launch script
player-page.html - common player page elements for three HLS playback examples

The videojs7 and videojs8 subfolders contain two VideoJS versions respectively:

video.js - the player library script (http://videojs.com/, Apache License Version 2.0)
video.min.js - the player library script (minimized)
video-js.css - the player library styles file

The example can be tested using the fiollowing URL:

https://host:8444/client2/examples/demo/streaming/hls-player/hls-player.html

Where host is WCS server address

Analyzing the code

To analyze the code get hls-player.js file version with hash 1703e13, which is available here and can be downloaded in build 2.0.244.

1. Loading the player page

code

const loadPlayerPage = function() {
    if (videojsVersion) {
        hideItem("videojsInputForm");
        loadVideoJS("videojs" + videojsVersion);
    } else {
        let videojsInput = document.getElementById("videojsInput");
        for (videojsType in VIDEOJS_VERSION_TYPE) {
            let option = document.createElement("option");
            let videojsFolder = "";
            switch (videojsType) {
                case 'VIDEOJS7':
                    videojsFolder = VIDEOJS_VERSION_TYPE.VIDEOJS7;
                    break;
                case 'VIDEOJS8':
                    videojsFolder = VIDEOJS_VERSION_TYPE.VIDEOJS8;
                    break;
            }
            option.text = videojsFolder;
            option.value = videojsFolder;
            videojsInput.appendChild(option);
        }

        setHandler("videojsBtn", "click", onVideojsBtnClick);
    }
}

2. Loading the VideoJS chosen version

code

const loadVideoJS = function (version) {
    if (version) {
        let playerPage = document.getElementById("playerPage");
        loadFile(version + "/video.js", "text/javascript").then( data  => {
            console.log("HLS library loaded successfully", data);
            loadFile(version + "/video-js.css", "stylesheet").then ( data => {
                console.log("HLS library stylesheet loaded successfully", data);
                hideItem("videojsInputForm");
                loadPage("player-page.html", "playerPage", initPage );
            }).catch( err => {
                playerPage.innerHTML = "Can't load VideoJS library stylesheet";
                playerPage.setAttribute("class", "text-danger");
                console.error(err);
            })
        }).catch( err => {
            setText("videojsError", "Can't load VideoJS library");
            console.error(err);
        });
    }
}

3. The player HTML page initializing

code

const initPage = function() {
    if (playSrc) {
        setValue("fullLink", decodeURIComponent(playSrc));
    } else if (autoplay) {
        console.warn("No HLS URL set, autoplay disabled");
        autoplay = false;
    }
    let remoteVideo = document.getElementById('remoteVideo');
    if (autoplay) {
        // There should not be any visible item on the page unless player
        hideAllToAutoplay();
        // The player should use all available page width
        setUpPlayerItem(true);
        // The player should be muted to automatically start playback
        player = initVideoJsPlayer(remoteVideo, true);
        playBtnClick();
    } else {
        // No autoplay, all the forms and buttons should be visible
        setText("header", "HLS VideoJS Player Minimal");
        displayCommonItems();
        setUpButtons();
        enablePlaybackStats();
        // The player should have a maximum fixed size
        setUpPlayerItem(false);
        // The player can be unmuted because user should click Play button
        player = initVideoJsPlayer(remoteVideo, false);
    }
}

4. Player initializing

videojs() code

The following parameters are passed to the player:

video - div tag to play the stream on the page
playsinline: true - play a video on the page without automatic full screen switching (ignored in iOS Safari)
playbackRates - playback rates list
liveui: true - enables rewind (DVR) interface
liveTracker - live playback thresholds setup
fill: true - scale the player to div tag dimensions

const initVideoJsPlayer = function(video, muted) {
    let videoJsPlayer = null;
    if (video) {
        video.className = "video-js vjs-default-skin";
        videoJsPlayer = videojs(video, {
            playsinline: true,
            playbackRates: [0.1, 0.25, 0.5, 1, 1.5, 2],
            liveui: true,
            liveTracker: {
                trackingThreshold: LIVE_THRESHOLD,
                liveTolerance: LIVE_TOLERANCE
            },
            fill: true,
            muted: muted
        });
        console.log("Using VideoJs " + videojs.VERSION);
        if (Browser.isSafariWebRTC() && Browser.isiOS()) {
            // iOS hack when using standard controls to leave fullscreen mode
            let videoTag = getActualVideoTag();
            if(videoTag) {
                setWebkitFullscreenHandlers(videoTag, false);
            }
        }
    }
    return videoJsPlayer;
}

5. HLS stream URL forming

encodeURIComponent() code

If authentication key and token are set, they will be included to stream URL

const getVideoSrc = function(src) {
    let videoSrc = src;
    if (validateForm()) {
        let streamName = getValue('playStream');
        streamName = encodeURIComponent(streamName);
        videoSrc = getValue("urlServer") + '/' + streamName + '/' + streamName + '.m3u8';
        let key = getValue('key');
        let token = getValue("token");
        if (key.length > 0 && token.length > 0) {
            videoSrc += "?" + key + "=" + token;
        }
    }
    setValue("fullLink", videoSrc);
    return videoSrc;
}

6. Player launching

player.on(), player.play() code

const playBtnClick = function() {
    let videoSrc = getVideoSrc(getValue("fullLink"));
    if (videoSrc) {
        player.on('loadedmetadata', function() {
            console.log("Play with VideoJs");
            player.play();
        });
        ...
        player.src({
            src: videoSrc,
            type: "application/vnd.apple.mpegurl"
        });
        onStarted();
    }
}

7. playing event handler

player.on() code

const playBtnClick = function() {
     let videoSrc = getVideoSrc(getValue("fullLink"));
     if (videoSrc) {
         ...
        player.on('playing', function() {
            console.log("playing event fired");
            displayPermalink(videoSrc);
            if (player.liveTracker) {
                if (!player.liveTracker.isLive()) {
                    // A cratch to display live UI for the first subscriber
                    liveUIDisplay();
                }
                if (player.liveTracker.atLiveEdge()) {
                    // Unlock backward buttons when seeked to live edge
                    toggleBackButtons(true);
                    // Stop live UI startup timer
                    stopLiveUITimer();
                }
            }
        });
        ...
    }
}

8. Enable rewind (DVR) interface for the first subscriber

player.liveTracker.seekToLiveEdge() code

const liveUIDisplay = function() {
    stopLiveUITimer()
    if (player && player.liveTracker) {
        liveUITimer = setInterval(function() {
            if (!player.liveTracker.isLive() && player.liveTracker.liveWindow() > LIVE_THRESHOLD) {
                // Live UI is not displayed yet, seek to live edge to display
                player.liveTracker.seekToLiveEdge();
            }
        }, LIVE_UI_INTERVAL)
    }
}

9. Rewind button click action

player.seekable(), player.currentTime() code

const backBtnClick = function(event) {
    if (player != null && player.liveTracker) {
        toggleBackButtons(false);
        let seekable = player.seekable();
        let backTime = -1;
        if (event.target.id.indexOf("10") !== -1) {
            backTime = player.currentTime() - 10;
        } else if (event.target.id.indexOf("30") !== -1) {
            backTime = player.currentTime() - 30;
        }
        if (backTime < 0) {
            backTime = seekable ? seekable.start(0) : player.currentTime();
        }
        player.currentTime(backTime);
    }
}

10. Live button click action

player.liveTracker.seekToLiveEdge() code

const liveBtnClick = function() {
    if (player != null && player.liveTracker) {
        player.liveTracker.seekToLiveEdge();
        toggleBackButtons(true);
    }
}

11. Playback stopping

player.dispose() code

This method removes the div container tag where player was initialized from the page

const stopBtnClick = function() {
    if (player != null) {
        console.log("Stop VideoJS player");
        stopLiveUITimer();
        player.dispose();
    }
    onStopped();
}

12. New div container tag creation after previous player was removed

code

const createRemoteVideo = function(parent) {
    let remoteVideo = document.createElement("video");
    remoteVideo.id = "remoteVideo";
    remoteVideo.controls="controls";
    remoteVideo.autoplay="autoplay";
    remoteVideo.type="application/vnd.apple.mpegurl";
    remoteVideo.className = "video-js vjs-default-skin";
    remoteVideo.setAttribute("playsinline","");
    remoteVideo.setAttribute("webkit-playsinline","");
    parent.appendChild(remoteVideo);
    player = initVideoJsPlayer(remoteVideo, autoplay);
}

13. Getting an available playback statistics from HTML5 video tag

HTML5Stats code

const PlaybackStats = function(interval) {
    const playbackStats = {
        interval: interval || STATS_INTERVAL,
        timer: null,
        stats: null,
        start: function() {
            let video = getActualVideoTag();

            playbackStats.stop();
            stats = HTML5Stats(video);
            playbackStats.timer = setInterval(playbackStats.displayStats, playbackStats.interval);
            setText("videoWidth", "N/A");
            setText("videoHeight", "N/A");
            setText("videoRate", "N/A");
            setText("videoFps", "N/A");
            showItem("stats");
        },
        stop: function() {
            if (playbackStats.timer) {
                clearInterval(playbackStats.timer);
                playbackStats.timer = null;
            }
            playbackStats.stats = null;
            hideItem("stats");
        },
        displayStats: function() {
            if (stats.collect()) {
                let width = stats.getWidth();
                let height = stats.getHeight();
                let bitrate = stats.getBitrate();
                let fps = stats.getFps();

                setText("videoWidth", width);
                setText("videoHeight", height);

                if (bitrate !== undefined) {
                    setText("videoRate", Math.round(bitrate));
                }
                if (fps !== undefined) {
                    setText("videoFps", fps.toFixed(1));
                }
            }
        }
    };
    return playbackStats;
}

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Overview

The code of the example

Analyzing the code