Chromecast 定制 CAF 接收器

Question

我遇到了新的 CAF 接收器未将 YouTube iframe 播放器注册为播放器并且它正在播放的问题。连接到接收器5分钟后，连接断开，因为它认为播放器处于空闲状态。

这是发件人代码

var metadata = new chrome.cast.media.GenericMediaMetadata();
metadata.title = "Foo - Bar";
metadata.image = 'https://img.youtube.com/vi/IXNrHusLXoM/mqdefault.jpg';
metadata.images = ['https://img.youtube.com/vi/IXNrHusLXoM/mqdefault.jpg'];
var mediaInfo = new chrome.cast.media.MediaInfo();
mediaInfo.contentType = "video/*";
mediaInfo.contentId ="IXNrHusLXoM";
mediaInfo.duration = 300;
var request = new chrome.cast.media.LoadRequest();
request.media = mediaInfo;
request.customData = customData;
request.metadata = metadata;
castSession.loadMedia(request).then(
  function() {
      console.log('Load succeed');
  },
  function(errorCode) {
      console.log('Error code: ' + errorCode);
});

接收器代码可以在这里找到：https://github.com/zoff-music/zoff-chromecast-receiver/blob/feature/v3/receiver.js

有没有办法让新的 CAF 接收器挂接到 YouTube iframe 播放器，或“手动”调度 LOADED、BUFFERING、PLAYING、PAUSED、STOPPED 事件，以便接收器不会与发送器断开连接？

编辑：使用上面的代码，PlayerState 进入缓冲阶段，但停在那里。永远不会触发带有“加载成功”日志的承诺。

Answer 1

我设法用假的 mediaEelement 欺骗了接收者。可以看代码in pastebin

const context = cast.framework.CastReceiverContext.getInstance();
const playerManager = context.getPlayerManager();

var yt_events = {};
var pause_request = false;
var yt_player;

var yt_video_fake = {
    removeAttribute: function(attr) {
    },
    setAttribute: function(attr, val) {
    },

    getCurrentTimeSec: function() { return yt_player && yt_player.getCurrentTime ? yt_player.getCurrentTime() : 0; },
    getDurationSec: function() { return yt_player ? yt_player.getDuration() : 0; },
    getVolume: function() {
        if(!yt_player || !yt_player.getVolume) {
            return 0;
        }

        var volume = new cast.framework.messages.Volume();

        volume.level = yt_player.getVolume() / 100;
        volume.muted = yt_player.isMuted() ? true : false;

        return volume;
    },
    setVolume: function(vol) { yt_player && yt_player.setVolume(vol.level * 100); },
    getState: function() {
        if(!yt_player || !yt_player.getPlayerState) {
            return 'IDLE';
        }

        var state = yt_player.getPlayerState();
        var _state;

        if(pause_request) {
            pause_request = false;
            state = YT.PlayerState.PAUSED;
        }

        switch(state) {
            default: case YT.PlayerState.UNSTARTED:
                _state = 'IDLE';
            break;

            case YT.PlayerState.PLAYING:
                _state = 'PLAYING';
            break;

            case YT.PlayerState.PAUSED:
                _state = 'PAUSED';
            break;

            case YT.PlayerState.BUFFERING:
                _state = 'BUFFERING';
            break;

            case YT.PlayerState.ENDED:
                _state = 'ENDED';
            break;
        }

        return _state;
    },

    addEventListener: function(e, func) { },
    load: function() {},
    play: function() { yt_player && yt_player.playVideo(); },
    pause: function() { if(yt_player && yt_player.pauseVideo) {pause_request = true; yt_player.pauseVideo(); }},
    seek: function(timeTo) { yt_player && yt_player.seekTo(timeTo, true);},
    reset: function() {
        if(yt_player) {
            try { yt_player.destroy && yt_player.destroy(); } catch(e) {
                //console.trace(e);
            };
            delete yt_player;
        }
    },

    registerErrorCallback: function(func) { yt_events['error'] = func; },
    registerEndedCallback: function(func) { yt_events['ended'] = func; },
    registerLoadCallback: function(func) { yt_events['load'] = func; },

    unregisterErrorCallback: function () { delete yt_events['error'] },
    unregisterEndedCallback: function () { delete yt_events['ended']},
    unregisterLoadCallback: function () { delete yt_events['load']}
};

Object.defineProperty(yt_video_fake, 'currentTime', {
    val1: null,
    get: function() { return yt_player && yt_player.getCurrentTime ? yt_player.getCurrentTime() : this.val1; },
    set: function(newValue) {
        yt_player && yt_player.seekTo(newValue, true);
        this.val1 = newValue;
    },
    enumerable      : true,
    configurable    : true
});

Object.defineProperty(yt_video_fake, 'volume', {
    val1: null,
    get: function() { var vol = this.getVolume(); if(vol) return vol['level']; return 1; },
    set: function(newValue) {
        yt_player && yt_player.setVolume && yt_player.setVolume(newValue * 100);
        this.val1 = newValue;
    },
    enumerable      : true,
    configurable    : true
});


Object.defineProperty(yt_video_fake, 'duration', {
    val1: null,
    get: function() { return this.getDurationSec(); },
    set: function() {},
    enumerable      : true,
    configurable    : true
});


function YoutubePlayMedia(videoid) {
    var yt_container = $('#yt_container');

    if(!yt_container.length) {
        yt_container = $('<div id="yt_container" style="position:absolute;top:0;left:0;width:100%;height:100%;"></div>');
        $('body').append(yt_container);
    }

    yt_container.html('<iframe id="youtube_container" style="width:100%;height:100%;" frameborder="0" allowfullscreen="1" allow="autoplay; encrypted-media" title="YouTube video player" src="//www.youtube.com/embed/' + videoid +'?autoplay=1&enablejsapi=1&modestbranding=1&controls=0&fs=0&iv_load_policy=3&rel=0&cc_load_policy=1&cc_lang_pref=bg"></iframe>');

    yt_player = new YT.Player('youtube_container', {
        events: {
            'onReady': function(e) {
                yt_player.is_loaded = true;
                yt_player.playVideo();
            },
            'onStateChange': function(e) {
                switch(e.data) {
                    case YT.PlayerState.PLAYING:
                        if(yt_player.is_loaded) {
                            if(yt_events['load']) {
                                yt_events['load']();
                            }
                        }

                    break;

                    case YT.PlayerState.ENDED:
                        //yt_events['ended'] && yt_events['ended'](e);
                    break;
                }
            },
            'onError': function(e) {
                //yt_events['error'] && yt_events['error'](e);
            }
        }
    });
}

function YoutubeLoadMedia(url) {
    current_media_type = 'Youtube';

    window.onYouTubeIframeAPIReady = function() {
        window.youtube_loaded = true;
        YoutubePlayMedia(url);
    }

    if(!window.youtube_script) {
        window.youtube_script = document.createElement('script');
        window.youtube_script.src = "https://www.youtube.com/iframe_api";
        var firstScriptTag = document.getElementsByTagName('script')[0];
        firstScriptTag.parentNode.insertBefore(window.youtube_script, firstScriptTag);
    } else {
        // Вече имаме api направо действаме
        YoutubePlayMedia(url);
    }
}


playerManager.setMessageInterceptor(
    cast.framework.messages.MessageType.LOAD,
    loadRequestData => {
        if (loadRequestData.media && loadRequestData.media.contentId) {
            YoutubeLoadMedia(loadRequestData.media.contentId);
            playerManager.setMediaElement(yt_video_fake);

            return false;
        }

        return loadRequestData;
    }
);

const options = new cast.framework.CastReceiverOptions();
options.disableIdleTimeout = true;

context.start(options);

Answer 2

YouTube iframe 播放器不是为 Cast 接收器而设计的。