Source: lib/media/media_source_engine.js

  1. /*! @license
  2.  * Shaka Player
  3.  * Copyright 2016 Google LLC
  4.  * SPDX-License-Identifier: Apache-2.0
  5.  */
  7. goog.provide('shaka.media.MediaSourceEngine');
  9. goog.require('goog.asserts');
  10. goog.require('shaka.log');
  11. goog.require('shaka.config.CodecSwitchingStrategy');
  12. goog.require('shaka.device.DeviceFactory');
  13. goog.require('shaka.media.Capabilities');
  14. goog.require('shaka.media.ContentWorkarounds');
  15. goog.require('shaka.media.ClosedCaptionParser');
  16. goog.require('shaka.media.IClosedCaptionParser');
  17. goog.require('shaka.media.ManifestParser');
  18. goog.require('shaka.media.SegmentReference');
  19. goog.require('shaka.media.TimeRangesUtils');
  20. goog.require('shaka.text.TextEngine');
  21. goog.require('shaka.transmuxer.TransmuxerEngine');
  22. goog.require('shaka.util.BufferUtils');
  23. goog.require('shaka.util.Destroyer');
  24. goog.require('shaka.util.Dom');
  25. goog.require('shaka.util.Error');
  26. goog.require('shaka.util.EventManager');
  27. goog.require('shaka.util.FakeEvent');
  28. goog.require('shaka.util.Functional');
  29. goog.require('shaka.util.IDestroyable');
  30. goog.require('shaka.util.Id3Utils');
  31. goog.require('shaka.util.ManifestParserUtils');
  32. goog.require('shaka.util.MimeUtils');
  33. goog.require('shaka.util.Mp4BoxParsers');
  34. goog.require('shaka.util.Mp4Parser');
  35. goog.require('shaka.util.PublicPromise');
  36. goog.require('shaka.util.StreamUtils');
  37. goog.require('shaka.util.TimeUtils');
  38. goog.require('shaka.util.TsParser');
  39. goog.require('shaka.lcevc.Dec');
  42. /**
  43.  * @summary
  44.  * MediaSourceEngine wraps all operations on MediaSource and SourceBuffers.
  45.  * All asynchronous operations return a Promise, and all operations are
  46.  * internally synchronized and serialized as needed.  Operations that can
  47.  * be done in parallel will be done in parallel.
  48.  *
  49.  * @implements {shaka.util.IDestroyable}
  50.  */
  51. shaka.media.MediaSourceEngine = class {
  52.   /**
  53.    * @param {HTMLMediaElement} video The video element, whose source is tied to
  54.    *   MediaSource during the lifetime of the MediaSourceEngine.
  55.    * @param {!shaka.extern.TextDisplayer} textDisplayer
  56.    *    The text displayer that will be used with the text engine.
  57.    *    MediaSourceEngine takes ownership of the displayer. When
  58.    *    MediaSourceEngine is destroyed, it will destroy the displayer.
  59.    * @param {!shaka.media.MediaSourceEngine.PlayerInterface} playerInterface
  60.    *   Interface for common player methods.
  61.    * @param {shaka.extern.MediaSourceConfiguration} config
  62.    * @param {?shaka.lcevc.Dec} [lcevcDec] Optional -  LCEVC Decoder Object
  63.    */
  64.   constructor(video, textDisplayer, playerInterface, config, lcevcDec) {
  65.     /** @private {HTMLMediaElement} */
  66.     this.video_ = video;
  68.     /** @private {?shaka.media.MediaSourceEngine.PlayerInterface} */
  69.     this.playerInterface_ = playerInterface;
  71.     /** @private {?shaka.extern.MediaSourceConfiguration} */
  72.     this.config_ = config;
  74.     /** @private {shaka.extern.TextDisplayer} */
  75.     this.textDisplayer_ = textDisplayer;
  77.     /**
  78.      * @private {!Map<shaka.util.ManifestParserUtils.ContentType, SourceBuffer>}
  79.      */
  80.     this.sourceBuffers_ = new Map();
  82.     /**
  83.      * @private {!Map<shaka.util.ManifestParserUtils.ContentType, string>}
  84.      */
  85.     this.sourceBufferTypes_ = new Map();
  88.     /**
  89.      * @private {!Map<shaka.util.ManifestParserUtils.ContentType,
  90.      *                    boolean>}
  91.      */
  92.     this.expectedEncryption_ = new Map();
  94.     /** @private {shaka.text.TextEngine} */
  95.     this.textEngine_ = null;
  97.     /** @private {boolean} */
  98.     this.segmentRelativeVttTiming_ = false;
  100.     /** @private {?shaka.lcevc.Dec} */
  101.     this.lcevcDec_ = lcevcDec || null;
  103.     /**
  104.      * @private {!Map<string, !Array<shaka.media.MediaSourceEngine.Operation>>}
  105.      */
  106.     this.queues_ = new Map();
  108.     /** @private {shaka.util.EventManager} */
  109.     this.eventManager_ = new shaka.util.EventManager();
  111.     /**
  112.      * @private {!Map<shaka.util.ManifestParserUtils.ContentType,
  113.                          !shaka.extern.Transmuxer>} */
  114.     this.transmuxers_ = new Map();
  116.     /** @private {?shaka.media.IClosedCaptionParser} */
  117.     this.captionParser_ = null;
  119.     /** @private {!shaka.util.PublicPromise} */
  120.     this.mediaSourceOpen_ = new shaka.util.PublicPromise();
  122.     /** @private {string} */
  123.     this.url_ = '';
  125.     /** @private {boolean} */
  126.     this.playbackHasBegun_ = false;
  128.     /** @private {boolean} */
  129.     this.streamingAllowed_ = true;
  131.     /** @private {boolean} */
  132.     this.usingRemotePlayback_ = false;
  134.     /** @private {HTMLSourceElement} */
  135.     this.source_ = null;
  137.     /**
  138.      * Fallback source element with direct media URI, used for casting
  139.      * purposes.
  140.      * @private {HTMLSourceElement}
  141.      */
  142.     this.secondarySource_ = null;
  144.     /** @private {MediaSource} */
  145.     this.mediaSource_ = this.createMediaSource(this.mediaSourceOpen_);
  147.     /** @private {boolean} */
  148.     this.reloadingMediaSource_ = false;
  150.     /** @private {boolean} */
  151.     this.playAfterReset_ = false;
  153.     /** @type {!shaka.util.Destroyer} */
  154.     this.destroyer_ = new shaka.util.Destroyer(() => this.doDestroy_());
  156.     /** @private {boolean} */
  157.     this.sequenceMode_ = false;
  159.     /** @private {string} */
  160.     this.manifestType_ = shaka.media.ManifestParser.UNKNOWN;
  162.     /** @private {boolean} */
  163.     this.ignoreManifestTimestampsInSegmentsMode_ = false;
  165.     /** @private {boolean} */
  166.     this.attemptTimestampOffsetCalculation_ = false;
  168.     /** @private {!shaka.util.PublicPromise<number>} */
  169.     this.textSequenceModeOffset_ = new shaka.util.PublicPromise();
  171.     /** @private {boolean} */
  172.     this.needSplitMuxedContent_ = false;
  174.     /** @private {?number} */
  175.     this.lastDuration_ = null;
  177.     /**
  178.      * @private {!Map<shaka.util.ManifestParserUtils.ContentType,
  179.      *                    !shaka.util.TsParser>}
  180.      */
  181.     this.tsParsers_ = new Map();
  183.     /** @private {?number} */
  184.     this.firstVideoTimestamp_ = null;
  186.     /** @private {?number} */
  187.     this.firstVideoReferenceStartTime_ = null;
  189.     /** @private {?number} */
  190.     this.firstAudioTimestamp_ = null;
  192.     /** @private {?number} */
  193.     this.firstAudioReferenceStartTime_ = null;
  195.     /** @private {!shaka.util.PublicPromise<number>} */
  196.     this.audioCompensation_ = new shaka.util.PublicPromise();
  198.     if (this.video_.remote) {
  199.       this.usingRemotePlayback_ = this.video_.remote.state != 'disconnected';
  201.       this.eventManager_.listen(this.video_.remote, 'connect', () => {
  202.         this.usingRemotePlayback_ = this.video_.remote.state != 'disconnected';
  203.       });
  205.       this.eventManager_.listen(this.video_.remote, 'connecting', () => {
  206.         this.usingRemotePlayback_ = this.video_.remote.state != 'disconnected';
  207.       });
  209.       this.eventManager_.listen(this.video_.remote, 'disconnect', () => {
  210.         this.usingRemotePlayback_ = this.video_.remote.state != 'disconnected';
  211.       });
  212.     }
  213.   }
  215.   /**
  216.    * Create a MediaSource object, attach it to the video element, and return it.
  217.    * Resolves the given promise when the MediaSource is ready.
  218.    *
  219.    * Replaced by unit tests.
  220.    *
  221.    * @param {!shaka.util.PublicPromise} p
  222.    * @return {!MediaSource}
  223.    */
  224.   createMediaSource(p) {
  225.     this.streamingAllowed_ = true;
  227.     /** @type {!MediaSource} */
  228.     let mediaSource;
  230.     if (window.ManagedMediaSource) {
  231.       if (!this.secondarySource_) {
  232.         this.video_.disableRemotePlayback = true;
  233.       }
  235.       mediaSource = new ManagedMediaSource();
  237.       this.eventManager_.listen(
  238.           mediaSource, 'startstreaming', () => {
  239.             shaka.log.info('MMS startstreaming');
  240.             this.streamingAllowed_ = true;
  241.           });
  243.       this.eventManager_.listen(
  244.           mediaSource, 'endstreaming', () => {
  245.             shaka.log.info('MMS endstreaming');
  246.             this.streamingAllowed_ = false;
  247.           });
  248.     } else {
  249.       mediaSource = new MediaSource();
  250.     }
  252.     // Set up MediaSource on the video element.
  253.     this.eventManager_.listenOnce(
  254.         mediaSource, 'sourceopen', () => this.onSourceOpen_(p));
  256.     // Correctly set when playback has begun.
  257.     this.eventManager_.listenOnce(this.video_, 'playing', () => {
  258.       this.playbackHasBegun_ = true;
  259.     });
  261.     // Store the object URL for releasing it later.
  262.     this.url_ = shaka.media.MediaSourceEngine.createObjectURL(mediaSource);
  263.     if (this.config_.useSourceElements) {
  264.       this.video_.removeAttribute('src');
  265.       if (this.source_) {
  266.         this.video_.removeChild(this.source_);
  267.       }
  268.       if (this.secondarySource_) {
  269.         this.video_.removeChild(this.secondarySource_);
  270.       }
  271.       this.source_ = shaka.util.Dom.createSourceElement(this.url_);
  272.       this.video_.appendChild(this.source_);
  273.       if (this.secondarySource_) {
  274.         this.video_.appendChild(this.secondarySource_);
  275.       }
  276.       this.video_.load();
  277.     } else {
  278.       this.video_.src = this.url_;
  279.     }
  281.     return mediaSource;
  282.   }
  284.   /**
  285.    * @param {string} uri
  286.    * @param {string} mimeType
  287.    */
  288.   addSecondarySource(uri, mimeType) {
  289.     if (!this.video_ || !window.ManagedMediaSource || !this.mediaSource_) {
  290.       shaka.log.warning(
  291.           'Secondary source is used only with ManagedMediaSource');
  292.       return;
  293.     }
  294.     if (!this.config_.useSourceElements) {
  295.       return;
  296.     }
  297.     if (this.secondarySource_) {
  298.       this.video_.removeChild(this.secondarySource_);
  299.     }
  300.     this.secondarySource_ = shaka.util.Dom.createSourceElement(uri, mimeType);
  301.     this.video_.appendChild(this.secondarySource_);
  302.     this.video_.disableRemotePlayback = false;
  303.   }
  305.   /**
  306.    * @param {shaka.util.PublicPromise} p
  307.    * @private
  308.    */
  309.   onSourceOpen_(p) {
  310.     goog.asserts.assert(this.url_, 'Must have object URL');
  312.     // Release the object URL that was previously created, to prevent memory
  313.     // leak.
  314.     // createObjectURL creates a strong reference to the MediaSource object
  315.     // inside the browser.  Setting the src of the video then creates another
  316.     // reference within the video element.  revokeObjectURL will remove the
  317.     // strong reference to the MediaSource object, and allow it to be
  318.     // garbage-collected later.
  319.     URL.revokeObjectURL(this.url_);
  320.     p.resolve();
  321.   }
  323.   /**
  324.    * Returns a map of MediaSource support for well-known types.
  325.    *
  326.    * @return {!Object<string, boolean>}
  327.    */
  328.   static probeSupport() {
  329.     const testMimeTypes = [
  330.       // MP4 types
  331.       'video/mp4; codecs="avc1.42E01E"',
  332.       'video/mp4; codecs="avc3.42E01E"',
  333.       'video/mp4; codecs="hev1.1.6.L93.90"',
  334.       'video/mp4; codecs="hvc1.1.6.L93.90"',
  335.       'video/mp4; codecs="hev1.2.4.L153.B0"; eotf="smpte2084"',  // HDR HEVC
  336.       'video/mp4; codecs="hvc1.2.4.L153.B0"; eotf="smpte2084"',  // HDR HEVC
  337.       'video/mp4; codecs="vp9"',
  338.       'video/mp4; codecs="vp09.00.10.08"',
  339.       'video/mp4; codecs="av01.0.01M.08"',
  340.       'video/mp4; codecs="dvh1.05.01"',
  341.       'video/mp4; codecs="dvh1.20.01"',
  342.       'audio/mp4; codecs="mp4a.40.2"',
  343.       'audio/mp4; codecs="ac-3"',
  344.       'audio/mp4; codecs="ec-3"',
  345.       'audio/mp4; codecs="ac-4.02.01.01"',
  346.       'audio/mp4; codecs="opus"',
  347.       'audio/mp4; codecs="flac"',
  348.       'audio/mp4; codecs="dtsc"', // DTS Digital Surround
  349.       'audio/mp4; codecs="dtse"', // DTS Express
  350.       'audio/mp4; codecs="dtsx"', // DTS:X
  351.       // WebM types
  352.       'video/webm; codecs="vp8"',
  353.       'video/webm; codecs="vp9"',
  354.       'video/webm; codecs="vp09.00.10.08"',
  355.       'audio/webm; codecs="vorbis"',
  356.       'audio/webm; codecs="opus"',
  357.       // MPEG2 TS types (video/ is also used for audio: https://bit.ly/TsMse)
  358.       'video/mp2t; codecs="avc1.42E01E"',
  359.       'video/mp2t; codecs="avc3.42E01E"',
  360.       'video/mp2t; codecs="hvc1.1.6.L93.90"',
  361.       'video/mp2t; codecs="mp4a.40.2"',
  362.       'video/mp2t; codecs="ac-3"',
  363.       'video/mp2t; codecs="ec-3"',
  364.       // WebVTT types
  365.       'text/vtt',
  366.       'application/mp4; codecs="wvtt"',
  367.       // TTML types
  368.       'application/ttml+xml',
  369.       'application/mp4; codecs="stpp"',
  370.       // Containerless types
  371.       ...shaka.util.MimeUtils.RAW_FORMATS,
  372.     ];
  374.     const support = {};
  375.     const device = shaka.device.DeviceFactory.getDevice();
  376.     for (const type of testMimeTypes) {
  377.       if (shaka.text.TextEngine.isTypeSupported(type)) {
  378.         support[type] = true;
  379.       } else if (device.supportsMediaSource()) {
  380.         support[type] = shaka.media.Capabilities.isTypeSupported(type) ||
  381.                         shaka.transmuxer.TransmuxerEngine.isSupported(type);
  382.       } else {
  383.         support[type] = device.supportsMediaType(type);
  384.       }
  386.       const basicType = type.split(';')[0];
  387.       support[basicType] = support[basicType] || support[type];
  388.     }
  390.     return support;
  391.   }
  393.   /** @override */
  394.   destroy() {
  395.     return this.destroyer_.destroy();
  396.   }
  398.   /** @private */
  399.   async doDestroy_() {
  400.     const Functional = shaka.util.Functional;
  402.     const cleanup = [];
  404.     for (const [key, q] of this.queues_) {
  405.       // Make a local copy of the queue and the first item.
  406.       const inProgress = q[0];
  408.       const contentType = /** @type {string} */(key);
  410.       // Drop everything else out of the original queue.
  411.       this.queues_.set(contentType, q.slice(0, 1));
  413.       // We will wait for this item to complete/fail.
  414.       if (inProgress) {
  415.         cleanup.push(inProgress.p.catch(Functional.noop));
  416.       }
  418.       // The rest will be rejected silently if possible.
  419.       for (const item of q.slice(1)) {
  420.         item.p.reject(shaka.util.Destroyer.destroyedError());
  421.       }
  422.     }
  424.     if (this.textEngine_) {
  425.       cleanup.push(this.textEngine_.destroy());
  426.     }
  428.     await Promise.all(cleanup);
  430.     for (const transmuxer of this.transmuxers_.values()) {
  431.       transmuxer.destroy();
  432.     }
  434.     if (this.eventManager_) {
  435.       this.eventManager_.release();
  436.       this.eventManager_ = null;
  437.     }
  439.     if (this.video_ && this.secondarySource_) {
  440.       this.video_.removeChild(this.secondarySource_);
  441.     }
  442.     if (this.video_ && this.source_) {
  443.       // "unload" the video element.
  444.       this.video_.removeChild(this.source_);
  445.       this.video_.load();
  446.       this.video_.disableRemotePlayback = false;
  447.     }
  449.     this.video_ = null;
  450.     this.source_ = null;
  451.     this.secondarySource_ = null;
  452.     this.config_ = null;
  453.     this.mediaSource_ = null;
  454.     this.textEngine_ = null;
  455.     this.textDisplayer_ = null;
  456.     this.sourceBuffers_.clear();
  457.     this.expectedEncryption_.clear();
  458.     this.transmuxers_.clear();
  459.     this.captionParser_ = null;
  460.     if (goog.DEBUG) {
  461.       for (const [contentType, q] of this.queues_) {
  462.         goog.asserts.assert(
  463.             q.length == 0,
  464.             contentType + ' queue should be empty after destroy!');
  465.       }
  466.     }
  467.     this.queues_.clear();
  469.     // This object is owned by Player
  470.     this.lcevcDec_ = null;
  472.     this.tsParsers_.clear();
  473.     this.playerInterface_ = null;
  474.   }
  476.   /**
  477.    * @return {!Promise} Resolved when MediaSource is open and attached to the
  478.    *   media element.  This process is actually initiated by the constructor.
  479.    */
  480.   open() {
  481.     return this.mediaSourceOpen_;
  482.   }
  484.   /**
  485.    * Initialize MediaSourceEngine.
  486.    *
  487.    * Note that it is not valid to call this multiple times, except to add or
  488.    * reinitialize text streams.
  489.    *
  490.    * @param {!Map<shaka.util.ManifestParserUtils.ContentType,
  491.    *               shaka.extern.Stream>} streamsByType
  492.    *   A map of content types to streams.
  493.    * @param {boolean=} sequenceMode
  494.    *   If true, the media segments are appended to the SourceBuffer in strict
  495.    *   sequence.
  496.    * @param {string=} manifestType
  497.    *   Indicates the type of the manifest.
  498.    * @param {boolean=} ignoreManifestTimestampsInSegmentsMode
  499.    *   If true, don't adjust the timestamp offset to account for manifest
  500.    *   segment durations being out of sync with segment durations. In other
  501.    *   words, assume that there are no gaps in the segments when appending
  502.    *   to the SourceBuffer, even if the manifest and segment times disagree.
  503.    *   Indicates if the manifest has text streams.
  504.    *
  505.    * @return {!Promise}
  506.    */
  507.   async init(streamsByType, sequenceMode=false,
  508.       manifestType=shaka.media.ManifestParser.UNKNOWN,
  509.       ignoreManifestTimestampsInSegmentsMode=false) {
  510.     const ContentType = shaka.util.ManifestParserUtils.ContentType;
  512.     await this.mediaSourceOpen_;
  513.     if (this.ended() || this.closed()) {
  514.       shaka.log.alwaysError('Expected MediaSource to be open during init(); ' +
  515.           'reopening the media source.');
  516.       this.mediaSourceOpen_ = new shaka.util.PublicPromise();
  517.       this.mediaSource_ = this.createMediaSource(this.mediaSourceOpen_);
  518.       await this.mediaSourceOpen_;
  519.     }
  521.     this.sequenceMode_ = sequenceMode;
  522.     this.manifestType_ = manifestType;
  523.     this.ignoreManifestTimestampsInSegmentsMode_ =
  524.       ignoreManifestTimestampsInSegmentsMode;
  526.     this.attemptTimestampOffsetCalculation_ = !this.sequenceMode_ &&
  527.         this.manifestType_ == shaka.media.ManifestParser.HLS &&
  528.         !this.ignoreManifestTimestampsInSegmentsMode_;
  530.     this.tsParsers_.clear();
  531.     this.firstVideoTimestamp_ = null;
  532.     this.firstVideoReferenceStartTime_ = null;
  533.     this.firstAudioTimestamp_ = null;
  534.     this.firstAudioReferenceStartTime_ = null;
  535.     this.audioCompensation_ = new shaka.util.PublicPromise();
  537.     for (const contentType of streamsByType.keys()) {
  538.       const stream = streamsByType.get(contentType);
  539.       this.initSourceBuffer_(contentType, stream, stream.codecs);
  540.       if (this.needSplitMuxedContent_) {
  541.         this.queues_.set(ContentType.AUDIO, []);
  542.         this.queues_.set(ContentType.VIDEO, []);
  543.       } else {
  544.         this.queues_.set(contentType, []);
  545.       }
  546.     }
  547.     const audio = streamsByType.get(ContentType.AUDIO);
  548.     if (audio && audio.isAudioMuxedInVideo) {
  549.       this.needSplitMuxedContent_ = true;
  550.     }
  551.   }
  553.   /**
  554.    * Initialize a specific SourceBuffer.
  555.    *
  556.    * @param {shaka.util.ManifestParserUtils.ContentType} contentType
  557.    * @param {shaka.extern.Stream} stream
  558.    * @param {string} codecs
  559.    * @private
  560.    */
  561.   initSourceBuffer_(contentType, stream, codecs) {
  562.     const ContentType = shaka.util.ManifestParserUtils.ContentType;
  564.     if (contentType == ContentType.AUDIO && codecs) {
  565.       codecs = shaka.util.StreamUtils.getCorrectAudioCodecs(
  566.           codecs, stream.mimeType);
  567.     }
  569.     let mimeType = shaka.util.MimeUtils.getFullType(
  570.         stream.mimeType, codecs);
  571.     if (contentType == ContentType.TEXT) {
  572.       this.reinitText(mimeType, this.sequenceMode_, stream.external);
  573.     } else {
  574.       let needTransmux = this.config_.forceTransmux;
  575.       if (!shaka.media.Capabilities.isTypeSupported(mimeType) ||
  576.           (!this.sequenceMode_ &&
  577.           shaka.util.MimeUtils.RAW_FORMATS.includes(mimeType))) {
  578.         needTransmux = true;
  579.       }
  580.       const mimeTypeWithAllCodecs =
  581.           shaka.util.MimeUtils.getFullTypeWithAllCodecs(
  582.               stream.mimeType, codecs);
  583.       if (needTransmux) {
  584.         const audioCodec = shaka.util.ManifestParserUtils.guessCodecsSafe(
  585.             ContentType.AUDIO, (codecs || '').split(','));
  586.         const videoCodec = shaka.util.ManifestParserUtils.guessCodecsSafe(
  587.             ContentType.VIDEO, (codecs || '').split(','));
  588.         if (audioCodec && videoCodec) {
  589.           this.needSplitMuxedContent_ = true;
  590.           this.initSourceBuffer_(ContentType.AUDIO, stream, audioCodec);
  591.           this.initSourceBuffer_(ContentType.VIDEO, stream, videoCodec);
  592.           return;
  593.         }
  594.         const transmuxerPlugin = shaka.transmuxer.TransmuxerEngine
  595.             .findTransmuxer(mimeTypeWithAllCodecs);
  596.         if (transmuxerPlugin) {
  597.           const transmuxer = transmuxerPlugin();
  598.           this.transmuxers_.set(contentType, transmuxer);
  599.           mimeType =
  600.               transmuxer.convertCodecs(contentType, mimeTypeWithAllCodecs);
  601.         }
  602.       }
  603.       const type = this.addExtraFeaturesToMimeType_(mimeType);
  605.       this.destroyer_.ensureNotDestroyed();
  607.       let sourceBuffer;
  609.       try {
  610.         sourceBuffer = this.mediaSource_.addSourceBuffer(type);
  611.       } catch (exception) {
  612.         throw new shaka.util.Error(
  613.             shaka.util.Error.Severity.CRITICAL,
  614.             shaka.util.Error.Category.MEDIA,
  615.             shaka.util.Error.Code.MEDIA_SOURCE_OPERATION_THREW,
  616.             exception,
  617.             'The mediaSource_ status was ' + this.mediaSource_.readyState +
  618.             ' expected \'open\'',
  619.             null);
  620.       }
  622.       if (this.sequenceMode_) {
  623.         sourceBuffer.mode =
  624.             shaka.media.MediaSourceEngine.SourceBufferMode_.SEQUENCE;
  625.       }
  627.       this.eventManager_.listen(
  628.           sourceBuffer, 'error',
  629.           () => this.onError_(contentType));
  630.       this.eventManager_.listen(
  631.           sourceBuffer, 'updateend',
  632.           () => this.onUpdateEnd_(contentType));
  633.       this.sourceBuffers_.set(contentType, sourceBuffer);
  634.       this.sourceBufferTypes_.set(contentType, mimeType);
  635.       this.expectedEncryption_.set(contentType, !!stream.drmInfos.length);
  636.     }
  637.   }
  639.   /**
  640.    * Called by the Player to provide an updated configuration any time it
  641.    * changes. Must be called at least once before init().
  642.    *
  643.    * @param {shaka.extern.MediaSourceConfiguration} config
  644.    */
  645.   configure(config) {
  646.     this.config_ = config;
  647.     if (this.textEngine_) {
  648.       this.textEngine_.setModifyCueCallback(config.modifyCueCallback);
  649.     }
  650.   }
  652.   /**
  653.    * Indicate if the streaming is allowed by MediaSourceEngine.
  654.    * If we using MediaSource we always returns true.
  655.    *
  656.    * @return {boolean}
  657.    */
  658.   isStreamingAllowed() {
  659.     return this.streamingAllowed_ && !this.usingRemotePlayback_ &&
  660.         !this.reloadingMediaSource_;
  661.   }
  663.   /**
  664.    * Reinitialize the TextEngine for a new text type.
  665.    * @param {string} mimeType
  666.    * @param {boolean} sequenceMode
  667.    * @param {boolean} external
  668.    */
  669.   reinitText(mimeType, sequenceMode, external) {
  670.     if (!this.textEngine_) {
  671.       this.textEngine_ = new shaka.text.TextEngine(this.textDisplayer_);
  672.       if (this.textEngine_) {
  673.         this.textEngine_.setModifyCueCallback(this.config_.modifyCueCallback);
  674.       }
  675.     }
  676.     this.textEngine_.initParser(mimeType, sequenceMode,
  677.         external || this.segmentRelativeVttTiming_, this.manifestType_);
  678.   }
  680.   /**
  681.    * @return {boolean} True if the MediaSource is in an "ended" state, or if the
  682.    *   object has been destroyed.
  683.    */
  684.   ended() {
  685.     if (this.reloadingMediaSource_) {
  686.       return false;
  687.     }
  688.     return this.mediaSource_ ? this.mediaSource_.readyState == 'ended' : true;
  689.   }
  691.   /**
  692.    * @return {boolean} True if the MediaSource is in an "closed" state, or if
  693.    *   the object has been destroyed.
  694.    */
  695.   closed() {
  696.     if (this.reloadingMediaSource_) {
  697.       return false;
  698.     }
  699.     return this.mediaSource_ ? this.mediaSource_.readyState == 'closed' : true;
  700.   }
  702.   /**
  703.    * Gets the first timestamp in buffer for the given content type.
  704.    *
  705.    * @param {shaka.util.ManifestParserUtils.ContentType} contentType
  706.    * @return {?number} The timestamp in seconds, or null if nothing is buffered.
  707.    */
  708.   bufferStart(contentType) {
  709.     if (!this.sourceBuffers_.size) {
  710.       return null;
  711.     }
  712.     const ContentType = shaka.util.ManifestParserUtils.ContentType;
  713.     if (contentType == ContentType.TEXT) {
  714.       return this.textEngine_.bufferStart();
  715.     }
  716.     return shaka.media.TimeRangesUtils.bufferStart(
  717.         this.getBuffered_(contentType));
  718.   }
  720.   /**
  721.    * Gets the last timestamp in buffer for the given content type.
  722.    *
  723.    * @param {shaka.util.ManifestParserUtils.ContentType} contentType
  724.    * @return {?number} The timestamp in seconds, or null if nothing is buffered.
  725.    */
  726.   bufferEnd(contentType) {
  727.     if (!this.sourceBuffers_.size) {
  728.       return null;
  729.     }
  730.     const ContentType = shaka.util.ManifestParserUtils.ContentType;
  731.     if (contentType == ContentType.TEXT) {
  732.       return this.textEngine_.bufferEnd();
  733.     }
  734.     return shaka.media.TimeRangesUtils.bufferEnd(
  735.         this.getBuffered_(contentType));
  736.   }
  738.   /**
  739.    * Determines if the given time is inside the buffered range of the given
  740.    * content type.
  741.    *
  742.    * @param {shaka.util.ManifestParserUtils.ContentType} contentType
  743.    * @param {number} time Playhead time
  744.    * @return {boolean}
  745.    */
  746.   isBuffered(contentType, time) {
  747.     const ContentType = shaka.util.ManifestParserUtils.ContentType;
  748.     if (contentType == ContentType.TEXT) {
  749.       return this.textEngine_.isBuffered(time);
  750.     } else {
  751.       const buffered = this.getBuffered_(contentType);
  752.       return shaka.media.TimeRangesUtils.isBuffered(buffered, time);
  753.     }
  754.   }
  756.   /**
  757.    * Computes how far ahead of the given timestamp is buffered for the given
  758.    * content type.
  759.    *
  760.    * @param {shaka.util.ManifestParserUtils.ContentType} contentType
  761.    * @param {number} time
  762.    * @return {number} The amount of time buffered ahead in seconds.
  763.    */
  764.   bufferedAheadOf(contentType, time) {
  765.     const ContentType = shaka.util.ManifestParserUtils.ContentType;
  766.     if (contentType == ContentType.TEXT) {
  767.       return this.textEngine_.bufferedAheadOf(time);
  768.     } else {
  769.       const buffered = this.getBuffered_(contentType);
  770.       return shaka.media.TimeRangesUtils.bufferedAheadOf(buffered, time);
  771.     }
  772.   }
  774.   /**
  775.    * Returns info about what is currently buffered.
  776.    * @return {shaka.extern.BufferedInfo}
  777.    */
  778.   getBufferedInfo() {
  779.     const ContentType = shaka.util.ManifestParserUtils.ContentType;
  780.     const TimeRangesUtils = shaka.media.TimeRangesUtils;
  782.     const info = {
  783.       total: this.reloadingMediaSource_ ? [] :
  784.         TimeRangesUtils.getBufferedInfo(this.video_.buffered),
  785.       audio:
  786.         TimeRangesUtils.getBufferedInfo(this.getBuffered_(ContentType.AUDIO)),
  787.       video:
  788.         TimeRangesUtils.getBufferedInfo(this.getBuffered_(ContentType.VIDEO)),
  789.       text: [],
  790.     };
  792.     if (this.textEngine_) {
  793.       const start = this.textEngine_.bufferStart();
  794.       const end = this.textEngine_.bufferEnd();
  796.       if (start != null && end != null) {
  797.         info.text.push({start: start, end: end});
  798.       }
  799.     }
  800.     return info;
  801.   }
  803.   /**
  804.    * @param {shaka.util.ManifestParserUtils.ContentType} contentType
  805.    * @return {TimeRanges} The buffered ranges for the given content type, or
  806.    *   null if the buffered ranges could not be obtained.
  807.    * @private
  808.    */
  809.   getBuffered_(contentType) {
  810.     if (this.reloadingMediaSource_ || this.usingRemotePlayback_) {
  811.       return null;
  812.     }
  813.     try {
  814.       return this.sourceBuffers_.get(contentType).buffered;
  815.     } catch (exception) {
  816.       if (this.sourceBuffers_.has(contentType)) {
  817.         // Note: previous MediaSource errors may cause access to |buffered| to
  818.         // throw.
  819.         shaka.log.error('failed to get buffered range for ' + contentType,
  820.             exception);
  821.       }
  822.       return null;
  823.     }
  824.   }
  826.   /**
  827.    * Create a new closed caption parser. This will ONLY be replaced by tests as
  828.    * a way to inject fake closed caption parser instances.
  829.    *
  830.    * @param {string} mimeType
  831.    * @return {!shaka.media.IClosedCaptionParser}
  832.    */
  833.   getCaptionParser(mimeType) {
  834.     return new shaka.media.ClosedCaptionParser(mimeType);
  835.   }
  837.   /**
  838.    * This method is only public for testing.
  839.    *
  840.    * @param {shaka.util.ManifestParserUtils.ContentType} contentType
  841.    * @param {!BufferSource} data
  842.    * @param {!shaka.media.SegmentReference} reference The segment reference
  843.    *   we are appending
  844.    * @param {shaka.extern.Stream} stream
  845.    * @param {!string} mimeType
  846.    * @return {{timestamp: ?number, metadata: !Array<shaka.extern.ID3Metadata>}}
  847.    */
  848.   getTimestampAndDispatchMetadata(contentType, data, reference, stream,
  849.       mimeType) {
  850.     let timestamp = null;
  851.     let metadata = [];
  853.     const uint8ArrayData = shaka.util.BufferUtils.toUint8(data);
  854.     if (shaka.util.MimeUtils.RAW_FORMATS.includes(mimeType)) {
  855.       const frames = shaka.util.Id3Utils.getID3Frames(uint8ArrayData);
  856.       if (frames.length && reference) {
  857.         const metadataTimestamp = frames.find((frame) => {
  858.           return frame.description ===
  859.               'com.apple.streaming.transportStreamTimestamp';
  860.         });
  861.         if (metadataTimestamp && typeof metadataTimestamp.data == 'number') {
  862.           timestamp = Math.round(metadataTimestamp.data) / 1000;
  863.         }
  864.         /** @private {shaka.extern.ID3Metadata} */
  865.         const id3Metadata = {
  866.           cueTime: reference.startTime,
  867.           data: uint8ArrayData,
  868.           frames: frames,
  869.           dts: reference.startTime,
  870.           pts: reference.startTime,
  871.         };
  872.         this.playerInterface_.onMetadata(
  873.             [id3Metadata], /* offset= */ 0, reference.endTime);
  874.       }
  875.     } else if (mimeType.includes('/mp4') &&
  876.         reference &&
  877.         reference.initSegmentReference &&
  878.         reference.initSegmentReference.timescale) {
  879.       const timescale = reference.initSegmentReference.timescale;
  880.       if (!isNaN(timescale)) {
  881.         const hasEmsg = ((stream.emsgSchemeIdUris != null &&
  882.             stream.emsgSchemeIdUris.length > 0) ||
  883.             this.config_.dispatchAllEmsgBoxes);
  884.         const Mp4Parser = shaka.util.Mp4Parser;
  885.         let startTime = 0;
  886.         let parsedMedia = false;
  887.         const parser = new Mp4Parser();
  888.         if (hasEmsg) {
  889.           parser.fullBox('emsg', (box) =>
  890.             this.parseEMSG_(reference, stream.emsgSchemeIdUris, box));
  891.         }
  892.         parser.fullBox('prft', (box) => this.parsePrft_(timescale, box))
  893.             .box('moof', Mp4Parser.children)
  894.             .box('traf', Mp4Parser.children)
  895.             .fullBox('tfdt', (box) => {
  896.               if (!parsedMedia) {
  897.                 goog.asserts.assert(
  898.                     box.version == 0 || box.version == 1,
  899.                     'TFDT version can only be 0 or 1');
  900.                 const parsed = shaka.util.Mp4BoxParsers.parseTFDTInaccurate(
  901.                     box.reader, box.version);
  902.                 startTime = parsed.baseMediaDecodeTime / timescale;
  903.                 parsedMedia = true;
  904.                 if (!hasEmsg) {
  905.                   box.parser.stop();
  906.                 }
  907.               }
  908.             }).parse(data, /* partialOkay= */ true);
  909.         if (parsedMedia && reference.timestampOffset == 0) {
  910.           timestamp = startTime;
  911.         }
  912.       }
  913.     } else if (!mimeType.includes('/mp4') && !mimeType.includes('/webm') &&
  914.         shaka.util.TsParser.probe(uint8ArrayData)) {
  915.       if (!this.tsParsers_.has(contentType)) {
  916.         this.tsParsers_.set(contentType, new shaka.util.TsParser());
  917.       } else {
  918.         this.tsParsers_.get(contentType).clearData();
  919.       }
  920.       const tsParser = this.tsParsers_.get(contentType).parse(uint8ArrayData);
  921.       const startTime = tsParser.getStartTime(contentType);
  922.       if (startTime != null) {
  923.         timestamp = startTime;
  924.       }
  925.       metadata = tsParser.getMetadata();
  926.     }
  927.     return {timestamp, metadata};
  928.   }
  931.   /**
  932.    * Parse the EMSG box from a MP4 container.
  933.    *
  934.    * @param {!shaka.media.SegmentReference} reference
  935.    * @param {?Array<string>} emsgSchemeIdUris Array of emsg
  936.    *     scheme_id_uri for which emsg boxes should be parsed.
  937.    * @param {!shaka.extern.ParsedBox} box
  938.    * @private
  939.    * https://dashif-documents.azurewebsites.net/Events/master/event.html#emsg-format
  940.    * aligned(8) class DASHEventMessageBox
  941.    *    extends FullBox(‘emsg’, version, flags = 0){
  942.    * if (version==0) {
  943.    *   string scheme_id_uri;
  944.    *   string value;
  945.    *   unsigned int(32) timescale;
  946.    *   unsigned int(32) presentation_time_delta;
  947.    *   unsigned int(32) event_duration;
  948.    *   unsigned int(32) id;
  949.    * } else if (version==1) {
  950.    *   unsigned int(32) timescale;
  951.    *   unsigned int(64) presentation_time;
  952.    *   unsigned int(32) event_duration;
  953.    *   unsigned int(32) id;
  954.    *   string scheme_id_uri;
  955.    *   string value;
  956.    * }
  957.    * unsigned int(8) message_data[];
  958.    */
  959.   parseEMSG_(reference, emsgSchemeIdUris, box) {
  960.     let timescale;
  961.     let id;
  962.     let eventDuration;
  963.     let schemeId;
  964.     let startTime;
  965.     let presentationTimeDelta;
  966.     let value;
  968.     if (box.version === 0) {
  969.       schemeId = box.reader.readTerminatedString();
  970.       value = box.reader.readTerminatedString();
  971.       timescale = box.reader.readUint32();
  972.       presentationTimeDelta = box.reader.readUint32();
  973.       eventDuration = box.reader.readUint32();
  974.       id = box.reader.readUint32();
  975.       startTime = reference.startTime + (presentationTimeDelta / timescale);
  976.     } else {
  977.       timescale = box.reader.readUint32();
  978.       const pts = box.reader.readUint64();
  979.       startTime = (pts / timescale) + reference.timestampOffset;
  980.       presentationTimeDelta = startTime - reference.startTime;
  981.       eventDuration = box.reader.readUint32();
  982.       id = box.reader.readUint32();
  983.       schemeId = box.reader.readTerminatedString();
  984.       value = box.reader.readTerminatedString();
  985.     }
  986.     const messageData = box.reader.readBytes(
  987.         box.reader.getLength() - box.reader.getPosition());
  989.     // See DASH sec. 5.10.3.3.1
  990.     // If a DASH client detects an event message box with a scheme that is not
  991.     // defined in MPD, the client is expected to ignore it.
  992.     if ((emsgSchemeIdUris && emsgSchemeIdUris.includes(schemeId)) ||
  993.         this.config_.dispatchAllEmsgBoxes) {
  994.       // See DASH sec. 5.10.4.1
  995.       // A special scheme in DASH used to signal manifest updates.
  996.       if (schemeId == 'urn:mpeg:dash:event:2012') {
  997.         this.playerInterface_.onManifestUpdate();
  998.       } else {
  999.         // All other schemes are dispatched as a general 'emsg' event.
  1000.         const endTime = startTime + (eventDuration / timescale);
  1001.         /** @type {shaka.extern.EmsgInfo} */
  1002.         const emsg = {
  1003.           startTime: startTime,
  1004.           endTime: endTime,
  1005.           schemeIdUri: schemeId,
  1006.           value: value,
  1007.           timescale: timescale,
  1008.           presentationTimeDelta: presentationTimeDelta,
  1009.           eventDuration: eventDuration,
  1010.           id: id,
  1011.           messageData: messageData,
  1012.         };
  1014.         // Dispatch an event to notify the application about the emsg box.
  1015.         const eventName = shaka.util.FakeEvent.EventName.Emsg;
  1016.         const data = (new Map()).set('detail', emsg);
  1017.         const event = new shaka.util.FakeEvent(eventName, data);
  1018.         // A user can call preventDefault() on a cancelable event.
  1019.         event.cancelable = true;
  1021.         this.playerInterface_.onEmsg(emsg);
  1023.         // Additionally, ID3 events generate a 'metadata' event.  This is a
  1024.         // pre-parsed version of the metadata blob already dispatched in the
  1025.         // 'emsg' event.
  1026.         if (schemeId == 'https://aomedia.org/emsg/ID3' ||
  1027.             schemeId == 'https://developer.apple.com/streaming/emsg-id3') {
  1028.           // See https://aomediacodec.github.io/id3-emsg/
  1029.           const frames = shaka.util.Id3Utils.getID3Frames(messageData);
  1030.           if (frames.length) {
  1031.             /** @private {shaka.extern.ID3Metadata} */
  1032.             const metadata = {
  1033.               cueTime: startTime,
  1034.               data: messageData,
  1035.               frames: frames,
  1036.               dts: startTime,
  1037.               pts: startTime,
  1038.             };
  1039.             this.playerInterface_.onMetadata(
  1040.                 [metadata], /* offset= */ 0, endTime);
  1041.           }
  1042.         }
  1043.       }
  1044.     }
  1045.   }
  1047.   /**
  1048.    * Parse PRFT box.
  1049.    * @param {number} timescale
  1050.    * @param {!shaka.extern.ParsedBox} box
  1051.    * @private
  1052.    */
  1053.   parsePrft_(timescale, box) {
  1054.     goog.asserts.assert(
  1055.         box.version == 0 || box.version == 1,
  1056.         'PRFT version can only be 0 or 1');
  1057.     const parsed = shaka.util.Mp4BoxParsers.parsePRFTInaccurate(
  1058.         box.reader, box.version);
  1060.     const wallClockTime = shaka.util.TimeUtils.convertNtp(parsed.ntpTimestamp);
  1061.     const programStartDate = new Date(wallClockTime -
  1062.       (parsed.mediaTime / timescale) * 1000);
  1063.     /** @type {shaka.extern.ProducerReferenceTime} */
  1064.     const prftInfo = {
  1065.       wallClockTime,
  1066.       programStartDate,
  1067.     };
  1069.     const eventName = shaka.util.FakeEvent.EventName.Prft;
  1070.     const data = (new Map()).set('detail', prftInfo);
  1071.     const event = new shaka.util.FakeEvent(
  1072.         eventName, data);
  1073.     this.playerInterface_.onEvent(event);
  1074.   }
  1076.   /**
  1077.    * Enqueue an operation to append data to the SourceBuffer.
  1078.    * Start and end times are needed for TextEngine, but not for MediaSource.
  1079.    * Start and end times may be null for initialization segments; if present
  1080.    * they are relative to the presentation timeline.
  1081.    *
  1082.    * @param {shaka.util.ManifestParserUtils.ContentType} contentType
  1083.    * @param {!BufferSource} data
  1084.    * @param {?shaka.media.SegmentReference} reference The segment reference
  1085.    *   we are appending, or null for init segments
  1086.    * @param {shaka.extern.Stream} stream
  1087.    * @param {?boolean} hasClosedCaptions True if the buffer contains CEA closed
  1088.    *   captions
  1089.    * @param {boolean=} seeked True if we just seeked
  1090.    * @param {boolean=} adaptation True if we just automatically switched active
  1091.    *   variant(s).
  1092.    * @param {boolean=} isChunkedData True if we add to the buffer from the
  1093.    * @param {boolean=} fromSplit
  1094.    * @param {number=} continuityTimeline an optional continuity timeline
  1095.    * @return {!Promise}
  1096.    */
  1097.   async appendBuffer(
  1098.       contentType, data, reference, stream, hasClosedCaptions, seeked = false,
  1099.       adaptation = false, isChunkedData = false, fromSplit = false,
  1100.       continuityTimeline) {
  1101.     const ContentType = shaka.util.ManifestParserUtils.ContentType;
  1103.     if (contentType == ContentType.TEXT) {
  1104.       if (this.manifestType_ == shaka.media.ManifestParser.HLS) {
  1105.         // This won't be known until the first video segment is appended.
  1106.         const offset = await this.textSequenceModeOffset_;
  1107.         this.textEngine_.setTimestampOffset(offset);
  1108.       }
  1109.       await this.textEngine_.appendBuffer(
  1110.           data,
  1111.           reference ? reference.startTime : null,
  1112.           reference ? reference.endTime : null,
  1113.           reference ? reference.getUris()[0] : null);
  1114.       return;
  1115.     }
  1117.     if (!fromSplit && this.needSplitMuxedContent_) {
  1118.       await this.appendBuffer(ContentType.AUDIO, data, reference, stream,
  1119.           hasClosedCaptions, seeked, adaptation, isChunkedData,
  1120.           /* fromSplit= */ true);
  1121.       await this.appendBuffer(ContentType.VIDEO, data, reference, stream,
  1122.           hasClosedCaptions, seeked, adaptation, isChunkedData,
  1123.           /* fromSplit= */ true);
  1124.       return;
  1125.     }
  1127.     if (!this.sourceBuffers_.has(contentType)) {
  1128.       shaka.log.warning('Attempted to restore a non-existent source buffer');
  1129.       return;
  1130.     }
  1132.     let timestampOffset = this.sourceBuffers_.get(contentType).timestampOffset;
  1134.     let mimeType = this.sourceBufferTypes_.get(contentType);
  1135.     if (this.transmuxers_.has(contentType)) {
  1136.       mimeType = this.transmuxers_.get(contentType).getOriginalMimeType();
  1137.     }
  1138.     if (reference) {
  1139.       const {timestamp, metadata} = this.getTimestampAndDispatchMetadata(
  1140.           contentType, data, reference, stream, mimeType);
  1141.       if (timestamp != null) {
  1142.         if (this.firstVideoTimestamp_ == null &&
  1143.             contentType == ContentType.VIDEO) {
  1144.           this.firstVideoTimestamp_ = timestamp;
  1145.           this.firstVideoReferenceStartTime_ = reference.startTime;
  1146.           if (this.firstAudioTimestamp_ != null) {
  1147.             let compensation = 0;
  1148.             // Only apply compensation if video and audio segment startTime
  1149.             // match, to avoid introducing sync issues.
  1150.             if (this.firstVideoReferenceStartTime_ ==
  1151.                 this.firstAudioReferenceStartTime_) {
  1152.               compensation =
  1153.                   this.firstVideoTimestamp_ - this.firstAudioTimestamp_;
  1154.             }
  1155.             this.audioCompensation_.resolve(compensation);
  1156.           }
  1157.         }
  1158.         if (this.firstAudioTimestamp_ == null &&
  1159.             contentType == ContentType.AUDIO) {
  1160.           this.firstAudioTimestamp_ = timestamp;
  1161.           this.firstAudioReferenceStartTime_ = reference.startTime;
  1162.           if (this.firstVideoTimestamp_ != null) {
  1163.             let compensation = 0;
  1164.             // Only apply compensation if video and audio segment startTime
  1165.             // match, to avoid introducing sync issues.
  1166.             if (this.firstVideoReferenceStartTime_ ==
  1167.                 this.firstAudioReferenceStartTime_) {
  1168.               compensation =
  1169.                   this.firstVideoTimestamp_ - this.firstAudioTimestamp_;
  1170.             }
  1171.             this.audioCompensation_.resolve(compensation);
  1172.           }
  1173.         }
  1174.         let realTimestamp = timestamp;
  1175.         const RAW_FORMATS = shaka.util.MimeUtils.RAW_FORMATS;
  1176.         // For formats without containers and using segments mode, we need to
  1177.         // adjust TimestampOffset relative to 0 because segments do not have
  1178.         // any timestamp information.
  1179.         if (!this.sequenceMode_ &&
  1180.             RAW_FORMATS.includes(this.sourceBufferTypes_.get(contentType))) {
  1181.           realTimestamp = 0;
  1182.         }
  1183.         const calculatedTimestampOffset = reference.startTime - realTimestamp;
  1184.         const timestampOffsetDifference =
  1185.             Math.abs(timestampOffset - calculatedTimestampOffset);
  1186.         if ((timestampOffsetDifference >= 0.001 || seeked || adaptation) &&
  1187.             (!isChunkedData || calculatedTimestampOffset > 0 ||
  1188.             !timestampOffset)) {
  1189.           timestampOffset = calculatedTimestampOffset;
  1190.           if (this.attemptTimestampOffsetCalculation_) {
  1191.             this.enqueueOperation_(
  1192.                 contentType,
  1193.                 () => this.abort_(contentType),
  1194.                 null);
  1195.             this.enqueueOperation_(
  1196.                 contentType,
  1197.                 () => this.setTimestampOffset_(contentType, timestampOffset),
  1198.                 null);
  1199.           }
  1200.         }
  1201.         // Timestamps can only be reliably extracted from video, not audio.
  1202.         // Packed audio formats do not have internal timestamps at all.
  1203.         // Prefer video for this when available.
  1204.         const isBestSourceBufferForTimestamps =
  1205.             contentType == ContentType.VIDEO ||
  1206.             !(this.sourceBuffers_.has(ContentType.VIDEO));
  1207.         if (isBestSourceBufferForTimestamps) {
  1208.           this.textSequenceModeOffset_.resolve(timestampOffset);
  1209.         }
  1210.       }
  1211.       if (metadata.length) {
  1212.         this.playerInterface_.onMetadata(metadata, timestampOffset,
  1213.             reference ? reference.endTime : null);
  1214.       }
  1215.     }
  1216.     if (hasClosedCaptions && contentType == ContentType.VIDEO) {
  1217.       if (!this.textEngine_) {
  1218.         this.reinitText(shaka.util.MimeUtils.CEA608_CLOSED_CAPTION_MIMETYPE,
  1219.             this.sequenceMode_, /* external= */ false);
  1220.       }
  1221.       if (!this.captionParser_) {
  1222.         const basicType = mimeType.split(';', 1)[0];
  1223.         this.captionParser_ = this.getCaptionParser(basicType);
  1224.       }
  1225.       // If it is the init segment for closed captions, initialize the closed
  1226.       // caption parser.
  1227.       if (!reference) {
  1228.         this.captionParser_.init(data, adaptation, continuityTimeline);
  1229.       } else {
  1230.         const closedCaptions = this.captionParser_.parseFrom(data);
  1231.         if (closedCaptions.length) {
  1232.           this.textEngine_.storeAndAppendClosedCaptions(
  1233.               closedCaptions,
  1234.               reference.startTime,
  1235.               reference.endTime,
  1236.               timestampOffset);
  1237.         }
  1238.       }
  1239.     }
  1241.     if (this.transmuxers_.has(contentType)) {
  1242.       data = await this.transmuxers_.get(contentType).transmux(
  1243.           data, stream, reference, this.mediaSource_.duration, contentType);
  1244.     }
  1246.     data = this.workAroundBrokenPlatforms_(
  1247.         stream, data, reference, contentType);
  1249.     if (reference && this.sequenceMode_ && contentType != ContentType.TEXT) {
  1250.       // In sequence mode, for non-text streams, if we just cleared the buffer
  1251.       // and are either performing an unbuffered seek or handling an automatic
  1252.       // adaptation, we need to set a new timestampOffset on the sourceBuffer.
  1253.       if (seeked || adaptation) {
  1254.         let timestampOffset = reference.startTime;
  1255.         // Audio and video may not be aligned, so we will compensate for audio
  1256.         // if necessary.
  1257.         if (this.manifestType_ == shaka.media.ManifestParser.HLS &&
  1258.             !this.needSplitMuxedContent_ &&
  1259.             contentType == ContentType.AUDIO &&
  1260.             this.sourceBuffers_.has(ContentType.VIDEO)) {
  1261.           const compensation = await this.audioCompensation_;
  1262.           // Only apply compensation if the difference is greater than 150ms
  1263.           if (Math.abs(compensation) > 0.15) {
  1264.             timestampOffset -= compensation;
  1265.           }
  1266.         }
  1267.         // The logic to call abort() before setting the timestampOffset is
  1268.         // extended during unbuffered seeks or automatic adaptations; it is
  1269.         // possible for the append state to be PARSING_MEDIA_SEGMENT from the
  1270.         // previous SourceBuffer#appendBuffer() call.
  1271.         this.enqueueOperation_(
  1272.             contentType,
  1273.             () => this.abort_(contentType),
  1274.             null);
  1275.         this.enqueueOperation_(
  1276.             contentType,
  1277.             () => this.setTimestampOffset_(contentType, timestampOffset),
  1278.             null);
  1279.       }
  1280.     }
  1282.     let bufferedBefore = null;
  1284.     await this.enqueueOperation_(contentType, () => {
  1285.       if (goog.DEBUG && reference && !reference.isPreload() && !isChunkedData) {
  1286.         bufferedBefore = this.getBuffered_(contentType);
  1287.       }
  1288.       this.append_(contentType, data, timestampOffset, stream);
  1289.     }, reference ? reference.getUris()[0] : null);
  1291.     if (goog.DEBUG && reference && !reference.isPreload() && !isChunkedData) {
  1292.       const bufferedAfter = this.getBuffered_(contentType);
  1293.       const newBuffered = shaka.media.TimeRangesUtils.computeAddedRange(
  1294.           bufferedBefore, bufferedAfter);
  1295.       if (newBuffered) {
  1296.         const segmentDuration = reference.endTime - reference.startTime;
  1297.         const timeAdded = newBuffered.end - newBuffered.start;
  1298.         // Check end times instead of start times.  We may be overwriting a
  1299.         // buffer and only the end changes, and that would be fine.
  1300.         // Also, exclude tiny segments.  Sometimes alignment segments as small
  1301.         // as 33ms are seen in Google DAI content.  For such tiny segments,
  1302.         // half a segment duration would be no issue.
  1303.         const offset = Math.abs(newBuffered.end - reference.endTime);
  1304.         if (segmentDuration > 0.100 && (offset > segmentDuration / 2 ||
  1305.             Math.abs(segmentDuration - timeAdded) > 0.030)) {
  1306.           shaka.log.error('Possible encoding problem detected!',
  1307.               'Unexpected buffered range for reference', reference,
  1308.               'from URIs', reference.getUris(),
  1309.               'should be', {start: reference.startTime, end: reference.endTime},
  1310.               'but got', newBuffered);
  1311.         }
  1312.       }
  1313.     }
  1314.   }
  1316.   /**
  1317.    * Set the selected closed captions Id and language.
  1318.    *
  1319.    * @param {string} id
  1320.    */
  1321.   setSelectedClosedCaptionId(id) {
  1322.     const VIDEO = shaka.util.ManifestParserUtils.ContentType.VIDEO;
  1323.     const videoBufferEndTime = this.bufferEnd(VIDEO) || 0;
  1324.     this.textEngine_.setSelectedClosedCaptionId(id, videoBufferEndTime);
  1325.   }
  1327.   /** Disable embedded closed captions. */
  1328.   clearSelectedClosedCaptionId() {
  1329.     if (this.textEngine_) {
  1330.       this.textEngine_.setSelectedClosedCaptionId('', 0);
  1331.     }
  1332.   }
  1334.   /**
  1335.    * Enqueue an operation to remove data from the SourceBuffer.
  1336.    *
  1337.    * @param {shaka.util.ManifestParserUtils.ContentType} contentType
  1338.    * @param {number} startTime relative to the start of the presentation
  1339.    * @param {number} endTime relative to the start of the presentation
  1340.    * @param {Array<number>=} continuityTimelines a list of continuity timelines
  1341.    *     that are still available on the stream.
  1342.    * @return {!Promise}
  1343.    */
  1344.   async remove(contentType, startTime, endTime, continuityTimelines) {
  1345.     const ContentType = shaka.util.ManifestParserUtils.ContentType;
  1346.     if (contentType == ContentType.VIDEO && this.captionParser_) {
  1347.       this.captionParser_.remove(continuityTimelines);
  1348.     }
  1349.     if (contentType == ContentType.TEXT) {
  1350.       await this.textEngine_.remove(startTime, endTime);
  1351.     } else if (endTime > startTime) {
  1352.       await this.enqueueOperation_(
  1353.           contentType,
  1354.           () => this.remove_(contentType, startTime, endTime),
  1355.           null);
  1356.       if (this.needSplitMuxedContent_) {
  1357.         await this.enqueueOperation_(
  1358.             ContentType.AUDIO,
  1359.             () => this.remove_(ContentType.AUDIO, startTime, endTime),
  1360.             null);
  1361.       }
  1362.     }
  1363.   }
  1365.   /**
  1366.    * Enqueue an operation to clear the SourceBuffer.
  1367.    *
  1368.    * @param {shaka.util.ManifestParserUtils.ContentType} contentType
  1369.    * @return {!Promise}
  1370.    */
  1371.   async clear(contentType) {
  1372.     const ContentType = shaka.util.ManifestParserUtils.ContentType;
  1373.     if (contentType == ContentType.TEXT) {
  1374.       if (!this.textEngine_) {
  1375.         return;
  1376.       }
  1377.       await this.textEngine_.remove(0, Infinity);
  1378.     } else {
  1379.       // Note that not all platforms allow clearing to Infinity.
  1380.       await this.enqueueOperation_(
  1381.           contentType,
  1382.           () => this.remove_(contentType, 0, this.mediaSource_.duration),
  1383.           null);
  1384.       if (this.needSplitMuxedContent_) {
  1385.         await this.enqueueOperation_(
  1386.             ContentType.AUDIO,
  1387.             () => this.remove_(
  1388.                 ContentType.AUDIO, 0, this.mediaSource_.duration),
  1389.             null);
  1390.       }
  1391.     }
  1392.   }
  1394.   /**
  1395.    * Fully reset the state of the caption parser owned by MediaSourceEngine.
  1396.    */
  1397.   resetCaptionParser() {
  1398.     if (this.captionParser_) {
  1399.       this.captionParser_.reset();
  1400.     }
  1401.   }
  1403.   /**
  1404.    * Enqueue an operation to flush the SourceBuffer.
  1405.    * This is a workaround for what we believe is a Chromecast bug.
  1406.    *
  1407.    * @param {shaka.util.ManifestParserUtils.ContentType} contentType
  1408.    * @return {!Promise}
  1409.    */
  1410.   async flush(contentType) {
  1411.     // Flush the pipeline.  Necessary on Chromecast, even though we have removed
  1412.     // everything.
  1413.     const ContentType = shaka.util.ManifestParserUtils.ContentType;
  1414.     if (contentType == ContentType.TEXT) {
  1415.       // Nothing to flush for text.
  1416.       return;
  1417.     }
  1418.     await this.enqueueOperation_(
  1419.         contentType,
  1420.         () => this.flush_(contentType),
  1421.         null);
  1422.     if (this.needSplitMuxedContent_) {
  1423.       await this.enqueueOperation_(
  1424.           ContentType.AUDIO,
  1425.           () => this.flush_(ContentType.AUDIO),
  1426.           null);
  1427.     }
  1428.   }
  1430.   /**
  1431.    * Sets the timestamp offset and append window end for the given content type.
  1432.    *
  1433.    * @param {shaka.util.ManifestParserUtils.ContentType} contentType
  1434.    * @param {number} timestampOffset The timestamp offset.  Segments which start
  1435.    *   at time t will be inserted at time t + timestampOffset instead.  This
  1436.    *   value does not affect segments which have already been inserted.
  1437.    * @param {number} appendWindowStart The timestamp to set the append window
  1438.    *   start to.  For future appends, frames/samples with timestamps less than
  1439.    *   this value will be dropped.
  1440.    * @param {number} appendWindowEnd The timestamp to set the append window end
  1441.    *   to.  For future appends, frames/samples with timestamps greater than this
  1442.    *   value will be dropped.
  1443.    * @param {boolean} ignoreTimestampOffset  If true, the timestampOffset will
  1444.    *   not be applied in this step.
  1445.    * @param {string} mimeType
  1446.    * @param {string} codecs
  1447.    * @param {!Map<shaka.util.ManifestParserUtils.ContentType,
  1448.    *               shaka.extern.Stream>} streamsByType
  1449.    *   A map of content types to streams.
  1450.    *
  1451.    * @return {!Promise}
  1452.    */
  1453.   async setStreamProperties(
  1454.       contentType, timestampOffset, appendWindowStart, appendWindowEnd,
  1455.       ignoreTimestampOffset, mimeType, codecs, streamsByType) {
  1456.     const ContentType = shaka.util.ManifestParserUtils.ContentType;
  1457.     if (contentType == ContentType.TEXT) {
  1458.       if (!ignoreTimestampOffset) {
  1459.         this.textEngine_.setTimestampOffset(timestampOffset);
  1460.       }
  1461.       this.textEngine_.setAppendWindow(appendWindowStart, appendWindowEnd);
  1462.       return;
  1463.     }
  1464.     const operations = [];
  1466.     const hasChangedCodecs = await this.codecSwitchIfNecessary_(
  1467.         contentType, mimeType, codecs, streamsByType);
  1469.     if (!hasChangedCodecs) {
  1470.       // Queue an abort() to help MSE splice together overlapping segments.
  1471.       // We set appendWindowEnd when we change periods in DASH content, and the
  1472.       // period transition may result in overlap.
  1473.       //
  1474.       // An abort() also helps with MPEG2-TS.  When we append a TS segment, we
  1475.       // always enter a PARSING_MEDIA_SEGMENT state and we can't change the
  1476.       // timestamp offset.  By calling abort(), we reset the state so we can
  1477.       // set it.
  1478.       operations.push(this.enqueueOperation_(
  1479.           contentType,
  1480.           () => this.abort_(contentType),
  1481.           null));
  1482.       if (this.needSplitMuxedContent_) {
  1483.         operations.push(this.enqueueOperation_(
  1484.             ContentType.AUDIO,
  1485.             () => this.abort_(ContentType.AUDIO),
  1486.             null));
  1487.       }
  1488.     }
  1489.     if (!ignoreTimestampOffset) {
  1490.       operations.push(this.enqueueOperation_(
  1491.           contentType,
  1492.           () => this.setTimestampOffset_(contentType, timestampOffset),
  1493.           null));
  1494.       if (this.needSplitMuxedContent_) {
  1495.         operations.push(this.enqueueOperation_(
  1496.             ContentType.AUDIO,
  1497.             () => this.setTimestampOffset_(
  1498.                 ContentType.AUDIO, timestampOffset),
  1499.             null));
  1500.       }
  1501.     }
  1502.     if (appendWindowStart != 0 || appendWindowEnd != Infinity) {
  1503.       operations.push(this.enqueueOperation_(
  1504.           contentType,
  1505.           () => this.setAppendWindow_(
  1506.               contentType, appendWindowStart, appendWindowEnd),
  1507.           null));
  1508.       if (this.needSplitMuxedContent_) {
  1509.         operations.push(this.enqueueOperation_(
  1510.             ContentType.AUDIO,
  1511.             () => this.setAppendWindow_(
  1512.                 ContentType.AUDIO, appendWindowStart, appendWindowEnd),
  1513.             null));
  1514.       }
  1515.     }
  1517.     if (operations.length) {
  1518.       await Promise.all(operations);
  1519.     }
  1520.   }
  1522.   /**
  1523.    * Adjust timestamp offset to maintain AV sync across discontinuities.
  1524.    *
  1525.    * @param {shaka.util.ManifestParserUtils.ContentType} contentType
  1526.    * @param {number} timestampOffset
  1527.    * @return {!Promise}
  1528.    */
  1529.   async resync(contentType, timestampOffset) {
  1530.     const ContentType = shaka.util.ManifestParserUtils.ContentType;
  1532.     if (contentType == ContentType.TEXT) {
  1533.       // This operation is for audio and video only.
  1534.       return;
  1535.     }
  1537.     // Reset the promise in case the timestamp offset changed during
  1538.     // a period/discontinuity transition.
  1539.     if (contentType == ContentType.VIDEO) {
  1540.       this.textSequenceModeOffset_ = new shaka.util.PublicPromise();
  1541.     }
  1543.     if (!this.sequenceMode_) {
  1544.       return;
  1545.     }
  1547.     // Avoid changing timestampOffset when the difference is less than 100 ms
  1548.     // from the end of the current buffer.
  1549.     const bufferEnd = this.bufferEnd(contentType);
  1550.     if (bufferEnd && Math.abs(bufferEnd - timestampOffset) < 0.1) {
  1551.       return;
  1552.     }
  1554.     // Queue an abort() to help MSE splice together overlapping segments.
  1555.     // We set appendWindowEnd when we change periods in DASH content, and the
  1556.     // period transition may result in overlap.
  1557.     //
  1558.     // An abort() also helps with MPEG2-TS.  When we append a TS segment, we
  1559.     // always enter a PARSING_MEDIA_SEGMENT state and we can't change the
  1560.     // timestamp offset.  By calling abort(), we reset the state so we can
  1561.     // set it.
  1562.     this.enqueueOperation_(
  1563.         contentType,
  1564.         () => this.abort_(contentType),
  1565.         null);
  1566.     if (this.needSplitMuxedContent_) {
  1567.       this.enqueueOperation_(
  1568.           ContentType.AUDIO,
  1569.           () => this.abort_(ContentType.AUDIO),
  1570.           null);
  1571.     }
  1572.     await this.enqueueOperation_(
  1573.         contentType,
  1574.         () => this.setTimestampOffset_(contentType, timestampOffset),
  1575.         null);
  1576.     if (this.needSplitMuxedContent_) {
  1577.       await this.enqueueOperation_(
  1578.           ContentType.AUDIO,
  1579.           () => this.setTimestampOffset_(ContentType.AUDIO, timestampOffset),
  1580.           null);
  1581.     }
  1582.   }
  1584.   /**
  1585.    * @param {string=} reason Valid reasons are 'network' and 'decode'.
  1586.    * @return {!Promise}
  1587.    * @see http://w3c.github.io/media-source/#idl-def-EndOfStreamError
  1588.    */
  1589.   async endOfStream(reason) {
  1590.     await this.enqueueBlockingOperation_(() => {
  1591.       // If endOfStream() has already been called on the media source,
  1592.       // don't call it again. Also do not call if readyState is
  1593.       // 'closed' (not attached to video element) since it is not a
  1594.       // valid operation.
  1595.       if (this.ended() || this.closed()) {
  1596.         return;
  1597.       }
  1598.       // Tizen won't let us pass undefined, but it will let us omit the
  1599.       // argument.
  1600.       if (reason) {
  1601.         this.mediaSource_.endOfStream(reason);
  1602.       } else {
  1603.         this.mediaSource_.endOfStream();
  1604.       }
  1605.     });
  1606.   }
  1608.   /**
  1609.    * @param {number} duration
  1610.    * @return {!Promise}
  1611.    */
  1612.   async setDuration(duration) {
  1613.     await this.enqueueBlockingOperation_(() => {
  1614.       // https://www.w3.org/TR/media-source-2/#duration-change-algorithm
  1615.       // "Duration reductions that would truncate currently buffered media
  1616.       // are disallowed.
  1617.       // When truncation is necessary, use remove() to reduce the buffered
  1618.       // range before updating duration."
  1619.       // But in some platforms, truncating the duration causes the
  1620.       // buffer range removal algorithm to run which triggers an
  1621.       // 'updateend' event to fire.
  1622.       // To handle this scenario, we have to insert a dummy operation into
  1623.       // the beginning of each queue, which the 'updateend' handler will remove.
  1624.       // Using config to disable it by default and enable only
  1625.       // on relevant platforms.
  1626.       if (this.config_.durationReductionEmitsUpdateEnd &&
  1627.                 duration < this.mediaSource_.duration) {
  1628.         for (const contentType of this.sourceBuffers_.keys()) {
  1629.           const dummyOperation = {
  1630.             start: () => {},
  1631.             p: new shaka.util.PublicPromise(),
  1632.             uri: null,
  1633.           };
  1634.           this.queues_.get(contentType).unshift(dummyOperation);
  1635.         }
  1636.       }
  1638.       this.mediaSource_.duration = duration;
  1639.       this.lastDuration_ = duration;
  1640.     });
  1641.   }
  1643.   /**
  1644.    * Get the current MediaSource duration.
  1645.    *
  1646.    * @return {number}
  1647.    */
  1648.   getDuration() {
  1649.     return this.mediaSource_.duration;
  1650.   }
  1652.   /**
  1653.    * Updates the live seekable range.
  1654.    *
  1655.    * @param {number} startTime
  1656.    * @param {number} endTime
  1657.    */
  1658.   async setLiveSeekableRange(startTime, endTime) {
  1659.     if (this.destroyer_.destroyed() || this.video_.error ||
  1660.         this.usingRemotePlayback_ || this.reloadingMediaSource_) {
  1661.       return;
  1662.     }
  1663.     goog.asserts.assert('setLiveSeekableRange' in this.mediaSource_,
  1664.         'Using setLiveSeekableRange on not supported platform');
  1665.     if (this.ended() || this.closed()) {
  1666.       return;
  1667.     }
  1668.     await this.enqueueBlockingOperation_(() => {
  1669.       if (this.ended() || this.closed()) {
  1670.         return;
  1671.       }
  1672.       this.mediaSource_.setLiveSeekableRange(startTime, endTime);
  1673.     });
  1674.   }
  1676.   /**
  1677.    * Clear the current live seekable range.
  1678.    */
  1679.   async clearLiveSeekableRange() {
  1680.     if (this.destroyer_.destroyed() || this.video_.error ||
  1681.         this.usingRemotePlayback_ || this.reloadingMediaSource_) {
  1682.       return;
  1683.     }
  1684.     goog.asserts.assert('clearLiveSeekableRange' in this.mediaSource_,
  1685.         'Using clearLiveSeekableRange on not supported platform');
  1686.     if (this.ended() || this.closed()) {
  1687.       return;
  1688.     }
  1689.     await this.enqueueBlockingOperation_(() => {
  1690.       if (this.ended() || this.closed()) {
  1691.         return;
  1692.       }
  1693.       this.mediaSource_.clearLiveSeekableRange();
  1694.     });
  1695.   }
  1697.   /**
  1698.    * Append dependency data.
  1699.    * @param {BufferSource} data
  1700.    * @param {number} timestampOffset
  1701.    * @param {shaka.extern.Stream} stream
  1702.    */
  1703.   appendDependency(data, timestampOffset, stream) {
  1704.     if (this.lcevcDec_) {
  1705.       // Append buffers to the LCEVC Dec for parsing and storing
  1706.       // of LCEVC data.
  1707.       this.lcevcDec_.appendBuffer(data, timestampOffset, stream);
  1708.     }
  1709.   }
  1711.   /**
  1712.    * Append data to the SourceBuffer.
  1713.    * @param {shaka.util.ManifestParserUtils.ContentType} contentType
  1714.    * @param {BufferSource} data
  1715.    * @param {number} timestampOffset
  1716.    * @param {shaka.extern.Stream} stream
  1717.    * @private
  1718.    */
  1719.   append_(contentType, data, timestampOffset, stream) {
  1720.     this.appendDependency(data, timestampOffset, stream);
  1722.     // This will trigger an 'updateend' event.
  1723.     this.sourceBuffers_.get(contentType).appendBuffer(data);
  1724.   }
  1726.   /**
  1727.    * Remove data from the SourceBuffer.
  1728.    * @param {shaka.util.ManifestParserUtils.ContentType} contentType
  1729.    * @param {number} startTime relative to the start of the presentation
  1730.    * @param {number} endTime relative to the start of the presentation
  1731.    * @private
  1732.    */
  1733.   remove_(contentType, startTime, endTime) {
  1734.     if (endTime <= startTime) {
  1735.       // Ignore removal of inverted or empty ranges.
  1736.       // Fake 'updateend' event to resolve the operation.
  1737.       this.onUpdateEnd_(contentType);
  1738.       return;
  1739.     }
  1741.     // This will trigger an 'updateend' event.
  1742.     this.sourceBuffers_.get(contentType).remove(startTime, endTime);
  1743.   }
  1745.   /**
  1746.    * Call abort() on the SourceBuffer.
  1747.    * This resets MSE's last_decode_timestamp on all track buffers, which should
  1748.    * trigger the splicing logic for overlapping segments.
  1749.    * @param {shaka.util.ManifestParserUtils.ContentType} contentType
  1750.    * @private
  1751.    */
  1752.   abort_(contentType) {
  1753.     const sourceBuffer = this.sourceBuffers_.get(contentType);
  1754.     // Save the append window, which is reset on abort().
  1755.     const appendWindowStart = sourceBuffer.appendWindowStart;
  1756.     const appendWindowEnd = sourceBuffer.appendWindowEnd;
  1758.     // This will not trigger an 'updateend' event, since nothing is happening.
  1759.     // This is only to reset MSE internals, not to abort an actual operation.
  1760.     sourceBuffer.abort();
  1762.     // Restore the append window.
  1763.     sourceBuffer.appendWindowStart = appendWindowStart;
  1764.     sourceBuffer.appendWindowEnd = appendWindowEnd;
  1766.     // Fake an 'updateend' event to resolve the operation.
  1767.     this.onUpdateEnd_(contentType);
  1768.   }
  1770.   /**
  1771.    * Nudge the playhead to force the media pipeline to be flushed.
  1772.    * This seems to be necessary on Chromecast to get new content to replace old
  1773.    * content.
  1774.    * @param {shaka.util.ManifestParserUtils.ContentType} contentType
  1775.    * @private
  1776.    */
  1777.   flush_(contentType) {
  1778.     // Never use flush_ if there's data.  It causes a hiccup in playback.
  1779.     goog.asserts.assert(
  1780.         this.video_.buffered.length == 0, 'MediaSourceEngine.flush_ should ' +
  1781.         'only be used after clearing all data!');
  1783.     // Seeking forces the pipeline to be flushed.
  1784.     this.video_.currentTime -= 0.001;
  1786.     // Fake an 'updateend' event to resolve the operation.
  1787.     this.onUpdateEnd_(contentType);
  1788.   }
  1790.   /**
  1791.    * Set the SourceBuffer's timestamp offset.
  1792.    * @param {shaka.util.ManifestParserUtils.ContentType} contentType
  1793.    * @param {number} timestampOffset
  1794.    * @private
  1795.    */
  1796.   setTimestampOffset_(contentType, timestampOffset) {
  1797.     // Work around for
  1798.     // https://github.com/shaka-project/shaka-player/issues/1281:
  1799.     // TODO(https://bit.ly/2ttKiBU): follow up when this is fixed in Edge
  1800.     if (timestampOffset < 0) {
  1801.       // Try to prevent rounding errors in Edge from removing the first
  1802.       // keyframe.
  1803.       timestampOffset += 0.001;
  1804.     }
  1807.     let shouldChangeTimestampOffset = true;
  1808.     if (this.manifestType_ == shaka.media.ManifestParser.HLS) {
  1809.       // Avoid changing timestampOffset when the difference is less than 150 ms
  1810.       // from the end of the current buffer when using sequenceMode
  1811.       const bufferEnd = this.bufferEnd(contentType);
  1812.       if (!bufferEnd || Math.abs(bufferEnd - timestampOffset) > 0.15) {
  1813.         shouldChangeTimestampOffset = true;
  1814.       } else {
  1815.         shouldChangeTimestampOffset = false;
  1816.       }
  1817.     }
  1818.     if (shouldChangeTimestampOffset) {
  1819.       this.sourceBuffers_.get(contentType).timestampOffset = timestampOffset;
  1820.     }
  1822.     // Fake an 'updateend' event to resolve the operation.
  1823.     this.onUpdateEnd_(contentType);
  1824.   }
  1826.   /**
  1827.    * Set the SourceBuffer's append window end.
  1828.    * @param {shaka.util.ManifestParserUtils.ContentType} contentType
  1829.    * @param {number} appendWindowStart
  1830.    * @param {number} appendWindowEnd
  1831.    * @private
  1832.    */
  1833.   setAppendWindow_(contentType, appendWindowStart, appendWindowEnd) {
  1834.     const sourceBuffer = this.sourceBuffers_.get(contentType);
  1835.     if (sourceBuffer.appendWindowEnd !== appendWindowEnd ||
  1836.         sourceBuffer.appendWindowStart !== appendWindowStart) {
  1837.       // You can't set start > end, so first set start to 0, then set the new
  1838.       // end, then set the new start.  That way, there are no intermediate
  1839.       // states which are invalid.
  1840.       sourceBuffer.appendWindowStart = 0;
  1841.       sourceBuffer.appendWindowEnd = appendWindowEnd;
  1842.       sourceBuffer.appendWindowStart = appendWindowStart;
  1843.     }
  1845.     // Fake an 'updateend' event to resolve the operation.
  1846.     this.onUpdateEnd_(contentType);
  1847.   }
  1849.   /**
  1850.    * @param {shaka.util.ManifestParserUtils.ContentType} contentType
  1851.    * @private
  1852.    */
  1853.   onError_(contentType) {
  1854.     const operation = this.queues_.get(contentType)[0];
  1855.     goog.asserts.assert(operation, 'Spurious error event!');
  1856.     goog.asserts.assert(!this.sourceBuffers_.get(contentType).updating,
  1857.         'SourceBuffer should not be updating on error!');
  1858.     const code = this.video_.error ? this.video_.error.code : 0;
  1859.     operation.p.reject(new shaka.util.Error(
  1860.         shaka.util.Error.Severity.CRITICAL,
  1861.         shaka.util.Error.Category.MEDIA,
  1862.         shaka.util.Error.Code.MEDIA_SOURCE_OPERATION_FAILED,
  1863.         code, operation.uri));
  1864.     // Do not pop from queue.  An 'updateend' event will fire next, and to
  1865.     // avoid synchronizing these two event handlers, we will allow that one to
  1866.     // pop from the queue as normal.  Note that because the operation has
  1867.     // already been rejected, the call to resolve() in the 'updateend' handler
  1868.     // will have no effect.
  1869.   }
  1871.   /**
  1872.    * @param {shaka.util.ManifestParserUtils.ContentType} contentType
  1873.    * @private
  1874.    */
  1875.   onUpdateEnd_(contentType) {
  1876.     // If we're reloading or have been destroyed, clear the queue for this
  1877.     // content type.
  1878.     if (this.reloadingMediaSource_ || this.destroyer_.destroyed()) {
  1879.       // Resolve any pending operations in this content type's queue
  1880.       const queue = this.queues_.get(contentType);
  1881.       if (queue && queue.length) {
  1882.         // Resolve the first operation that triggered this updateEnd
  1883.         const firstOperation = queue[0];
  1884.         if (firstOperation && firstOperation.p) {
  1885.           firstOperation.p.resolve();
  1886.         }
  1887.         // Clear the rest of the queue
  1888.         this.queues_.set(contentType, []);
  1889.       }
  1890.       return;
  1891.     }
  1892.     const operation = this.queues_.get(contentType)[0];
  1893.     goog.asserts.assert(operation, 'Spurious updateend event!');
  1894.     if (!operation) {
  1895.       return;
  1896.     }
  1897.     goog.asserts.assert(!this.sourceBuffers_.get(contentType).updating,
  1898.         'SourceBuffer should not be updating on updateend!');
  1899.     operation.p.resolve();
  1900.     this.popFromQueue_(contentType);
  1901.   }
  1903.   /**
  1904.    * Enqueue an operation and start it if appropriate.
  1905.    *
  1906.    * @param {shaka.util.ManifestParserUtils.ContentType} contentType
  1907.    * @param {function()} start
  1908.    * @param {?string} uri
  1909.    * @return {!Promise}
  1910.    * @private
  1911.    */
  1912.   enqueueOperation_(contentType, start, uri) {
  1913.     this.destroyer_.ensureNotDestroyed();
  1914.     const operation = {
  1915.       start: start,
  1916.       p: new shaka.util.PublicPromise(),
  1917.       uri,
  1918.     };
  1919.     this.queues_.get(contentType).push(operation);
  1921.     if (this.queues_.get(contentType).length == 1) {
  1922.       this.startOperation_(contentType);
  1923.     }
  1924.     return operation.p;
  1925.   }
  1927.   /**
  1928.    * Enqueue an operation which must block all other operations on all
  1929.    * SourceBuffers.
  1930.    *
  1931.    * @param {function():(Promise|undefined)} run
  1932.    * @return {!Promise}
  1933.    * @private
  1934.    */
  1935.   async enqueueBlockingOperation_(run) {
  1936.     this.destroyer_.ensureNotDestroyed();
  1938.     /** @type {!Array<!shaka.util.PublicPromise>} */
  1939.     const allWaiters = [];
  1940.     /** @type {!Array<!shaka.util.ManifestParserUtils.ContentType>} */
  1941.     const contentTypes = Array.from(this.sourceBuffers_.keys());
  1943.     // Enqueue a 'wait' operation onto each queue.
  1944.     // This operation signals its readiness when it starts.
  1945.     // When all wait operations are ready, the real operation takes place.
  1946.     for (const contentType of contentTypes) {
  1947.       const ready = new shaka.util.PublicPromise();
  1948.       const operation = {
  1949.         start: () => ready.resolve(),
  1950.         p: ready,
  1951.         uri: null,
  1952.       };
  1954.       const queue = this.queues_.get(contentType);
  1956.       queue.push(operation);
  1957.       allWaiters.push(ready);
  1959.       if (queue.length == 1) {
  1960.         operation.start();
  1961.       }
  1962.     }
  1964.     // Return a Promise to the real operation, which waits to begin until
  1965.     // there are no other in-progress operations on any SourceBuffers.
  1966.     try {
  1967.       await Promise.all(allWaiters);
  1968.     } catch (error) {
  1969.       // One of the waiters failed, which means we've been destroyed.
  1970.       goog.asserts.assert(
  1971.           this.destroyer_.destroyed(), 'Should be destroyed by now');
  1972.       // We haven't popped from the queue.  Canceled waiters have been removed
  1973.       // by destroy.  What's left now should just be resolved waiters.  In
  1974.       // uncompiled mode, we will maintain good hygiene and make sure the
  1975.       // assert at the end of destroy passes.  In compiled mode, the queues
  1976.       // are wiped in destroy.
  1977.       if (goog.DEBUG) {
  1978.         for (const contentType of contentTypes) {
  1979.           const queue = this.queues_.get(contentType);
  1980.           if (queue.length) {
  1981.             goog.asserts.assert(queue.length == 1,
  1982.                 'Should be at most one item in queue!');
  1983.             goog.asserts.assert(allWaiters.includes(queue[0].p),
  1984.                 'The item in queue should be one of our waiters!');
  1985.             queue.shift();
  1986.           }
  1987.         }
  1988.       }
  1989.       throw error;
  1990.     }
  1992.     if (goog.DEBUG) {
  1993.       // If we did it correctly, nothing is updating.
  1994.       for (const contentType of contentTypes) {
  1995.         goog.asserts.assert(
  1996.             this.sourceBuffers_.get(contentType).updating == false,
  1997.             'SourceBuffers should not be updating after a blocking op!');
  1998.       }
  1999.     }
  2001.     // Run the real operation, which can be asynchronous.
  2002.     try {
  2003.       await run();
  2004.     } catch (exception) {
  2005.       throw new shaka.util.Error(
  2006.           shaka.util.Error.Severity.CRITICAL,
  2007.           shaka.util.Error.Category.MEDIA,
  2008.           shaka.util.Error.Code.MEDIA_SOURCE_OPERATION_THREW,
  2009.           exception,
  2010.           this.video_.error || 'No error in the media element',
  2011.           null);
  2012.     } finally {
  2013.       // Unblock the queues.
  2014.       for (const contentType of contentTypes) {
  2015.         this.popFromQueue_(contentType);
  2016.       }
  2017.     }
  2018.   }
  2020.   /**
  2021.    * Pop from the front of the queue and start a new operation.
  2022.    * @param {shaka.util.ManifestParserUtils.ContentType} contentType
  2023.    * @private
  2024.    */
  2025.   popFromQueue_(contentType) {
  2026.     goog.asserts.assert(this.queues_.has(contentType), 'Queue should exist');
  2027.     // Remove the in-progress operation, which is now complete.
  2028.     this.queues_.get(contentType).shift();
  2029.     this.startOperation_(contentType);
  2030.   }
  2032.   /**
  2033.    * Starts the next operation in the queue.
  2034.    * @param {shaka.util.ManifestParserUtils.ContentType} contentType
  2035.    * @private
  2036.    */
  2037.   startOperation_(contentType) {
  2038.     // Retrieve the next operation, if any, from the queue and start it.
  2039.     const next = this.queues_.get(contentType)[0];
  2040.     if (next) {
  2041.       try {
  2042.         next.start();
  2043.       } catch (exception) {
  2044.         if (exception.name == 'QuotaExceededError') {
  2045.           next.p.reject(new shaka.util.Error(
  2046.               shaka.util.Error.Severity.CRITICAL,
  2047.               shaka.util.Error.Category.MEDIA,
  2048.               shaka.util.Error.Code.QUOTA_EXCEEDED_ERROR,
  2049.               contentType));
  2050.         } else if (!this.isStreamingAllowed()) {
  2051.           next.p.reject(new shaka.util.Error(
  2052.               shaka.util.Error.Severity.CRITICAL,
  2053.               shaka.util.Error.Category.MEDIA,
  2054.               shaka.util.Error.Code.STREAMING_NOT_ALLOWED,
  2055.               contentType));
  2056.         } else {
  2057.           next.p.reject(new shaka.util.Error(
  2058.               shaka.util.Error.Severity.CRITICAL,
  2059.               shaka.util.Error.Category.MEDIA,
  2060.               shaka.util.Error.Code.MEDIA_SOURCE_OPERATION_THREW,
  2061.               exception,
  2062.               this.video_.error || 'No error in the media element',
  2063.               next.uri));
  2064.         }
  2065.         this.popFromQueue_(contentType);
  2066.       }
  2067.     }
  2068.   }
  2070.   /**
  2071.    * @return {!shaka.extern.TextDisplayer}
  2072.    */
  2073.   getTextDisplayer() {
  2074.     goog.asserts.assert(
  2075.         this.textDisplayer_,
  2076.         'TextDisplayer should only be null when this is destroyed');
  2078.     return this.textDisplayer_;
  2079.   }
  2081.   /**
  2082.    * @param {!shaka.extern.TextDisplayer} textDisplayer
  2083.    */
  2084.   setTextDisplayer(textDisplayer) {
  2085.     this.textDisplayer_ = textDisplayer;
  2086.     if (this.textEngine_) {
  2087.       this.textEngine_.setDisplayer(textDisplayer);
  2088.     }
  2089.   }
  2091.   /**
  2092.    * @param {boolean} segmentRelativeVttTiming
  2093.    */
  2094.   setSegmentRelativeVttTiming(segmentRelativeVttTiming) {
  2095.     this.segmentRelativeVttTiming_ = segmentRelativeVttTiming;
  2096.   }
  2098.   /**
  2099.    * Apply platform-specific transformations to this segment to work around
  2100.    * issues in the platform.
  2101.    *
  2102.    * @param {shaka.extern.Stream} stream
  2103.    * @param {!BufferSource} segment
  2104.    * @param {?shaka.media.SegmentReference} reference
  2105.    * @param {shaka.util.ManifestParserUtils.ContentType} contentType
  2106.    * @return {!BufferSource}
  2107.    * @private
  2108.    */
  2109.   workAroundBrokenPlatforms_(stream, segment, reference, contentType) {
  2110.     const ContentType = shaka.util.ManifestParserUtils.ContentType;
  2112.     const isMp4 = shaka.util.MimeUtils.getContainerType(
  2113.         this.sourceBufferTypes_.get(contentType)) == 'mp4';
  2114.     if (!isMp4) {
  2115.       return segment;
  2116.     }
  2118.     const isInitSegment = reference === null;
  2119.     const encryptionExpected = this.expectedEncryption_.get(contentType);
  2120.     const keySystem = this.playerInterface_.getKeySystem();
  2121.     let isEncrypted = false;
  2122.     if (reference && reference.initSegmentReference) {
  2123.       isEncrypted = reference.initSegmentReference.encrypted;
  2124.     }
  2125.     const uri = reference ? reference.getUris()[0] : null;
  2126.     const device = shaka.device.DeviceFactory.getDevice();
  2128.     if (this.config_.correctEc3Enca &&
  2129.       isInitSegment &&
  2130.       contentType === ContentType.AUDIO) {
  2131.       segment = shaka.media.ContentWorkarounds.correctEnca(segment);
  2132.     }
  2134.     // If:
  2135.     //   1. the configuration tells to insert fake encryption,
  2136.     //   2. and this is an init segment or media segment,
  2137.     //   3. and encryption is expected,
  2138.     //   4. and the platform requires encryption in all init or media segments
  2139.     //      of current content type,
  2140.     // then insert fake encryption metadata for init segments that lack it.
  2141.     // The MP4 requirement is because we can currently only do this
  2142.     // transformation on MP4 containers.
  2143.     // See: https://github.com/shaka-project/shaka-player/issues/2759
  2144.     if (this.config_.insertFakeEncryptionInInit && encryptionExpected &&
  2145.         device.requiresEncryptionInfoInAllInitSegments(keySystem,
  2146.             contentType)) {
  2147.       if (isInitSegment) {
  2148.         shaka.log.debug('Forcing fake encryption information in init segment.');
  2149.         segment =
  2150.             shaka.media.ContentWorkarounds.fakeEncryption(stream, segment, uri);
  2151.       } else if (!isEncrypted && device.requiresTfhdFix(contentType)) {
  2152.         shaka.log.debug(
  2153.             'Forcing fake encryption information in media segment.');
  2154.         segment = shaka.media.ContentWorkarounds.fakeMediaEncryption(segment);
  2155.       }
  2156.     }
  2158.     if (isInitSegment && device.requiresEC3InitSegments()) {
  2159.       shaka.log.debug('Forcing fake EC-3 information in init segment.');
  2160.       segment = shaka.media.ContentWorkarounds.fakeEC3(segment);
  2161.     }
  2163.     return segment;
  2164.   }
  2166.   /**
  2167.    * Prepare the SourceBuffer to parse a potentially new type or codec.
  2168.    *
  2169.    * @param {shaka.util.ManifestParserUtils.ContentType} contentType
  2170.    * @param {string} mimeType
  2171.    * @param {?shaka.extern.Transmuxer} transmuxer
  2172.    * @private
  2173.    */
  2174.   change_(contentType, mimeType, transmuxer) {
  2175.     const ContentType = shaka.util.ManifestParserUtils.ContentType;
  2176.     if (contentType === ContentType.TEXT) {
  2177.       shaka.log.debug(`Change not supported for ${contentType}`);
  2178.       return;
  2179.     }
  2180.     const sourceBuffer = this.sourceBufferTypes_.get(contentType);
  2181.     shaka.log.debug(
  2182.         `Change Type: ${sourceBuffer} -> ${mimeType}`);
  2183.     if (shaka.media.Capabilities.isChangeTypeSupported()) {
  2184.       if (this.transmuxers_.has(contentType)) {
  2185.         this.transmuxers_.get(contentType).destroy();
  2186.         this.transmuxers_.delete(contentType);
  2187.       }
  2188.       if (transmuxer) {
  2189.         this.transmuxers_.set(contentType, transmuxer);
  2190.       }
  2191.       const type = this.addExtraFeaturesToMimeType_(mimeType);
  2192.       this.sourceBuffers_.get(contentType).changeType(type);
  2193.       this.sourceBufferTypes_.set(contentType, mimeType);
  2194.     } else {
  2195.       shaka.log.debug('Change Type not supported');
  2196.     }
  2198.     // Fake an 'updateend' event to resolve the operation.
  2199.     this.onUpdateEnd_(contentType);
  2200.   }
  2202.   /**
  2203.    * Enqueue an operation to prepare the SourceBuffer to parse a potentially new
  2204.    * type or codec.
  2205.    *
  2206.    * @param {shaka.util.ManifestParserUtils.ContentType} contentType
  2207.    * @param {string} mimeType
  2208.    * @param {?shaka.extern.Transmuxer} transmuxer
  2209.    * @return {!Promise}
  2210.    */
  2211.   changeType(contentType, mimeType, transmuxer) {
  2212.     return this.enqueueOperation_(
  2213.         contentType,
  2214.         () => this.change_(contentType, mimeType, transmuxer),
  2215.         null);
  2216.   }
  2218.   /**
  2219.    * Resets the MediaSource and re-adds source buffers due to codec mismatch
  2220.    *
  2221.    * @param {!Map<shaka.util.ManifestParserUtils.ContentType,
  2222.    *               shaka.extern.Stream>} streamsByType
  2223.    * @private
  2224.    */
  2225.   async reset_(streamsByType) {
  2226.     if (this.reloadingMediaSource_ || this.usingRemotePlayback_) {
  2227.       return;
  2228.     }
  2229.     const ContentType = shaka.util.ManifestParserUtils.ContentType;
  2230.     this.reloadingMediaSource_ = true;
  2231.     this.needSplitMuxedContent_ = false;
  2232.     const currentTime = this.video_.currentTime;
  2234.     // When codec switching if the user is currently paused we don't want
  2235.     // to trigger a play when switching codec.
  2236.     // Playing can also end up in a paused state after a codec switch
  2237.     // so we need to remember the current states.
  2238.     const previousAutoPlayState = this.video_.autoplay;
  2239.     if (!this.video_.paused) {
  2240.       this.playAfterReset_ = true;
  2241.     }
  2242.     if (this.playbackHasBegun_) {
  2243.       // Only set autoplay to false if the video playback has already begun.
  2244.       // When a codec switch happens before playback has begun this can cause
  2245.       // autoplay not to work as expected.
  2246.       this.video_.autoplay = false;
  2247.     }
  2249.     try {
  2250.       this.eventManager_.removeAll();
  2252.       for (const transmuxer of this.transmuxers_.values()) {
  2253.         transmuxer.destroy();
  2254.       }
  2255.       for (const sourceBuffer of this.sourceBuffers_.values()) {
  2256.         try {
  2257.           this.mediaSource_.removeSourceBuffer(sourceBuffer);
  2258.         } catch (e) {
  2259.           shaka.log.debug('Exception on removeSourceBuffer', e);
  2260.         }
  2261.       }
  2262.       this.transmuxers_.clear();
  2263.       this.sourceBuffers_.clear();
  2265.       const previousDuration = this.mediaSource_.duration;
  2266.       this.mediaSourceOpen_ = new shaka.util.PublicPromise();
  2267.       this.mediaSource_ = this.createMediaSource(this.mediaSourceOpen_);
  2268.       await this.mediaSourceOpen_;
  2269.       if (!isNaN(previousDuration) && previousDuration) {
  2270.         this.mediaSource_.duration = previousDuration;
  2271.       } else if (!isNaN(this.lastDuration_) && this.lastDuration_) {
  2272.         this.mediaSource_.duration = this.lastDuration_;
  2273.       }
  2275.       const sourceBufferAdded = new shaka.util.PublicPromise();
  2276.       const sourceBuffers =
  2277.         /** @type {EventTarget} */(this.mediaSource_.sourceBuffers);
  2279.       const totalOfBuffers = streamsByType.size;
  2280.       let numberOfSourceBufferAdded = 0;
  2281.       const onSourceBufferAdded = () => {
  2282.         numberOfSourceBufferAdded++;
  2283.         if (numberOfSourceBufferAdded === totalOfBuffers) {
  2284.           sourceBufferAdded.resolve();
  2285.           this.eventManager_.unlisten(sourceBuffers, 'addsourcebuffer',
  2286.               onSourceBufferAdded);
  2287.         }
  2288.       };
  2290.       this.eventManager_.listen(sourceBuffers, 'addsourcebuffer',
  2291.           onSourceBufferAdded);
  2293.       for (const contentType of streamsByType.keys()) {
  2294.         const stream = streamsByType.get(contentType);
  2295.         this.initSourceBuffer_(contentType, stream, stream.codecs);
  2296.       }
  2297.       const audio = streamsByType.get(ContentType.AUDIO);
  2298.       if (audio && audio.isAudioMuxedInVideo) {
  2299.         this.needSplitMuxedContent_ = true;
  2300.       }
  2301.       if (this.needSplitMuxedContent_ && !this.queues_.has(ContentType.AUDIO)) {
  2302.         this.queues_.set(ContentType.AUDIO, []);
  2303.       }
  2305.       // Fake a seek to catchup the playhead.
  2306.       this.video_.currentTime = currentTime;
  2308.       await sourceBufferAdded;
  2309.     } finally {
  2310.       this.reloadingMediaSource_ = false;
  2312.       this.destroyer_.ensureNotDestroyed();
  2314.       this.eventManager_.listenOnce(this.video_, 'canplaythrough', () => {
  2315.         // Don't use ensureNotDestroyed() from this event listener, because
  2316.         // that results in an uncaught exception.  Instead, just check the
  2317.         // flag.
  2318.         if (this.destroyer_.destroyed()) {
  2319.           return;
  2320.         }
  2322.         this.video_.autoplay = previousAutoPlayState;
  2323.         if (this.playAfterReset_) {
  2324.           this.playAfterReset_ = false;
  2325.           this.video_.play();
  2326.         }
  2327.       });
  2328.     }
  2329.   }
  2331.   /**
  2332.    * Resets the Media Source
  2333.    * @param {!Map<shaka.util.ManifestParserUtils.ContentType,
  2334.    *               shaka.extern.Stream>} streamsByType
  2335.    * @return {!Promise}
  2336.    */
  2337.   reset(streamsByType) {
  2338.     return this.enqueueBlockingOperation_(
  2339.         () => this.reset_(streamsByType));
  2340.   }
  2342.   /**
  2343.    * @param {shaka.util.ManifestParserUtils.ContentType} contentType
  2344.    * @param {string} mimeType
  2345.    * @param {string} codecs
  2346.    * @return {{transmuxer: ?shaka.extern.Transmuxer,
  2347.    *          transmuxerMuxed: boolean, basicType: string, codec: string,
  2348.    *          mimeType: string}}
  2349.    * @private
  2350.    */
  2351.   getRealInfo_(contentType, mimeType, codecs) {
  2352.     const ContentType = shaka.util.ManifestParserUtils.ContentType;
  2353.     const MimeUtils = shaka.util.MimeUtils;
  2354.     /** @type {?shaka.extern.Transmuxer} */
  2355.     let transmuxer;
  2356.     let transmuxerMuxed = false;
  2357.     const audioCodec = shaka.util.ManifestParserUtils.guessCodecsSafe(
  2358.         ContentType.AUDIO, (codecs || '').split(','));
  2359.     const videoCodec = shaka.util.ManifestParserUtils.guessCodecsSafe(
  2360.         ContentType.VIDEO, (codecs || '').split(','));
  2361.     let codec = videoCodec;
  2362.     if (contentType == ContentType.AUDIO) {
  2363.       codec = audioCodec;
  2364.     }
  2365.     if (!codec) {
  2366.       codec = codecs;
  2367.     }
  2368.     let newMimeType = shaka.util.MimeUtils.getFullType(mimeType, codec);
  2369.     let needTransmux = this.config_.forceTransmux;
  2370.     if (!shaka.media.Capabilities.isTypeSupported(newMimeType) ||
  2371.         (!this.sequenceMode_ &&
  2372.         shaka.util.MimeUtils.RAW_FORMATS.includes(newMimeType))) {
  2373.       needTransmux = true;
  2374.     }
  2375.     const TransmuxerEngine = shaka.transmuxer.TransmuxerEngine;
  2376.     if (needTransmux) {
  2377.       const newMimeTypeWithAllCodecs =
  2378.           shaka.util.MimeUtils.getFullTypeWithAllCodecs(mimeType, codec);
  2379.       const transmuxerPlugin =
  2380.           TransmuxerEngine.findTransmuxer(newMimeTypeWithAllCodecs);
  2381.       if (transmuxerPlugin) {
  2382.         transmuxer = transmuxerPlugin();
  2383.         if (audioCodec && videoCodec) {
  2384.           transmuxerMuxed = true;
  2385.         }
  2386.         newMimeType =
  2387.             transmuxer.convertCodecs(contentType, newMimeTypeWithAllCodecs);
  2388.       }
  2389.     }
  2391.     const newCodec = MimeUtils.getNormalizedCodec(
  2392.         MimeUtils.getCodecs(newMimeType));
  2393.     const newBasicType = MimeUtils.getBasicType(newMimeType);
  2394.     return {
  2395.       transmuxer,
  2396.       transmuxerMuxed,
  2397.       basicType: newBasicType,
  2398.       codec: newCodec,
  2399.       mimeType: newMimeType,
  2400.     };
  2401.   }
  2403.   /**
  2404.    * Codec switch if necessary, this will not resolve until the codec
  2405.    * switch is over.
  2406.    * @param {shaka.util.ManifestParserUtils.ContentType} contentType
  2407.    * @param {string} mimeType
  2408.    * @param {string} codecs
  2409.    * @param {!Map<shaka.util.ManifestParserUtils.ContentType,
  2410.    *               shaka.extern.Stream>} streamsByType
  2411.    * @return {!Promise<boolean>} true if there was a codec switch,
  2412.    *                              false otherwise.
  2413.    * @private
  2414.    */
  2415.   async codecSwitchIfNecessary_(contentType, mimeType, codecs, streamsByType) {
  2416.     const ContentType = shaka.util.ManifestParserUtils.ContentType;
  2417.     if (contentType == ContentType.TEXT) {
  2418.       return false;
  2419.     }
  2420.     const MimeUtils = shaka.util.MimeUtils;
  2421.     const currentCodec = MimeUtils.getNormalizedCodec(
  2422.         MimeUtils.getCodecs(this.sourceBufferTypes_.get(contentType)));
  2423.     const currentBasicType = MimeUtils.getBasicType(
  2424.         this.sourceBufferTypes_.get(contentType));
  2426.     const realInfo = this.getRealInfo_(contentType, mimeType, codecs);
  2427.     const transmuxer = realInfo.transmuxer;
  2428.     const transmuxerMuxed = realInfo.transmuxerMuxed;
  2429.     const newBasicType = realInfo.basicType;
  2430.     const newCodec = realInfo.codec;
  2431.     const newMimeType = realInfo.mimeType;
  2433.     let muxedContentCheck = true;
  2434.     if (transmuxerMuxed &&
  2435.         this.sourceBufferTypes_.has(ContentType.AUDIO)) {
  2436.       const muxedRealInfo =
  2437.           this.getRealInfo_(ContentType.AUDIO, mimeType, codecs);
  2438.       const muxedCurrentCodec = MimeUtils.getNormalizedCodec(
  2439.           MimeUtils.getCodecs(this.sourceBufferTypes_.get(ContentType.AUDIO)));
  2440.       const muxedCurrentBasicType = MimeUtils.getBasicType(
  2441.           this.sourceBufferTypes_.get(ContentType.AUDIO));
  2442.       muxedContentCheck = muxedCurrentCodec == muxedRealInfo.codec &&
  2443.         muxedCurrentBasicType == muxedRealInfo.basicType;
  2444.       if (muxedRealInfo.transmuxer) {
  2445.         muxedRealInfo.transmuxer.destroy();
  2446.       }
  2447.     }
  2449.     // Current/new codecs base and basic type match then no need to switch
  2450.     if (currentCodec === newCodec && currentBasicType === newBasicType &&
  2451.         muxedContentCheck) {
  2452.       if (this.transmuxers_.has(contentType) && !transmuxer) {
  2453.         this.transmuxers_.get(contentType).destroy();
  2454.         this.transmuxers_.delete(contentType);
  2455.       } else if (!this.transmuxers_.has(contentType) && transmuxer) {
  2456.         this.transmuxers_.set(contentType, transmuxer);
  2457.       } else if (transmuxer) {
  2458.         // Compare if the transmuxer is different
  2459.         if (this.transmuxers_.has(contentType) &&
  2460.             this.transmuxers_.get(contentType).transmux !=
  2461.               transmuxer.transmux) {
  2462.           this.transmuxers_.get(contentType).destroy();
  2463.           this.transmuxers_.delete(contentType);
  2464.           this.transmuxers_.set(contentType, transmuxer);
  2465.         } else {
  2466.           transmuxer.destroy();
  2467.         }
  2468.       }
  2469.       return false;
  2470.     }
  2472.     let allowChangeType = true;
  2473.     if (this.needSplitMuxedContent_ || (transmuxerMuxed &&
  2474.         transmuxer && !this.transmuxers_.has(contentType))) {
  2475.       allowChangeType = false;
  2476.     }
  2478.     if (allowChangeType && this.config_.codecSwitchingStrategy ===
  2479.         shaka.config.CodecSwitchingStrategy.SMOOTH &&
  2480.           shaka.media.Capabilities.isChangeTypeSupported()) {
  2481.       await this.changeType(contentType, newMimeType, transmuxer);
  2482.     } else {
  2483.       if (transmuxer) {
  2484.         transmuxer.destroy();
  2485.       }
  2486.       await this.reset(streamsByType);
  2487.     }
  2488.     return true;
  2489.   }
  2491.   /**
  2492.    * Returns true if it's necessary codec switch to load the new stream.
  2493.    *
  2494.    * @param {shaka.util.ManifestParserUtils.ContentType} contentType
  2495.    * @param {string} refMimeType
  2496.    * @param {string} refCodecs
  2497.    * @return {boolean}
  2498.    * @private
  2499.    */
  2500.   isCodecSwitchNecessary_(contentType, refMimeType, refCodecs) {
  2501.     if (contentType == shaka.util.ManifestParserUtils.ContentType.TEXT) {
  2502.       return false;
  2503.     }
  2504.     const MimeUtils = shaka.util.MimeUtils;
  2505.     const currentCodec = MimeUtils.getNormalizedCodec(
  2506.         MimeUtils.getCodecs(this.sourceBufferTypes_.get(contentType)));
  2507.     const currentBasicType = MimeUtils.getBasicType(
  2508.         this.sourceBufferTypes_.get(contentType));
  2510.     let newMimeType = shaka.util.MimeUtils.getFullType(refMimeType, refCodecs);
  2511.     let needTransmux = this.config_.forceTransmux;
  2512.     if (!shaka.media.Capabilities.isTypeSupported(newMimeType) ||
  2513.         (!this.sequenceMode_ &&
  2514.         shaka.util.MimeUtils.RAW_FORMATS.includes(newMimeType))) {
  2515.       needTransmux = true;
  2516.     }
  2517.     const newMimeTypeWithAllCodecs =
  2518.         shaka.util.MimeUtils.getFullTypeWithAllCodecs(
  2519.             refMimeType, refCodecs);
  2520.     const TransmuxerEngine = shaka.transmuxer.TransmuxerEngine;
  2521.     if (needTransmux) {
  2522.       const transmuxerPlugin =
  2523.           TransmuxerEngine.findTransmuxer(newMimeTypeWithAllCodecs);
  2524.       if (transmuxerPlugin) {
  2525.         const transmuxer = transmuxerPlugin();
  2526.         newMimeType =
  2527.             transmuxer.convertCodecs(contentType, newMimeTypeWithAllCodecs);
  2528.         transmuxer.destroy();
  2529.       }
  2530.     }
  2532.     const newCodec = MimeUtils.getNormalizedCodec(
  2533.         MimeUtils.getCodecs(newMimeType));
  2534.     const newBasicType = MimeUtils.getBasicType(newMimeType);
  2536.     return currentCodec !== newCodec || currentBasicType !== newBasicType;
  2537.   }
  2539.   /**
  2540.    * Returns true if it's necessary reset the media source to load the
  2541.    * new stream.
  2542.    *
  2543.    * @param {shaka.util.ManifestParserUtils.ContentType} contentType
  2544.    * @param {string} mimeType
  2545.    * @param {string} codecs
  2546.    * @return {boolean}
  2547.    */
  2548.   isResetMediaSourceNecessary(contentType, mimeType, codecs) {
  2549.     if (!this.isCodecSwitchNecessary_(contentType, mimeType, codecs)) {
  2550.       return false;
  2551.     }
  2553.     return this.config_.codecSwitchingStrategy !==
  2554.         shaka.config.CodecSwitchingStrategy.SMOOTH ||
  2555.         !shaka.media.Capabilities.isChangeTypeSupported() ||
  2556.         this.needSplitMuxedContent_;
  2557.   }
  2559.   /**
  2560.    * Update LCEVC Decoder object when ready for LCEVC Decode.
  2561.    * @param {?shaka.lcevc.Dec} lcevcDec
  2562.    */
  2563.   updateLcevcDec(lcevcDec) {
  2564.     this.lcevcDec_ = lcevcDec;
  2565.   }
  2567.   /**
  2568.    * @param {string} mimeType
  2569.    * @return {string}
  2570.    * @private
  2571.    */
  2572.   addExtraFeaturesToMimeType_(mimeType) {
  2573.     const extraFeatures = this.config_.addExtraFeaturesToSourceBuffer(mimeType);
  2574.     const extendedType = mimeType + extraFeatures;
  2575.     shaka.log.debug('Using full mime type', extendedType);
  2577.     return extendedType;
  2578.   }
  2579. };
  2582. /**
  2583.  * Internal reference to window.URL.createObjectURL function to avoid
  2584.  * compatibility issues with other libraries and frameworks such as React
  2585.  * Native. For use in unit tests only, not meant for external use.
  2586.  *
  2587.  * @type {function(?):string}
  2588.  */
  2589. shaka.media.MediaSourceEngine.createObjectURL = window.URL.createObjectURL;
  2592. /**
  2593.  * @typedef {{
  2594.  *   start: function(),
  2595.  *   p: !shaka.util.PublicPromise,
  2596.  *   uri: ?string
  2597.  * }}
  2598.  *
  2599.  * @summary An operation in queue.
  2600.  * @property {function()} start
  2601.  *   The function which starts the operation.
  2602.  * @property {!shaka.util.PublicPromise} p
  2603.  *   The PublicPromise which is associated with this operation.
  2604.  * @property {?string} uri
  2605.  *   A segment URI (if any) associated with this operation.
  2606.  */
  2607. shaka.media.MediaSourceEngine.Operation;
  2610. /**
  2611.  * @enum {string}
  2612.  * @private
  2613.  */
  2614. shaka.media.MediaSourceEngine.SourceBufferMode_ = {
  2615.   SEQUENCE: 'sequence',
  2616.   SEGMENTS: 'segments',
  2617. };
  2620. /**
  2621.  * @typedef {{
  2622.  *   getKeySystem: function():?string,
  2623.  *   onMetadata: function(!Array<shaka.extern.ID3Metadata>, number, ?number),
  2624.  *   onEmsg: function(!shaka.extern.EmsgInfo),
  2625.  *   onEvent: function(!Event),
  2626.  *   onManifestUpdate: function()
  2627.  * }}
  2628.  *
  2629.  * @summary Player interface
  2630.  * @property {function():?string} getKeySystem
  2631.  *   Gets currently used key system or null if not used.
  2632.  * @property {function(
  2633.  *     !Array<shaka.extern.ID3Metadata>, number, ?number)} onMetadata
  2634.  *   Callback to use when metadata arrives.
  2635.  * @property {function(!shaka.extern.EmsgInfo)} onEmsg
  2636.  *   Callback to use when EMSG arrives.
  2637.  * @property {function(!Event)} onEvent
  2638.  *   Called when an event occurs that should be sent to the app.
  2639.  * @property {function()} onManifestUpdate
  2640.  *   Called when an embedded 'emsg' box should trigger a manifest update.
  2641.  */
  2642. shaka.media.MediaSourceEngine.PlayerInterface;