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.media.Capabilities');
  13. goog.require('shaka.media.ContentWorkarounds');
  14. goog.require('shaka.media.ClosedCaptionParser');
  15. goog.require('shaka.media.IClosedCaptionParser');
  16. goog.require('shaka.media.ManifestParser');
  17. goog.require('shaka.media.SegmentReference');
  18. goog.require('shaka.media.TimeRangesUtils');
  19. goog.require('shaka.text.TextEngine');
  20. goog.require('shaka.transmuxer.TransmuxerEngine');
  21. goog.require('shaka.util.BufferUtils');
  22. goog.require('shaka.util.Destroyer');
  23. goog.require('shaka.util.Error');
  24. goog.require('shaka.util.EventManager');
  25. goog.require('shaka.util.Functional');
  26. goog.require('shaka.util.IDestroyable');
  27. goog.require('shaka.util.Id3Utils');
  28. goog.require('shaka.util.ManifestParserUtils');
  29. goog.require('shaka.util.MimeUtils');
  30. goog.require('shaka.util.Mp4BoxParsers');
  31. goog.require('shaka.util.Mp4Parser');
  32. goog.require('shaka.util.Platform');
  33. goog.require('shaka.util.PublicPromise');
  34. goog.require('shaka.util.StreamUtils');
  35. goog.require('shaka.util.TsParser');
  36. goog.require('shaka.lcevc.Dec');
  39. /**
  40.  * @summary
  41.  * MediaSourceEngine wraps all operations on MediaSource and SourceBuffers.
  42.  * All asynchronous operations return a Promise, and all operations are
  43.  * internally synchronized and serialized as needed.  Operations that can
  44.  * be done in parallel will be done in parallel.
  45.  *
  46.  * @implements {shaka.util.IDestroyable}
  47.  */
  48. shaka.media.MediaSourceEngine = class {
  49.   /**
  50.    * @param {HTMLMediaElement} video The video element, whose source is tied to
  51.    *   MediaSource during the lifetime of the MediaSourceEngine.
  52.    * @param {!shaka.extern.TextDisplayer} textDisplayer
  53.    *    The text displayer that will be used with the text engine.
  54.    *    MediaSourceEngine takes ownership of the displayer. When
  55.    *    MediaSourceEngine is destroyed, it will destroy the displayer.
  56.    * @param {!function(!Array.<shaka.extern.ID3Metadata>, number, ?number)=}
  57.    *    onMetadata
  58.    * @param {?shaka.lcevc.Dec} [lcevcDec] Optional -  LCEVC Decoder Object
  59.    *
  60.    */
  61.   constructor(video, textDisplayer, onMetadata, lcevcDec) {
  62.     /** @private {HTMLMediaElement} */
  63.     this.video_ = video;
  65.     /** @private {?shaka.extern.MediaSourceConfiguration} */
  66.     this.config_ = null;
  68.     /** @private {shaka.extern.TextDisplayer} */
  69.     this.textDisplayer_ = textDisplayer;
  71.     /** @private {!Object.<shaka.util.ManifestParserUtils.ContentType,
  72.                            SourceBuffer>} */
  73.     this.sourceBuffers_ = {};
  75.     /** @private {!Object.<shaka.util.ManifestParserUtils.ContentType,
  76.                            string>} */
  77.     this.sourceBufferTypes_ = {};
  80.     /** @private {!Object.<shaka.util.ManifestParserUtils.ContentType,
  81.                            boolean>} */
  82.     this.expectedEncryption_ = {};
  84.     /** @private {shaka.text.TextEngine} */
  85.     this.textEngine_ = null;
  87.     /** @private {boolean} */
  88.     this.segmentRelativeVttTiming_ = false;
  90.     const onMetadataNoOp = (metadata, timestampOffset, segmentEnd) => {};
  92.     /** @private {!function(!Array.<shaka.extern.ID3Metadata>,
  93.                     number, ?number)} */
  94.     this.onMetadata_ = onMetadata || onMetadataNoOp;
  96.     /** @private {?shaka.lcevc.Dec} */
  97.     this.lcevcDec_ = lcevcDec || null;
  99.     /**
  100.      * @private {!Object.<string,
  101.      *                    !Array.<shaka.media.MediaSourceEngine.Operation>>}
  102.      */
  103.     this.queues_ = {};
  105.     /** @private {shaka.util.EventManager} */
  106.     this.eventManager_ = new shaka.util.EventManager();
  108.     /** @private {!Object.<string, !shaka.extern.Transmuxer>} */
  109.     this.transmuxers_ = {};
  111.     /** @private {?shaka.media.IClosedCaptionParser} */
  112.     this.captionParser_ = null;
  114.     /** @private {!shaka.util.PublicPromise} */
  115.     this.mediaSourceOpen_ = new shaka.util.PublicPromise();
  117.     /** @private {string} */
  118.     this.url_ = '';
  120.     /** @private {boolean} */
  121.     this.playbackHasBegun_ = false;
  123.     /** @private {(MediaSource|ManagedMediaSource)} */
  124.     this.mediaSource_ = this.createMediaSource(this.mediaSourceOpen_);
  126.     /** @private {boolean} */
  127.     this.reloadingMediaSource_ = false;
  129.     /** @type {!shaka.util.Destroyer} */
  130.     this.destroyer_ = new shaka.util.Destroyer(() => this.doDestroy_());
  132.     /** @private {boolean} */
  133.     this.sequenceMode_ = false;
  135.     /** @private {string} */
  136.     this.manifestType_ = shaka.media.ManifestParser.UNKNOWN;
  138.     /** @private {boolean} */
  139.     this.ignoreManifestTimestampsInSegmentsMode_ = false;
  141.     /** @private {boolean} */
  142.     this.attemptTimestampOffsetCalculation_ = false;
  144.     /** @private {!shaka.util.PublicPromise.<number>} */
  145.     this.textSequenceModeOffset_ = new shaka.util.PublicPromise();
  147.     /** @private {boolean} */
  148.     this.needSplitMuxedContent_ = false;
  150.     /** @private {boolean} */
  151.     this.streamingAllowed_ = true;
  153.     /** @private {?number} */
  154.     this.lastDuration_ = null;
  156.     /** @private {?shaka.util.TsParser} */
  157.     this.tsParser_ = null;
  158.   }
  160.   /**
  161.    * Create a MediaSource object, attach it to the video element, and return it.
  162.    * Resolves the given promise when the MediaSource is ready.
  163.    *
  164.    * Replaced by unit tests.
  165.    *
  166.    * @param {!shaka.util.PublicPromise} p
  167.    * @return {!(MediaSource|ManagedMediaSource)}
  168.    */
  169.   createMediaSource(p) {
  170.     if (window.ManagedMediaSource) {
  171.       this.video_.disableRemotePlayback = true;
  173.       const mediaSource = new ManagedMediaSource();
  175.       this.eventManager_.listen(
  176.           mediaSource, 'startstreaming', () => {
  177.             this.streamingAllowed_ = true;
  178.           });
  180.       this.eventManager_.listen(
  181.           mediaSource, 'endstreaming', () => {
  182.             this.streamingAllowed_ = false;
  183.           });
  185.       this.eventManager_.listenOnce(
  186.           mediaSource, 'sourceopen', () => this.onSourceOpen_(p));
  188.       // Correctly set when playback has begun.
  189.       this.eventManager_.listenOnce(this.video_, 'playing', () => {
  190.         this.playbackHasBegun_ = true;
  191.       });
  193.       this.url_ = shaka.media.MediaSourceEngine.createObjectURL(mediaSource);
  195.       this.video_.src = this.url_;
  197.       return mediaSource;
  198.     } else {
  199.       const mediaSource = new MediaSource();
  201.       // Set up MediaSource on the video element.
  202.       this.eventManager_.listenOnce(
  203.           mediaSource, 'sourceopen', () => this.onSourceOpen_(p));
  205.       // Correctly set when playback has begun.
  206.       this.eventManager_.listenOnce(this.video_, 'playing', () => {
  207.         this.playbackHasBegun_ = true;
  208.       });
  210.       // Store the object URL for releasing it later.
  211.       this.url_ = shaka.media.MediaSourceEngine.createObjectURL(mediaSource);
  213.       this.video_.src = this.url_;
  215.       return mediaSource;
  216.     }
  217.   }
  219.   /**
  220.    * @param {shaka.util.PublicPromise} p
  221.    * @private
  222.    */
  223.   onSourceOpen_(p) {
  224.     goog.asserts.assert(this.url_, 'Must have object URL');
  226.     // Release the object URL that was previously created, to prevent memory
  227.     // leak.
  228.     // createObjectURL creates a strong reference to the MediaSource object
  229.     // inside the browser.  Setting the src of the video then creates another
  230.     // reference within the video element.  revokeObjectURL will remove the
  231.     // strong reference to the MediaSource object, and allow it to be
  232.     // garbage-collected later.
  233.     URL.revokeObjectURL(this.url_);
  234.     p.resolve();
  235.   }
  237.   /**
  238.    * Checks if a certain type is supported.
  239.    *
  240.    * @param {shaka.extern.Stream} stream
  241.    * @param {shaka.util.ManifestParserUtils.ContentType} contentType
  242.    * @return {!Promise.<boolean>}
  243.    */
  244.   static async isStreamSupported(stream, contentType) {
  245.     if (stream.createSegmentIndex) {
  246.       await stream.createSegmentIndex();
  247.     }
  248.     if (!stream.segmentIndex) {
  249.       return false;
  250.     }
  251.     if (stream.segmentIndex.isEmpty()) {
  252.       return true;
  253.     }
  254.     const MimeUtils = shaka.util.MimeUtils;
  255.     const TransmuxerEngine = shaka.transmuxer.TransmuxerEngine;
  256.     const ContentType = shaka.util.ManifestParserUtils.ContentType;
  257.     const StreamUtils = shaka.util.StreamUtils;
  258.     const seenCombos = new Set();
  259.     // Check each combination of mimeType and codecs within the segment index.
  260.     // Unfortunately we cannot use fullMimeTypes, as we ALSO need to check the
  261.     // getFullTypeWithAllCodecs (for the sake of the transmuxer) and we have no
  262.     // way of going from a full mimeType to a full mimeType with all codecs.
  263.     // As this function is only called in debug mode, a little inefficiency is
  264.     // acceptable.
  265.     for (const ref of stream.segmentIndex) {
  266.       const mimeType = ref.mimeType || stream.mimeType || '';
  267.       let codecs = ref.codecs || stream.codecs || '';
  268.       // Don't check the same combination of mimetype + codecs twice.
  269.       const combo = mimeType + ':' + codecs;
  270.       if (seenCombos.has(combo)) {
  271.         continue;
  272.       }
  273.       seenCombos.add(combo);
  274.       if (contentType == ContentType.TEXT) {
  275.         const fullMimeType = MimeUtils.getFullType(mimeType, codecs);
  276.         if (!shaka.text.TextEngine.isTypeSupported(fullMimeType)) {
  277.           return false;
  278.         }
  279.       } else {
  280.         if (contentType == ContentType.VIDEO) {
  281.           codecs = StreamUtils.getCorrectVideoCodecs(codecs);
  282.         } else if (contentType == ContentType.AUDIO) {
  283.           codecs = StreamUtils.getCorrectAudioCodecs(codecs, mimeType);
  284.         }
  285.         const extendedMimeType = MimeUtils.getExtendedType(
  286.             stream, mimeType, codecs);
  287.         const fullMimeType = MimeUtils.getFullTypeWithAllCodecs(
  288.             mimeType, codecs);
  289.         if (!shaka.media.Capabilities.isTypeSupported(extendedMimeType) &&
  290.             !TransmuxerEngine.isSupported(fullMimeType, stream.type)) {
  291.           return false;
  292.         }
  293.       }
  294.     }
  295.     return true;
  296.   }
  298.   /**
  299.    * Returns a map of MediaSource support for well-known types.
  300.    *
  301.    * @return {!Object.<string, boolean>}
  302.    */
  303.   static probeSupport() {
  304.     const testMimeTypes = [
  305.       // MP4 types
  306.       'video/mp4; codecs="avc1.42E01E"',
  307.       'video/mp4; codecs="avc3.42E01E"',
  308.       'video/mp4; codecs="hev1.1.6.L93.90"',
  309.       'video/mp4; codecs="hvc1.1.6.L93.90"',
  310.       'video/mp4; codecs="hev1.2.4.L153.B0"; eotf="smpte2084"',  // HDR HEVC
  311.       'video/mp4; codecs="hvc1.2.4.L153.B0"; eotf="smpte2084"',  // HDR HEVC
  312.       'video/mp4; codecs="vp9"',
  313.       'video/mp4; codecs="vp09.00.10.08"',
  314.       'video/mp4; codecs="av01.0.01M.08"',
  315.       'video/mp4; codecs="dvh1.20.01"',
  316.       'audio/mp4; codecs="mp4a.40.2"',
  317.       'audio/mp4; codecs="ac-3"',
  318.       'audio/mp4; codecs="ec-3"',
  319.       'audio/mp4; codecs="ac-4"',
  320.       'audio/mp4; codecs="opus"',
  321.       'audio/mp4; codecs="flac"',
  322.       'audio/mp4; codecs="dtsc"', // DTS Digital Surround
  323.       'audio/mp4; codecs="dtse"', // DTS Express
  324.       'audio/mp4; codecs="dtsx"', // DTS:X
  325.       // WebM types
  326.       'video/webm; codecs="vp8"',
  327.       'video/webm; codecs="vp9"',
  328.       'video/webm; codecs="vp09.00.10.08"',
  329.       'audio/webm; codecs="vorbis"',
  330.       'audio/webm; codecs="opus"',
  331.       // MPEG2 TS types (video/ is also used for audio: https://bit.ly/TsMse)
  332.       'video/mp2t; codecs="avc1.42E01E"',
  333.       'video/mp2t; codecs="avc3.42E01E"',
  334.       'video/mp2t; codecs="hvc1.1.6.L93.90"',
  335.       'video/mp2t; codecs="mp4a.40.2"',
  336.       'video/mp2t; codecs="ac-3"',
  337.       'video/mp2t; codecs="ec-3"',
  338.       // WebVTT types
  339.       'text/vtt',
  340.       'application/mp4; codecs="wvtt"',
  341.       // TTML types
  342.       'application/ttml+xml',
  343.       'application/mp4; codecs="stpp"',
  344.       // Containerless types
  345.       ...shaka.util.MimeUtils.RAW_FORMATS,
  346.     ];
  348.     const support = {};
  349.     for (const type of testMimeTypes) {
  350.       if (shaka.text.TextEngine.isTypeSupported(type)) {
  351.         support[type] = true;
  352.       } else if (shaka.util.Platform.supportsMediaSource()) {
  353.         support[type] = shaka.media.Capabilities.isTypeSupported(type) ||
  354.                         shaka.transmuxer.TransmuxerEngine.isSupported(type);
  355.       } else {
  356.         support[type] = shaka.util.Platform.supportsMediaType(type);
  357.       }
  359.       const basicType = type.split(';')[0];
  360.       support[basicType] = support[basicType] || support[type];
  361.     }
  363.     return support;
  364.   }
  366.   /** @override */
  367.   destroy() {
  368.     return this.destroyer_.destroy();
  369.   }
  371.   /** @private */
  372.   async doDestroy_() {
  373.     const Functional = shaka.util.Functional;
  375.     const cleanup = [];
  377.     for (const contentType in this.queues_) {
  378.       // Make a local copy of the queue and the first item.
  379.       const q = this.queues_[contentType];
  380.       const inProgress = q[0];
  382.       // Drop everything else out of the original queue.
  383.       this.queues_[contentType] = q.slice(0, 1);
  385.       // We will wait for this item to complete/fail.
  386.       if (inProgress) {
  387.         cleanup.push(inProgress.p.catch(Functional.noop));
  388.       }
  390.       // The rest will be rejected silently if possible.
  391.       for (const item of q.slice(1)) {
  392.         item.p.reject(shaka.util.Destroyer.destroyedError());
  393.       }
  394.     }
  396.     if (this.textEngine_) {
  397.       cleanup.push(this.textEngine_.destroy());
  398.     }
  399.     if (this.textDisplayer_) {
  400.       cleanup.push(this.textDisplayer_.destroy());
  401.     }
  403.     for (const contentType in this.transmuxers_) {
  404.       cleanup.push(this.transmuxers_[contentType].destroy());
  405.     }
  408.     await Promise.all(cleanup);
  409.     if (this.eventManager_) {
  410.       this.eventManager_.release();
  411.       this.eventManager_ = null;
  412.     }
  414.     if (this.video_) {
  415.       // "unload" the video element.
  416.       this.video_.removeAttribute('src');
  417.       this.video_.load();
  418.       this.video_ = null;
  419.     }
  421.     this.config_ = null;
  422.     this.mediaSource_ = null;
  423.     this.textEngine_ = null;
  424.     this.textDisplayer_ = null;
  425.     this.sourceBuffers_ = {};
  426.     this.transmuxers_ = {};
  427.     this.captionParser_ = null;
  428.     if (goog.DEBUG) {
  429.       for (const contentType in this.queues_) {
  430.         goog.asserts.assert(
  431.             this.queues_[contentType].length == 0,
  432.             contentType + ' queue should be empty after destroy!');
  433.       }
  434.     }
  435.     this.queues_ = {};
  437.     // This object is owned by Player
  438.     this.lcevcDec_ = null;
  440.     this.tsParser_ = null;
  441.   }
  443.   /**
  444.    * @return {!Promise} Resolved when MediaSource is open and attached to the
  445.    *   media element.  This process is actually initiated by the constructor.
  446.    */
  447.   open() {
  448.     return this.mediaSourceOpen_;
  449.   }
  451.   /**
  452.    * Initialize MediaSourceEngine.
  453.    *
  454.    * Note that it is not valid to call this multiple times, except to add or
  455.    * reinitialize text streams.
  456.    *
  457.    * @param {!Map.<shaka.util.ManifestParserUtils.ContentType,
  458.    *               shaka.extern.Stream>} streamsByType
  459.    *   A map of content types to streams.  All streams must be supported
  460.    *   according to MediaSourceEngine.isStreamSupported.
  461.    * @param {boolean=} sequenceMode
  462.    *   If true, the media segments are appended to the SourceBuffer in strict
  463.    *   sequence.
  464.    * @param {string=} manifestType
  465.    *   Indicates the type of the manifest.
  466.    * @param {boolean=} ignoreManifestTimestampsInSegmentsMode
  467.    *   If true, don't adjust the timestamp offset to account for manifest
  468.    *   segment durations being out of sync with segment durations. In other
  469.    *   words, assume that there are no gaps in the segments when appending
  470.    *   to the SourceBuffer, even if the manifest and segment times disagree.
  471.    *   Indicates if the manifest has text streams.
  472.    *
  473.    * @return {!Promise}
  474.    */
  475.   async init(streamsByType, sequenceMode=false,
  476.       manifestType=shaka.media.ManifestParser.UNKNOWN,
  477.       ignoreManifestTimestampsInSegmentsMode=false) {
  478.     const ContentType = shaka.util.ManifestParserUtils.ContentType;
  480.     await this.mediaSourceOpen_;
  482.     this.sequenceMode_ = sequenceMode;
  483.     this.manifestType_ = manifestType;
  484.     this.ignoreManifestTimestampsInSegmentsMode_ =
  485.       ignoreManifestTimestampsInSegmentsMode;
  487.     this.attemptTimestampOffsetCalculation_ = !this.sequenceMode_ &&
  488.         this.manifestType_ == shaka.media.ManifestParser.HLS &&
  489.         !this.ignoreManifestTimestampsInSegmentsMode_;
  491.     this.tsParser_ = null;
  493.     for (const contentType of streamsByType.keys()) {
  494.       const stream = streamsByType.get(contentType);
  495.       // eslint-disable-next-line no-await-in-loop
  496.       await this.initSourceBuffer_(contentType, stream, stream.codecs);
  497.       if (this.needSplitMuxedContent_) {
  498.         this.queues_[ContentType.AUDIO] = [];
  499.         this.queues_[ContentType.VIDEO] = [];
  500.       } else {
  501.         this.queues_[contentType] = [];
  502.       }
  503.     }
  504.   }
  506.   /**
  507.    * Initialize a specific SourceBuffer.
  508.    *
  509.    * @param {shaka.util.ManifestParserUtils.ContentType} contentType
  510.    * @param {shaka.extern.Stream} stream
  511.    * @param {string} codecs
  512.    * @return {!Promise}
  513.    * @private
  514.    */
  515.   async initSourceBuffer_(contentType, stream, codecs) {
  516.     const ContentType = shaka.util.ManifestParserUtils.ContentType;
  518.     goog.asserts.assert(
  519.         await shaka.media.MediaSourceEngine.isStreamSupported(
  520.             stream, contentType),
  521.         'Type negotiation should happen before MediaSourceEngine.init!');
  523.     let mimeType = shaka.util.MimeUtils.getFullType(
  524.         stream.mimeType, codecs);
  525.     if (contentType == ContentType.TEXT) {
  526.       this.reinitText(mimeType, this.sequenceMode_, stream.external);
  527.     } else {
  528.       let needTransmux = this.config_.forceTransmux;
  529.       if (!shaka.media.Capabilities.isTypeSupported(mimeType) ||
  530.           (!this.sequenceMode_ &&
  531.           shaka.util.MimeUtils.RAW_FORMATS.includes(mimeType))) {
  532.         needTransmux = true;
  533.       }
  534.       const mimeTypeWithAllCodecs =
  535.           shaka.util.MimeUtils.getFullTypeWithAllCodecs(
  536.               stream.mimeType, codecs);
  537.       if (needTransmux) {
  538.         const audioCodec = shaka.util.ManifestParserUtils.guessCodecsSafe(
  539.             ContentType.AUDIO, (codecs || '').split(','));
  540.         const videoCodec = shaka.util.ManifestParserUtils.guessCodecsSafe(
  541.             ContentType.VIDEO, (codecs || '').split(','));
  542.         if (audioCodec && videoCodec) {
  543.           this.needSplitMuxedContent_ = true;
  544.           await this.initSourceBuffer_(ContentType.AUDIO, stream, audioCodec);
  545.           await this.initSourceBuffer_(ContentType.VIDEO, stream, videoCodec);
  546.           return;
  547.         }
  548.         const transmuxerPlugin = shaka.transmuxer.TransmuxerEngine
  549.             .findTransmuxer(mimeTypeWithAllCodecs);
  550.         if (transmuxerPlugin) {
  551.           const transmuxer = transmuxerPlugin();
  552.           this.transmuxers_[contentType] = transmuxer;
  553.           mimeType =
  554.               transmuxer.convertCodecs(contentType, mimeTypeWithAllCodecs);
  555.         }
  556.       }
  557.       const type = this.addExtraFeaturesToMimeType_(mimeType);
  559.       this.destroyer_.ensureNotDestroyed();
  561.       let sourceBuffer;
  563.       try {
  564.         sourceBuffer = this.mediaSource_.addSourceBuffer(type);
  565.       } catch (exception) {
  566.         throw new shaka.util.Error(
  567.             shaka.util.Error.Severity.CRITICAL,
  568.             shaka.util.Error.Category.MEDIA,
  569.             shaka.util.Error.Code.MEDIA_SOURCE_OPERATION_THREW,
  570.             exception,
  571.             'The mediaSource_ status was ' + this.mediaSource_.readyState +
  572.             ' expected \'open\'',
  573.             null);
  574.       }
  576.       if (this.sequenceMode_) {
  577.         sourceBuffer.mode =
  578.             shaka.media.MediaSourceEngine.SourceBufferMode_.SEQUENCE;
  579.       }
  581.       this.eventManager_.listen(
  582.           sourceBuffer, 'error',
  583.           () => this.onError_(contentType));
  584.       this.eventManager_.listen(
  585.           sourceBuffer, 'updateend',
  586.           () => this.onUpdateEnd_(contentType));
  587.       this.sourceBuffers_[contentType] = sourceBuffer;
  588.       this.sourceBufferTypes_[contentType] = mimeType;
  589.       this.expectedEncryption_[contentType] = !!stream.drmInfos.length;
  590.     }
  591.   }
  593.   /**
  594.    * Called by the Player to provide an updated configuration any time it
  595.    * changes. Must be called at least once before init().
  596.    *
  597.    * @param {shaka.extern.MediaSourceConfiguration} config
  598.    */
  599.   configure(config) {
  600.     this.config_ = config;
  601.     if (this.textEngine_) {
  602.       this.textEngine_.setModifyCueCallback(config.modifyCueCallback);
  603.     }
  604.   }
  606.   /**
  607.    * Indicate if the streaming is allowed by MediaSourceEngine.
  608.    * If we using MediaSource we allways returns true.
  609.    *
  610.    * @return {boolean}
  611.    */
  612.   isStreamingAllowed() {
  613.     return this.streamingAllowed_;
  614.   }
  616.   /**
  617.    * Reinitialize the TextEngine for a new text type.
  618.    * @param {string} mimeType
  619.    * @param {boolean} sequenceMode
  620.    * @param {boolean} external
  621.    */
  622.   reinitText(mimeType, sequenceMode, external) {
  623.     if (!this.textEngine_) {
  624.       this.textEngine_ = new shaka.text.TextEngine(this.textDisplayer_);
  625.       if (this.textEngine_) {
  626.         this.textEngine_.setModifyCueCallback(this.config_.modifyCueCallback);
  627.       }
  628.     }
  629.     this.textEngine_.initParser(mimeType, sequenceMode,
  630.         external || this.segmentRelativeVttTiming_, this.manifestType_);
  631.   }
  633.   /**
  634.    * @return {boolean} True if the MediaSource is in an "ended" state, or if the
  635.    *   object has been destroyed.
  636.    */
  637.   ended() {
  638.     if (this.reloadingMediaSource_) {
  639.       return false;
  640.     }
  641.     return this.mediaSource_ ? this.mediaSource_.readyState == 'ended' : true;
  642.   }
  644.   /**
  645.    * Gets the first timestamp in buffer for the given content type.
  646.    *
  647.    * @param {shaka.util.ManifestParserUtils.ContentType} contentType
  648.    * @return {?number} The timestamp in seconds, or null if nothing is buffered.
  649.    */
  650.   bufferStart(contentType) {
  651.     if (this.reloadingMediaSource_ ||
  652.           !Object.keys(this.sourceBuffers_).length) {
  653.       return null;
  654.     }
  655.     const ContentType = shaka.util.ManifestParserUtils.ContentType;
  656.     if (contentType == ContentType.TEXT) {
  657.       return this.textEngine_.bufferStart();
  658.     }
  659.     return shaka.media.TimeRangesUtils.bufferStart(
  660.         this.getBuffered_(contentType));
  661.   }
  663.   /**
  664.    * Gets the last timestamp in buffer for the given content type.
  665.    *
  666.    * @param {shaka.util.ManifestParserUtils.ContentType} contentType
  667.    * @return {?number} The timestamp in seconds, or null if nothing is buffered.
  668.    */
  669.   bufferEnd(contentType) {
  670.     if (this.reloadingMediaSource_) {
  671.       return null;
  672.     }
  673.     const ContentType = shaka.util.ManifestParserUtils.ContentType;
  674.     if (contentType == ContentType.TEXT) {
  675.       return this.textEngine_.bufferEnd();
  676.     }
  677.     return shaka.media.TimeRangesUtils.bufferEnd(
  678.         this.getBuffered_(contentType));
  679.   }
  681.   /**
  682.    * Determines if the given time is inside the buffered range of the given
  683.    * content type.
  684.    *
  685.    * @param {shaka.util.ManifestParserUtils.ContentType} contentType
  686.    * @param {number} time Playhead time
  687.    * @return {boolean}
  688.    */
  689.   isBuffered(contentType, time) {
  690.     if (this.reloadingMediaSource_) {
  691.       return false;
  692.     }
  693.     const ContentType = shaka.util.ManifestParserUtils.ContentType;
  694.     if (contentType == ContentType.TEXT) {
  695.       return this.textEngine_.isBuffered(time);
  696.     } else {
  697.       const buffered = this.getBuffered_(contentType);
  698.       return shaka.media.TimeRangesUtils.isBuffered(buffered, time);
  699.     }
  700.   }
  702.   /**
  703.    * Computes how far ahead of the given timestamp is buffered for the given
  704.    * content type.
  705.    *
  706.    * @param {shaka.util.ManifestParserUtils.ContentType} contentType
  707.    * @param {number} time
  708.    * @return {number} The amount of time buffered ahead in seconds.
  709.    */
  710.   bufferedAheadOf(contentType, time) {
  711.     if (this.reloadingMediaSource_) {
  712.       return 0;
  713.     }
  714.     const ContentType = shaka.util.ManifestParserUtils.ContentType;
  715.     if (contentType == ContentType.TEXT) {
  716.       return this.textEngine_.bufferedAheadOf(time);
  717.     } else {
  718.       const buffered = this.getBuffered_(contentType);
  719.       return shaka.media.TimeRangesUtils.bufferedAheadOf(buffered, time);
  720.     }
  721.   }
  723.   /**
  724.    * Returns info about what is currently buffered.
  725.    * @return {shaka.extern.BufferedInfo}
  726.    */
  727.   getBufferedInfo() {
  728.     const ContentType = shaka.util.ManifestParserUtils.ContentType;
  729.     const TimeRangesUtils = shaka.media.TimeRangesUtils;
  731.     const info = {
  732.       total: this.reloadingMediaSource_ ? [] :
  733.         TimeRangesUtils.getBufferedInfo(this.video_.buffered),
  734.       audio: this.reloadingMediaSource_ ? [] :
  735.         TimeRangesUtils.getBufferedInfo(this.getBuffered_(ContentType.AUDIO)),
  736.       video: this.reloadingMediaSource_ ? [] :
  737.         TimeRangesUtils.getBufferedInfo(this.getBuffered_(ContentType.VIDEO)),
  738.       text: [],
  739.     };
  741.     if (this.textEngine_) {
  742.       const start = this.textEngine_.bufferStart();
  743.       const end = this.textEngine_.bufferEnd();
  745.       if (start != null && end != null) {
  746.         info.text.push({start: start, end: end});
  747.       }
  748.     }
  749.     return info;
  750.   }
  752.   /**
  753.    * @param {shaka.util.ManifestParserUtils.ContentType} contentType
  754.    * @return {TimeRanges} The buffered ranges for the given content type, or
  755.    *   null if the buffered ranges could not be obtained.
  756.    * @private
  757.    */
  758.   getBuffered_(contentType) {
  759.     try {
  760.       return this.sourceBuffers_[contentType].buffered;
  761.     } catch (exception) {
  762.       if (contentType in this.sourceBuffers_) {
  763.         // Note: previous MediaSource errors may cause access to |buffered| to
  764.         // throw.
  765.         shaka.log.error('failed to get buffered range for ' + contentType,
  766.             exception);
  767.       }
  768.       return null;
  769.     }
  770.   }
  772.   /**
  773.    * Create a new closed caption parser. This will ONLY be replaced by tests as
  774.    * a way to inject fake closed caption parser instances.
  775.    *
  776.    * @param {string} mimeType
  777.    * @return {!shaka.media.IClosedCaptionParser}
  778.    */
  779.   getCaptionParser(mimeType) {
  780.     return new shaka.media.ClosedCaptionParser(mimeType);
  781.   }
  783.   /**
  784.    * @param {shaka.util.ManifestParserUtils.ContentType} contentType
  785.    * @param {!BufferSource} data
  786.    * @param {?shaka.media.SegmentReference} reference The segment reference
  787.    *   we are appending, or null for init segments
  788.    * @param {!string} mimeType
  789.    * @param {!number} timestampOffset
  790.    * @return {?number}
  791.    * @private
  792.    */
  793.   getTimestampAndDispatchMetadata_(contentType, data, reference, mimeType,
  794.       timestampOffset) {
  795.     let timestamp = null;
  797.     const uint8ArrayData = shaka.util.BufferUtils.toUint8(data);
  798.     if (shaka.util.MimeUtils.RAW_FORMATS.includes(mimeType)) {
  799.       const frames = shaka.util.Id3Utils.getID3Frames(uint8ArrayData);
  800.       if (frames.length && reference) {
  801.         const metadataTimestamp = frames.find((frame) => {
  802.           return frame.description ===
  803.               'com.apple.streaming.transportStreamTimestamp';
  804.         });
  805.         if (metadataTimestamp && metadataTimestamp.data) {
  806.           timestamp = Math.round(metadataTimestamp.data) / 1000;
  807.         }
  808.         /** @private {shaka.extern.ID3Metadata} */
  809.         const metadata = {
  810.           cueTime: reference.startTime,
  811.           data: uint8ArrayData,
  812.           frames: frames,
  813.           dts: reference.startTime,
  814.           pts: reference.startTime,
  815.         };
  816.         this.onMetadata_([metadata], /* offset= */ 0, reference.endTime);
  817.       }
  818.     } else if (mimeType.includes('/mp4') &&
  819.         reference && reference.timestampOffset == 0 &&
  820.         reference.initSegmentReference &&
  821.         reference.initSegmentReference.timescale) {
  822.       const timescale = reference.initSegmentReference.timescale;
  823.       if (!isNaN(timescale)) {
  824.         const Mp4Parser = shaka.util.Mp4Parser;
  825.         let startTime = 0;
  826.         let parsedMedia = false;
  827.         new Mp4Parser()
  828.             .box('moof', Mp4Parser.children)
  829.             .box('traf', Mp4Parser.children)
  830.             .fullBox('tfdt', (box) => {
  831.               goog.asserts.assert(
  832.                   box.version == 0 || box.version == 1,
  833.                   'TFDT version can only be 0 or 1');
  834.               const parsed = shaka.util.Mp4BoxParsers.parseTFDTInaccurate(
  835.                   box.reader, box.version);
  836.               startTime = parsed.baseMediaDecodeTime / timescale;
  837.               parsedMedia = true;
  838.               box.parser.stop();
  839.             }).parse(data, /* partialOkay= */ true);
  840.         if (parsedMedia) {
  841.           timestamp = startTime;
  842.         }
  843.       }
  844.     } else if (!mimeType.includes('/mp4') && !mimeType.includes('/webm') &&
  845.         shaka.util.TsParser.probe(uint8ArrayData)) {
  846.       if (!this.tsParser_) {
  847.         this.tsParser_ = new shaka.util.TsParser();
  848.       } else {
  849.         this.tsParser_.clearData();
  850.       }
  851.       const tsParser = this.tsParser_.parse(uint8ArrayData);
  852.       const startTime = tsParser.getStartTime(contentType);
  853.       if (startTime != null) {
  854.         timestamp = startTime;
  855.       }
  856.       const metadata = tsParser.getMetadata();
  857.       if (metadata.length) {
  858.         this.onMetadata_(metadata, timestampOffset,
  859.             reference ? reference.endTime : null);
  860.       }
  861.     }
  862.     return timestamp;
  863.   }
  865.   /**
  866.    * Enqueue an operation to append data to the SourceBuffer.
  867.    * Start and end times are needed for TextEngine, but not for MediaSource.
  868.    * Start and end times may be null for initialization segments; if present
  869.    * they are relative to the presentation timeline.
  870.    *
  871.    * @param {shaka.util.ManifestParserUtils.ContentType} contentType
  872.    * @param {!BufferSource} data
  873.    * @param {?shaka.media.SegmentReference} reference The segment reference
  874.    *   we are appending, or null for init segments
  875.    * @param {shaka.extern.Stream} stream
  876.    * @param {?boolean} hasClosedCaptions True if the buffer contains CEA closed
  877.    *   captions
  878.    * @param {boolean=} seeked True if we just seeked
  879.    * @param {boolean=} adaptation True if we just automatically switched active
  880.    *   variant(s).
  881.    * @param {boolean=} isChunkedData True if we add to the buffer from the
  882.    *   partial read of the segment.
  883.    * @return {!Promise}
  884.    */
  885.   async appendBuffer(
  886.       contentType, data, reference, stream, hasClosedCaptions, seeked = false,
  887.       adaptation = false, isChunkedData = false, fromSplit = false) {
  888.     const ContentType = shaka.util.ManifestParserUtils.ContentType;
  890.     if (contentType == ContentType.TEXT) {
  891.       if (this.sequenceMode_) {
  892.         // This won't be known until the first video segment is appended.
  893.         const offset = await this.textSequenceModeOffset_;
  894.         this.textEngine_.setTimestampOffset(offset);
  895.       }
  896.       await this.textEngine_.appendBuffer(
  897.           data,
  898.           reference ? reference.startTime : null,
  899.           reference ? reference.endTime : null,
  900.           reference ? reference.getUris()[0] : null);
  901.       return;
  902.     }
  904.     if (!fromSplit && this.needSplitMuxedContent_) {
  905.       await this.appendBuffer(ContentType.AUDIO, data, reference, stream,
  906.           hasClosedCaptions, seeked, adaptation, isChunkedData,
  907.           /* fromSplit= */ true);
  908.       await this.appendBuffer(ContentType.VIDEO, data, reference, stream,
  909.           hasClosedCaptions, seeked, adaptation, isChunkedData,
  910.           /* fromSplit= */ true);
  911.       return;
  912.     }
  914.     if (!this.sourceBuffers_[contentType]) {
  915.       shaka.log.warning('Attempted to restore a non-existent source buffer');
  916.       return;
  917.     }
  919.     let timestampOffset = this.sourceBuffers_[contentType].timestampOffset;
  921.     let mimeType = this.sourceBufferTypes_[contentType];
  922.     if (this.transmuxers_[contentType]) {
  923.       mimeType = this.transmuxers_[contentType].getOriginalMimeType();
  924.     }
  925.     if (reference) {
  926.       const timestamp = this.getTimestampAndDispatchMetadata_(
  927.           contentType, data, reference, mimeType, timestampOffset);
  928.       if (timestamp != null) {
  929.         const calculatedTimestampOffset = reference.startTime - timestamp;
  930.         const timestampOffsetDifference =
  931.             Math.abs(timestampOffset - calculatedTimestampOffset);
  932.         if ((timestampOffsetDifference >= 0.001 || seeked || adaptation) &&
  933.             (!isChunkedData || calculatedTimestampOffset > 0 ||
  934.             !timestampOffset)) {
  935.           timestampOffset = calculatedTimestampOffset;
  936.           if (this.attemptTimestampOffsetCalculation_) {
  937.             this.enqueueOperation_(
  938.                 contentType,
  939.                 () => this.abort_(contentType),
  940.                 null);
  941.             this.enqueueOperation_(
  942.                 contentType,
  943.                 () => this.setTimestampOffset_(contentType, timestampOffset),
  944.                 null);
  945.           }
  946.         }
  947.         // Timestamps can only be reliably extracted from video, not audio.
  948.         // Packed audio formats do not have internal timestamps at all.
  949.         // Prefer video for this when available.
  950.         const isBestSourceBufferForTimestamps =
  951.             contentType == ContentType.VIDEO ||
  952.             !(ContentType.VIDEO in this.sourceBuffers_);
  953.         if (this.sequenceMode_ && isBestSourceBufferForTimestamps) {
  954.           this.textSequenceModeOffset_.resolve(timestampOffset);
  955.         }
  956.       }
  957.     }
  958.     if (hasClosedCaptions && contentType == ContentType.VIDEO) {
  959.       if (!this.textEngine_) {
  960.         this.reinitText(shaka.util.MimeUtils.CEA608_CLOSED_CAPTION_MIMETYPE,
  961.             this.sequenceMode_, /* external= */ false);
  962.       }
  963.       if (!this.captionParser_) {
  964.         const basicType = mimeType.split(';', 1)[0];
  965.         this.captionParser_ = this.getCaptionParser(basicType);
  966.       }
  967.       // If it is the init segment for closed captions, initialize the closed
  968.       // caption parser.
  969.       if (!reference) {
  970.         this.captionParser_.init(data, adaptation);
  971.       } else {
  972.         const closedCaptions = this.captionParser_.parseFrom(data);
  973.         if (closedCaptions.length) {
  974.           this.textEngine_.storeAndAppendClosedCaptions(
  975.               closedCaptions,
  976.               reference.startTime,
  977.               reference.endTime,
  978.               timestampOffset);
  979.         }
  980.       }
  981.     }
  983.     if (this.transmuxers_[contentType]) {
  984.       data = await this.transmuxers_[contentType].transmux(
  985.           data, stream, reference, this.mediaSource_.duration, contentType);
  986.     }
  988.     data = this.workAroundBrokenPlatforms_(
  989.         data, reference ? reference.startTime : null, contentType,
  990.         reference ? reference.getUris()[0] : null);
  992.     if (reference && this.sequenceMode_ && contentType != ContentType.TEXT) {
  993.       // In sequence mode, for non-text streams, if we just cleared the buffer
  994.       // and are either performing an unbuffered seek or handling an automatic
  995.       // adaptation, we need to set a new timestampOffset on the sourceBuffer.
  996.       if (seeked || adaptation) {
  997.         const timestampOffset = reference.startTime;
  998.         // The logic to call abort() before setting the timestampOffset is
  999.         // extended during unbuffered seeks or automatic adaptations; it is
  1000.         // possible for the append state to be PARSING_MEDIA_SEGMENT from the
  1001.         // previous SourceBuffer#appendBuffer() call.
  1002.         this.enqueueOperation_(
  1003.             contentType,
  1004.             () => this.abort_(contentType),
  1005.             null);
  1006.         this.enqueueOperation_(
  1007.             contentType,
  1008.             () => this.setTimestampOffset_(contentType, timestampOffset),
  1009.             null);
  1010.       }
  1011.     }
  1013.     let bufferedBefore = null;
  1015.     await this.enqueueOperation_(contentType, () => {
  1016.       if (goog.DEBUG && reference && !reference.isPreload() && !isChunkedData) {
  1017.         bufferedBefore = this.getBuffered_(contentType);
  1018.       }
  1019.       this.append_(contentType, data, timestampOffset);
  1020.     }, reference ? reference.getUris()[0] : null);
  1022.     if (goog.DEBUG && reference && !reference.isPreload() && !isChunkedData) {
  1023.       const bufferedAfter = this.getBuffered_(contentType);
  1024.       const newBuffered = shaka.media.TimeRangesUtils.computeAddedRange(
  1025.           bufferedBefore, bufferedAfter);
  1026.       if (newBuffered) {
  1027.         const segmentDuration = reference.endTime - reference.startTime;
  1028.         // Check end times instead of start times.  We may be overwriting a
  1029.         // buffer and only the end changes, and that would be fine.
  1030.         // Also, exclude tiny segments.  Sometimes alignment segments as small
  1031.         // as 33ms are seen in Google DAI content.  For such tiny segments,
  1032.         // half a segment duration would be no issue.
  1033.         const offset = Math.abs(newBuffered.end - reference.endTime);
  1034.         if (segmentDuration > 0.100 && offset > segmentDuration / 2) {
  1035.           shaka.log.error('Possible encoding problem detected!',
  1036.               'Unexpected buffered range for reference', reference,
  1037.               'from URIs', reference.getUris(),
  1038.               'should be', {start: reference.startTime, end: reference.endTime},
  1039.               'but got', newBuffered);
  1040.         }
  1041.       }
  1042.     }
  1043.   }
  1045.   /**
  1046.    * Set the selected closed captions Id and language.
  1047.    *
  1048.    * @param {string} id
  1049.    */
  1050.   setSelectedClosedCaptionId(id) {
  1051.     const VIDEO = shaka.util.ManifestParserUtils.ContentType.VIDEO;
  1052.     const videoBufferEndTime = this.bufferEnd(VIDEO) || 0;
  1053.     this.textEngine_.setSelectedClosedCaptionId(id, videoBufferEndTime);
  1054.   }
  1056.   /** Disable embedded closed captions. */
  1057.   clearSelectedClosedCaptionId() {
  1058.     if (this.textEngine_) {
  1059.       this.textEngine_.setSelectedClosedCaptionId('', 0);
  1060.     }
  1061.   }
  1063.   /**
  1064.    * Enqueue an operation to remove data from the SourceBuffer.
  1065.    *
  1066.    * @param {shaka.util.ManifestParserUtils.ContentType} contentType
  1067.    * @param {number} startTime relative to the start of the presentation
  1068.    * @param {number} endTime relative to the start of the presentation
  1069.    * @return {!Promise}
  1070.    */
  1071.   async remove(contentType, startTime, endTime) {
  1072.     const ContentType = shaka.util.ManifestParserUtils.ContentType;
  1073.     if (contentType == ContentType.TEXT) {
  1074.       await this.textEngine_.remove(startTime, endTime);
  1075.     } else {
  1076.       await this.enqueueOperation_(
  1077.           contentType,
  1078.           () => this.remove_(contentType, startTime, endTime),
  1079.           null);
  1080.       if (this.needSplitMuxedContent_) {
  1081.         await this.enqueueOperation_(
  1082.             ContentType.AUDIO,
  1083.             () => this.remove_(ContentType.AUDIO, startTime, endTime),
  1084.             null);
  1085.       }
  1086.     }
  1087.   }
  1089.   /**
  1090.    * Enqueue an operation to clear the SourceBuffer.
  1091.    *
  1092.    * @param {shaka.util.ManifestParserUtils.ContentType} contentType
  1093.    * @return {!Promise}
  1094.    */
  1095.   async clear(contentType) {
  1096.     const ContentType = shaka.util.ManifestParserUtils.ContentType;
  1097.     if (contentType == ContentType.TEXT) {
  1098.       if (!this.textEngine_) {
  1099.         return;
  1100.       }
  1101.       await this.textEngine_.remove(0, Infinity);
  1102.     } else {
  1103.       // Note that not all platforms allow clearing to Infinity.
  1104.       await this.enqueueOperation_(
  1105.           contentType,
  1106.           () => this.remove_(contentType, 0, this.mediaSource_.duration),
  1107.           null);
  1108.       if (this.needSplitMuxedContent_) {
  1109.         await this.enqueueOperation_(
  1110.             ContentType.AUDIO,
  1111.             () => this.remove_(
  1112.                 ContentType.AUDIO, 0, this.mediaSource_.duration),
  1113.             null);
  1114.       }
  1115.     }
  1116.   }
  1118.   /**
  1119.    * Fully reset the state of the caption parser owned by MediaSourceEngine.
  1120.    */
  1121.   resetCaptionParser() {
  1122.     if (this.captionParser_) {
  1123.       this.captionParser_.reset();
  1124.     }
  1125.   }
  1127.   /**
  1128.    * Enqueue an operation to flush the SourceBuffer.
  1129.    * This is a workaround for what we believe is a Chromecast bug.
  1130.    *
  1131.    * @param {shaka.util.ManifestParserUtils.ContentType} contentType
  1132.    * @return {!Promise}
  1133.    */
  1134.   async flush(contentType) {
  1135.     // Flush the pipeline.  Necessary on Chromecast, even though we have removed
  1136.     // everything.
  1137.     const ContentType = shaka.util.ManifestParserUtils.ContentType;
  1138.     if (contentType == ContentType.TEXT) {
  1139.       // Nothing to flush for text.
  1140.       return;
  1141.     }
  1142.     await this.enqueueOperation_(
  1143.         contentType,
  1144.         () => this.flush_(contentType),
  1145.         null);
  1146.     if (this.needSplitMuxedContent_) {
  1147.       await this.enqueueOperation_(
  1148.           ContentType.AUDIO,
  1149.           () => this.flush_(ContentType.AUDIO),
  1150.           null);
  1151.     }
  1152.   }
  1154.   /**
  1155.    * Sets the timestamp offset and append window end for the given content type.
  1156.    *
  1157.    * @param {shaka.util.ManifestParserUtils.ContentType} contentType
  1158.    * @param {number} timestampOffset The timestamp offset.  Segments which start
  1159.    *   at time t will be inserted at time t + timestampOffset instead.  This
  1160.    *   value does not affect segments which have already been inserted.
  1161.    * @param {number} appendWindowStart The timestamp to set the append window
  1162.    *   start to.  For future appends, frames/samples with timestamps less than
  1163.    *   this value will be dropped.
  1164.    * @param {number} appendWindowEnd The timestamp to set the append window end
  1165.    *   to.  For future appends, frames/samples with timestamps greater than this
  1166.    *   value will be dropped.
  1167.    * @param {boolean} ignoreTimestampOffset  If true, the timestampOffset will
  1168.    *   not be applied in this step.
  1169.    * @param {string} mimeType
  1170.    * @param {string} codecs
  1171.    * @param {!Map.<shaka.util.ManifestParserUtils.ContentType,
  1172.    *               shaka.extern.Stream>} streamsByType
  1173.    *   A map of content types to streams.  All streams must be supported
  1174.    *   according to MediaSourceEngine.isStreamSupported.
  1175.    *
  1176.    * @return {!Promise}
  1177.    */
  1178.   async setStreamProperties(
  1179.       contentType, timestampOffset, appendWindowStart, appendWindowEnd,
  1180.       ignoreTimestampOffset, mimeType, codecs, streamsByType) {
  1181.     const ContentType = shaka.util.ManifestParserUtils.ContentType;
  1182.     if (contentType == ContentType.TEXT) {
  1183.       if (!ignoreTimestampOffset) {
  1184.         this.textEngine_.setTimestampOffset(timestampOffset);
  1185.       }
  1186.       this.textEngine_.setAppendWindow(appendWindowStart, appendWindowEnd);
  1187.       return;
  1188.     }
  1189.     const operations = [];
  1191.     const hasChangedCodecs = await this.codecSwitchIfNecessary_(
  1192.         contentType, mimeType, codecs, streamsByType);
  1194.     if (!hasChangedCodecs) {
  1195.       // Queue an abort() to help MSE splice together overlapping segments.
  1196.       // We set appendWindowEnd when we change periods in DASH content, and the
  1197.       // period transition may result in overlap.
  1198.       //
  1199.       // An abort() also helps with MPEG2-TS.  When we append a TS segment, we
  1200.       // always enter a PARSING_MEDIA_SEGMENT state and we can't change the
  1201.       // timestamp offset.  By calling abort(), we reset the state so we can
  1202.       // set it.
  1203.       operations.push(this.enqueueOperation_(
  1204.           contentType,
  1205.           () => this.abort_(contentType),
  1206.           null));
  1207.       if (this.needSplitMuxedContent_) {
  1208.         operations.push(this.enqueueOperation_(
  1209.             ContentType.AUDIO,
  1210.             () => this.abort_(ContentType.AUDIO),
  1211.             null));
  1212.       }
  1213.     }
  1214.     if (!ignoreTimestampOffset) {
  1215.       operations.push(this.enqueueOperation_(
  1216.           contentType,
  1217.           () => this.setTimestampOffset_(contentType, timestampOffset),
  1218.           null));
  1219.       if (this.needSplitMuxedContent_) {
  1220.         operations.push(this.enqueueOperation_(
  1221.             ContentType.AUDIO,
  1222.             () => this.setTimestampOffset_(
  1223.                 ContentType.AUDIO, timestampOffset),
  1224.             null));
  1225.       }
  1226.     }
  1227.     operations.push(this.enqueueOperation_(
  1228.         contentType,
  1229.         () => this.setAppendWindow_(
  1230.             contentType, appendWindowStart, appendWindowEnd),
  1231.         null));
  1232.     if (this.needSplitMuxedContent_) {
  1233.       operations.push(this.enqueueOperation_(
  1234.           ContentType.AUDIO,
  1235.           () => this.setAppendWindow_(
  1236.               ContentType.AUDIO, appendWindowStart, appendWindowEnd),
  1237.           null));
  1238.     }
  1240.     await Promise.all(operations);
  1241.   }
  1243.   /**
  1244.    * Adjust timestamp offset to maintain AV sync across discontinuities.
  1245.    *
  1246.    * @param {shaka.util.ManifestParserUtils.ContentType} contentType
  1247.    * @param {number} timestampOffset
  1248.    * @return {!Promise}
  1249.    */
  1250.   async resync(contentType, timestampOffset) {
  1251.     const ContentType = shaka.util.ManifestParserUtils.ContentType;
  1253.     if (contentType == ContentType.TEXT) {
  1254.       // This operation is for audio and video only.
  1255.       return;
  1256.     }
  1258.     // Reset the promise in case the timestamp offset changed during
  1259.     // a period/discontinuity transition.
  1260.     if (contentType == ContentType.VIDEO) {
  1261.       this.textSequenceModeOffset_ = new shaka.util.PublicPromise();
  1262.     }
  1264.     // Queue an abort() to help MSE splice together overlapping segments.
  1265.     // We set appendWindowEnd when we change periods in DASH content, and the
  1266.     // period transition may result in overlap.
  1267.     //
  1268.     // An abort() also helps with MPEG2-TS.  When we append a TS segment, we
  1269.     // always enter a PARSING_MEDIA_SEGMENT state and we can't change the
  1270.     // timestamp offset.  By calling abort(), we reset the state so we can
  1271.     // set it.
  1272.     this.enqueueOperation_(
  1273.         contentType,
  1274.         () => this.abort_(contentType),
  1275.         null);
  1276.     if (this.needSplitMuxedContent_) {
  1277.       this.enqueueOperation_(
  1278.           ContentType.AUDIO,
  1279.           () => this.abort_(ContentType.AUDIO),
  1280.           null);
  1281.     }
  1282.     await this.enqueueOperation_(
  1283.         contentType,
  1284.         () => this.setTimestampOffset_(contentType, timestampOffset),
  1285.         null);
  1286.     if (this.needSplitMuxedContent_) {
  1287.       await this.enqueueOperation_(
  1288.           ContentType.AUDIO,
  1289.           () => this.setTimestampOffset_(ContentType.AUDIO, timestampOffset),
  1290.           null);
  1291.     }
  1292.   }
  1294.   /**
  1295.    * @param {string=} reason Valid reasons are 'network' and 'decode'.
  1296.    * @return {!Promise}
  1297.    * @see http://w3c.github.io/media-source/#idl-def-EndOfStreamError
  1298.    */
  1299.   async endOfStream(reason) {
  1300.     await this.enqueueBlockingOperation_(() => {
  1301.       // If endOfStream() has already been called on the media source,
  1302.       // don't call it again. Also do not call if readyState is
  1303.       // 'closed' (not attached to video element) since it is not a
  1304.       // valid operation.
  1305.       if (this.ended() || this.mediaSource_.readyState === 'closed') {
  1306.         return;
  1307.       }
  1308.       // Tizen won't let us pass undefined, but it will let us omit the
  1309.       // argument.
  1310.       if (reason) {
  1311.         this.mediaSource_.endOfStream(reason);
  1312.       } else {
  1313.         this.mediaSource_.endOfStream();
  1314.       }
  1315.     });
  1316.   }
  1318.   /**
  1319.    * @param {number} duration
  1320.    * @return {!Promise}
  1321.    */
  1322.   async setDuration(duration) {
  1323.     await this.enqueueBlockingOperation_(() => {
  1324.       // Reducing the duration causes the MSE removal algorithm to run, which
  1325.       // triggers an 'updateend' event to fire.  To handle this scenario, we
  1326.       // have to insert a dummy operation into the beginning of each queue,
  1327.       // which the 'updateend' handler will remove.
  1328.       if (duration < this.mediaSource_.duration) {
  1329.         for (const contentType in this.sourceBuffers_) {
  1330.           const dummyOperation = {
  1331.             start: () => {},
  1332.             p: new shaka.util.PublicPromise(),
  1333.             uri: null,
  1334.           };
  1335.           this.queues_[contentType].unshift(dummyOperation);
  1336.         }
  1337.       }
  1339.       this.mediaSource_.duration = duration;
  1340.       this.lastDuration_ = duration;
  1341.     });
  1342.   }
  1344.   /**
  1345.    * Get the current MediaSource duration.
  1346.    *
  1347.    * @return {number}
  1348.    */
  1349.   getDuration() {
  1350.     return this.mediaSource_.duration;
  1351.   }
  1353.   /**
  1354.    * Append data to the SourceBuffer.
  1355.    * @param {shaka.util.ManifestParserUtils.ContentType} contentType
  1356.    * @param {BufferSource} data
  1357.    * @param {number} timestampOffset
  1358.    * @private
  1359.    */
  1360.   append_(contentType, data, timestampOffset) {
  1361.     const ContentType = shaka.util.ManifestParserUtils.ContentType;
  1363.     // Append only video data to the LCEVC Dec.
  1364.     if (contentType == ContentType.VIDEO && this.lcevcDec_) {
  1365.       // Append video buffers to the LCEVC Dec for parsing and storing
  1366.       // of LCEVC data.
  1367.       this.lcevcDec_.appendBuffer(data, timestampOffset);
  1368.     }
  1370.     // This will trigger an 'updateend' event.
  1371.     this.sourceBuffers_[contentType].appendBuffer(data);
  1372.   }
  1374.   /**
  1375.    * Remove data from the SourceBuffer.
  1376.    * @param {shaka.util.ManifestParserUtils.ContentType} contentType
  1377.    * @param {number} startTime relative to the start of the presentation
  1378.    * @param {number} endTime relative to the start of the presentation
  1379.    * @private
  1380.    */
  1381.   remove_(contentType, startTime, endTime) {
  1382.     if (endTime <= startTime) {
  1383.       // Ignore removal of inverted or empty ranges.
  1384.       // Fake 'updateend' event to resolve the operation.
  1385.       this.onUpdateEnd_(contentType);
  1386.       return;
  1387.     }
  1389.     // This will trigger an 'updateend' event.
  1390.     this.sourceBuffers_[contentType].remove(startTime, endTime);
  1391.   }
  1393.   /**
  1394.    * Call abort() on the SourceBuffer.
  1395.    * This resets MSE's last_decode_timestamp on all track buffers, which should
  1396.    * trigger the splicing logic for overlapping segments.
  1397.    * @param {shaka.util.ManifestParserUtils.ContentType} contentType
  1398.    * @private
  1399.    */
  1400.   abort_(contentType) {
  1401.     // Save the append window, which is reset on abort().
  1402.     const appendWindowStart =
  1403.         this.sourceBuffers_[contentType].appendWindowStart;
  1404.     const appendWindowEnd = this.sourceBuffers_[contentType].appendWindowEnd;
  1406.     // This will not trigger an 'updateend' event, since nothing is happening.
  1407.     // This is only to reset MSE internals, not to abort an actual operation.
  1408.     this.sourceBuffers_[contentType].abort();
  1410.     // Restore the append window.
  1411.     this.sourceBuffers_[contentType].appendWindowStart = appendWindowStart;
  1412.     this.sourceBuffers_[contentType].appendWindowEnd = appendWindowEnd;
  1414.     // Fake an 'updateend' event to resolve the operation.
  1415.     this.onUpdateEnd_(contentType);
  1416.   }
  1418.   /**
  1419.    * Nudge the playhead to force the media pipeline to be flushed.
  1420.    * This seems to be necessary on Chromecast to get new content to replace old
  1421.    * content.
  1422.    * @param {shaka.util.ManifestParserUtils.ContentType} contentType
  1423.    * @private
  1424.    */
  1425.   flush_(contentType) {
  1426.     // Never use flush_ if there's data.  It causes a hiccup in playback.
  1427.     goog.asserts.assert(
  1428.         this.video_.buffered.length == 0, 'MediaSourceEngine.flush_ should ' +
  1429.         'only be used after clearing all data!');
  1431.     // Seeking forces the pipeline to be flushed.
  1432.     this.video_.currentTime -= 0.001;
  1434.     // Fake an 'updateend' event to resolve the operation.
  1435.     this.onUpdateEnd_(contentType);
  1436.   }
  1438.   /**
  1439.    * Set the SourceBuffer's timestamp offset.
  1440.    * @param {shaka.util.ManifestParserUtils.ContentType} contentType
  1441.    * @param {number} timestampOffset
  1442.    * @private
  1443.    */
  1444.   setTimestampOffset_(contentType, timestampOffset) {
  1445.     // Work around for
  1446.     // https://github.com/shaka-project/shaka-player/issues/1281:
  1447.     // TODO(https://bit.ly/2ttKiBU): follow up when this is fixed in Edge
  1448.     if (timestampOffset < 0) {
  1449.       // Try to prevent rounding errors in Edge from removing the first
  1450.       // keyframe.
  1451.       timestampOffset += 0.001;
  1452.     }
  1454.     this.sourceBuffers_[contentType].timestampOffset = timestampOffset;
  1456.     // Fake an 'updateend' event to resolve the operation.
  1457.     this.onUpdateEnd_(contentType);
  1458.   }
  1460.   /**
  1461.    * Set the SourceBuffer's append window end.
  1462.    * @param {shaka.util.ManifestParserUtils.ContentType} contentType
  1463.    * @param {number} appendWindowStart
  1464.    * @param {number} appendWindowEnd
  1465.    * @private
  1466.    */
  1467.   setAppendWindow_(contentType, appendWindowStart, appendWindowEnd) {
  1468.     // You can't set start > end, so first set start to 0, then set the new
  1469.     // end, then set the new start.  That way, there are no intermediate
  1470.     // states which are invalid.
  1471.     this.sourceBuffers_[contentType].appendWindowStart = 0;
  1472.     this.sourceBuffers_[contentType].appendWindowEnd = appendWindowEnd;
  1473.     this.sourceBuffers_[contentType].appendWindowStart = appendWindowStart;
  1475.     // Fake an 'updateend' event to resolve the operation.
  1476.     this.onUpdateEnd_(contentType);
  1477.   }
  1479.   /**
  1480.    * @param {shaka.util.ManifestParserUtils.ContentType} contentType
  1481.    * @private
  1482.    */
  1483.   onError_(contentType) {
  1484.     const operation = this.queues_[contentType][0];
  1485.     goog.asserts.assert(operation, 'Spurious error event!');
  1486.     goog.asserts.assert(!this.sourceBuffers_[contentType].updating,
  1487.         'SourceBuffer should not be updating on error!');
  1488.     const code = this.video_.error ? this.video_.error.code : 0;
  1489.     operation.p.reject(new shaka.util.Error(
  1490.         shaka.util.Error.Severity.CRITICAL,
  1491.         shaka.util.Error.Category.MEDIA,
  1492.         shaka.util.Error.Code.MEDIA_SOURCE_OPERATION_FAILED,
  1493.         code, operation.uri));
  1494.     // Do not pop from queue.  An 'updateend' event will fire next, and to
  1495.     // avoid synchronizing these two event handlers, we will allow that one to
  1496.     // pop from the queue as normal.  Note that because the operation has
  1497.     // already been rejected, the call to resolve() in the 'updateend' handler
  1498.     // will have no effect.
  1499.   }
  1501.   /**
  1502.    * @param {shaka.util.ManifestParserUtils.ContentType} contentType
  1503.    * @private
  1504.    */
  1505.   onUpdateEnd_(contentType) {
  1506.     if (this.reloadingMediaSource_) {
  1507.       return;
  1508.     }
  1509.     const operation = this.queues_[contentType][0];
  1510.     goog.asserts.assert(operation, 'Spurious updateend event!');
  1511.     if (!operation) {
  1512.       return;
  1513.     }
  1514.     goog.asserts.assert(!this.sourceBuffers_[contentType].updating,
  1515.         'SourceBuffer should not be updating on updateend!');
  1516.     operation.p.resolve();
  1517.     this.popFromQueue_(contentType);
  1518.   }
  1520.   /**
  1521.    * Enqueue an operation and start it if appropriate.
  1522.    *
  1523.    * @param {shaka.util.ManifestParserUtils.ContentType} contentType
  1524.    * @param {function()} start
  1525.    * @param {?string} uri
  1526.    * @return {!Promise}
  1527.    * @private
  1528.    */
  1529.   enqueueOperation_(contentType, start, uri) {
  1530.     this.destroyer_.ensureNotDestroyed();
  1531.     const operation = {
  1532.       start: start,
  1533.       p: new shaka.util.PublicPromise(),
  1534.       uri,
  1535.     };
  1536.     this.queues_[contentType].push(operation);
  1538.     if (this.queues_[contentType].length == 1) {
  1539.       this.startOperation_(contentType);
  1540.     }
  1541.     return operation.p;
  1542.   }
  1544.   /**
  1545.    * Enqueue an operation which must block all other operations on all
  1546.    * SourceBuffers.
  1547.    *
  1548.    * @param {function():(Promise|undefined)} run
  1549.    * @return {!Promise}
  1550.    * @private
  1551.    */
  1552.   async enqueueBlockingOperation_(run) {
  1553.     this.destroyer_.ensureNotDestroyed();
  1555.     /** @type {!Array.<!shaka.util.PublicPromise>} */
  1556.     const allWaiters = [];
  1558.     // Enqueue a 'wait' operation onto each queue.
  1559.     // This operation signals its readiness when it starts.
  1560.     // When all wait operations are ready, the real operation takes place.
  1561.     for (const contentType in this.sourceBuffers_) {
  1562.       const ready = new shaka.util.PublicPromise();
  1563.       const operation = {
  1564.         start: () => ready.resolve(),
  1565.         p: ready,
  1566.         uri: null,
  1567.       };
  1569.       this.queues_[contentType].push(operation);
  1570.       allWaiters.push(ready);
  1572.       if (this.queues_[contentType].length == 1) {
  1573.         operation.start();
  1574.       }
  1575.     }
  1577.     // Return a Promise to the real operation, which waits to begin until
  1578.     // there are no other in-progress operations on any SourceBuffers.
  1579.     try {
  1580.       await Promise.all(allWaiters);
  1581.     } catch (error) {
  1582.       // One of the waiters failed, which means we've been destroyed.
  1583.       goog.asserts.assert(
  1584.           this.destroyer_.destroyed(), 'Should be destroyed by now');
  1585.       // We haven't popped from the queue.  Canceled waiters have been removed
  1586.       // by destroy.  What's left now should just be resolved waiters.  In
  1587.       // uncompiled mode, we will maintain good hygiene and make sure the
  1588.       // assert at the end of destroy passes.  In compiled mode, the queues
  1589.       // are wiped in destroy.
  1590.       if (goog.DEBUG) {
  1591.         for (const contentType in this.sourceBuffers_) {
  1592.           if (this.queues_[contentType].length) {
  1593.             goog.asserts.assert(
  1594.                 this.queues_[contentType].length == 1,
  1595.                 'Should be at most one item in queue!');
  1596.             goog.asserts.assert(
  1597.                 allWaiters.includes(this.queues_[contentType][0].p),
  1598.                 'The item in queue should be one of our waiters!');
  1599.             this.queues_[contentType].shift();
  1600.           }
  1601.         }
  1602.       }
  1603.       throw error;
  1604.     }
  1606.     if (goog.DEBUG) {
  1607.       // If we did it correctly, nothing is updating.
  1608.       for (const contentType in this.sourceBuffers_) {
  1609.         goog.asserts.assert(
  1610.             this.sourceBuffers_[contentType].updating == false,
  1611.             'SourceBuffers should not be updating after a blocking op!');
  1612.       }
  1613.     }
  1615.     // Run the real operation, which can be asynchronous.
  1616.     try {
  1617.       await run();
  1618.     } catch (exception) {
  1619.       throw new shaka.util.Error(
  1620.           shaka.util.Error.Severity.CRITICAL,
  1621.           shaka.util.Error.Category.MEDIA,
  1622.           shaka.util.Error.Code.MEDIA_SOURCE_OPERATION_THREW,
  1623.           exception,
  1624.           this.video_.error || 'No error in the media element',
  1625.           null);
  1626.     } finally {
  1627.       // Unblock the queues.
  1628.       for (const contentType in this.sourceBuffers_) {
  1629.         this.popFromQueue_(contentType);
  1630.       }
  1631.     }
  1632.   }
  1634.   /**
  1635.    * Pop from the front of the queue and start a new operation.
  1636.    * @param {shaka.util.ManifestParserUtils.ContentType} contentType
  1637.    * @private
  1638.    */
  1639.   popFromQueue_(contentType) {
  1640.     // Remove the in-progress operation, which is now complete.
  1641.     this.queues_[contentType].shift();
  1642.     this.startOperation_(contentType);
  1643.   }
  1645.   /**
  1646.    * Starts the next operation in the queue.
  1647.    * @param {shaka.util.ManifestParserUtils.ContentType} contentType
  1648.    * @private
  1649.    */
  1650.   startOperation_(contentType) {
  1651.     // Retrieve the next operation, if any, from the queue and start it.
  1652.     const next = this.queues_[contentType][0];
  1653.     if (next) {
  1654.       try {
  1655.         next.start();
  1656.       } catch (exception) {
  1657.         if (exception.name == 'QuotaExceededError') {
  1658.           next.p.reject(new shaka.util.Error(
  1659.               shaka.util.Error.Severity.CRITICAL,
  1660.               shaka.util.Error.Category.MEDIA,
  1661.               shaka.util.Error.Code.QUOTA_EXCEEDED_ERROR,
  1662.               contentType));
  1663.         } else {
  1664.           next.p.reject(new shaka.util.Error(
  1665.               shaka.util.Error.Severity.CRITICAL,
  1666.               shaka.util.Error.Category.MEDIA,
  1667.               shaka.util.Error.Code.MEDIA_SOURCE_OPERATION_THREW,
  1668.               exception,
  1669.               this.video_.error || 'No error in the media element',
  1670.               next.uri));
  1671.         }
  1672.         this.popFromQueue_(contentType);
  1673.       }
  1674.     }
  1675.   }
  1677.   /**
  1678.    * @return {!shaka.extern.TextDisplayer}
  1679.    */
  1680.   getTextDisplayer() {
  1681.     goog.asserts.assert(
  1682.         this.textDisplayer_,
  1683.         'TextDisplayer should only be null when this is destroyed');
  1685.     return this.textDisplayer_;
  1686.   }
  1688.   /**
  1689.    * @param {!shaka.extern.TextDisplayer} textDisplayer
  1690.    */
  1691.   setTextDisplayer(textDisplayer) {
  1692.     const oldTextDisplayer = this.textDisplayer_;
  1693.     this.textDisplayer_ = textDisplayer;
  1694.     if (oldTextDisplayer) {
  1695.       textDisplayer.setTextVisibility(oldTextDisplayer.isTextVisible());
  1696.       oldTextDisplayer.destroy();
  1697.     }
  1698.     if (this.textEngine_) {
  1699.       this.textEngine_.setDisplayer(textDisplayer);
  1700.     }
  1701.   }
  1703.   /**
  1704.    * @param {boolean} segmentRelativeVttTiming
  1705.    */
  1706.   setSegmentRelativeVttTiming(segmentRelativeVttTiming) {
  1707.     this.segmentRelativeVttTiming_ = segmentRelativeVttTiming;
  1708.   }
  1710.   /**
  1711.    * Apply platform-specific transformations to this segment to work around
  1712.    * issues in the platform.
  1713.    *
  1714.    * @param {!BufferSource} segment
  1715.    * @param {?number} startTime
  1716.    * @param {shaka.util.ManifestParserUtils.ContentType} contentType
  1717.    * @param {?string} uri
  1718.    * @return {!BufferSource}
  1719.    * @private
  1720.    */
  1721.   workAroundBrokenPlatforms_(segment, startTime, contentType, uri) {
  1722.     const isInitSegment = startTime == null;
  1723.     const encryptionExpected = this.expectedEncryption_[contentType];
  1725.     // If:
  1726.     //   1. the configuration tells to insert fake encryption,
  1727.     //   2. and this is an init segment,
  1728.     //   3. and encryption is expected,
  1729.     //   4. and the platform requires encryption in all init segments,
  1730.     //   5. and the content is MP4 (mimeType == "video/mp4" or "audio/mp4"),
  1731.     // then insert fake encryption metadata for init segments that lack it.
  1732.     // The MP4 requirement is because we can currently only do this
  1733.     // transformation on MP4 containers.
  1734.     // See: https://github.com/shaka-project/shaka-player/issues/2759
  1735.     if (this.config_.insertFakeEncryptionInInit &&
  1736.         isInitSegment &&
  1737.         encryptionExpected &&
  1738.         shaka.util.Platform.requiresEncryptionInfoInAllInitSegments() &&
  1739.         shaka.util.MimeUtils.getContainerType(
  1740.             this.sourceBufferTypes_[contentType]) == 'mp4') {
  1741.       shaka.log.debug('Forcing fake encryption information in init segment.');
  1742.       segment = shaka.media.ContentWorkarounds.fakeEncryption(segment, uri);
  1743.     }
  1745.     return segment;
  1746.   }
  1748.   /**
  1749.    * Prepare the SourceBuffer to parse a potentially new type or codec.
  1750.    *
  1751.    * @param {shaka.util.ManifestParserUtils.ContentType} contentType
  1752.    * @param {string} mimeType
  1753.    * @param {?shaka.extern.Transmuxer} transmuxer
  1754.    * @private
  1755.    */
  1756.   change_(contentType, mimeType, transmuxer) {
  1757.     const ContentType = shaka.util.ManifestParserUtils.ContentType;
  1758.     if (contentType === ContentType.TEXT) {
  1759.       shaka.log.debug(`Change not supported for ${contentType}`);
  1760.       return;
  1761.     }
  1762.     shaka.log.debug(
  1763.         `Change Type: ${this.sourceBufferTypes_[contentType]} -> ${mimeType}`);
  1764.     if (shaka.media.Capabilities.isChangeTypeSupported()) {
  1765.       if (this.transmuxers_[contentType]) {
  1766.         this.transmuxers_[contentType].destroy();
  1767.         delete this.transmuxers_[contentType];
  1768.       }
  1769.       if (transmuxer) {
  1770.         this.transmuxers_[contentType] = transmuxer;
  1771.       }
  1772.       const type = this.addExtraFeaturesToMimeType_(mimeType);
  1773.       this.sourceBuffers_[contentType].changeType(type);
  1774.       this.sourceBufferTypes_[contentType] = mimeType;
  1775.     } else {
  1776.       shaka.log.debug('Change Type not supported');
  1777.     }
  1779.     // Fake an 'updateend' event to resolve the operation.
  1780.     this.onUpdateEnd_(contentType);
  1781.   }
  1783.   /**
  1784.    * Enqueue an operation to prepare the SourceBuffer to parse a potentially new
  1785.    * type or codec.
  1786.    *
  1787.    * @param {shaka.util.ManifestParserUtils.ContentType} contentType
  1788.    * @param {string} mimeType
  1789.    * @param {?shaka.extern.Transmuxer} transmuxer
  1790.    * @return {!Promise}
  1791.    */
  1792.   changeType(contentType, mimeType, transmuxer) {
  1793.     return this.enqueueOperation_(
  1794.         contentType,
  1795.         () => this.change_(contentType, mimeType, transmuxer),
  1796.         null);
  1797.   }
  1799.   /**
  1800.    * Resets the MediaSource and re-adds source buffers due to codec mismatch
  1801.    *
  1802.    * @param {!Map.<shaka.util.ManifestParserUtils.ContentType,
  1803.    *               shaka.extern.Stream>} streamsByType
  1804.    * @private
  1805.    */
  1806.   async reset_(streamsByType) {
  1807.     const Functional = shaka.util.Functional;
  1808.     const ContentType = shaka.util.ManifestParserUtils.ContentType;
  1809.     this.reloadingMediaSource_ = true;
  1810.     this.needSplitMuxedContent_ = false;
  1811.     const currentTime = this.video_.currentTime;
  1813.     // When codec switching if the user is currently paused we don't want
  1814.     // to trigger a play when switching codec.
  1815.     // Playing can also end up in a paused state after a codec switch
  1816.     // so we need to remember the current states.
  1817.     const previousAutoPlayState = this.video_.autoplay;
  1818.     const previousPausedState = this.video_.paused;
  1819.     if (this.playbackHasBegun_) {
  1820.       // Only set autoplay to false if the video playback has already begun.
  1821.       // When a codec switch happens before playback has begun this can cause
  1822.       // autoplay not to work as expected.
  1823.       this.video_.autoplay = false;
  1824.     }
  1826.     try {
  1827.       this.eventManager_.removeAll();
  1829.       const cleanup = [];
  1830.       for (const contentType in this.transmuxers_) {
  1831.         cleanup.push(this.transmuxers_[contentType].destroy());
  1832.       }
  1833.       for (const contentType in this.queues_) {
  1834.         // Make a local copy of the queue and the first item.
  1835.         const q = this.queues_[contentType];
  1836.         const inProgress = q[0];
  1838.         // Drop everything else out of the original queue.
  1839.         this.queues_[contentType] = q.slice(0, 1);
  1841.         // We will wait for this item to complete/fail.
  1842.         if (inProgress) {
  1843.           cleanup.push(inProgress.p.catch(Functional.noop));
  1844.         }
  1846.         // The rest will be rejected silently if possible.
  1847.         for (const item of q.slice(1)) {
  1848.           item.p.reject(shaka.util.Destroyer.destroyedError());
  1849.         }
  1850.       }
  1851.       for (const contentType in this.sourceBuffers_) {
  1852.         const sourceBuffer = this.sourceBuffers_[contentType];
  1853.         try {
  1854.           this.mediaSource_.removeSourceBuffer(sourceBuffer);
  1855.         } catch (e) {}
  1856.       }
  1857.       await Promise.all(cleanup);
  1858.       this.transmuxers_ = {};
  1859.       this.sourceBuffers_ = {};
  1861.       const previousDuration = this.mediaSource_.duration;
  1862.       this.mediaSourceOpen_ = new shaka.util.PublicPromise();
  1863.       this.mediaSource_ = this.createMediaSource(this.mediaSourceOpen_);
  1864.       await this.mediaSourceOpen_;
  1865.       if (!isNaN(previousDuration) && previousDuration) {
  1866.         this.mediaSource_.duration = previousDuration;
  1867.       } else if (!isNaN(this.lastDuration_) && this.lastDuration_) {
  1868.         this.mediaSource_.duration = this.lastDuration_;
  1869.       }
  1871.       const sourceBufferAdded = new shaka.util.PublicPromise();
  1872.       const sourceBuffers =
  1873.         /** @type {EventTarget} */(this.mediaSource_.sourceBuffers);
  1875.       const totalOfBuffers = streamsByType.size;
  1876.       let numberOfSourceBufferAdded = 0;
  1877.       const onSourceBufferAdded = () => {
  1878.         numberOfSourceBufferAdded++;
  1879.         if (numberOfSourceBufferAdded === totalOfBuffers) {
  1880.           sourceBufferAdded.resolve();
  1881.           this.eventManager_.unlisten(sourceBuffers, 'addsourcebuffer',
  1882.               onSourceBufferAdded);
  1883.         }
  1884.       };
  1886.       this.eventManager_.listen(sourceBuffers, 'addsourcebuffer',
  1887.           onSourceBufferAdded);
  1889.       for (const contentType of streamsByType.keys()) {
  1890.         const stream = streamsByType.get(contentType);
  1891.         // eslint-disable-next-line no-await-in-loop
  1892.         await this.initSourceBuffer_(contentType, stream, stream.codecs);
  1893.         if (this.needSplitMuxedContent_) {
  1894.           this.queues_[ContentType.AUDIO] = [];
  1895.           this.queues_[ContentType.VIDEO] = [];
  1896.         } else {
  1897.           this.queues_[contentType] = [];
  1898.         }
  1899.       }
  1901.       // Fake a seek to catchup the playhead.
  1902.       this.video_.currentTime = currentTime;
  1904.       await sourceBufferAdded;
  1905.     } finally {
  1906.       this.reloadingMediaSource_ = false;
  1908.       this.destroyer_.ensureNotDestroyed();
  1910.       this.eventManager_.listenOnce(this.video_, 'canplaythrough', () => {
  1911.         // Don't use ensureNotDestroyed() from this event listener, because
  1912.         // that results in an uncaught exception.  Instead, just check the
  1913.         // flag.
  1914.         if (this.destroyer_.destroyed()) {
  1915.           return;
  1916.         }
  1918.         this.video_.autoplay = previousAutoPlayState;
  1919.         if (!previousPausedState) {
  1920.           this.video_.play();
  1921.         }
  1922.       });
  1923.     }
  1924.   }
  1926.   /**
  1927.    * Resets the Media Source
  1928.    * @param {!Map.<shaka.util.ManifestParserUtils.ContentType,
  1929.    *               shaka.extern.Stream>} streamsByType
  1930.    * @return {!Promise}
  1931.    */
  1932.   reset(streamsByType) {
  1933.     return this.enqueueBlockingOperation_(
  1934.         () => this.reset_(streamsByType));
  1935.   }
  1937.   /**
  1938.    * Codec switch if necessary, this will not resolve until the codec
  1939.    * switch is over.
  1940.    * @param {shaka.util.ManifestParserUtils.ContentType} contentType
  1941.    * @param {string} mimeType
  1942.    * @param {string} codecs
  1943.    * @param {!Map.<shaka.util.ManifestParserUtils.ContentType,
  1944.    *               shaka.extern.Stream>} streamsByType
  1945.    * @return {!Promise.<boolean>} true if there was a codec switch,
  1946.    *                              false otherwise.
  1947.    * @private
  1948.    */
  1949.   async codecSwitchIfNecessary_(contentType, mimeType, codecs, streamsByType) {
  1950.     const ContentType = shaka.util.ManifestParserUtils.ContentType;
  1951.     if (contentType == ContentType.TEXT) {
  1952.       return false;
  1953.     }
  1954.     const MimeUtils = shaka.util.MimeUtils;
  1955.     const currentCodec = MimeUtils.getCodecBase(
  1956.         MimeUtils.getCodecs(this.sourceBufferTypes_[contentType]));
  1957.     const currentBasicType = MimeUtils.getBasicType(
  1958.         this.sourceBufferTypes_[contentType]);
  1960.     /** @type {?shaka.extern.Transmuxer} */
  1961.     let transmuxer;
  1962.     let transmuxerMuxed = false;
  1963.     let newMimeType = shaka.util.MimeUtils.getFullType(mimeType, codecs);
  1964.     let needTransmux = this.config_.forceTransmux;
  1965.     if (!shaka.media.Capabilities.isTypeSupported(newMimeType) ||
  1966.         (!this.sequenceMode_ &&
  1967.         shaka.util.MimeUtils.RAW_FORMATS.includes(newMimeType))) {
  1968.       needTransmux = true;
  1969.     }
  1970.     const TransmuxerEngine = shaka.transmuxer.TransmuxerEngine;
  1971.     if (needTransmux) {
  1972.       const newMimeTypeWithAllCodecs =
  1973.           shaka.util.MimeUtils.getFullTypeWithAllCodecs(mimeType, codecs);
  1974.       const transmuxerPlugin =
  1975.           TransmuxerEngine.findTransmuxer(newMimeTypeWithAllCodecs);
  1976.       if (transmuxerPlugin) {
  1977.         transmuxer = transmuxerPlugin();
  1978.         const audioCodec = shaka.util.ManifestParserUtils.guessCodecsSafe(
  1979.             ContentType.AUDIO, (codecs || '').split(','));
  1980.         const videoCodec = shaka.util.ManifestParserUtils.guessCodecsSafe(
  1981.             ContentType.VIDEO, (codecs || '').split(','));
  1982.         if (audioCodec && videoCodec) {
  1983.           transmuxerMuxed = true;
  1984.           let codec = videoCodec;
  1985.           if (contentType == ContentType.AUDIO) {
  1986.             codec = audioCodec;
  1987.           }
  1988.           newMimeType = transmuxer.convertCodecs(contentType,
  1989.               shaka.util.MimeUtils.getFullTypeWithAllCodecs(mimeType, codec));
  1990.         } else {
  1991.           newMimeType =
  1992.               transmuxer.convertCodecs(contentType, newMimeTypeWithAllCodecs);
  1993.         }
  1994.       }
  1995.     }
  1997.     const newCodec = MimeUtils.getCodecBase(
  1998.         MimeUtils.getCodecs(newMimeType));
  1999.     const newBasicType = MimeUtils.getBasicType(newMimeType);
  2001.     // Current/new codecs base and basic type match then no need to switch
  2002.     if (currentCodec === newCodec && currentBasicType === newBasicType) {
  2003.       return false;
  2004.     }
  2006.     let allowChangeType = true;
  2007.     if (this.needSplitMuxedContent_ || (transmuxerMuxed &&
  2008.         transmuxer && !this.transmuxers_[contentType])) {
  2009.       allowChangeType = false;
  2010.     }
  2012.     if (allowChangeType && this.config_.codecSwitchingStrategy ===
  2013.         shaka.config.CodecSwitchingStrategy.SMOOTH &&
  2014.           shaka.media.Capabilities.isChangeTypeSupported()) {
  2015.       await this.changeType(contentType, newMimeType, transmuxer);
  2016.     } else {
  2017.       if (transmuxer) {
  2018.         transmuxer.destroy();
  2019.       }
  2020.       await this.reset(streamsByType);
  2021.     }
  2022.     return true;
  2023.   }
  2025.   /**
  2026.    * Returns true if it's necessary codec switch to load the new stream.
  2027.    *
  2028.    * @param {shaka.util.ManifestParserUtils.ContentType} contentType
  2029.    * @param {shaka.extern.Stream} stream
  2030.    * @param {string} refMimeType
  2031.    * @param {string} refCodecs
  2032.    * @return {boolean}
  2033.    * @private
  2034.    */
  2035.   isCodecSwitchNecessary_(contentType, stream, refMimeType, refCodecs) {
  2036.     if (contentType == shaka.util.ManifestParserUtils.ContentType.TEXT) {
  2037.       return false;
  2038.     }
  2039.     const MimeUtils = shaka.util.MimeUtils;
  2040.     const currentCodec = MimeUtils.getCodecBase(
  2041.         MimeUtils.getCodecs(this.sourceBufferTypes_[contentType]));
  2042.     const currentBasicType = MimeUtils.getBasicType(
  2043.         this.sourceBufferTypes_[contentType]);
  2045.     let newMimeType = shaka.util.MimeUtils.getFullType(refMimeType, refCodecs);
  2046.     let needTransmux = this.config_.forceTransmux;
  2047.     if (!shaka.media.Capabilities.isTypeSupported(newMimeType) ||
  2048.         (!this.sequenceMode_ &&
  2049.         shaka.util.MimeUtils.RAW_FORMATS.includes(newMimeType))) {
  2050.       needTransmux = true;
  2051.     }
  2052.     const newMimeTypeWithAllCodecs =
  2053.         shaka.util.MimeUtils.getFullTypeWithAllCodecs(
  2054.             refMimeType, refCodecs);
  2055.     const TransmuxerEngine = shaka.transmuxer.TransmuxerEngine;
  2056.     if (needTransmux) {
  2057.       const transmuxerPlugin =
  2058.           TransmuxerEngine.findTransmuxer(newMimeTypeWithAllCodecs);
  2059.       if (transmuxerPlugin) {
  2060.         const transmuxer = transmuxerPlugin();
  2061.         newMimeType =
  2062.             transmuxer.convertCodecs(contentType, newMimeTypeWithAllCodecs);
  2063.         transmuxer.destroy();
  2064.       }
  2065.     }
  2067.     const newCodec = MimeUtils.getCodecBase(
  2068.         MimeUtils.getCodecs(newMimeType));
  2069.     const newBasicType = MimeUtils.getBasicType(newMimeType);
  2071.     return currentCodec !== newCodec || currentBasicType !== newBasicType;
  2072.   }
  2074.   /**
  2075.    * Returns true if it's necessary reset the media source to load the
  2076.    * new stream.
  2077.    *
  2078.    * @param {shaka.util.ManifestParserUtils.ContentType} contentType
  2079.    * @param {shaka.extern.Stream} stream
  2080.    * @param {string} mimeType
  2081.    * @param {string} codecs
  2082.    * @return {boolean}
  2083.    */
  2084.   isResetMediaSourceNecessary(contentType, stream, mimeType, codecs) {
  2085.     if (!this.isCodecSwitchNecessary_(contentType, stream, mimeType, codecs)) {
  2086.       return false;
  2087.     }
  2089.     return this.config_.codecSwitchingStrategy !==
  2090.         shaka.config.CodecSwitchingStrategy.SMOOTH ||
  2091.         !shaka.media.Capabilities.isChangeTypeSupported() ||
  2092.         this.needSplitMuxedContent_;
  2093.   }
  2095.   /**
  2096.    * Update LCEVC Decoder object when ready for LCEVC Decode.
  2097.    * @param {?shaka.lcevc.Dec} lcevcDec
  2098.    */
  2099.   updateLcevcDec(lcevcDec) {
  2100.     this.lcevcDec_ = lcevcDec;
  2101.   }
  2103.   /**
  2104.    * @param {string} mimeType
  2105.    * @return {string}
  2106.    * @private
  2107.    */
  2108.   addExtraFeaturesToMimeType_(mimeType) {
  2109.     const extraFeatures = this.config_.addExtraFeaturesToSourceBuffer(mimeType);
  2110.     const extendedType = mimeType + extraFeatures;
  2111.     shaka.log.debug('Using full mime type', extendedType);
  2113.     return extendedType;
  2114.   }
  2115. };
  2118. /**
  2119.  * Internal reference to window.URL.createObjectURL function to avoid
  2120.  * compatibility issues with other libraries and frameworks such as React
  2121.  * Native. For use in unit tests only, not meant for external use.
  2122.  *
  2123.  * @type {function(?):string}
  2124.  */
  2125. shaka.media.MediaSourceEngine.createObjectURL = window.URL.createObjectURL;
  2128. /**
  2129.  * @typedef {{
  2130.  *   start: function(),
  2131.  *   p: !shaka.util.PublicPromise,
  2132.  *   uri: ?string
  2133.  * }}
  2134.  *
  2135.  * @summary An operation in queue.
  2136.  * @property {function()} start
  2137.  *   The function which starts the operation.
  2138.  * @property {!shaka.util.PublicPromise} p
  2139.  *   The PublicPromise which is associated with this operation.
  2140.  * @property {?string} uri
  2141.  *   A segment URI (if any) associated with this operation.
  2142.  */
  2143. shaka.media.MediaSourceEngine.Operation;
  2146. /**
  2147.  * @enum {string}
  2148.  * @private
  2149.  */
  2150. shaka.media.MediaSourceEngine.SourceBufferMode_ = {
  2151.   SEQUENCE: 'sequence',
  2152.   SEGMENTS: 'segments',
  2153. };