mirror of
https://github.com/shaka-project/shaka-player.git
synced 2026-06-24 17:35:10 +03:00
Michelle Zhuo
41ad98a99f
When the user chooses not to show captions, we unload the text stream, by canceling the update of text mediaState, and deleting the text mediaState. Since setupStreams_() is an async function, I'm adding a boolean variable to mark the request of unloading text stream, so as to prevent the race condition caused by quickly hiding and showing captions. Closes #1058. Change-Id: I554522b542bde5db037d74aa3a499d1ac0001151
2162 lines
76 KiB
JavaScript
2162 lines
76 KiB
JavaScript
/**
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* @license
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* Copyright 2016 Google Inc.
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*
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* Licensed under the Apache License, Version 2.0 (the "License");
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* you may not use this file except in compliance with the License.
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* You may obtain a copy of the License at
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*
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* http://www.apache.org/licenses/LICENSE-2.0
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*
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* Unless required by applicable law or agreed to in writing, software
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* distributed under the License is distributed on an "AS IS" BASIS,
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* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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* See the License for the specific language governing permissions and
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* limitations under the License.
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*/
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goog.provide('shaka.media.StreamingEngine');
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goog.require('goog.asserts');
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goog.require('shaka.log');
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goog.require('shaka.media.MediaSourceEngine');
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goog.require('shaka.media.Playhead');
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goog.require('shaka.net.Backoff');
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goog.require('shaka.net.NetworkingEngine');
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goog.require('shaka.util.Error');
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goog.require('shaka.util.FakeEvent');
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goog.require('shaka.util.Functional');
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goog.require('shaka.util.IDestroyable');
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goog.require('shaka.util.ManifestParserUtils');
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goog.require('shaka.util.MapUtils');
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goog.require('shaka.util.MimeUtils');
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goog.require('shaka.util.Mp4Parser');
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goog.require('shaka.util.PublicPromise');
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goog.require('shaka.util.StreamUtils');
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/**
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* Creates a StreamingEngine.
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*
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* The StreamingEngine is responsible for setting up the Manifest's Streams
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* (i.e., for calling each Stream's createSegmentIndex() function), for
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* downloading segments, for co-ordinating audio, video, and text buffering,
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* and for handling Period transitions. The StreamingEngine provides an
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* interface to switch between Streams, but it does not choose which Streams to
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* switch to.
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*
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* The StreamingEngine notifies its owner when it needs to buffer a new Period,
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* so its owner can choose which Streams within that Period to initially
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* buffer. Moreover, the StreamingEngine also notifies its owner when any
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* Stream within the current Period may be switched to, so its owner can switch
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* bitrates, resolutions, or languages.
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*
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* The StreamingEngine does not need to be notified about changes to the
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* Manifest's SegmentIndexes; however, it does need to be notified when new
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* Periods are added to the Manifest, so it can set up that Period's Streams.
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*
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* To start the StreamingEngine the owner must first call configure() followed
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* by init(). The StreamingEngine will then call onChooseStreams(p) when it
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* needs to buffer Period p; it will then switch to the Streams returned from
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* that function. The StreamingEngine will call onCanSwitch() when any
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* Stream within the current Period may be switched to.
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*
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* The owner must call seeked() each time the playhead moves to a new location
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* within the presentation timeline; however, the owner may forego calling
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* seeked() when the playhead moves outside the presentation timeline.
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*
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* @param {shakaExtern.Manifest} manifest
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* @param {shaka.media.StreamingEngine.PlayerInterface} playerInterface
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*
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* @constructor
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* @struct
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* @implements {shaka.util.IDestroyable}
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*/
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shaka.media.StreamingEngine = function(manifest, playerInterface) {
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/** @private {?shaka.media.StreamingEngine.PlayerInterface} */
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this.playerInterface_ = playerInterface;
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/** @private {?shakaExtern.Manifest} */
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this.manifest_ = manifest;
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/** @private {?shakaExtern.StreamingConfiguration} */
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this.config_ = null;
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/** @private {number} */
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this.bufferingGoalScale_ = 1;
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/** @private {Promise} */
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this.setupPeriodPromise_ = Promise.resolve();
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/**
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* Maps a Period's index to an object that indicates that either
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* 1. the Period has not been set up (undefined)
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* 2. the Period is being set up ([a PublicPromise, false]),
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* 3. the Period is set up (i.e., all Streams within the Period are set up)
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* and can be switched to ([a PublicPromise, true]).
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*
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* @private {Array.<?{promise: shaka.util.PublicPromise, resolved: boolean}>}
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*/
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this.canSwitchPeriod_ = [];
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/**
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* Maps a Stream's ID to an object that indicates that either
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* 1. the Stream has not been set up (undefined)
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* 2. the Stream is being set up ([a Promise instance, false]),
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* 3. the Stream is set up and can be switched to
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* ([a Promise instance, true]).
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*
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* @private {Object.<number,
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* ?{promise: shaka.util.PublicPromise, resolved: boolean}>}
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*/
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this.canSwitchStream_ = {};
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/**
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* Maps a content type, e.g., 'audio', 'video', or 'text', to a MediaState.
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*
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* @private {Object.<shaka.util.ManifestParserUtils.ContentType,
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!shaka.media.StreamingEngine.MediaState_>}
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*/
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this.mediaStates_ = {};
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/**
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* Set to true once one segment of each content type has been buffered.
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*
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* @private {boolean}
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*/
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this.startupComplete_ = false;
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/**
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* Used for delay and backoff of failure callbacks, so that apps do not retry
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* instantly.
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*
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* @private {shaka.net.Backoff}
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*/
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this.failureCallbackBackoff_ = null;
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/**
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* Set to true on fatal error. Interrupts fetchAndAppend_().
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*
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* @private {boolean}
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*/
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this.fatalError_ = false;
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/** @private {boolean} */
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this.destroyed_ = false;
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/**
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* Set to true when a request to unload text stream comes in. This is used
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* since loading new text stream is async, the request of unloading text
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* stream might come in before setting up new text stream is finished.
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* @private {boolean}
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*/
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this.unloadingTextStream_ = false;
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/** @private {number} */
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this.textStreamSequenceId_ = 0;
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};
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/**
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* @typedef {{
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* variant: (?shakaExtern.Variant|undefined),
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* text: ?shakaExtern.Stream
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* }}
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*
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* @property {(?shakaExtern.Variant|undefined)} variant
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* The chosen variant. May be omitted for text re-init.
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* @property {?shakaExtern.Stream} text
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* The chosen text stream.
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*/
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shaka.media.StreamingEngine.ChosenStreams;
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/**
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* @typedef {{
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* playhead: !shaka.media.Playhead,
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* mediaSourceEngine: !shaka.media.MediaSourceEngine,
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* netEngine: shaka.net.NetworkingEngine,
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* onChooseStreams: function(!shakaExtern.Period):
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* shaka.media.StreamingEngine.ChosenStreams,
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* onCanSwitch: function(),
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* onError: function(!shaka.util.Error),
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* onEvent: function(!Event),
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* onManifestUpdate: function(),
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* onSegmentAppended: function(),
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* onInitialStreamsSetup: (function()|undefined),
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* onStartupComplete: (function()|undefined)}
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* }}
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*
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* @property {!shaka.media.Playhead} playhead
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* The Playhead. The caller retains ownership.
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* @property {!shaka.media.MediaSourceEngine} mediaSourceEngine
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* The MediaSourceEngine. The caller retains ownership.
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* @property {shaka.net.NetworkingEngine} netEngine
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* The NetworkingEngine instance to use. The caller retains ownership.
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* @property {function(!shakaExtern.Period):
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* shaka.media.StreamingEngine.ChosenStreams} onChooseStreams
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* Called by StreamingEngine when the given Period needs to be buffered.
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* StreamingEngine will switch to the variant and text stream returned from
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* this function.
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* The owner cannot call switch() directly until the StreamingEngine calls
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* onCanSwitch().
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* @property {function()} onCanSwitch
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* Called by StreamingEngine when the Period is set up and switching is
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* permitted.
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* @property {function(!shaka.util.Error)} onError
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* Called when an error occurs. If the error is recoverable (see
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* @link{shaka.util.Error}) then the caller may invoke either
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* StreamingEngine.switch*() or StreamingEngine.seeked() to attempt recovery.
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* @property {function(!Event)} onEvent
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* Called when an event occurs that should be sent to the app.
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* @property {function()} onManifestUpdate
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* Called when an embedded 'emsg' box should trigger a manifest update.
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* @property {function()} onSegmentAppended
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* Called after a segment is successfully appended to a MediaSource.
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* @property {(function()|undefined)} onInitialStreamsSetup
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* Optional callback which is called when the initial set of Streams have been
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* setup. Intended to be used by tests.
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* @property {(function()|undefined)} onStartupComplete
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* Optional callback which is called when startup has completed. Intended to
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* be used by tests.
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*/
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shaka.media.StreamingEngine.PlayerInterface;
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/**
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* @typedef {{
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* type: shaka.util.ManifestParserUtils.ContentType,
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* stream: shakaExtern.Stream,
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* lastStream: ?shakaExtern.Stream,
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* lastSegmentReference: shaka.media.SegmentReference,
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* restoreStreamAfterTrickPlay: ?shakaExtern.Stream,
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* needInitSegment: boolean,
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* needPeriodIndex: number,
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* endOfStream: boolean,
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* performingUpdate: boolean,
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* updateTimer: ?number,
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* waitingToClearBuffer: boolean,
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* waitingToFlushBuffer: boolean,
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* clearingBuffer: boolean,
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* recovering: boolean,
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* hasError: boolean,
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* resumeAt: number
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* }}
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*
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* @description
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* Contains the state of a logical stream, i.e., a sequence of segmented data
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* for a particular content type. At any given time there is a Stream object
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* associated with the state of the logical stream.
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*
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* @property {shaka.util.ManifestParserUtils.ContentType} type
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* The stream's content type, e.g., 'audio', 'video', or 'text'.
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* @property {shakaExtern.Stream} stream
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* The current Stream.
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* @property {?shakaExtern.Stream} lastStream
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* The Stream of the last segment that was appended.
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* @property {shaka.media.SegmentReference} lastSegmentReference
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* The SegmentReference of the last segment that was appended.
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* @property {?shakaExtern.Stream} restoreStreamAfterTrickPlay
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* The Stream to restore after trick play mode is turned off.
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* @property {boolean} needInitSegment
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* True indicates that |stream|'s init segment must be inserted before the
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* next media segment is appended.
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* @property {boolean} endOfStream
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* True indicates that the end of the buffer has hit the end of the
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* presentation.
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* @property {number} needPeriodIndex
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* The index of the Period which needs to be buffered.
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* @property {boolean} performingUpdate
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* True indicates that an update is in progress.
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* @property {?number} updateTimer
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* A non-null value indicates that an update is scheduled.
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* @property {boolean} waitingToClearBuffer
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* True indicates that the buffer must be cleared after the current update
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* finishes.
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* @property {boolean} waitingToFlushBuffer
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* True indicates that the buffer must be flushed after it is cleared.
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* @property {boolean} clearingBuffer
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* True indicates that the buffer is being cleared.
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* @property {boolean} recovering
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* True indicates that the last segment was not appended because it could not
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* fit in the buffer.
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* @property {boolean} hasError
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* True indicates that the stream has encountered an error and has stopped
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* updates.
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* @property {number} resumeAt
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* An override for the time to start performing updates at. If the playhead
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* is behind this time, update_() will still start fetching segments from
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* this time. If the playhead is ahead of the time, this field is ignored.
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*/
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shaka.media.StreamingEngine.MediaState_;
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/**
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* The minimum number seconds that will remain buffered after evicting media.
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*
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* @const {number}
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*/
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shaka.media.StreamingEngine.prototype.MIN_BUFFER_LENGTH = 2;
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/** @override */
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shaka.media.StreamingEngine.prototype.destroy = function() {
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for (var type in this.mediaStates_) {
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this.cancelUpdate_(this.mediaStates_[type]);
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}
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this.playerInterface_ = null;
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this.manifest_ = null;
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this.setupPeriodPromise_ = null;
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this.canSwitchPeriod_ = null;
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this.canSwitchStream_ = null;
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this.mediaStates_ = null;
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this.config_ = null;
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this.destroyed_ = true;
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return Promise.resolve();
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};
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/**
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* Called by the Player to provide an updated configuration any time it changes.
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* Will be called at least once before init().
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*
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* @param {shakaExtern.StreamingConfiguration} config
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*/
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shaka.media.StreamingEngine.prototype.configure = function(config) {
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this.config_ = config;
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// Create separate parameters for backoff during streaming failure.
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/** @type {shakaExtern.RetryParameters} */
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var failureRetryParams = {
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// The term "attempts" includes the initial attempt, plus all retries.
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// In order to see a delay, there would have to be at least 2 attempts.
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maxAttempts: Math.max(config.retryParameters.maxAttempts, 2),
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baseDelay: config.retryParameters.baseDelay,
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backoffFactor: config.retryParameters.backoffFactor,
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fuzzFactor: config.retryParameters.fuzzFactor,
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timeout: 0 // irrelevant
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};
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// We don't want to ever run out of attempts. The application should be
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// allowed to retry streaming infinitely if it wishes.
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var autoReset = true;
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this.failureCallbackBackoff_ =
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new shaka.net.Backoff(failureRetryParams, autoReset);
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};
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/**
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* Initializes the StreamingEngine.
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*
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* After this function is called the StreamingEngine will call
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* onChooseStreams(p) when it needs to buffer Period p and onCanSwitch() when
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* any Stream within that Period may be switched to.
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*
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* After the StreamingEngine calls onChooseStreams(p) for the first time, it
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* will begin setting up the Streams returned from that function and
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* subsequently switch to them. However, the StreamingEngine will not begin
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* setting up any other Streams until at least one segment from each of the
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* initial set of Streams has been buffered (this reduces startup latency).
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* After the StreamingEngine completes this startup phase it will begin setting
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* up each Period's Streams (while buffering in parrallel).
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*
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* When the StreamingEngine needs to buffer the next Period it will have
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* already set up that Period's Streams. So, when the StreamingEngine calls
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* onChooseStreams(p) after the first time, the StreamingEngine will
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* immediately switch to the Streams returned from that function.
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*
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* @return {!Promise}
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*/
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shaka.media.StreamingEngine.prototype.init = function() {
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goog.asserts.assert(this.config_,
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'StreamingEngine configure() must be called before init()!');
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// Determine which Period we must buffer.
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var playheadTime = this.playerInterface_.playhead.getTime();
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var needPeriodIndex = this.findPeriodContainingTime_(playheadTime);
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// Get the initial set of Streams.
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var initialStreams = this.playerInterface_.onChooseStreams(
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this.manifest_.periods[needPeriodIndex]);
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if (!initialStreams.variant && !initialStreams.text) {
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shaka.log.error('init: no Streams chosen');
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return Promise.reject(new shaka.util.Error(
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shaka.util.Error.Severity.CRITICAL,
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shaka.util.Error.Category.STREAMING,
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shaka.util.Error.Code.INVALID_STREAMS_CHOSEN));
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}
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// Setup the initial set of Streams and then begin each update cycle. After
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// startup completes onUpdate_() will set up the remaining Periods.
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return this.initStreams_(initialStreams).then(function() {
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shaka.log.debug('init: completed initial Stream setup');
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// Subtlety: onInitialStreamsSetup() may call switch() or seeked(), so we
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// must schedule an update beforehand so |updateTimer| is set.
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if (this.playerInterface_ && this.playerInterface_.onInitialStreamsSetup) {
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shaka.log.v1('init: calling onInitialStreamsSetup()...');
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this.playerInterface_.onInitialStreamsSetup();
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}
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}.bind(this));
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};
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/**
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* Gets the current Period the stream is in. This Period may not be initialized
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* yet if canSwitch(period) has not been called yet.
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* @return {shakaExtern.Period}
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*/
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shaka.media.StreamingEngine.prototype.getCurrentPeriod = function() {
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var playheadTime = this.playerInterface_.playhead.getTime();
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var needPeriodIndex = this.findPeriodContainingTime_(playheadTime);
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return this.manifest_.periods[needPeriodIndex];
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};
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/**
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* Gets the Period in which we are currently buffering. This may be different
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* from the Period which contains the Playhead.
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* @return {?shakaExtern.Period}
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*/
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shaka.media.StreamingEngine.prototype.getActivePeriod = function() {
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goog.asserts.assert(this.mediaStates_, 'Must be initialized');
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var ContentType = shaka.util.ManifestParserUtils.ContentType;
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var anyMediaState = this.mediaStates_[ContentType.VIDEO] ||
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this.mediaStates_[ContentType.AUDIO];
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return anyMediaState ?
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this.manifest_.periods[anyMediaState.needPeriodIndex] : null;
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};
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/**
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* Get the active audio stream. Returns null if there is no audio streaming.
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* @return {?shakaExtern.Stream}
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*/
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shaka.media.StreamingEngine.prototype.getActiveAudio = function() {
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var ContentType = shaka.util.ManifestParserUtils.ContentType;
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return this.getStream_(ContentType.AUDIO);
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};
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/**
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* Get the active video stream. Returns null if there is no video streaming.
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* @return {?shakaExtern.Stream}
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*/
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shaka.media.StreamingEngine.prototype.getActiveVideo = function() {
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var ContentType = shaka.util.ManifestParserUtils.ContentType;
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return this.getStream_(ContentType.VIDEO);
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};
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/**
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* Get the active text stream. Returns null if there is no text streaming.
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* @return {?shakaExtern.Stream}
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*/
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shaka.media.StreamingEngine.prototype.getActiveText = function() {
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var ContentType = shaka.util.ManifestParserUtils.ContentType;
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return this.getStream_(ContentType.TEXT);
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};
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/**
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* Get the active stream for the given type. Returns null if there is no stream
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* for the given type.
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* @param {shaka.util.ManifestParserUtils.ContentType} type
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* @return {?shakaExtern.Stream}
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* @private
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*/
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shaka.media.StreamingEngine.prototype.getStream_ = function(type) {
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goog.asserts.assert(this.mediaStates_, 'Must be initialized');
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var state = this.mediaStates_[type];
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if (state) {
|
|
// Don't tell the caller about trick play streams. If we're in trick
|
|
// play, return the stream we will go back to after we exit trick play.
|
|
return state.restoreStreamAfterTrickPlay || state.stream;
|
|
} else {
|
|
return null;
|
|
}
|
|
};
|
|
|
|
|
|
/**
|
|
* Notifies StreamingEngine that a new text stream was added to the manifest.
|
|
* This initializes the given stream. This returns a Promise that resolves when
|
|
* the stream has been set up, and a media state has been created.
|
|
*
|
|
* @param {shakaExtern.Stream} stream
|
|
* @return {!Promise}
|
|
*/
|
|
shaka.media.StreamingEngine.prototype.loadNewTextStream = function(stream) {
|
|
var ContentType = shaka.util.ManifestParserUtils.ContentType;
|
|
|
|
// Since setupStreams_() is async, if the user hides/shows captions quickly,
|
|
// there would be a race condition that a new text media state is created
|
|
// but the old media state is not yet deleted.
|
|
// The Sequence Id is to avoid the risk condition.
|
|
this.textStreamSequenceId_++;
|
|
this.unloadingTextStream_ = false;
|
|
var currentSequenceId = this.textStreamSequenceId_;
|
|
this.playerInterface_.mediaSourceEngine.init({text: stream});
|
|
|
|
return this.setupStreams_([stream]).then(function() {
|
|
if ((this.textStreamSequenceId_ == currentSequenceId) &&
|
|
!this.mediaStates_[ContentType.TEXT] && !this.unloadingTextStream_) {
|
|
var playheadTime = this.playerInterface_.playhead.getTime();
|
|
var needPeriodIndex = this.findPeriodContainingTime_(playheadTime);
|
|
this.mediaStates_[ContentType.TEXT] =
|
|
this.createMediaState_(stream, needPeriodIndex);
|
|
this.scheduleUpdate_(this.mediaStates_[ContentType.TEXT], 0);
|
|
}
|
|
}.bind(this));
|
|
};
|
|
|
|
|
|
/**
|
|
* Stop fetching text stream when the user chooses to hide the caption.
|
|
*/
|
|
shaka.media.StreamingEngine.prototype.unloadTextStream = function() {
|
|
var ContentType = shaka.util.ManifestParserUtils.ContentType;
|
|
this.unloadingTextStream_ = true;
|
|
if (this.mediaStates_[ContentType.TEXT]) {
|
|
this.cancelUpdate_(this.mediaStates_[ContentType.TEXT]);
|
|
delete this.mediaStates_[ContentType.TEXT];
|
|
}
|
|
};
|
|
|
|
|
|
/**
|
|
* Set trick play on or off.
|
|
* If trick play is on, related trick play streams will be used when possible.
|
|
* @param {boolean} on
|
|
*/
|
|
shaka.media.StreamingEngine.prototype.setTrickPlay = function(on) {
|
|
var ContentType = shaka.util.ManifestParserUtils.ContentType;
|
|
|
|
var mediaState = this.mediaStates_[ContentType.VIDEO];
|
|
if (!mediaState) return;
|
|
|
|
var stream = mediaState.stream;
|
|
if (!stream) return;
|
|
|
|
shaka.log.debug('setTrickPlay', on);
|
|
if (on) {
|
|
var trickModeVideo = stream.trickModeVideo;
|
|
if (!trickModeVideo) return; // Can't engage trick play.
|
|
|
|
var normalVideo = mediaState.restoreStreamAfterTrickPlay;
|
|
if (normalVideo) return; // Already in trick play.
|
|
|
|
shaka.log.debug('Engaging trick mode stream', trickModeVideo);
|
|
this.switchInternal_(trickModeVideo, false);
|
|
mediaState.restoreStreamAfterTrickPlay = stream;
|
|
} else {
|
|
var normalVideo = mediaState.restoreStreamAfterTrickPlay;
|
|
if (!normalVideo) return;
|
|
|
|
shaka.log.debug('Restoring non-trick-mode stream', normalVideo);
|
|
mediaState.restoreStreamAfterTrickPlay = null;
|
|
this.switchInternal_(normalVideo, true);
|
|
}
|
|
};
|
|
|
|
|
|
/**
|
|
* @param {shakaExtern.Variant} variant
|
|
* @param {boolean} clearBuffer
|
|
*/
|
|
shaka.media.StreamingEngine.prototype.switchVariant =
|
|
function(variant, clearBuffer) {
|
|
if (variant.video) {
|
|
this.switchInternal_(variant.video, clearBuffer);
|
|
}
|
|
|
|
if (variant.audio) {
|
|
this.switchInternal_(variant.audio, clearBuffer);
|
|
}
|
|
};
|
|
|
|
|
|
/**
|
|
* @param {shakaExtern.Stream} textStream
|
|
*/
|
|
shaka.media.StreamingEngine.prototype.switchTextStream = function(textStream) {
|
|
goog.asserts.assert(textStream && textStream.type == 'text',
|
|
'Wrong stream type passed to switchTextStream!');
|
|
this.switchInternal_(textStream, /* clearBuffer */ true);
|
|
};
|
|
|
|
|
|
/**
|
|
* Switches to the given Stream. |stream| may be from any Variant or any
|
|
* Period.
|
|
*
|
|
* @param {shakaExtern.Stream} stream
|
|
* @param {boolean} clearBuffer
|
|
* @private
|
|
*/
|
|
shaka.media.StreamingEngine.prototype.switchInternal_ = function(
|
|
stream, clearBuffer) {
|
|
var ContentType = shaka.util.ManifestParserUtils.ContentType;
|
|
var mediaState = this.mediaStates_[/** @type {!ContentType} */(stream.type)];
|
|
|
|
if (!mediaState && stream.type == ContentType.TEXT &&
|
|
this.config_.ignoreTextStreamFailures) {
|
|
this.loadNewTextStream(stream);
|
|
return;
|
|
}
|
|
goog.asserts.assert(mediaState, 'switch: expected mediaState to exist');
|
|
if (!mediaState) return;
|
|
|
|
// If we are selecting a stream from a different Period, then we need to
|
|
// handle a Period transition. Simply ignore the given stream, assuming that
|
|
// Player will select the same track in onChooseStreams.
|
|
var periodIndex = this.findPeriodContainingStream_(stream);
|
|
if (clearBuffer && periodIndex != mediaState.needPeriodIndex) {
|
|
shaka.log.debug('switch: switching to stream in another Period; clearing ' +
|
|
'buffer and changing Periods');
|
|
// handlePeriodTransition_ will be called on the next update because the
|
|
// current Period won't match the playhead Period.
|
|
this.clearAllBuffers_();
|
|
return;
|
|
}
|
|
|
|
if (mediaState.restoreStreamAfterTrickPlay) {
|
|
shaka.log.debug('switch during trick play mode', stream);
|
|
|
|
// Already in trick play mode, so stick with trick mode tracks if possible.
|
|
if (stream.trickModeVideo) {
|
|
// Use the trick mode stream, but revert to the new selection later.
|
|
mediaState.restoreStreamAfterTrickPlay = stream;
|
|
stream = stream.trickModeVideo;
|
|
shaka.log.debug('switch found trick play stream', stream);
|
|
} else {
|
|
// No special trick mode video for this stream!
|
|
mediaState.restoreStreamAfterTrickPlay = null;
|
|
shaka.log.debug('switch found no special trick play stream');
|
|
}
|
|
}
|
|
|
|
// Ensure the Period is ready.
|
|
var canSwitchRecord = this.canSwitchPeriod_[periodIndex];
|
|
goog.asserts.assert(
|
|
canSwitchRecord && canSwitchRecord.resolved,
|
|
'switch: expected Period ' + periodIndex + ' to be ready');
|
|
if (!canSwitchRecord || !canSwitchRecord.resolved) return;
|
|
|
|
// Sanity check. If the Period is ready then the Stream should be ready too.
|
|
canSwitchRecord = this.canSwitchStream_[stream.id];
|
|
goog.asserts.assert(canSwitchRecord && canSwitchRecord.resolved,
|
|
'switch: expected Stream ' + stream.id + ' to be ready');
|
|
if (!canSwitchRecord || !canSwitchRecord.resolved) return;
|
|
|
|
if (mediaState.stream == stream) {
|
|
var streamTag = shaka.media.StreamingEngine.logPrefix_(mediaState);
|
|
shaka.log.debug('switch: Stream ' + streamTag + ' already active');
|
|
return;
|
|
}
|
|
|
|
if (stream.type == ContentType.TEXT) {
|
|
// Mime types are allowed to change for text streams.
|
|
// Reinitialize the text parser, but only if we are going to fetch the init
|
|
// segment again.
|
|
var fullMimeType = shaka.util.MimeUtils.getFullType(
|
|
stream.mimeType, stream.codecs);
|
|
this.playerInterface_.mediaSourceEngine.reinitText(fullMimeType);
|
|
}
|
|
|
|
mediaState.stream = stream;
|
|
mediaState.needInitSegment = true;
|
|
|
|
var streamTag = shaka.media.StreamingEngine.logPrefix_(mediaState);
|
|
shaka.log.debug('switch: switching to Stream ' + streamTag);
|
|
|
|
if (clearBuffer) {
|
|
if (mediaState.clearingBuffer) {
|
|
// We are already going to clear the buffer, but make sure it is also
|
|
// flushed.
|
|
mediaState.waitingToFlushBuffer = true;
|
|
} else if (mediaState.performingUpdate) {
|
|
// We are performing an update, so we have to wait until it's finished.
|
|
// onUpdate_() will call clearBuffer_() when the update has
|
|
// finished.
|
|
mediaState.waitingToClearBuffer = true;
|
|
mediaState.waitingToFlushBuffer = true;
|
|
} else {
|
|
// Cancel the update timer, if any.
|
|
this.cancelUpdate_(mediaState);
|
|
// Clear right away.
|
|
this.clearBuffer_(mediaState, /* flush */ true);
|
|
}
|
|
}
|
|
};
|
|
|
|
|
|
/**
|
|
* Notifies the StreamingEngine that the playhead has moved to a valid time
|
|
* within the presentation timeline.
|
|
*/
|
|
shaka.media.StreamingEngine.prototype.seeked = function() {
|
|
goog.asserts.assert(this.mediaStates_, 'Must not be destroyed');
|
|
|
|
var playheadTime = this.playerInterface_.playhead.getTime();
|
|
var isAllBuffered = Object.keys(this.mediaStates_).every(function(type) {
|
|
return this.playerInterface_.mediaSourceEngine.isBuffered(
|
|
type, playheadTime);
|
|
}.bind(this));
|
|
|
|
// Only treat as a buffered seek if every media state has a buffer. For
|
|
// example, if we have buffered text but not video, we should still clear
|
|
// every buffer so all media states need the same Period.
|
|
if (isAllBuffered) {
|
|
shaka.log.debug(
|
|
'(all): seeked: buffered seek: playheadTime=' + playheadTime);
|
|
return;
|
|
}
|
|
|
|
// This was an unbuffered seek (for at least one stream), clear all buffers.
|
|
// Don't clear only some of the buffers because we can become stalled since
|
|
// the media states are waiting for different Periods.
|
|
shaka.log.debug('(all): seeked: unbuffered seek: clearing all buffers');
|
|
this.clearAllBuffers_();
|
|
};
|
|
|
|
|
|
/**
|
|
* Clears the buffer for every stream. Unlike clearBuffer_, this will handle
|
|
* cases where a MediaState is performing an update. After this runs, every
|
|
* MediaState will have a pending update.
|
|
* @private
|
|
*/
|
|
shaka.media.StreamingEngine.prototype.clearAllBuffers_ = function() {
|
|
for (var type in this.mediaStates_) {
|
|
var mediaState = this.mediaStates_[type];
|
|
var logPrefix = shaka.media.StreamingEngine.logPrefix_(mediaState);
|
|
|
|
if (mediaState.clearingBuffer) {
|
|
// We're already clearing the buffer, so we don't need to clear the
|
|
// buffer again.
|
|
shaka.log.debug(logPrefix, 'clear: already clearing the buffer');
|
|
continue;
|
|
}
|
|
|
|
if (mediaState.waitingToClearBuffer) {
|
|
// May not be performing an update, but an update will still happen.
|
|
// See: https://github.com/google/shaka-player/issues/334
|
|
shaka.log.debug(logPrefix, 'clear: already waiting');
|
|
continue;
|
|
}
|
|
|
|
if (mediaState.performingUpdate) {
|
|
// We are performing an update, so we have to wait until it's finished.
|
|
// onUpdate_() will call clearBuffer_() when the update has
|
|
// finished.
|
|
shaka.log.debug(logPrefix, 'clear: currently updating');
|
|
mediaState.waitingToClearBuffer = true;
|
|
continue;
|
|
}
|
|
|
|
if (this.playerInterface_.mediaSourceEngine.bufferStart(type) == null) {
|
|
// Nothing buffered.
|
|
shaka.log.debug(logPrefix, 'clear: nothing buffered');
|
|
if (mediaState.updateTimer == null) {
|
|
// Note: an update cycle stops when we buffer to the end of the
|
|
// presentation or Period, or when we raise an error.
|
|
this.scheduleUpdate_(mediaState, 0);
|
|
}
|
|
continue;
|
|
}
|
|
|
|
// An update may be scheduled, but we can just cancel it and clear the
|
|
// buffer right away. Note: clearBuffer_() will schedule the next update.
|
|
shaka.log.debug(logPrefix, 'clear: handling right now');
|
|
this.cancelUpdate_(mediaState);
|
|
this.clearBuffer_(mediaState, /* flush */ false);
|
|
}
|
|
};
|
|
|
|
|
|
/**
|
|
* Initializes the given streams and media states if required. This will
|
|
* schedule updates for the given types.
|
|
*
|
|
* @param {shaka.media.StreamingEngine.ChosenStreams} chosenStreams
|
|
* @param {number=} opt_resumeAt
|
|
* @return {!Promise}
|
|
* @private
|
|
*/
|
|
shaka.media.StreamingEngine.prototype.initStreams_ = function(
|
|
chosenStreams, opt_resumeAt) {
|
|
goog.asserts.assert(this.config_,
|
|
'StreamingEngine configure() must be called before init()!');
|
|
|
|
// Determine which Period we must buffer.
|
|
var playheadTime = this.playerInterface_.playhead.getTime();
|
|
var needPeriodIndex = this.findPeriodContainingTime_(playheadTime);
|
|
|
|
// Init/re-init MediaSourceEngine. Note that a re-init is only valid for text.
|
|
var ContentType = shaka.util.ManifestParserUtils.ContentType;
|
|
|
|
/** @type {!Object.<!ContentType, shakaExtern.Stream>} */
|
|
var streamsByType = {};
|
|
/** @type {!Array.<shakaExtern.Stream>} */
|
|
var streams = [];
|
|
|
|
if (chosenStreams.variant && chosenStreams.variant.audio) {
|
|
streamsByType[ContentType.AUDIO] = chosenStreams.variant.audio;
|
|
streams.push(chosenStreams.variant.audio);
|
|
}
|
|
if (chosenStreams.variant && chosenStreams.variant.video) {
|
|
streamsByType[ContentType.VIDEO] = chosenStreams.variant.video;
|
|
streams.push(chosenStreams.variant.video);
|
|
}
|
|
if (chosenStreams.text) {
|
|
streamsByType[ContentType.TEXT] = chosenStreams.text;
|
|
streams.push(chosenStreams.text);
|
|
}
|
|
|
|
// Init MediaSourceEngine.
|
|
this.playerInterface_.mediaSourceEngine.init(streamsByType);
|
|
|
|
this.setDuration_();
|
|
|
|
// Setup the initial set of Streams and then begin each update cycle. After
|
|
// startup completes onUpdate_() will set up the remaining Periods.
|
|
return this.setupStreams_(streams).then(function() {
|
|
if (this.destroyed_) return;
|
|
|
|
for (var type in streamsByType) {
|
|
var stream = streamsByType[type];
|
|
if (!this.mediaStates_[type]) {
|
|
this.mediaStates_[type] =
|
|
this.createMediaState_(stream, needPeriodIndex, opt_resumeAt);
|
|
this.scheduleUpdate_(this.mediaStates_[type], 0);
|
|
}
|
|
}
|
|
}.bind(this));
|
|
};
|
|
|
|
|
|
/**
|
|
* Creates a media state.
|
|
*
|
|
* @param {shakaExtern.Stream} stream
|
|
* @param {number} needPeriodIndex
|
|
* @param {number=} opt_resumeAt
|
|
* @return {shaka.media.StreamingEngine.MediaState_}
|
|
* @private
|
|
*/
|
|
shaka.media.StreamingEngine.prototype.createMediaState_ = function(
|
|
stream, needPeriodIndex, opt_resumeAt) {
|
|
return /** @type {shaka.media.StreamingEngine.MediaState_} */ ({
|
|
stream: stream,
|
|
type: stream.type,
|
|
lastStream: null,
|
|
lastSegmentReference: null,
|
|
restoreStreamAfterTrickPlay: null,
|
|
needInitSegment: true,
|
|
needPeriodIndex: needPeriodIndex,
|
|
endOfStream: false,
|
|
performingUpdate: false,
|
|
updateTimer: null,
|
|
waitingToClearBuffer: false,
|
|
waitingToFlushBuffer: false,
|
|
clearingBuffer: false,
|
|
recovering: false,
|
|
hasError: false,
|
|
resumeAt: opt_resumeAt || 0
|
|
});
|
|
};
|
|
|
|
|
|
/**
|
|
* Sets up the given Period if necessary. Calls onError() if an error
|
|
* occurs.
|
|
*
|
|
* @param {number} periodIndex The Period's index.
|
|
* @return {!Promise} A Promise which is resolved when the given Period is
|
|
* setup.
|
|
* @private
|
|
*/
|
|
shaka.media.StreamingEngine.prototype.setupPeriod_ = function(periodIndex) {
|
|
var Functional = shaka.util.Functional;
|
|
var canSwitchRecord = this.canSwitchPeriod_[periodIndex];
|
|
if (canSwitchRecord) {
|
|
shaka.log.debug(
|
|
'(all) Period ' + periodIndex + ' is being or has been set up');
|
|
goog.asserts.assert(canSwitchRecord.promise, 'promise must not be null');
|
|
return canSwitchRecord.promise;
|
|
}
|
|
|
|
shaka.log.debug('(all) setting up Period ' + periodIndex);
|
|
canSwitchRecord = {
|
|
promise: new shaka.util.PublicPromise(),
|
|
resolved: false
|
|
};
|
|
this.canSwitchPeriod_[periodIndex] = canSwitchRecord;
|
|
|
|
var streams = this.manifest_.periods[periodIndex].variants
|
|
.map(function(variant) {
|
|
var result = [];
|
|
if (variant.audio)
|
|
result.push(variant.audio);
|
|
if (variant.video)
|
|
result.push(variant.video);
|
|
if (variant.video && variant.video.trickModeVideo)
|
|
result.push(variant.video.trickModeVideo);
|
|
return result;
|
|
})
|
|
.reduce(Functional.collapseArrays, [])
|
|
.filter(Functional.isNotDuplicate);
|
|
|
|
// Add text streams
|
|
streams.push.apply(streams, this.manifest_.periods[periodIndex].textStreams);
|
|
|
|
// Serialize Period set up.
|
|
this.setupPeriodPromise_ = this.setupPeriodPromise_.then(function() {
|
|
if (this.destroyed_) return;
|
|
return this.setupStreams_(streams);
|
|
}.bind(this)).then(function() {
|
|
if (this.destroyed_) return;
|
|
this.canSwitchPeriod_[periodIndex].promise.resolve();
|
|
this.canSwitchPeriod_[periodIndex].resolved = true;
|
|
shaka.log.v1('(all) setup Period ' + periodIndex);
|
|
}.bind(this)).catch(function(error) {
|
|
if (this.destroyed_) return;
|
|
this.canSwitchPeriod_[periodIndex].promise.reject();
|
|
delete this.canSwitchPeriod_[periodIndex];
|
|
shaka.log.warning('(all) failed to setup Period ' + periodIndex);
|
|
this.playerInterface_.onError(error);
|
|
// Don't stop other Periods from being set up.
|
|
}.bind(this));
|
|
|
|
return canSwitchRecord.promise;
|
|
};
|
|
|
|
|
|
/**
|
|
* Sets up the given Streams if necessary. Does NOT call onError() if an
|
|
* error occurs.
|
|
*
|
|
* @param {!Array.<!shakaExtern.Stream>} streams
|
|
* @return {!Promise}
|
|
* @private
|
|
*/
|
|
shaka.media.StreamingEngine.prototype.setupStreams_ = function(streams) {
|
|
// Make sure that all the streams have unique ids.
|
|
// (Duplicate ids will cause the player to hang).
|
|
var uniqueStreamIds = streams.map(function(s) { return s.id; })
|
|
.filter(shaka.util.Functional.isNotDuplicate);
|
|
|
|
goog.asserts.assert(uniqueStreamIds.length == streams.length,
|
|
'streams should have unique ids');
|
|
// Parallelize Stream set up.
|
|
var async = [];
|
|
|
|
for (var i = 0; i < streams.length; ++i) {
|
|
var stream = streams[i];
|
|
var canSwitchRecord = this.canSwitchStream_[stream.id];
|
|
|
|
if (canSwitchRecord) {
|
|
shaka.log.debug(
|
|
'(all) Stream ' + stream.id + ' is being or has been set up');
|
|
async.push(canSwitchRecord.promise);
|
|
} else {
|
|
shaka.log.v1('(all) setting up Stream ' + stream.id);
|
|
this.canSwitchStream_[stream.id] = {
|
|
promise: new shaka.util.PublicPromise(),
|
|
resolved: false
|
|
};
|
|
async.push(stream.createSegmentIndex());
|
|
}
|
|
}
|
|
|
|
return Promise.all(async).then(function() {
|
|
if (this.destroyed_) return;
|
|
|
|
for (var i = 0; i < streams.length; ++i) {
|
|
var stream = streams[i];
|
|
var canSwitchRecord = this.canSwitchStream_[stream.id];
|
|
if (!canSwitchRecord.resolved) {
|
|
canSwitchRecord.promise.resolve();
|
|
canSwitchRecord.resolved = true;
|
|
shaka.log.v1('(all) setup Stream ' + stream.id);
|
|
}
|
|
}
|
|
}.bind(this)).catch(function(error) {
|
|
if (this.destroyed_) return;
|
|
this.canSwitchStream_[stream.id].promise.reject();
|
|
delete this.canSwitchStream_[stream.id];
|
|
return Promise.reject(error);
|
|
}.bind(this));
|
|
};
|
|
|
|
|
|
/**
|
|
* Sets the MediaSource's duration.
|
|
* @private
|
|
*/
|
|
shaka.media.StreamingEngine.prototype.setDuration_ = function() {
|
|
var duration = this.manifest_.presentationTimeline.getDuration();
|
|
if (duration < Infinity) {
|
|
this.playerInterface_.mediaSourceEngine.setDuration(duration);
|
|
} else {
|
|
// Not all platforms support infinite durations, so set a finite duration
|
|
// so we can append segments and so the user agent can seek.
|
|
this.playerInterface_.mediaSourceEngine.setDuration(Math.pow(2, 32));
|
|
}
|
|
};
|
|
|
|
|
|
/**
|
|
* Called when |mediaState|'s update timer has expired.
|
|
*
|
|
* @param {!shaka.media.StreamingEngine.MediaState_} mediaState
|
|
* @private
|
|
*/
|
|
shaka.media.StreamingEngine.prototype.onUpdate_ = function(mediaState) {
|
|
var MapUtils = shaka.util.MapUtils;
|
|
if (this.destroyed_) return;
|
|
|
|
var logPrefix = shaka.media.StreamingEngine.logPrefix_(mediaState);
|
|
|
|
// Sanity check.
|
|
goog.asserts.assert(
|
|
!mediaState.performingUpdate && (mediaState.updateTimer != null),
|
|
logPrefix + ' unexpected call to onUpdate_()');
|
|
if (mediaState.performingUpdate || (mediaState.updateTimer == null)) return;
|
|
|
|
goog.asserts.assert(
|
|
!mediaState.clearingBuffer,
|
|
logPrefix + ' onUpdate_() should not be called when clearing the buffer');
|
|
if (mediaState.clearingBuffer) return;
|
|
|
|
mediaState.updateTimer = null;
|
|
|
|
// Handle pending buffer clears.
|
|
if (mediaState.waitingToClearBuffer) {
|
|
// Note: clearBuffer_() will schedule the next update.
|
|
shaka.log.debug(logPrefix, 'skipping update and clearing the buffer');
|
|
this.clearBuffer_(mediaState, mediaState.waitingToFlushBuffer);
|
|
return;
|
|
}
|
|
|
|
// Update the MediaState.
|
|
try {
|
|
var delay = this.update_(mediaState);
|
|
if (delay != null) {
|
|
this.scheduleUpdate_(mediaState, delay);
|
|
mediaState.hasError = false;
|
|
}
|
|
} catch (error) {
|
|
this.handleStreamingError_(error);
|
|
return;
|
|
}
|
|
|
|
goog.asserts.assert(this.mediaStates_, 'must not be destroyed');
|
|
|
|
var mediaStates = MapUtils.values(this.mediaStates_);
|
|
|
|
// Check if we've buffered to the end of the Period.
|
|
this.handlePeriodTransition_(mediaState);
|
|
|
|
// Check if we've buffered to the end of the presentation.
|
|
if (mediaStates.every(function(ms) { return ms.endOfStream; })) {
|
|
shaka.log.v1(logPrefix, 'calling endOfStream()...');
|
|
this.playerInterface_.mediaSourceEngine.endOfStream().then(function() {
|
|
// If the media segments don't reach the end, then we need to update the
|
|
// timeline duration to match the final media duration to avoid buffering
|
|
// forever at the end.
|
|
var duration = this.playerInterface_.mediaSourceEngine.getDuration();
|
|
this.manifest_.presentationTimeline.setDuration(duration);
|
|
}.bind(this));
|
|
}
|
|
};
|
|
|
|
|
|
/**
|
|
* Updates the given MediaState.
|
|
*
|
|
* @param {shaka.media.StreamingEngine.MediaState_} mediaState
|
|
* @return {?number} The number of seconds to wait until updating again or
|
|
* null if another update does not need to be scheduled.
|
|
* @throws {!shaka.util.Error} if an error occurs.
|
|
* @private
|
|
*/
|
|
shaka.media.StreamingEngine.prototype.update_ = function(mediaState) {
|
|
var logPrefix = shaka.media.StreamingEngine.logPrefix_(mediaState);
|
|
|
|
// Compute how far we've buffered ahead of the playhead.
|
|
var playheadTime = this.playerInterface_.playhead.getTime();
|
|
|
|
// Get the next timestamp we need.
|
|
var timeNeeded = this.getTimeNeeded_(mediaState, playheadTime);
|
|
shaka.log.v2(logPrefix, 'timeNeeded=' + timeNeeded);
|
|
|
|
var currentPeriodIndex = this.findPeriodContainingStream_(mediaState.stream);
|
|
var needPeriodIndex = this.findPeriodContainingTime_(timeNeeded);
|
|
|
|
// Get the amount of content we have buffered, accounting for drift. This
|
|
// is only used to determine if we have meet the buffering goal. This should
|
|
// be the same way that PlayheadObserver uses.
|
|
var bufferedAhead = this.playerInterface_.mediaSourceEngine.bufferedAheadOf(
|
|
mediaState.type, playheadTime);
|
|
|
|
shaka.log.v2(logPrefix,
|
|
'update_:',
|
|
'playheadTime=' + playheadTime,
|
|
'bufferedAhead=' + bufferedAhead);
|
|
|
|
var bufferingGoal = this.getBufferingGoal_();
|
|
|
|
// Check if we've buffered to the end of the presentation.
|
|
if (timeNeeded >= this.manifest_.presentationTimeline.getDuration()) {
|
|
// We shouldn't rebuffer if the playhead is close to the end of the
|
|
// presentation.
|
|
shaka.log.debug(logPrefix, 'buffered to end of presentation');
|
|
mediaState.endOfStream = true;
|
|
return null;
|
|
}
|
|
mediaState.endOfStream = false;
|
|
|
|
// Check if we've buffered to the end of the Period. This should be done
|
|
// before checking segment availability because the new Period may become
|
|
// available once it's switched to. Note that we don't use the non-existence
|
|
// of SegmentReferences as an indicator to determine Period boundaries
|
|
// because SegmentIndexes can provide SegmentReferences outside its Period.
|
|
mediaState.needPeriodIndex = needPeriodIndex;
|
|
if (needPeriodIndex != currentPeriodIndex) {
|
|
shaka.log.debug(logPrefix,
|
|
'need Period ' + needPeriodIndex,
|
|
'playheadTime=' + playheadTime,
|
|
'timeNeeded=' + timeNeeded,
|
|
'currentPeriodIndex=' + currentPeriodIndex);
|
|
return null;
|
|
}
|
|
|
|
// If we've buffered to the buffering goal then schedule an update.
|
|
if (bufferedAhead >= bufferingGoal) {
|
|
shaka.log.v2(logPrefix, 'buffering goal met');
|
|
|
|
// Do not try to predict the next update. Just poll twice every second.
|
|
// The playback rate can change at any time, so any prediction we make now
|
|
// could be terribly invalid soon.
|
|
return 0.5;
|
|
}
|
|
|
|
var bufferEnd =
|
|
this.playerInterface_.mediaSourceEngine.bufferEnd(mediaState.type);
|
|
var reference = this.getSegmentReferenceNeeded_(
|
|
mediaState, playheadTime, bufferEnd, currentPeriodIndex);
|
|
if (!reference) {
|
|
// The segment could not be found, does not exist, or is not available. In
|
|
// any case just try again... if the manifest is incomplete or is not being
|
|
// updated then we'll idle forever; otherwise, we'll end up getting a
|
|
// SegmentReference eventually.
|
|
return 1;
|
|
}
|
|
|
|
mediaState.resumeAt = 0;
|
|
this.fetchAndAppend_(mediaState, playheadTime, currentPeriodIndex, reference);
|
|
return null;
|
|
};
|
|
|
|
|
|
/**
|
|
* Computes buffering goal.
|
|
*
|
|
* @return {number}
|
|
* @private
|
|
*/
|
|
shaka.media.StreamingEngine.prototype.getBufferingGoal_ = function() {
|
|
goog.asserts.assert(this.manifest_, 'manifest_ should not be null');
|
|
goog.asserts.assert(this.config_, 'config_ should not be null');
|
|
|
|
var rebufferingGoal = shaka.util.StreamUtils.getRebufferingGoal(
|
|
this.manifest_, this.config_, this.bufferingGoalScale_);
|
|
|
|
return Math.max(
|
|
rebufferingGoal,
|
|
this.bufferingGoalScale_ * this.config_.bufferingGoal);
|
|
};
|
|
|
|
|
|
/**
|
|
* Gets the next timestamp needed. Returns the playhead's position if the
|
|
* buffer is empty; otherwise, returns the time at which the last segment
|
|
* appended ends.
|
|
*
|
|
* @param {shaka.media.StreamingEngine.MediaState_} mediaState
|
|
* @param {number} playheadTime
|
|
* @return {number} The next timestamp needed.
|
|
* @throws {!shaka.util.Error} if the buffer is inconsistent with our
|
|
* expectations.
|
|
* @private
|
|
*/
|
|
shaka.media.StreamingEngine.prototype.getTimeNeeded_ = function(
|
|
mediaState, playheadTime) {
|
|
// Get the next timestamp we need. We must use |lastSegmentReference|
|
|
// to determine this and not the actual buffer for two reasons:
|
|
// 1. actual segments end slightly before their advertised end times, so
|
|
// the next timestamp we need is actually larger than |bufferEnd|; and
|
|
// 2. there may be drift (the timestamps in the segments are ahead/behind
|
|
// of the timestamps in the manifest), but we need drift free times when
|
|
// comparing times against presentation and Period boundaries.
|
|
if (!mediaState.lastStream || !mediaState.lastSegmentReference) {
|
|
return Math.max(playheadTime, mediaState.resumeAt);
|
|
}
|
|
|
|
var lastPeriodIndex =
|
|
this.findPeriodContainingStream_(mediaState.lastStream);
|
|
var lastPeriod = this.manifest_.periods[lastPeriodIndex];
|
|
return lastPeriod.startTime + mediaState.lastSegmentReference.endTime;
|
|
};
|
|
|
|
|
|
/**
|
|
* Gets the SegmentReference of the next segment needed.
|
|
*
|
|
* @param {shaka.media.StreamingEngine.MediaState_} mediaState
|
|
* @param {number} playheadTime
|
|
* @param {?number} bufferEnd
|
|
* @param {number} currentPeriodIndex
|
|
* @return {shaka.media.SegmentReference} The SegmentReference of the
|
|
* next segment needed, or null if a segment could not be found, does not
|
|
* exist, or is not available.
|
|
* @private
|
|
*/
|
|
shaka.media.StreamingEngine.prototype.getSegmentReferenceNeeded_ = function(
|
|
mediaState, playheadTime, bufferEnd, currentPeriodIndex) {
|
|
var logPrefix = shaka.media.StreamingEngine.logPrefix_(mediaState);
|
|
|
|
if (mediaState.lastSegmentReference &&
|
|
mediaState.stream == mediaState.lastStream) {
|
|
// Something is buffered from the same Stream.
|
|
var position = mediaState.lastSegmentReference.position + 1;
|
|
shaka.log.v2(logPrefix, 'next position known:', 'position=' + position);
|
|
|
|
return this.getSegmentReferenceIfAvailable_(
|
|
mediaState, currentPeriodIndex, position);
|
|
}
|
|
|
|
var position;
|
|
|
|
if (mediaState.lastSegmentReference) {
|
|
// Something is buffered from another Stream.
|
|
goog.asserts.assert(mediaState.lastStream, 'lastStream should not be null');
|
|
shaka.log.v1(logPrefix, 'next position unknown: another Stream buffered');
|
|
var lastPeriodIndex =
|
|
this.findPeriodContainingStream_(mediaState.lastStream);
|
|
var lastPeriod = this.manifest_.periods[lastPeriodIndex];
|
|
position = this.lookupSegmentPosition_(
|
|
mediaState,
|
|
lastPeriod.startTime + mediaState.lastSegmentReference.endTime,
|
|
currentPeriodIndex);
|
|
} else {
|
|
// Either nothing is buffered, or we have cleared part of the buffer. If
|
|
// we still have some buffered, use that time to find the segment, otherwise
|
|
// start at the playhead time.
|
|
goog.asserts.assert(!mediaState.lastStream, 'lastStream should be null');
|
|
shaka.log.v1(logPrefix, 'next position unknown: nothing buffered');
|
|
position = this.lookupSegmentPosition_(
|
|
mediaState, bufferEnd || playheadTime, currentPeriodIndex);
|
|
}
|
|
|
|
if (position == null)
|
|
return null;
|
|
|
|
var reference = null;
|
|
if (bufferEnd == null) {
|
|
// If there's positive drift then we need to get the previous segment;
|
|
// however, we don't actually know how much drift there is, so we must
|
|
// unconditionally get the previous segment. If it turns out that there's
|
|
// non-positive drift then we'll just end up buffering beind the playhead a
|
|
// little more than we needed.
|
|
var optimalPosition = Math.max(0, position - 1);
|
|
reference = this.getSegmentReferenceIfAvailable_(
|
|
mediaState, currentPeriodIndex, optimalPosition);
|
|
}
|
|
return reference ||
|
|
this.getSegmentReferenceIfAvailable_(
|
|
mediaState, currentPeriodIndex, position);
|
|
};
|
|
|
|
|
|
/**
|
|
* Looks up the position of the segment containing the given timestamp.
|
|
*
|
|
* @param {shaka.media.StreamingEngine.MediaState_} mediaState
|
|
* @param {number} presentationTime The timestamp needed, relative to the
|
|
* start of the presentation.
|
|
* @param {number} currentPeriodIndex
|
|
* @return {?number} A segment position, or null if a segment was not be found.
|
|
* @private
|
|
*/
|
|
shaka.media.StreamingEngine.prototype.lookupSegmentPosition_ = function(
|
|
mediaState, presentationTime, currentPeriodIndex) {
|
|
var logPrefix = shaka.media.StreamingEngine.logPrefix_(mediaState);
|
|
var currentPeriod = this.manifest_.periods[currentPeriodIndex];
|
|
|
|
shaka.log.debug(logPrefix,
|
|
'looking up segment:',
|
|
'presentationTime=' + presentationTime,
|
|
'currentPeriod.startTime=' + currentPeriod.startTime);
|
|
|
|
var lookupTime = Math.max(0, presentationTime - currentPeriod.startTime);
|
|
var position = mediaState.stream.findSegmentPosition(lookupTime);
|
|
|
|
if (position == null) {
|
|
shaka.log.warning(logPrefix,
|
|
'cannot find segment:',
|
|
'currentPeriod.startTime=' + currentPeriod.startTime,
|
|
'lookupTime=' + lookupTime);
|
|
}
|
|
|
|
return position;
|
|
};
|
|
|
|
|
|
/**
|
|
* Gets the SegmentReference at the given position if it's available.
|
|
*
|
|
* @param {shaka.media.StreamingEngine.MediaState_} mediaState
|
|
* @param {number} currentPeriodIndex
|
|
* @param {number} position
|
|
* @return {shaka.media.SegmentReference}
|
|
*
|
|
* @private
|
|
*/
|
|
shaka.media.StreamingEngine.prototype.getSegmentReferenceIfAvailable_ =
|
|
function(mediaState, currentPeriodIndex, position) {
|
|
var logPrefix = shaka.media.StreamingEngine.logPrefix_(mediaState);
|
|
var currentPeriod = this.manifest_.periods[currentPeriodIndex];
|
|
|
|
var reference = mediaState.stream.getSegmentReference(position);
|
|
if (!reference) {
|
|
shaka.log.v1(logPrefix,
|
|
'segment does not exist:',
|
|
'currentPeriod.startTime=' + currentPeriod.startTime,
|
|
'position=' + position);
|
|
return null;
|
|
}
|
|
|
|
var timeline = this.manifest_.presentationTimeline;
|
|
var availabilityStart = timeline.getSegmentAvailabilityStart();
|
|
var availabilityEnd = timeline.getSegmentAvailabilityEnd();
|
|
|
|
if ((currentPeriod.startTime + reference.endTime < availabilityStart) ||
|
|
(currentPeriod.startTime + reference.startTime > availabilityEnd)) {
|
|
shaka.log.v2(logPrefix,
|
|
'segment is not available:',
|
|
'currentPeriod.startTime=' + currentPeriod.startTime,
|
|
'reference.startTime=' + reference.startTime,
|
|
'reference.endTime=' + reference.endTime,
|
|
'availabilityStart=' + availabilityStart,
|
|
'availabilityEnd=' + availabilityEnd);
|
|
return null;
|
|
}
|
|
|
|
return reference;
|
|
};
|
|
|
|
|
|
/**
|
|
* Fetches and appends the given segment; sets up the given MediaState's
|
|
* associated SourceBuffer and evicts segments if either are required
|
|
* beforehand. Schedules another update after completing successfully.
|
|
*
|
|
* @param {!shaka.media.StreamingEngine.MediaState_} mediaState
|
|
* @param {number} playheadTime
|
|
* @param {number} currentPeriodIndex The index of the current Period.
|
|
* @param {!shaka.media.SegmentReference} reference
|
|
* @private
|
|
*/
|
|
shaka.media.StreamingEngine.prototype.fetchAndAppend_ = function(
|
|
mediaState, playheadTime, currentPeriodIndex, reference) {
|
|
var logPrefix = shaka.media.StreamingEngine.logPrefix_(mediaState);
|
|
var ContentType = shaka.util.ManifestParserUtils.ContentType;
|
|
var currentPeriod = this.manifest_.periods[currentPeriodIndex];
|
|
|
|
shaka.log.v1(logPrefix,
|
|
'fetchAndAppend_:',
|
|
'playheadTime=' + playheadTime,
|
|
'currentPeriod.startTime=' + currentPeriod.startTime,
|
|
'reference.position=' + reference.position,
|
|
'reference.startTime=' + reference.startTime,
|
|
'reference.endTime=' + reference.endTime);
|
|
|
|
// Subtlety: The playhead may move while asynchronous update operations are
|
|
// in progress, so we should avoid calling playhead.getTime() in any
|
|
// callbacks. Furthermore, switch() may be called at any time, so we should
|
|
// also avoid using mediaState.stream or mediaState.needInitSegment in any
|
|
// callbacks too.
|
|
var stream = mediaState.stream;
|
|
|
|
// Compute the append window.
|
|
var duration = this.manifest_.presentationTimeline.getDuration();
|
|
var followingPeriod = this.manifest_.periods[currentPeriodIndex + 1];
|
|
var appendWindowStart = currentPeriod.startTime;
|
|
var appendWindowEnd = followingPeriod ? followingPeriod.startTime : duration;
|
|
goog.asserts.assert(
|
|
reference.startTime <= appendWindowEnd,
|
|
logPrefix + ' segment should start before append window end');
|
|
|
|
var initSourceBuffer = this.initSourceBuffer_(
|
|
mediaState, currentPeriodIndex, appendWindowStart, appendWindowEnd);
|
|
|
|
mediaState.performingUpdate = true;
|
|
|
|
// We may set |needInitSegment| to true in switch(), so set it to false here,
|
|
// since we want it to remain true if switch() is called.
|
|
mediaState.needInitSegment = false;
|
|
|
|
shaka.log.v2(logPrefix, 'fetching segment');
|
|
var fetchSegment = this.fetch_(reference);
|
|
|
|
Promise.all([initSourceBuffer, fetchSegment]).then(function(results) {
|
|
if (this.destroyed_ || this.fatalError_) return;
|
|
return this.append_(mediaState,
|
|
playheadTime,
|
|
currentPeriod,
|
|
stream,
|
|
reference,
|
|
results[1]);
|
|
}.bind(this)).then(function() {
|
|
if (this.destroyed_ || this.fatalError_) return;
|
|
|
|
mediaState.performingUpdate = false;
|
|
mediaState.recovering = false;
|
|
|
|
if (!mediaState.waitingToClearBuffer)
|
|
this.playerInterface_.onSegmentAppended();
|
|
|
|
// Update right away.
|
|
this.scheduleUpdate_(mediaState, 0);
|
|
|
|
// Subtlety: handleStartup_() calls onStartupComplete() which may call
|
|
// switch() or seeked(), so we must schedule an update beforehand so
|
|
// |updateTimer| is set.
|
|
this.handleStartup_(mediaState, stream);
|
|
|
|
shaka.log.v1(logPrefix, 'finished fetch and append');
|
|
}.bind(this)).catch(function(error) {
|
|
if (this.destroyed_ || this.fatalError_) return;
|
|
goog.asserts.assert(error instanceof shaka.util.Error,
|
|
'Should only receive a Shaka error');
|
|
|
|
mediaState.performingUpdate = false;
|
|
|
|
if (mediaState.type == ContentType.TEXT &&
|
|
this.config_.ignoreTextStreamFailures) {
|
|
if (error.code == shaka.util.Error.Code.BAD_HTTP_STATUS) {
|
|
shaka.log.warning(logPrefix,
|
|
'Text stream failed to download. Proceeding without it.');
|
|
} else {
|
|
shaka.log.warning(logPrefix,
|
|
'Text stream failed to parse. Proceeding without it.');
|
|
}
|
|
|
|
delete this.mediaStates_[ContentType.TEXT];
|
|
} else if (error.code == shaka.util.Error.Code.QUOTA_EXCEEDED_ERROR) {
|
|
this.handleQuotaExceeded_(mediaState, error);
|
|
} else {
|
|
shaka.log.error(logPrefix, 'failed fetch and append: code=' + error.code);
|
|
mediaState.hasError = true;
|
|
|
|
error.severity = shaka.util.Error.Severity.CRITICAL;
|
|
this.handleStreamingError_(error);
|
|
}
|
|
}.bind(this));
|
|
};
|
|
|
|
|
|
/**
|
|
* Clear per-stream error states and retry any failed streams.
|
|
* @return {boolean} False if unable to retry.
|
|
*/
|
|
shaka.media.StreamingEngine.prototype.retry = function() {
|
|
if (this.destroyed_) {
|
|
shaka.log.error('Unable to retry after StreamingEngine is destroyed!');
|
|
return false;
|
|
}
|
|
|
|
if (this.fatalError_) {
|
|
shaka.log.error('Unable to retry after StreamingEngine encountered a ' +
|
|
'fatal error!');
|
|
return false;
|
|
}
|
|
|
|
for (var type in this.mediaStates_) {
|
|
var mediaState = this.mediaStates_[type];
|
|
var logPrefix = shaka.media.StreamingEngine.logPrefix_(mediaState);
|
|
if (mediaState.hasError) {
|
|
shaka.log.info(logPrefix, 'Retrying after failure...');
|
|
mediaState.hasError = false;
|
|
this.scheduleUpdate_(mediaState, 0.1);
|
|
}
|
|
}
|
|
|
|
return true;
|
|
};
|
|
|
|
|
|
/**
|
|
* Handles a QUOTA_EXCEEDED_ERROR.
|
|
*
|
|
* @param {shaka.media.StreamingEngine.MediaState_} mediaState
|
|
* @param {!shaka.util.Error} error
|
|
* @private
|
|
*/
|
|
shaka.media.StreamingEngine.prototype.handleQuotaExceeded_ = function(
|
|
mediaState, error) {
|
|
var logPrefix = shaka.media.StreamingEngine.logPrefix_(mediaState);
|
|
|
|
// The segment cannot fit into the SourceBuffer. Ideally, MediaSource would
|
|
// have evicted old data to accommodate the segment; however, it may have
|
|
// failed to do this if the segment is very large, or if it could not find
|
|
// a suitable time range to remove.
|
|
//
|
|
// We can overcome the latter by trying to append the segment again;
|
|
// however, to avoid continuous QuotaExceededErrors we must reduce the size
|
|
// of the buffer going forward.
|
|
//
|
|
// If we've recently reduced the buffering goals, wait until the stream
|
|
// which caused the first QuotaExceededError recovers. Doing this ensures
|
|
// we don't reduce the buffering goals too quickly.
|
|
|
|
goog.asserts.assert(this.mediaStates_, 'must not be destroyed');
|
|
var mediaStates = shaka.util.MapUtils.values(this.mediaStates_);
|
|
var waitingForAnotherStreamToRecover = mediaStates.some(function(ms) {
|
|
return ms != mediaState && ms.recovering;
|
|
});
|
|
|
|
if (!waitingForAnotherStreamToRecover) {
|
|
// Reduction schedule: 80%, 60%, 40%, 20%, 16%, 12%, 8%, 4%, fail.
|
|
// Note: percentages are used for comparisons to avoid rounding errors.
|
|
var percentBefore = Math.round(100 * this.bufferingGoalScale_);
|
|
if (percentBefore > 20) {
|
|
this.bufferingGoalScale_ -= 0.2;
|
|
} else if (percentBefore > 4) {
|
|
this.bufferingGoalScale_ -= 0.04;
|
|
} else {
|
|
shaka.log.error(
|
|
logPrefix, 'MediaSource threw QuotaExceededError too many times');
|
|
mediaState.hasError = true;
|
|
this.fatalError_ = true;
|
|
this.playerInterface_.onError(error);
|
|
return;
|
|
}
|
|
var percentAfter = Math.round(100 * this.bufferingGoalScale_);
|
|
shaka.log.warning(
|
|
logPrefix,
|
|
'MediaSource threw QuotaExceededError:',
|
|
'reducing buffering goals by ' + (100 - percentAfter) + '%');
|
|
mediaState.recovering = true;
|
|
} else {
|
|
shaka.log.debug(
|
|
logPrefix,
|
|
'MediaSource threw QuotaExceededError:',
|
|
'waiting for another stream to recover...');
|
|
}
|
|
|
|
// QuotaExceededError gets thrown if evication didn't help to make room
|
|
// for a segment. We want to wait for a while (4 seconds is just an
|
|
// arbitrary number) before updating to give the playhead a chance to
|
|
// advance, so we don't immidiately throw again.
|
|
this.scheduleUpdate_(mediaState, 4);
|
|
};
|
|
|
|
|
|
/**
|
|
* Sets the given MediaState's associated SourceBuffer's timestamp offset and
|
|
* init segment if either are required. If an error occurs then neither the
|
|
* timestamp offset or init segment are unset, since another call to switch()
|
|
* will end up superseding them.
|
|
*
|
|
* @param {shaka.media.StreamingEngine.MediaState_} mediaState
|
|
* @param {number} currentPeriodIndex
|
|
* @param {number} appendWindowStart
|
|
* @param {number} appendWindowEnd
|
|
* @return {!Promise}
|
|
* @private
|
|
*/
|
|
shaka.media.StreamingEngine.prototype.initSourceBuffer_ = function(
|
|
mediaState, currentPeriodIndex, appendWindowStart, appendWindowEnd) {
|
|
if (!mediaState.needInitSegment)
|
|
return Promise.resolve();
|
|
|
|
var logPrefix = shaka.media.StreamingEngine.logPrefix_(mediaState);
|
|
var currentPeriod = this.manifest_.periods[currentPeriodIndex];
|
|
|
|
// If we need an init segment then the Stream switched, so we've either
|
|
// changed bitrates, Periods, or both. If we've changed Periods then we must
|
|
// set a new timestamp offset and append window end. Note that by setting
|
|
// these values here, we avoid having to co-ordinate ongoing updates, which
|
|
// we would have to do if we instead set them in switch().
|
|
var timestampOffset =
|
|
currentPeriod.startTime - mediaState.stream.presentationTimeOffset;
|
|
shaka.log.v1(logPrefix, 'setting timestamp offset to ' + timestampOffset);
|
|
shaka.log.v1(logPrefix,
|
|
'setting appstart window start to ' + appendWindowStart);
|
|
shaka.log.v1(logPrefix, 'setting append window end to ' + appendWindowEnd);
|
|
var setStreamProperties =
|
|
this.playerInterface_.mediaSourceEngine.setStreamProperties(
|
|
mediaState.type, timestampOffset, appendWindowStart, appendWindowEnd);
|
|
|
|
if (!mediaState.stream.initSegmentReference) {
|
|
// The Stream is self initializing.
|
|
return setStreamProperties;
|
|
}
|
|
|
|
shaka.log.v1(logPrefix, 'fetching init segment');
|
|
var fetchInit = this.fetch_(mediaState.stream.initSegmentReference);
|
|
var appendInit = fetchInit.then(function(initSegment) {
|
|
if (this.destroyed_) return;
|
|
shaka.log.v1(logPrefix, 'appending init segment');
|
|
|
|
return this.playerInterface_.mediaSourceEngine.appendBuffer(
|
|
mediaState.type, initSegment, null /* startTime */, null /* endTime */);
|
|
}.bind(this)).catch(function(error) {
|
|
mediaState.needInitSegment = true;
|
|
return Promise.reject(error);
|
|
});
|
|
|
|
return Promise.all([setStreamProperties, appendInit]);
|
|
};
|
|
|
|
|
|
/**
|
|
* Appends the given segment and evicts content if required to append.
|
|
*
|
|
* @param {!shaka.media.StreamingEngine.MediaState_} mediaState
|
|
* @param {number} playheadTime
|
|
* @param {shakaExtern.Period} period
|
|
* @param {shakaExtern.Stream} stream
|
|
* @param {!shaka.media.SegmentReference} reference
|
|
* @param {!ArrayBuffer} segment
|
|
* @return {!Promise}
|
|
* @private
|
|
*/
|
|
shaka.media.StreamingEngine.prototype.append_ = function(
|
|
mediaState, playheadTime, period, stream, reference, segment) {
|
|
var logPrefix = shaka.media.StreamingEngine.logPrefix_(mediaState);
|
|
|
|
if (stream.containsEmsgBoxes) {
|
|
new shaka.util.Mp4Parser()
|
|
.fullBox('emsg', this.parseEMSG_.bind(this, period, reference))
|
|
.parse(segment);
|
|
}
|
|
|
|
return this.evict_(mediaState, playheadTime).then(function() {
|
|
if (this.destroyed_) return;
|
|
shaka.log.v1(logPrefix, 'appending media segment');
|
|
|
|
return this.playerInterface_.mediaSourceEngine.appendBuffer(
|
|
mediaState.type, segment, reference.startTime + period.startTime,
|
|
reference.endTime + period.startTime);
|
|
}.bind(this)).then(function() {
|
|
if (this.destroyed_) return;
|
|
shaka.log.v2(logPrefix, 'appended media segment');
|
|
|
|
// We must use |stream| because switch() may have been called.
|
|
mediaState.lastStream = stream;
|
|
mediaState.lastSegmentReference = reference;
|
|
|
|
return Promise.resolve();
|
|
}.bind(this));
|
|
};
|
|
|
|
|
|
/**
|
|
* Parse the EMSG box from a MP4 container.
|
|
*
|
|
* @param {!shakaExtern.Period} period
|
|
* @param {!shaka.media.SegmentReference} reference
|
|
* @param {!shaka.util.Mp4Parser.ParsedBox} box
|
|
* @private
|
|
*/
|
|
shaka.media.StreamingEngine.prototype.parseEMSG_ = function(
|
|
period, reference, box) {
|
|
|
|
var schemeId = box.reader.readTerminatedString();
|
|
// read rest of the data and dispatch event to the application
|
|
var value = box.reader.readTerminatedString();
|
|
var timescale = box.reader.readUint32();
|
|
var presentationTimeDelta = box.reader.readUint32();
|
|
var eventDuration = box.reader.readUint32();
|
|
var id = box.reader.readUint32();
|
|
var messageData = box.reader.readBytes(
|
|
box.reader.getLength() - box.reader.getPosition());
|
|
|
|
var startTime = period.startTime + reference.startTime +
|
|
(presentationTimeDelta / timescale);
|
|
|
|
// See DASH sec. 5.10.4.1
|
|
// A special scheme in DASH used to signal manifest updates.
|
|
if (schemeId == 'urn:mpeg:dash:event:2012') {
|
|
this.playerInterface_.onManifestUpdate();
|
|
} else {
|
|
/** @type {shakaExtern.EmsgInfo} */
|
|
var emsg = {
|
|
startTime: startTime,
|
|
endTime: startTime + (eventDuration / timescale),
|
|
schemeIdUri: schemeId,
|
|
value: value,
|
|
timescale: timescale,
|
|
presentationTimeDelta: presentationTimeDelta,
|
|
eventDuration: eventDuration,
|
|
id: id,
|
|
messageData: messageData
|
|
};
|
|
|
|
var event = new shaka.util.FakeEvent('emsg', {'detail': emsg});
|
|
this.playerInterface_.onEvent(event);
|
|
}
|
|
|
|
box.parser.stop();
|
|
};
|
|
|
|
|
|
/**
|
|
* Evicts media to meet the max buffer behind limit.
|
|
*
|
|
* @param {shaka.media.StreamingEngine.MediaState_} mediaState
|
|
* @param {number} playheadTime
|
|
* @return {!Promise}
|
|
* @private
|
|
*/
|
|
shaka.media.StreamingEngine.prototype.evict_ = function(
|
|
mediaState, playheadTime) {
|
|
var logPrefix = shaka.media.StreamingEngine.logPrefix_(mediaState);
|
|
shaka.log.v2(logPrefix, 'checking buffer length');
|
|
|
|
var startTime =
|
|
this.playerInterface_.mediaSourceEngine.bufferStart(mediaState.type);
|
|
if (startTime == null) {
|
|
shaka.log.v2(logPrefix,
|
|
'buffer behind okay because nothing buffered:',
|
|
'playheadTime=' + playheadTime,
|
|
'bufferBehind=' + this.config_.bufferBehind);
|
|
return Promise.resolve();
|
|
}
|
|
var bufferedBehind = playheadTime - startTime;
|
|
|
|
var overflow = bufferedBehind - this.config_.bufferBehind;
|
|
if (overflow <= 0) {
|
|
shaka.log.v2(logPrefix,
|
|
'buffer behind okay:',
|
|
'playheadTime=' + playheadTime,
|
|
'bufferedBehind=' + bufferedBehind,
|
|
'bufferBehind=' + this.config_.bufferBehind,
|
|
'underflow=' + (-overflow));
|
|
return Promise.resolve();
|
|
}
|
|
|
|
shaka.log.v1(logPrefix,
|
|
'buffer behind too large:',
|
|
'playheadTime=' + playheadTime,
|
|
'bufferedBehind=' + bufferedBehind,
|
|
'bufferBehind=' + this.config_.bufferBehind,
|
|
'overflow=' + overflow);
|
|
|
|
return this.playerInterface_.mediaSourceEngine.remove(
|
|
mediaState.type, startTime, startTime + overflow).then(function() {
|
|
if (this.destroyed_) return;
|
|
shaka.log.v1(logPrefix, 'evicted ' + overflow + ' seconds');
|
|
}.bind(this));
|
|
};
|
|
|
|
|
|
/**
|
|
* Sets up all known Periods when startup completes; otherwise, does nothing.
|
|
*
|
|
* @param {shaka.media.StreamingEngine.MediaState_} mediaState The last
|
|
* MediaState updated.
|
|
* @param {shakaExtern.Stream} stream
|
|
* @private
|
|
*/
|
|
shaka.media.StreamingEngine.prototype.handleStartup_ = function(
|
|
mediaState, stream) {
|
|
var Functional = shaka.util.Functional;
|
|
var MapUtils = shaka.util.MapUtils;
|
|
var ContentType = shaka.util.ManifestParserUtils.ContentType;
|
|
if (this.startupComplete_)
|
|
return;
|
|
|
|
var logPrefix = shaka.media.StreamingEngine.logPrefix_(mediaState);
|
|
|
|
goog.asserts.assert(this.mediaStates_, 'must not be destroyed');
|
|
var mediaStates = MapUtils.values(this.mediaStates_);
|
|
this.startupComplete_ = mediaStates.every(function(ms) {
|
|
// Startup completes once we have buffered at least one segment from each
|
|
// MediaState, not counting text.
|
|
if (ms.type == ContentType.TEXT) return true;
|
|
return !ms.waitingToClearBuffer &&
|
|
!ms.clearingBuffer &&
|
|
ms.lastSegmentReference;
|
|
});
|
|
|
|
if (!this.startupComplete_)
|
|
return;
|
|
|
|
shaka.log.debug(logPrefix, 'startup complete');
|
|
|
|
// We must use |stream| because switch() may have been called.
|
|
var currentPeriodIndex = this.findPeriodContainingStream_(stream);
|
|
|
|
goog.asserts.assert(
|
|
mediaStates.every(function(ms) {
|
|
// It is possible for one stream (usually text) to buffer the whole
|
|
// Period and need the next one.
|
|
return ms.needPeriodIndex == currentPeriodIndex ||
|
|
ms.needPeriodIndex == currentPeriodIndex + 1;
|
|
}),
|
|
logPrefix + ' expected all MediaStates to need same Period');
|
|
|
|
// Setup the current Period if necessary, which is likely since the current
|
|
// Period is probably the initial one.
|
|
if (!this.canSwitchPeriod_[currentPeriodIndex]) {
|
|
this.setupPeriod_(currentPeriodIndex).then(function() {
|
|
shaka.log.v1(logPrefix, 'calling onCanSwitch()...');
|
|
this.playerInterface_.onCanSwitch();
|
|
}.bind(this)).catch(Functional.noop);
|
|
}
|
|
|
|
// Now setup all known Periods.
|
|
for (var i = 0; i < this.manifest_.periods.length; ++i) {
|
|
this.setupPeriod_(i).catch(Functional.noop);
|
|
}
|
|
|
|
if (this.playerInterface_.onStartupComplete) {
|
|
shaka.log.v1(logPrefix, 'calling onStartupComplete()...');
|
|
this.playerInterface_.onStartupComplete();
|
|
}
|
|
};
|
|
|
|
|
|
/**
|
|
* Calls onChooseStreams() when necessary.
|
|
*
|
|
* @param {shaka.media.StreamingEngine.MediaState_} mediaState The last
|
|
* MediaState updated.
|
|
* @private
|
|
*/
|
|
shaka.media.StreamingEngine.prototype.handlePeriodTransition_ = function(
|
|
mediaState) {
|
|
var Functional = shaka.util.Functional;
|
|
var MapUtils = shaka.util.MapUtils;
|
|
var logPrefix = shaka.media.StreamingEngine.logPrefix_(mediaState);
|
|
var ContentType = shaka.util.ManifestParserUtils.ContentType;
|
|
|
|
var currentPeriodIndex = this.findPeriodContainingStream_(mediaState.stream);
|
|
if (mediaState.needPeriodIndex == currentPeriodIndex)
|
|
return;
|
|
|
|
var needPeriodIndex = mediaState.needPeriodIndex;
|
|
|
|
goog.asserts.assert(this.mediaStates_, 'must not be destroyed');
|
|
var mediaStates = MapUtils.values(this.mediaStates_);
|
|
|
|
// For a Period transition to work, all media states must need the same
|
|
// Period. If a stream needs a different Period than the one it currently
|
|
// has, it will try to transition or stop updates assuming that another stream
|
|
// will handle it. This only works when all streams either need the same
|
|
// Period or are still performing updates.
|
|
goog.asserts.assert(
|
|
mediaStates.every(function(ms) {
|
|
return ms.needPeriodIndex == needPeriodIndex || ms.hasError ||
|
|
!shaka.media.StreamingEngine.isIdle_(ms);
|
|
}),
|
|
'All MediaStates should need the same Period or be performing updates.');
|
|
|
|
// Only call onChooseStreams() when all MediaStates need the same Period.
|
|
var needSamePeriod = mediaStates.every(function(ms) {
|
|
return ms.needPeriodIndex == needPeriodIndex;
|
|
});
|
|
if (!needSamePeriod) {
|
|
shaka.log.debug(
|
|
logPrefix, 'not all MediaStates need Period ' + needPeriodIndex);
|
|
return;
|
|
}
|
|
|
|
// Only call onChooseStreams() once per Period transition.
|
|
var allAreIdle = mediaStates.every(shaka.media.StreamingEngine.isIdle_);
|
|
if (!allAreIdle) {
|
|
shaka.log.debug(
|
|
logPrefix,
|
|
'all MediaStates need Period ' + needPeriodIndex + ', ' +
|
|
'but not all MediaStates are idle');
|
|
return;
|
|
}
|
|
|
|
shaka.log.debug(logPrefix, 'all need Period ' + needPeriodIndex);
|
|
|
|
// Ensure the Period which we need to buffer is setup and then call
|
|
// onChooseStreams().
|
|
this.setupPeriod_(needPeriodIndex).then(function() {
|
|
if (this.destroyed_) return;
|
|
|
|
// If we seek during a Period transition, we can start another transition.
|
|
// So we need to verify that:
|
|
// - We are still in need of the same Period.
|
|
// - All streams are still idle.
|
|
// - The current stream is not in the needed Period (another transition
|
|
// handled it).
|
|
var allReady = mediaStates.every(function(ms) {
|
|
var isIdle = shaka.media.StreamingEngine.isIdle_(ms);
|
|
var currentPeriodIndex = this.findPeriodContainingStream_(ms.stream);
|
|
return isIdle && ms.needPeriodIndex == needPeriodIndex &&
|
|
currentPeriodIndex != needPeriodIndex;
|
|
}.bind(this));
|
|
if (!allReady) {
|
|
// TODO: Write unit tests for this case.
|
|
shaka.log.debug(logPrefix, 'ignoring transition to Period',
|
|
needPeriodIndex, 'since another is happening');
|
|
return;
|
|
}
|
|
|
|
var needPeriod = this.manifest_.periods[needPeriodIndex];
|
|
|
|
shaka.log.v1(logPrefix, 'calling onChooseStreams()...');
|
|
var chosenStreams = this.playerInterface_.onChooseStreams(needPeriod);
|
|
var streamsByType = {};
|
|
if (chosenStreams.variant && chosenStreams.variant.video) {
|
|
streamsByType[ContentType.VIDEO] = chosenStreams.variant.video;
|
|
}
|
|
if (chosenStreams.variant && chosenStreams.variant.audio) {
|
|
streamsByType[ContentType.AUDIO] = chosenStreams.variant.audio;
|
|
}
|
|
if (chosenStreams.text) {
|
|
streamsByType[ContentType.TEXT] = chosenStreams.text;
|
|
}
|
|
|
|
// Vet |streamsByType| before switching.
|
|
for (var type in this.mediaStates_) {
|
|
if (streamsByType[type] || type == ContentType.TEXT) continue;
|
|
|
|
shaka.log.error(logPrefix,
|
|
'invalid Streams chosen: missing ' + type + ' Stream');
|
|
this.playerInterface_.onError(new shaka.util.Error(
|
|
shaka.util.Error.Severity.CRITICAL,
|
|
shaka.util.Error.Category.STREAMING,
|
|
shaka.util.Error.Code.INVALID_STREAMS_CHOSEN));
|
|
return;
|
|
}
|
|
|
|
for (var type in streamsByType) {
|
|
if (this.mediaStates_[/** @type {!ContentType} */(type)]) continue;
|
|
|
|
if (type == ContentType.TEXT) {
|
|
// initStreams_ will switch streams and schedule an update.
|
|
this.initStreams_(
|
|
{text: streamsByType[ContentType.TEXT]}, needPeriod.startTime);
|
|
delete streamsByType[type];
|
|
continue;
|
|
}
|
|
|
|
shaka.log.error(logPrefix,
|
|
'invalid Streams chosen: unusable ' + type + ' Stream');
|
|
this.playerInterface_.onError(new shaka.util.Error(
|
|
shaka.util.Error.Severity.CRITICAL,
|
|
shaka.util.Error.Category.STREAMING,
|
|
shaka.util.Error.Code.INVALID_STREAMS_CHOSEN));
|
|
return;
|
|
}
|
|
|
|
for (var type in this.mediaStates_) {
|
|
var stream = streamsByType[type];
|
|
if (stream) {
|
|
this.switchInternal_(stream, /* clearBuffer */ false);
|
|
this.scheduleUpdate_(this.mediaStates_[type], 0);
|
|
} else {
|
|
goog.asserts.assert(type == ContentType.TEXT, 'Invalid streams chosen');
|
|
delete this.mediaStates_[type];
|
|
}
|
|
}
|
|
|
|
// We've already set up the Period so call onCanSwitch() right now.
|
|
shaka.log.v1(logPrefix, 'calling onCanSwitch()...');
|
|
this.playerInterface_.onCanSwitch();
|
|
}.bind(this)).catch(Functional.noop);
|
|
};
|
|
|
|
|
|
/**
|
|
* @param {shaka.media.StreamingEngine.MediaState_} mediaState
|
|
* @return {boolean} True if the given MediaState is idle; otherwise, return
|
|
* false.
|
|
* @private
|
|
*/
|
|
shaka.media.StreamingEngine.isIdle_ = function(mediaState) {
|
|
return !mediaState.performingUpdate &&
|
|
(mediaState.updateTimer == null) &&
|
|
!mediaState.waitingToClearBuffer &&
|
|
!mediaState.clearingBuffer;
|
|
};
|
|
|
|
|
|
/**
|
|
* @param {number} time The time, in seconds, relative to the start of the
|
|
* presentation.
|
|
* @return {number} The index of the Period which starts after |time|
|
|
* @private
|
|
*/
|
|
shaka.media.StreamingEngine.prototype.findPeriodContainingTime_ = function(
|
|
time) {
|
|
goog.asserts.assert(this.manifest_, 'Must not be destroyed');
|
|
return shaka.util.StreamUtils.findPeriodContainingTime(this.manifest_, time);
|
|
};
|
|
|
|
|
|
/**
|
|
* @param {!shakaExtern.Stream} stream
|
|
* @return {number} The index of the Period which contains |stream|, or -1 if
|
|
* no Period contains |stream|.
|
|
* @private
|
|
*/
|
|
shaka.media.StreamingEngine.prototype.findPeriodContainingStream_ = function(
|
|
stream) {
|
|
goog.asserts.assert(this.manifest_, 'Must not be destroyed');
|
|
return shaka.util.StreamUtils.findPeriodContainingStream(
|
|
this.manifest_, stream);
|
|
};
|
|
|
|
|
|
/**
|
|
* Fetches the given segment.
|
|
*
|
|
* @param {(!shaka.media.InitSegmentReference|!shaka.media.SegmentReference)}
|
|
* reference
|
|
*
|
|
* @return {!Promise.<!ArrayBuffer>}
|
|
* @private
|
|
*/
|
|
shaka.media.StreamingEngine.prototype.fetch_ = function(reference) {
|
|
var requestType = shaka.net.NetworkingEngine.RequestType.SEGMENT;
|
|
var request = shaka.net.NetworkingEngine.makeRequest(
|
|
reference.getUris(), this.config_.retryParameters);
|
|
|
|
// Set Range header. Note that some web servers don't accept Range headers,
|
|
// so don't set one if it's not strictly required.
|
|
if ((reference.startByte != 0) || (reference.endByte != null)) {
|
|
var range = 'bytes=' + reference.startByte + '-';
|
|
if (reference.endByte != null) range += reference.endByte;
|
|
request.headers['Range'] = range;
|
|
}
|
|
|
|
shaka.log.v2('fetching: reference=' + reference);
|
|
var p = this.playerInterface_.netEngine.request(requestType, request);
|
|
return p.then(function(response) {
|
|
return response.data;
|
|
});
|
|
};
|
|
|
|
|
|
/**
|
|
* Clears the buffer and schedules another update.
|
|
*
|
|
* @param {!shaka.media.StreamingEngine.MediaState_} mediaState
|
|
* @param {boolean} flush
|
|
* @private
|
|
*/
|
|
shaka.media.StreamingEngine.prototype.clearBuffer_ =
|
|
function(mediaState, flush) {
|
|
var logPrefix = shaka.media.StreamingEngine.logPrefix_(mediaState);
|
|
|
|
goog.asserts.assert(
|
|
!mediaState.performingUpdate && (mediaState.updateTimer == null),
|
|
logPrefix + ' unexpected call to clearBuffer_()');
|
|
|
|
mediaState.waitingToClearBuffer = false;
|
|
mediaState.waitingToFlushBuffer = false;
|
|
mediaState.clearingBuffer = true;
|
|
|
|
shaka.log.debug(logPrefix, 'clearing buffer');
|
|
var p = this.playerInterface_.mediaSourceEngine.clear(mediaState.type);
|
|
p.then(function() {
|
|
if (!this.destroyed_ && flush) {
|
|
return this.playerInterface_.mediaSourceEngine.flush(mediaState.type);
|
|
}
|
|
}.bind(this)).then(function() {
|
|
if (this.destroyed_) return;
|
|
shaka.log.debug(logPrefix, 'cleared buffer');
|
|
mediaState.lastStream = null;
|
|
mediaState.lastSegmentReference = null;
|
|
mediaState.clearingBuffer = false;
|
|
mediaState.endOfStream = false;
|
|
this.scheduleUpdate_(mediaState, 0);
|
|
}.bind(this));
|
|
};
|
|
|
|
|
|
/**
|
|
* Schedules |mediaState|'s next update.
|
|
*
|
|
* @param {!shaka.media.StreamingEngine.MediaState_} mediaState
|
|
* @param {number} delay The delay in seconds.
|
|
* @private
|
|
*/
|
|
shaka.media.StreamingEngine.prototype.scheduleUpdate_ = function(
|
|
mediaState, delay) {
|
|
var logPrefix = shaka.media.StreamingEngine.logPrefix_(mediaState);
|
|
shaka.log.v2(logPrefix, 'updating in ' + delay + ' seconds');
|
|
goog.asserts.assert(mediaState.updateTimer == null,
|
|
logPrefix + ' did not expect update to be scheduled');
|
|
mediaState.updateTimer = window.setTimeout(
|
|
this.onUpdate_.bind(this, mediaState), delay * 1000);
|
|
};
|
|
|
|
|
|
/**
|
|
* Cancels |mediaState|'s next update if one exists.
|
|
*
|
|
* @param {!shaka.media.StreamingEngine.MediaState_} mediaState
|
|
* @private
|
|
*/
|
|
shaka.media.StreamingEngine.prototype.cancelUpdate_ = function(mediaState) {
|
|
if (mediaState.updateTimer != null) {
|
|
window.clearTimeout(mediaState.updateTimer);
|
|
mediaState.updateTimer = null;
|
|
}
|
|
};
|
|
|
|
|
|
/**
|
|
* Handle streaming errors by delaying, then notifying the application by error
|
|
* callback and by streaming failure callback.
|
|
*
|
|
* @param {!shaka.util.Error} error
|
|
* @private
|
|
*/
|
|
shaka.media.StreamingEngine.prototype.handleStreamingError_ = function(error) {
|
|
// If we invoke the callback right away, the application could trigger a
|
|
// rapid retry cycle that could be very unkind to the server. Instead,
|
|
// use the backoff system to delay and backoff the error handling.
|
|
this.failureCallbackBackoff_.attempt().then(function() {
|
|
// First fire an error event.
|
|
this.playerInterface_.onError(error);
|
|
|
|
// If the error was not handled by the application, call the failure
|
|
// callback.
|
|
if (!error.handled) {
|
|
this.config_.failureCallback(error);
|
|
}
|
|
}.bind(this));
|
|
};
|
|
|
|
|
|
/**
|
|
* @param {shaka.media.StreamingEngine.MediaState_} mediaState
|
|
* @return {string} A log prefix of the form ($CONTENT_TYPE:$STREAM_ID), e.g.,
|
|
* "(audio:5)" or "(video:hd)".
|
|
* @private
|
|
*/
|
|
shaka.media.StreamingEngine.logPrefix_ = function(mediaState) {
|
|
return '(' + mediaState.type + ':' + mediaState.stream.id + ')';
|
|
};
|