mirror of
https://github.com/shaka-project/shaka-player.git
synced 2026-06-15 16:06:41 +03:00
has992
3f9dec2342
This PR excludes the use of text segments when calculating the max segment size. This is due to Shaka using the max value between the buffer behind and max segment size. The max segment size of text segments can be a lot larger than video segments. This can cause the buffer behind to be extremely large and is a particular problem for low powered devices, which have memory constraints. --------- Co-authored-by: Joey Parrish <joeyparrish@users.noreply.github.com>
1200 lines
41 KiB
JavaScript
1200 lines
41 KiB
JavaScript
/*! @license
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* Shaka Player
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* Copyright 2016 Google LLC
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* SPDX-License-Identifier: Apache-2.0
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*/
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goog.provide('shaka.dash.SegmentTemplate');
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goog.require('goog.asserts');
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goog.require('shaka.dash.MpdUtils');
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goog.require('shaka.dash.SegmentBase');
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goog.require('shaka.log');
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goog.require('shaka.media.InitSegmentReference');
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goog.require('shaka.media.SegmentIndex');
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goog.require('shaka.media.SegmentReference');
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goog.require('shaka.util.Error');
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goog.require('shaka.util.IReleasable');
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goog.require('shaka.util.ManifestParserUtils');
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goog.require('shaka.util.ObjectUtils');
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goog.require('shaka.util.StringUtils');
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goog.require('shaka.util.TXml');
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goog.requireType('shaka.dash.DashParser');
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goog.requireType('shaka.media.PresentationTimeline');
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/**
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* @summary A set of functions for parsing SegmentTemplate elements.
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*/
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shaka.dash.SegmentTemplate = class {
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/**
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* Creates a new StreamInfo object.
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* Updates the existing SegmentIndex, if any.
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*
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* @param {shaka.dash.DashParser.Context} context
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* @param {shaka.dash.DashParser.RequestSegmentCallback} requestSegment
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* @param {!Object.<string, !shaka.extern.Stream>} streamMap
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* @param {boolean} isUpdate True if the manifest is being updated.
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* @param {number} segmentLimit The maximum number of segments to generate for
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* a SegmentTemplate with fixed duration.
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* @param {!Object.<string, number>} periodDurationMap
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* @param {shaka.extern.aesKey|undefined} aesKey
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* @param {?number} lastSegmentNumber
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* @param {boolean} isPatchUpdate
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* @return {shaka.dash.DashParser.StreamInfo}
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*/
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static createStreamInfo(
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context, requestSegment, streamMap, isUpdate, segmentLimit,
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periodDurationMap, aesKey, lastSegmentNumber, isPatchUpdate) {
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goog.asserts.assert(context.representation.segmentTemplate,
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'Should only be called with SegmentTemplate ' +
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'or segment info defined');
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const MpdUtils = shaka.dash.MpdUtils;
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const SegmentTemplate = shaka.dash.SegmentTemplate;
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const TimelineSegmentIndex = shaka.dash.TimelineSegmentIndex;
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if (!isPatchUpdate && !context.representation.initialization) {
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context.representation.initialization =
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MpdUtils.inheritAttribute(
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context, SegmentTemplate.fromInheritance_, 'initialization');
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}
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const initSegmentReference = context.representation.initialization ?
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SegmentTemplate.createInitSegment_(context, aesKey) : null;
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/** @type {shaka.dash.SegmentTemplate.SegmentTemplateInfo} */
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const info = SegmentTemplate.parseSegmentTemplateInfo_(context);
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SegmentTemplate.checkSegmentTemplateInfo_(context, info);
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// Direct fields of context will be reassigned by the parser before
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// generateSegmentIndex is called. So we must make a shallow copy first,
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// and use that in the generateSegmentIndex callbacks.
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const shallowCopyOfContext =
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shaka.util.ObjectUtils.shallowCloneObject(context);
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if (info.indexTemplate) {
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shaka.dash.SegmentBase.checkSegmentIndexSupport(
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context, initSegmentReference);
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return {
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generateSegmentIndex: () => {
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return SegmentTemplate.generateSegmentIndexFromIndexTemplate_(
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shallowCopyOfContext, requestSegment, initSegmentReference,
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info);
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},
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};
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} else if (info.segmentDuration) {
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if (!isUpdate &&
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context.adaptationSet.contentType !== 'image' &&
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context.adaptationSet.contentType !== 'text') {
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const periodStart = context.periodInfo.start;
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const periodId = context.period.id;
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const initialPeriodDuration = context.periodInfo.duration;
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const periodDuration =
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(periodId != null && periodDurationMap[periodId]) ||
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initialPeriodDuration;
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const periodEnd = periodDuration ?
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(periodStart + periodDuration) : Infinity;
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context.presentationTimeline.notifyMaxSegmentDuration(
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info.segmentDuration);
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context.presentationTimeline.notifyPeriodDuration(
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periodStart, periodEnd);
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}
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return {
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generateSegmentIndex: () => {
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return SegmentTemplate.generateSegmentIndexFromDuration_(
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shallowCopyOfContext, info, segmentLimit, initSegmentReference,
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periodDurationMap, aesKey, lastSegmentNumber,
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context.representation.segmentSequenceCadence);
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},
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};
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} else {
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/** @type {shaka.media.SegmentIndex} */
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let segmentIndex = null;
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let id = null;
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let stream = null;
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if (context.period.id && context.representation.id) {
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// Only check/store the index if period and representation IDs are set.
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id = context.period.id + ',' + context.representation.id;
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stream = streamMap[id];
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if (stream) {
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segmentIndex = stream.segmentIndex;
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}
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}
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const periodStart = context.periodInfo.start;
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const periodEnd = context.periodInfo.duration ? periodStart +
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context.periodInfo.duration : Infinity;
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shaka.log.debug(`New manifest ${periodStart} - ${periodEnd}`);
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/* When to fit segments. All refactors should honor/update this table:
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*
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* | dynamic | infinite | last | should | notes |
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* | | period | period | fit | |
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* | ------- | -------- | ------ | ------ | ------------------------- |
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* | F | F | X | T | typical VOD |
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* | F | T | X | X | impossible: infinite VOD |
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* | T | F | F | T | typical live, old period |
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* | T | F | T | F | typical IPR |
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* | T | T | F | X | impossible: old, infinite |
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* | T | T | T | F | typical live, new period |
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*/
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// We never fit the final period of dynamic content, which could be
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// infinite live (with no limit to fit to) or IPR (which would expand the
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// most recent segment to the end of the presentation).
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const shouldFit = !(context.dynamic && context.periodInfo.isLastPeriod);
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if (!segmentIndex) {
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shaka.log.debug(`Creating TSI with end ${periodEnd}`);
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segmentIndex = new TimelineSegmentIndex(
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info,
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context.representation.id,
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context.bandwidth,
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context.representation.getBaseUris,
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context.urlParams,
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periodStart,
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periodEnd,
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initSegmentReference,
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shouldFit,
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aesKey,
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context.representation.segmentSequenceCadence,
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);
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} else {
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const tsi = /** @type {!TimelineSegmentIndex} */(segmentIndex);
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tsi.appendTemplateInfo(
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info, periodStart, periodEnd, shouldFit, initSegmentReference);
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const availabilityStart =
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context.presentationTimeline.getSegmentAvailabilityStart();
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tsi.evict(availabilityStart);
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}
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if (info.timeline &&
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context.adaptationSet.contentType !== 'image' &&
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context.adaptationSet.contentType !== 'text') {
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const timeline = info.timeline;
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context.presentationTimeline.notifyTimeRange(
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timeline,
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periodStart);
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}
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if (stream && context.dynamic) {
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stream.segmentIndex = segmentIndex;
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}
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return {
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generateSegmentIndex: () => {
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// If segmentIndex is deleted, or segmentIndex's references are
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// released by closeSegmentIndex(), we should set the value of
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// segmentIndex again.
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if (segmentIndex instanceof shaka.dash.TimelineSegmentIndex &&
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segmentIndex.isEmpty()) {
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segmentIndex.appendTemplateInfo(info, periodStart,
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periodEnd, shouldFit, initSegmentReference);
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}
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return Promise.resolve(segmentIndex);
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},
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};
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}
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}
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/**
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* Ingests Patch MPD segments into timeline.
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*
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* @param {!shaka.dash.DashParser.Context} context
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* @param {shaka.extern.xml.Node} patchNode
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*/
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static modifyTimepoints(context, patchNode) {
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const MpdUtils = shaka.dash.MpdUtils;
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const SegmentTemplate = shaka.dash.SegmentTemplate;
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const TXml = shaka.util.TXml;
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const timelineNode = MpdUtils.inheritChild(context,
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SegmentTemplate.fromInheritance_, 'SegmentTimeline');
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goog.asserts.assert(timelineNode, 'timeline node not found');
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const timepoints = TXml.findChildren(timelineNode, 'S');
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goog.asserts.assert(timepoints, 'timepoints should exist');
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TXml.modifyNodes(timepoints, patchNode);
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timelineNode.children = timepoints;
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}
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/**
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* Removes all segments from timeline.
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*
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* @param {!shaka.dash.DashParser.Context} context
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*/
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static removeTimepoints(context) {
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const MpdUtils = shaka.dash.MpdUtils;
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const SegmentTemplate = shaka.dash.SegmentTemplate;
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const timelineNode = MpdUtils.inheritChild(context,
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SegmentTemplate.fromInheritance_, 'SegmentTimeline');
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goog.asserts.assert(timelineNode, 'timeline node not found');
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timelineNode.children = [];
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}
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/**
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* @param {?shaka.dash.DashParser.InheritanceFrame} frame
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* @return {?shaka.extern.xml.Node}
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* @private
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*/
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static fromInheritance_(frame) {
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return frame.segmentTemplate;
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}
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/**
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* Parses a SegmentTemplate element into an info object.
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*
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* @param {shaka.dash.DashParser.Context} context
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* @return {shaka.dash.SegmentTemplate.SegmentTemplateInfo}
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* @private
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*/
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static parseSegmentTemplateInfo_(context) {
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const SegmentTemplate = shaka.dash.SegmentTemplate;
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const MpdUtils = shaka.dash.MpdUtils;
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const StringUtils = shaka.util.StringUtils;
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const segmentInfo =
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MpdUtils.parseSegmentInfo(context, SegmentTemplate.fromInheritance_);
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const media = MpdUtils.inheritAttribute(
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context, SegmentTemplate.fromInheritance_, 'media');
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const index = MpdUtils.inheritAttribute(
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context, SegmentTemplate.fromInheritance_, 'index');
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const k = MpdUtils.inheritAttribute(
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context, SegmentTemplate.fromInheritance_, 'k');
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let numChunks = 0;
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if (k) {
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numChunks = parseInt(k, 10);
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}
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return {
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segmentDuration: segmentInfo.segmentDuration,
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timescale: segmentInfo.timescale,
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startNumber: segmentInfo.startNumber,
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scaledPresentationTimeOffset: segmentInfo.scaledPresentationTimeOffset,
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unscaledPresentationTimeOffset:
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segmentInfo.unscaledPresentationTimeOffset,
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timeline: segmentInfo.timeline,
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mediaTemplate: media && StringUtils.htmlUnescape(media),
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indexTemplate: index,
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mimeType: context.representation.mimeType,
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codecs: context.representation.codecs,
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bandwidth: context.bandwidth,
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numChunks: numChunks,
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};
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}
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/**
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* Verifies a SegmentTemplate info object.
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*
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* @param {shaka.dash.DashParser.Context} context
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* @param {shaka.dash.SegmentTemplate.SegmentTemplateInfo} info
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* @private
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*/
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static checkSegmentTemplateInfo_(context, info) {
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let n = 0;
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n += info.indexTemplate ? 1 : 0;
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n += info.timeline ? 1 : 0;
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n += info.segmentDuration ? 1 : 0;
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if (n == 0) {
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shaka.log.error(
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'SegmentTemplate does not contain any segment information:',
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'the SegmentTemplate must contain either an index URL template',
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'a SegmentTimeline, or a segment duration.',
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context.representation);
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throw new shaka.util.Error(
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shaka.util.Error.Severity.CRITICAL,
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shaka.util.Error.Category.MANIFEST,
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shaka.util.Error.Code.DASH_NO_SEGMENT_INFO);
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} else if (n != 1) {
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shaka.log.warning(
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'SegmentTemplate containes multiple segment information sources:',
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'the SegmentTemplate should only contain an index URL template,',
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'a SegmentTimeline or a segment duration.',
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context.representation);
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if (info.indexTemplate) {
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shaka.log.info('Using the index URL template by default.');
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info.timeline = null;
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info.segmentDuration = null;
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} else {
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goog.asserts.assert(info.timeline, 'There should be a timeline');
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shaka.log.info('Using the SegmentTimeline by default.');
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info.segmentDuration = null;
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}
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}
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if (!info.indexTemplate && !info.mediaTemplate) {
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shaka.log.error(
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'SegmentTemplate does not contain sufficient segment information:',
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'the SegmentTemplate\'s media URL template is missing.',
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context.representation);
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throw new shaka.util.Error(
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shaka.util.Error.Severity.CRITICAL,
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shaka.util.Error.Category.MANIFEST,
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shaka.util.Error.Code.DASH_NO_SEGMENT_INFO);
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}
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}
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/**
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* Generates a SegmentIndex from an index URL template.
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*
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* @param {shaka.dash.DashParser.Context} context
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* @param {shaka.dash.DashParser.RequestSegmentCallback} requestSegment
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* @param {shaka.media.InitSegmentReference} init
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* @param {shaka.dash.SegmentTemplate.SegmentTemplateInfo} info
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* @return {!Promise.<shaka.media.SegmentIndex>}
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* @private
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*/
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static generateSegmentIndexFromIndexTemplate_(
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context, requestSegment, init, info) {
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const MpdUtils = shaka.dash.MpdUtils;
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const ManifestParserUtils = shaka.util.ManifestParserUtils;
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goog.asserts.assert(info.indexTemplate, 'must be using index template');
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const filledTemplate = MpdUtils.fillUriTemplate(
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info.indexTemplate, context.representation.id,
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null, null, context.bandwidth || null, null);
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const resolvedUris = ManifestParserUtils.resolveUris(
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context.representation.getBaseUris(), [filledTemplate]);
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return shaka.dash.SegmentBase.generateSegmentIndexFromUris(
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context, requestSegment, init, resolvedUris, 0, null,
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info.scaledPresentationTimeOffset);
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}
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/**
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* Generates a SegmentIndex from fixed-duration segments.
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*
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* @param {shaka.dash.DashParser.Context} context
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* @param {shaka.dash.SegmentTemplate.SegmentTemplateInfo} info
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* @param {number} segmentLimit The maximum number of segments to generate.
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* @param {shaka.media.InitSegmentReference} initSegmentReference
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* @param {!Object.<string, number>} periodDurationMap
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* @param {shaka.extern.aesKey|undefined} aesKey
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* @param {?number} lastSegmentNumber
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* @param {number} segmentSequenceCadence
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* @return {!Promise.<shaka.media.SegmentIndex>}
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* @private
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*/
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static generateSegmentIndexFromDuration_(
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context, info, segmentLimit, initSegmentReference, periodDurationMap,
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aesKey, lastSegmentNumber, segmentSequenceCadence) {
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goog.asserts.assert(info.mediaTemplate,
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'There should be a media template with duration');
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const MpdUtils = shaka.dash.MpdUtils;
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const ManifestParserUtils = shaka.util.ManifestParserUtils;
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const presentationTimeline = context.presentationTimeline;
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// Capture values that could change as the parsing context moves on to
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// other parts of the manifest.
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const periodStart = context.periodInfo.start;
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const periodId = context.period.id;
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const initialPeriodDuration = context.periodInfo.duration;
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// For multi-period live streams the period duration may not be known until
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// the following period appears in an updated manifest. periodDurationMap
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// provides the updated period duration.
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const getPeriodEnd = () => {
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const periodDuration =
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(periodId != null && periodDurationMap[periodId]) ||
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initialPeriodDuration;
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const periodEnd = periodDuration ?
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(periodStart + periodDuration) : Infinity;
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return periodEnd;
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};
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const segmentDuration = info.segmentDuration;
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goog.asserts.assert(
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segmentDuration != null, 'Segment duration must not be null!');
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const startNumber = info.startNumber;
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const timescale = info.timescale;
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const template = info.mediaTemplate;
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const bandwidth = context.bandwidth || null;
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const id = context.representation.id;
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const getBaseUris = context.representation.getBaseUris;
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const urlParams = context.urlParams;
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const timestampOffset = periodStart - info.scaledPresentationTimeOffset;
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// Computes the range of presentation timestamps both within the period and
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// available. This is an intersection of the period range and the
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// availability window.
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const computeAvailablePeriodRange = () => {
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return [
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Math.max(
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presentationTimeline.getSegmentAvailabilityStart(),
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periodStart),
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Math.min(
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presentationTimeline.getSegmentAvailabilityEnd(),
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getPeriodEnd()),
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];
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};
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// Computes the range of absolute positions both within the period and
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// available. The range is inclusive. These are the positions for which we
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// will generate segment references.
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const computeAvailablePositionRange = () => {
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// In presentation timestamps.
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const availablePresentationTimes = computeAvailablePeriodRange();
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goog.asserts.assert(availablePresentationTimes.every(isFinite),
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'Available presentation times must be finite!');
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goog.asserts.assert(availablePresentationTimes.every((x) => x >= 0),
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'Available presentation times must be positive!');
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goog.asserts.assert(segmentDuration != null,
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'Segment duration must not be null!');
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// In period-relative timestamps.
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const availablePeriodTimes =
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availablePresentationTimes.map((x) => x - periodStart);
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// These may sometimes be reversed ([1] <= [0]) if the period is
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// completely unavailable. The logic will still work if this happens,
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// because we will simply generate no references.
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// In period-relative positions (0-based).
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const availablePeriodPositions = [
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Math.ceil(availablePeriodTimes[0] / segmentDuration),
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Math.ceil(availablePeriodTimes[1] / segmentDuration) - 1,
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];
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// For Low Latency we can request the partial current position.
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if (context.representation.availabilityTimeOffset) {
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availablePeriodPositions[1]++;
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}
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// In absolute positions.
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const availablePresentationPositions =
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availablePeriodPositions.map((x) => x + startNumber);
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return availablePresentationPositions;
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};
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// For Live, we must limit the initial SegmentIndex in size, to avoid
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// consuming too much CPU or memory for content with gigantic
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// timeShiftBufferDepth (which can have values up to and including
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// Infinity).
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const range = computeAvailablePositionRange();
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const minPosition = context.dynamic ?
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Math.max(range[0], range[1] - segmentLimit + 1) :
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range[0];
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const maxPosition = lastSegmentNumber || range[1];
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const references = [];
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const createReference = (position) => {
|
|
// These inner variables are all scoped to the inner loop, and can be used
|
|
// safely in the callback below.
|
|
|
|
goog.asserts.assert(segmentDuration != null,
|
|
'Segment duration must not be null!');
|
|
|
|
// Relative to the period start.
|
|
const positionWithinPeriod = position - startNumber;
|
|
const segmentPeriodTime = positionWithinPeriod * segmentDuration;
|
|
|
|
// What will appear in the actual segment files. The media timestamp is
|
|
// what is expected in the $Time$ template.
|
|
const segmentMediaTime = segmentPeriodTime +
|
|
info.scaledPresentationTimeOffset;
|
|
|
|
// Relative to the presentation.
|
|
const segmentStart = segmentPeriodTime + periodStart;
|
|
const trueSegmentEnd = segmentStart + segmentDuration;
|
|
// Cap the segment end at the period end so that references from the
|
|
// next period will fit neatly after it.
|
|
const segmentEnd = Math.min(trueSegmentEnd, getPeriodEnd());
|
|
|
|
// This condition will be true unless the segmentStart was >= periodEnd.
|
|
// If we've done the position calculations correctly, this won't happen.
|
|
goog.asserts.assert(segmentStart < segmentEnd,
|
|
'Generated a segment outside of the period!');
|
|
|
|
const partialSegmentRefs = [];
|
|
|
|
const numChunks = info.numChunks;
|
|
if (numChunks) {
|
|
const partialDuration = (segmentEnd - segmentStart) / numChunks;
|
|
|
|
for (let i = 0; i < numChunks; i++) {
|
|
const start = segmentStart + partialDuration * i;
|
|
const end = start + partialDuration;
|
|
const subNumber = i + 1;
|
|
const getPartialUris = () => {
|
|
let time = segmentMediaTime * timescale;
|
|
if ('BigInt' in window && time > Number.MAX_SAFE_INTEGER) {
|
|
time = BigInt(segmentMediaTime) * BigInt(timescale);
|
|
}
|
|
const mediaUri = MpdUtils.fillUriTemplate(
|
|
template, id, position, subNumber, bandwidth, time);
|
|
return ManifestParserUtils.resolveUris(
|
|
getBaseUris(), [mediaUri], urlParams());
|
|
};
|
|
const partial = new shaka.media.SegmentReference(
|
|
start,
|
|
end,
|
|
getPartialUris,
|
|
/* startByte= */ 0,
|
|
/* endByte= */ null,
|
|
initSegmentReference,
|
|
timestampOffset,
|
|
/* appendWindowStart= */ periodStart,
|
|
/* appendWindowEnd= */ getPeriodEnd(),
|
|
/* partialReferences= */ [],
|
|
/* tilesLayout= */ '',
|
|
/* tileDuration= */ null,
|
|
/* syncTime= */ null,
|
|
shaka.media.SegmentReference.Status.AVAILABLE,
|
|
aesKey);
|
|
partial.codecs = context.representation.codecs;
|
|
partial.mimeType = context.representation.mimeType;
|
|
if (segmentSequenceCadence == 0) {
|
|
if (i > 0) {
|
|
partial.markAsNonIndependent();
|
|
}
|
|
} else if ((i % segmentSequenceCadence) != 0) {
|
|
partial.markAsNonIndependent();
|
|
}
|
|
partialSegmentRefs.push(partial);
|
|
}
|
|
}
|
|
|
|
const getUris = () => {
|
|
if (numChunks) {
|
|
return [];
|
|
}
|
|
let time = segmentMediaTime * timescale;
|
|
if ('BigInt' in window && time > Number.MAX_SAFE_INTEGER) {
|
|
time = BigInt(segmentMediaTime) * BigInt(timescale);
|
|
}
|
|
const mediaUri = MpdUtils.fillUriTemplate(
|
|
template, id, position, /* subNumber= */ null, bandwidth, time);
|
|
return ManifestParserUtils.resolveUris(
|
|
getBaseUris(), [mediaUri], urlParams());
|
|
};
|
|
|
|
const ref = new shaka.media.SegmentReference(
|
|
segmentStart,
|
|
segmentEnd,
|
|
getUris,
|
|
/* startByte= */ 0,
|
|
/* endByte= */ null,
|
|
initSegmentReference,
|
|
timestampOffset,
|
|
/* appendWindowStart= */ periodStart,
|
|
/* appendWindowEnd= */ getPeriodEnd(),
|
|
partialSegmentRefs,
|
|
/* tilesLayout= */ '',
|
|
/* tileDuration= */ null,
|
|
/* syncTime= */ null,
|
|
shaka.media.SegmentReference.Status.AVAILABLE,
|
|
aesKey,
|
|
partialSegmentRefs.length > 0);
|
|
ref.codecs = context.representation.codecs;
|
|
ref.mimeType = context.representation.mimeType;
|
|
ref.bandwidth = context.bandwidth;
|
|
// This is necessary information for thumbnail streams:
|
|
ref.trueEndTime = trueSegmentEnd;
|
|
return ref;
|
|
};
|
|
|
|
for (let position = minPosition; position <= maxPosition; ++position) {
|
|
const reference = createReference(position);
|
|
references.push(reference);
|
|
}
|
|
|
|
/** @type {shaka.media.SegmentIndex} */
|
|
const segmentIndex = new shaka.media.SegmentIndex(references);
|
|
|
|
// If the availability timeline currently ends before the period, we will
|
|
// need to add references over time.
|
|
const willNeedToAddReferences =
|
|
presentationTimeline.getSegmentAvailabilityEnd() < getPeriodEnd();
|
|
|
|
// When we start a live stream with a period that ends within the
|
|
// availability window we will not need to add more references, but we will
|
|
// need to evict old references.
|
|
const willNeedToEvictReferences = presentationTimeline.isLive();
|
|
|
|
if (willNeedToAddReferences || willNeedToEvictReferences) {
|
|
// The period continues to get longer over time, so check for new
|
|
// references once every |segmentDuration| seconds.
|
|
// We clamp to |minPosition| in case the initial range was reversed and no
|
|
// references were generated. Otherwise, the update would start creating
|
|
// negative positions for segments in periods which begin in the future.
|
|
let nextPosition = Math.max(minPosition, maxPosition + 1);
|
|
let updateTime = segmentDuration;
|
|
// For low latency we need to evict very frequently.
|
|
if (context.representation.availabilityTimeOffset) {
|
|
updateTime = 0.1;
|
|
}
|
|
segmentIndex.updateEvery(updateTime, () => {
|
|
// Evict any references outside the window.
|
|
const availabilityStartTime =
|
|
presentationTimeline.getSegmentAvailabilityStart();
|
|
segmentIndex.evict(availabilityStartTime);
|
|
|
|
// Compute any new references that need to be added.
|
|
const [_, maxPosition] = computeAvailablePositionRange();
|
|
const references = [];
|
|
while (nextPosition <= maxPosition) {
|
|
const reference = createReference(nextPosition);
|
|
references.push(reference);
|
|
nextPosition++;
|
|
}
|
|
|
|
// The timer must continue firing until the entire period is
|
|
// unavailable, so that all references will be evicted.
|
|
if (availabilityStartTime > getPeriodEnd() && !references.length) {
|
|
// Signal stop.
|
|
return null;
|
|
}
|
|
return references;
|
|
});
|
|
}
|
|
|
|
return Promise.resolve(segmentIndex);
|
|
}
|
|
|
|
/**
|
|
* Creates an init segment reference from a context object.
|
|
*
|
|
* @param {shaka.dash.DashParser.Context} context
|
|
* @param {shaka.extern.aesKey|undefined} aesKey
|
|
* @return {shaka.media.InitSegmentReference}
|
|
* @private
|
|
*/
|
|
static createInitSegment_(context, aesKey) {
|
|
const MpdUtils = shaka.dash.MpdUtils;
|
|
const ManifestParserUtils = shaka.util.ManifestParserUtils;
|
|
const SegmentTemplate = shaka.dash.SegmentTemplate;
|
|
|
|
let initialization = context.representation.initialization;
|
|
if (!initialization) {
|
|
initialization = MpdUtils.inheritAttribute(
|
|
context, SegmentTemplate.fromInheritance_, 'initialization');
|
|
}
|
|
if (!initialization) {
|
|
return null;
|
|
}
|
|
initialization = shaka.util.StringUtils.htmlUnescape(initialization);
|
|
|
|
const repId = context.representation.id;
|
|
const bandwidth = context.bandwidth || null;
|
|
const getBaseUris = context.representation.getBaseUris;
|
|
const urlParams = context.urlParams;
|
|
const getUris = () => {
|
|
goog.asserts.assert(initialization, 'Should have returned earler');
|
|
const filledTemplate = MpdUtils.fillUriTemplate(
|
|
initialization, repId, null, null, bandwidth, null);
|
|
const resolvedUris = ManifestParserUtils.resolveUris(
|
|
getBaseUris(), [filledTemplate], urlParams());
|
|
return resolvedUris;
|
|
};
|
|
const qualityInfo = shaka.dash.SegmentBase.createQualityInfo(context);
|
|
const ref = new shaka.media.InitSegmentReference(
|
|
getUris,
|
|
/* startByte= */ 0,
|
|
/* endByte= */ null,
|
|
qualityInfo,
|
|
/* timescale= */ null,
|
|
/* segmentData= */ null,
|
|
aesKey);
|
|
ref.codecs = context.representation.codecs;
|
|
ref.mimeType = context.representation.mimeType;
|
|
return ref;
|
|
}
|
|
};
|
|
|
|
|
|
/**
|
|
* A SegmentIndex that returns segments references on demand from
|
|
* a segment timeline.
|
|
*
|
|
* @extends shaka.media.SegmentIndex
|
|
* @implements {shaka.util.IReleasable}
|
|
* @implements {Iterable.<!shaka.media.SegmentReference>}
|
|
*
|
|
* @private
|
|
*
|
|
*/
|
|
shaka.dash.TimelineSegmentIndex = class extends shaka.media.SegmentIndex {
|
|
/**
|
|
*
|
|
* @param {!shaka.dash.SegmentTemplate.SegmentTemplateInfo} templateInfo
|
|
* @param {?string} representationId
|
|
* @param {number} bandwidth
|
|
* @param {function():Array.<string>} getBaseUris
|
|
* @param {function():string} urlParams
|
|
* @param {number} periodStart
|
|
* @param {number} periodEnd
|
|
* @param {shaka.media.InitSegmentReference} initSegmentReference
|
|
* @param {boolean} shouldFit
|
|
* @param {shaka.extern.aesKey|undefined} aesKey
|
|
* @param {number} segmentSequenceCadence
|
|
*/
|
|
constructor(templateInfo, representationId, bandwidth, getBaseUris,
|
|
urlParams, periodStart, periodEnd, initSegmentReference, shouldFit,
|
|
aesKey, segmentSequenceCadence) {
|
|
super([]);
|
|
|
|
/** @private {?shaka.dash.SegmentTemplate.SegmentTemplateInfo} */
|
|
this.templateInfo_ = templateInfo;
|
|
/** @private {?string} */
|
|
this.representationId_ = representationId;
|
|
/** @private {number} */
|
|
this.bandwidth_ = bandwidth;
|
|
/** @private {function():Array.<string>} */
|
|
this.getBaseUris_ = getBaseUris;
|
|
/** @private {function():string} */
|
|
this.urlParams_ = urlParams;
|
|
/** @private {number} */
|
|
this.periodStart_ = periodStart;
|
|
/** @private {number} */
|
|
this.periodEnd_ = periodEnd;
|
|
/** @private {shaka.media.InitSegmentReference} */
|
|
this.initSegmentReference_ = initSegmentReference;
|
|
/** @private {shaka.extern.aesKey|undefined} */
|
|
this.aesKey_ = aesKey;
|
|
/** @private {number} */
|
|
this.segmentSequenceCadence_ = segmentSequenceCadence;
|
|
|
|
|
|
if (shouldFit) {
|
|
this.fitTimeline();
|
|
}
|
|
}
|
|
|
|
/**
|
|
* @override
|
|
*/
|
|
getNumReferences() {
|
|
if (this.templateInfo_) {
|
|
return this.templateInfo_.timeline.length;
|
|
} else {
|
|
return 0;
|
|
}
|
|
}
|
|
|
|
/**
|
|
* @override
|
|
*/
|
|
release() {
|
|
super.release();
|
|
this.templateInfo_ = null;
|
|
// We cannot release other fields, as segment index can
|
|
// be recreated using only template info.
|
|
}
|
|
|
|
|
|
/**
|
|
* @override
|
|
*/
|
|
evict(time) {
|
|
if (!this.templateInfo_) {
|
|
return;
|
|
}
|
|
shaka.log.debug(`${this.representationId_} Evicting at ${time}`);
|
|
let numToEvict = 0;
|
|
const timeline = this.templateInfo_.timeline;
|
|
|
|
for (let i = 0; i < timeline.length; i += 1) {
|
|
const range = timeline[i];
|
|
const end = range.end + this.periodStart_;
|
|
const start = range.start + this.periodStart_;
|
|
|
|
if (end <= time) {
|
|
shaka.log.debug(`Evicting ${start} - ${end}`);
|
|
numToEvict += 1;
|
|
} else {
|
|
break;
|
|
}
|
|
}
|
|
|
|
if (numToEvict > 0) {
|
|
this.templateInfo_.timeline = timeline.slice(numToEvict);
|
|
if (this.references.length >= numToEvict) {
|
|
this.references = this.references.slice(numToEvict);
|
|
}
|
|
|
|
this.numEvicted_ += numToEvict;
|
|
|
|
if (this.getNumReferences() === 0) {
|
|
this.release();
|
|
}
|
|
}
|
|
}
|
|
|
|
/**
|
|
* Merge new template info
|
|
* @param {shaka.dash.SegmentTemplate.SegmentTemplateInfo} info
|
|
* @param {number} periodStart
|
|
* @param {number} periodEnd
|
|
* @param {boolean} shouldFit
|
|
* @param {shaka.media.InitSegmentReference} initSegmentReference
|
|
*/
|
|
appendTemplateInfo(info, periodStart, periodEnd, shouldFit,
|
|
initSegmentReference) {
|
|
this.updateInitSegmentReference(initSegmentReference);
|
|
if (!this.templateInfo_) {
|
|
this.templateInfo_ = info;
|
|
this.periodStart_ = periodStart;
|
|
this.periodEnd_ = periodEnd;
|
|
} else {
|
|
const currentTimeline = this.templateInfo_.timeline;
|
|
|
|
if (this.templateInfo_.mediaTemplate !== info.mediaTemplate) {
|
|
this.templateInfo_.mediaTemplate = info.mediaTemplate;
|
|
}
|
|
|
|
// Append timeline
|
|
let newEntries;
|
|
if (currentTimeline.length) {
|
|
const lastCurrentEntry = currentTimeline[currentTimeline.length - 1];
|
|
newEntries = info.timeline.filter((entry) => {
|
|
return entry.end > lastCurrentEntry.end;
|
|
});
|
|
} else {
|
|
newEntries = info.timeline.slice();
|
|
}
|
|
|
|
if (newEntries.length > 0) {
|
|
shaka.log.debug(`Appending ${newEntries.length} entries`);
|
|
this.templateInfo_.timeline.push(...newEntries);
|
|
}
|
|
|
|
if (this.periodEnd_ !== periodEnd) {
|
|
this.periodEnd_ = periodEnd;
|
|
}
|
|
}
|
|
|
|
if (shouldFit) {
|
|
this.fitTimeline();
|
|
}
|
|
}
|
|
|
|
/**
|
|
* Updates the init segment reference and propagates the update to all
|
|
* references.
|
|
* @param {shaka.media.InitSegmentReference} initSegmentReference
|
|
*/
|
|
updateInitSegmentReference(initSegmentReference) {
|
|
if (this.initSegmentReference_ === initSegmentReference) {
|
|
return;
|
|
}
|
|
|
|
this.initSegmentReference_ = initSegmentReference;
|
|
for (const reference of this.references) {
|
|
if (reference) {
|
|
reference.updateInitSegmentReference(initSegmentReference);
|
|
}
|
|
}
|
|
}
|
|
|
|
/**
|
|
*
|
|
* @param {number} time
|
|
*/
|
|
isBeforeFirstEntry(time) {
|
|
const hasTimeline = this.templateInfo_ &&
|
|
this.templateInfo_.timeline && this.templateInfo_.timeline.length;
|
|
|
|
if (hasTimeline) {
|
|
const timeline = this.templateInfo_.timeline;
|
|
return time < timeline[0].start + this.periodStart_;
|
|
} else {
|
|
return false;
|
|
}
|
|
}
|
|
|
|
/**
|
|
* Fit timeline entries to period boundaries
|
|
*/
|
|
fitTimeline() {
|
|
if (this.getIsImmutable()) {
|
|
return;
|
|
}
|
|
const timeline = this.templateInfo_.timeline;
|
|
while (timeline.length) {
|
|
const lastTimePeriod = timeline[timeline.length - 1];
|
|
if (lastTimePeriod.start >= this.periodEnd_) {
|
|
timeline.pop();
|
|
} else {
|
|
break;
|
|
}
|
|
}
|
|
|
|
this.evict(this.periodStart_);
|
|
|
|
// Do NOT adjust last range to match period end! With high precision
|
|
// timestamps several recalculations may give wrong results on less precise
|
|
// platforms. To mitigate that, we're using cached |periodEnd_| value in
|
|
// find/get() methods whenever possible.
|
|
}
|
|
|
|
/**
|
|
* @override
|
|
*/
|
|
find(time) {
|
|
shaka.log.debug(`Find ${time}`);
|
|
|
|
if (this.isBeforeFirstEntry(time)) {
|
|
return this.numEvicted_;
|
|
}
|
|
|
|
if (!this.templateInfo_) {
|
|
return null;
|
|
}
|
|
|
|
const timeline = this.templateInfo_.timeline;
|
|
|
|
// Early exit if the time isn't within this period
|
|
if (time < this.periodStart_ || time >= this.periodEnd_) {
|
|
return null;
|
|
}
|
|
|
|
const lastIndex = timeline.length - 1;
|
|
|
|
for (let i = 0; i < timeline.length; i++) {
|
|
const range = timeline[i];
|
|
const start = range.start + this.periodStart_;
|
|
// A rounding error can cause /time/ to equal e.endTime or fall in between
|
|
// the references by a fraction of a second. To account for this, we use
|
|
// the start of the next segment as /end/, unless this is the last
|
|
// reference, in which case we use the period end as the /end/
|
|
let end;
|
|
|
|
if (i < lastIndex) {
|
|
end = timeline[i + 1].start + this.periodStart_;
|
|
} else if (this.periodEnd_ === Infinity) {
|
|
end = range.end + this.periodStart_;
|
|
} else {
|
|
end = this.periodEnd_;
|
|
}
|
|
|
|
if ((time >= start) && (time < end)) {
|
|
return i + this.numEvicted_;
|
|
}
|
|
}
|
|
|
|
return null;
|
|
}
|
|
|
|
/**
|
|
* @override
|
|
*/
|
|
get(position) {
|
|
const correctedPosition = position - this.numEvicted_;
|
|
if (correctedPosition < 0 ||
|
|
correctedPosition >= this.getNumReferences() || !this.templateInfo_) {
|
|
return null;
|
|
}
|
|
|
|
let ref = this.references[correctedPosition];
|
|
|
|
if (!ref) {
|
|
const range = this.templateInfo_.timeline[correctedPosition];
|
|
const segmentReplacement = range.segmentPosition;
|
|
const timeReplacement = this.templateInfo_
|
|
.unscaledPresentationTimeOffset + range.unscaledStart;
|
|
const timestampOffset = this.periodStart_ -
|
|
this.templateInfo_.scaledPresentationTimeOffset;
|
|
const trueSegmentEnd = this.periodStart_ + range.end;
|
|
let segmentEnd = trueSegmentEnd;
|
|
if (correctedPosition === this.getNumReferences() - 1 &&
|
|
this.periodEnd_ !== Infinity) {
|
|
segmentEnd = this.periodEnd_;
|
|
}
|
|
const codecs = this.templateInfo_.codecs;
|
|
const mimeType = this.templateInfo_.mimeType;
|
|
const bandwidth = this.templateInfo_.bandwidth;
|
|
|
|
const partialSegmentRefs = [];
|
|
|
|
const partialDuration = (range.end - range.start) / range.partialSegments;
|
|
|
|
for (let i = 0; i < range.partialSegments; i++) {
|
|
const start = range.start + partialDuration * i;
|
|
const end = start + partialDuration;
|
|
const subNumber = i + 1;
|
|
let uris = null;
|
|
const getPartialUris = () => {
|
|
if (!this.templateInfo_) {
|
|
return [];
|
|
}
|
|
if (uris == null) {
|
|
uris = shaka.dash.TimelineSegmentIndex.createUris_(
|
|
this.templateInfo_.mediaTemplate,
|
|
this.representationId_,
|
|
segmentReplacement,
|
|
this.bandwidth_,
|
|
timeReplacement,
|
|
subNumber,
|
|
this.getBaseUris_,
|
|
this.urlParams_);
|
|
}
|
|
return uris;
|
|
};
|
|
const partial = new shaka.media.SegmentReference(
|
|
this.periodStart_ + start,
|
|
this.periodStart_ + end,
|
|
getPartialUris,
|
|
/* startByte= */ 0,
|
|
/* endByte= */ null,
|
|
this.initSegmentReference_,
|
|
timestampOffset,
|
|
this.periodStart_,
|
|
this.periodEnd_,
|
|
/* partialReferences= */ [],
|
|
/* tilesLayout= */ '',
|
|
/* tileDuration= */ null,
|
|
/* syncTime= */ null,
|
|
shaka.media.SegmentReference.Status.AVAILABLE,
|
|
this.aesKey_);
|
|
partial.codecs = codecs;
|
|
partial.mimeType = mimeType;
|
|
partial.bandwidth = bandwidth;
|
|
if (this.segmentSequenceCadence_ == 0) {
|
|
if (i > 0) {
|
|
partial.markAsNonIndependent();
|
|
}
|
|
} else if ((i % this.segmentSequenceCadence_) != 0) {
|
|
partial.markAsNonIndependent();
|
|
}
|
|
partialSegmentRefs.push(partial);
|
|
}
|
|
|
|
const createUrisCb = () => {
|
|
if (range.partialSegments > 0 || !this.templateInfo_) {
|
|
return [];
|
|
}
|
|
return shaka.dash.TimelineSegmentIndex
|
|
.createUris_(
|
|
this.templateInfo_.mediaTemplate,
|
|
this.representationId_,
|
|
segmentReplacement,
|
|
this.bandwidth_,
|
|
timeReplacement,
|
|
/* subNumber= */ null,
|
|
this.getBaseUris_,
|
|
this.urlParams_,
|
|
);
|
|
};
|
|
|
|
ref = new shaka.media.SegmentReference(
|
|
this.periodStart_ + range.start,
|
|
segmentEnd,
|
|
createUrisCb,
|
|
/* startByte= */ 0,
|
|
/* endByte= */ null,
|
|
this.initSegmentReference_,
|
|
timestampOffset,
|
|
this.periodStart_,
|
|
this.periodEnd_,
|
|
partialSegmentRefs,
|
|
/* tilesLayout= */ '',
|
|
/* tileDuration= */ null,
|
|
/* syncTime= */ null,
|
|
shaka.media.SegmentReference.Status.AVAILABLE,
|
|
this.aesKey_,
|
|
/* allPartialSegments= */ range.partialSegments > 0);
|
|
ref.codecs = codecs;
|
|
ref.mimeType = mimeType;
|
|
ref.trueEndTime = trueSegmentEnd;
|
|
ref.bandwidth = bandwidth;
|
|
this.references[correctedPosition] = ref;
|
|
}
|
|
|
|
return ref;
|
|
}
|
|
|
|
/**
|
|
* @override
|
|
*/
|
|
forEachTopLevelReference(fn) {
|
|
this.fitTimeline();
|
|
for (let i = 0; i < this.getNumReferences(); i++) {
|
|
const reference = this.get(i + this.numEvicted_);
|
|
if (reference) {
|
|
fn(reference);
|
|
}
|
|
}
|
|
}
|
|
|
|
/**
|
|
* Fill in a specific template with values to get the segment uris
|
|
*
|
|
* @return {!Array.<string>}
|
|
* @private
|
|
*/
|
|
static createUris_(mediaTemplate, repId, segmentReplacement,
|
|
bandwidth, timeReplacement, subNumber, getBaseUris, urlParams) {
|
|
const mediaUri = shaka.dash.MpdUtils.fillUriTemplate(
|
|
mediaTemplate, repId,
|
|
segmentReplacement, subNumber, bandwidth || null, timeReplacement);
|
|
return shaka.util.ManifestParserUtils
|
|
.resolveUris(getBaseUris(), [mediaUri], urlParams())
|
|
.map((g) => {
|
|
return g.toString();
|
|
});
|
|
}
|
|
};
|
|
|
|
/**
|
|
* @typedef {{
|
|
* timescale: number,
|
|
* segmentDuration: ?number,
|
|
* startNumber: number,
|
|
* scaledPresentationTimeOffset: number,
|
|
* unscaledPresentationTimeOffset: number,
|
|
* timeline: Array.<shaka.media.PresentationTimeline.TimeRange>,
|
|
* mediaTemplate: ?string,
|
|
* indexTemplate: ?string,
|
|
* mimeType: string,
|
|
* codecs: string,
|
|
* bandwidth: number,
|
|
* numChunks: number
|
|
* }}
|
|
*
|
|
* @description
|
|
* Contains information about a SegmentTemplate.
|
|
*
|
|
* @property {number} timescale
|
|
* The time-scale of the representation.
|
|
* @property {?number} segmentDuration
|
|
* The duration of the segments in seconds, if given.
|
|
* @property {number} startNumber
|
|
* The start number of the segments; 1 or greater.
|
|
* @property {number} scaledPresentationTimeOffset
|
|
* The presentation time offset of the representation, in seconds.
|
|
* @property {number} unscaledPresentationTimeOffset
|
|
* The presentation time offset of the representation, in timescale units.
|
|
* @property {Array.<shaka.media.PresentationTimeline.TimeRange>} timeline
|
|
* The timeline of the representation, if given. Times in seconds.
|
|
* @property {?string} mediaTemplate
|
|
* The media URI template, if given.
|
|
* @property {?string} indexTemplate
|
|
* The index URI template, if given.
|
|
* @property {string} mimeType
|
|
* The mimeType.
|
|
* @property {string} codecs
|
|
* The codecs.
|
|
* @property {number} bandwidth
|
|
* The bandwidth.
|
|
* @property {number} numChunks
|
|
* The number of chunks in each segment.
|
|
*/
|
|
shaka.dash.SegmentTemplate.SegmentTemplateInfo;
|