/*! @license
* Shaka Player
* Copyright 2016 Google LLC
* SPDX-License-Identifier: Apache-2.0
*/
goog.provide('shaka.mss.MssParser');
goog.require('goog.asserts');
goog.require('shaka.abr.Ewma');
goog.require('shaka.log');
goog.require('shaka.media.InitSegmentReference');
goog.require('shaka.media.ManifestParser');
goog.require('shaka.media.PresentationTimeline');
goog.require('shaka.media.SegmentIndex');
goog.require('shaka.media.SegmentReference');
goog.require('shaka.mss.ContentProtection');
goog.require('shaka.net.NetworkingEngine');
goog.require('shaka.util.Error');
goog.require('shaka.util.LanguageUtils');
goog.require('shaka.util.ManifestParserUtils');
goog.require('shaka.util.Mp4Generator');
goog.require('shaka.util.OperationManager');
goog.require('shaka.util.Timer');
goog.require('shaka.util.XmlUtils');
/**
* Creates a new MSS parser.
*
* @implements {shaka.extern.ManifestParser}
* @export
*/
shaka.mss.MssParser = class {
/** Creates a new MSS parser. */
constructor() {
/** @private {?shaka.extern.ManifestConfiguration} */
this.config_ = null;
/** @private {?shaka.extern.ManifestParser.PlayerInterface} */
this.playerInterface_ = null;
/** @private {!Array.<string>} */
this.manifestUris_ = [];
/** @private {?shaka.extern.Manifest} */
this.manifest_ = null;
/** @private {number} */
this.globalId_ = 1;
/**
* The update period in seconds, or 0 for no updates.
* @private {number}
*/
this.updatePeriod_ = 0;
/** @private {?shaka.media.PresentationTimeline} */
this.presentationTimeline_ = null;
/**
* An ewma that tracks how long updates take.
* This is to mitigate issues caused by slow parsing on embedded devices.
* @private {!shaka.abr.Ewma}
*/
this.averageUpdateDuration_ = new shaka.abr.Ewma(5);
/** @private {shaka.util.Timer} */
this.updateTimer_ = new shaka.util.Timer(() => {
this.onUpdate_();
});
/** @private {!shaka.util.OperationManager} */
this.operationManager_ = new shaka.util.OperationManager();
/**
* @private {!Map.<number, !BufferSource>}
*/
this.initSegmentDataByStreamId_ = new Map();
}
/**
* @override
* @exportInterface
*/
configure(config) {
goog.asserts.assert(config.mss != null,
'MssManifestConfiguration should not be null!');
this.config_ = config;
}
/**
* @override
* @exportInterface
*/
async start(uri, playerInterface) {
goog.asserts.assert(this.config_, 'Must call configure() before start()!');
this.manifestUris_ = [uri];
this.playerInterface_ = playerInterface;
await this.requestManifest_();
// Make sure that the parser has not been destroyed.
if (!this.playerInterface_) {
throw new shaka.util.Error(
shaka.util.Error.Severity.CRITICAL,
shaka.util.Error.Category.PLAYER,
shaka.util.Error.Code.OPERATION_ABORTED);
}
this.setUpdateTimer_();
goog.asserts.assert(this.manifest_, 'Manifest should be non-null!');
return this.manifest_;
}
/**
* Called when the update timer ticks.
*
* @return {!Promise}
* @private
*/
async onUpdate_() {
goog.asserts.assert(this.updatePeriod_ >= 0,
'There should be an update period');
shaka.log.info('Updating manifest...');
try {
await this.requestManifest_();
} catch (error) {
goog.asserts.assert(error instanceof shaka.util.Error,
'Should only receive a Shaka error');
// Try updating again, but ensure we haven't been destroyed.
if (this.playerInterface_) {
// We will retry updating, so override the severity of the error.
error.severity = shaka.util.Error.Severity.RECOVERABLE;
this.playerInterface_.onError(error);
}
}
// Detect a call to stop()
if (!this.playerInterface_) {
return;
}
this.setUpdateTimer_();
}
/**
* Sets the update timer. Does nothing if the manifest is not live.
*
* @private
*/
setUpdateTimer_() {
if (this.updatePeriod_ <= 0) {
return;
}
const finalDelay = Math.max(
shaka.mss.MssParser.MIN_UPDATE_PERIOD_,
this.updatePeriod_,
this.averageUpdateDuration_.getEstimate());
// We do not run the timer as repeating because part of update is async and
// we need schedule the update after it finished.
this.updateTimer_.tickAfter(/* seconds= */ finalDelay);
}
/**
* @override
* @exportInterface
*/
stop() {
this.playerInterface_ = null;
this.config_ = null;
this.manifestUris_ = [];
this.manifest_ = null;
if (this.updateTimer_ != null) {
this.updateTimer_.stop();
this.updateTimer_ = null;
}
this.initSegmentDataByStreamId_.clear();
return this.operationManager_.destroy();
}
/**
* @override
* @exportInterface
*/
async update() {
try {
await this.requestManifest_();
} catch (error) {
if (!this.playerInterface_ || !error) {
return;
}
goog.asserts.assert(error instanceof shaka.util.Error, 'Bad error type');
this.playerInterface_.onError(error);
}
}
/**
* @override
* @exportInterface
*/
onExpirationUpdated(sessionId, expiration) {
// No-op
}
/**
* Makes a network request for the manifest and parses the resulting data.
*
* @private
*/
async requestManifest_() {
const requestType = shaka.net.NetworkingEngine.RequestType.MANIFEST;
const type = shaka.net.NetworkingEngine.AdvancedRequestType.MSS;
const request = shaka.net.NetworkingEngine.makeRequest(
this.manifestUris_, this.config_.retryParameters);
const networkingEngine = this.playerInterface_.networkingEngine;
const startTime = Date.now();
const operation = networkingEngine.request(requestType, request, {type});
this.operationManager_.manage(operation);
const response = await operation.promise;
// Detect calls to stop().
if (!this.playerInterface_) {
return;
}
// For redirections add the response uri to the first entry in the
// Manifest Uris array.
if (response.uri && !this.manifestUris_.includes(response.uri)) {
this.manifestUris_.unshift(response.uri);
}
// This may throw, but it will result in a failed promise.
this.parseManifest_(response.data, response.uri);
// Keep track of how long the longest manifest update took.
const endTime = Date.now();
const updateDuration = (endTime - startTime) / 1000.0;
this.averageUpdateDuration_.sample(1, updateDuration);
}
/**
* Parses the manifest XML. This also handles updates and will update the
* stored manifest.
*
* @param {BufferSource} data
* @param {string} finalManifestUri The final manifest URI, which may
* differ from this.manifestUri_ if there has been a redirect.
* @return {!Promise}
* @private
*/
parseManifest_(data, finalManifestUri) {
const mss = shaka.util.XmlUtils.parseXml(data, 'SmoothStreamingMedia');
if (!mss) {
throw new shaka.util.Error(
shaka.util.Error.Severity.CRITICAL,
shaka.util.Error.Category.MANIFEST,
shaka.util.Error.Code.MSS_INVALID_XML,
finalManifestUri);
}
this.processManifest_(mss, finalManifestUri);
return Promise.resolve();
}
/**
* Takes a formatted MSS and converts it into a manifest.
*
* @param {!Element} mss
* @param {string} finalManifestUri The final manifest URI, which may
* differ from this.manifestUri_ if there has been a redirect.
* @private
*/
processManifest_(mss, finalManifestUri) {
const XmlUtils = shaka.util.XmlUtils;
const manifestPreprocessor = this.config_.mss.manifestPreprocessor;
if (manifestPreprocessor) {
manifestPreprocessor(mss);
}
if (!this.presentationTimeline_) {
this.presentationTimeline_ = new shaka.media.PresentationTimeline(
/* presentationStartTime= */ null, /* delay= */ 0);
}
const isLive = XmlUtils.parseAttr(mss, 'IsLive',
XmlUtils.parseBoolean, /* defaultValue= */ false);
if (isLive) {
throw new shaka.util.Error(
shaka.util.Error.Severity.CRITICAL,
shaka.util.Error.Category.MANIFEST,
shaka.util.Error.Code.MSS_LIVE_CONTENT_NOT_SUPPORTED);
}
this.presentationTimeline_.setStatic(!isLive);
const timescale = XmlUtils.parseAttr(mss, 'TimeScale',
XmlUtils.parseNonNegativeInt, shaka.mss.MssParser.DEFAULT_TIME_SCALE_);
goog.asserts.assert(timescale && timescale >= 0,
'Timescale must be defined!');
let dvrWindowLength = XmlUtils.parseAttr(mss, 'DVRWindowLength',
XmlUtils.parseNonNegativeInt);
// If the DVRWindowLength field is omitted for a live presentation or set
// to 0, the DVR window is effectively infinite
if (isLive && (dvrWindowLength === 0 || isNaN(dvrWindowLength))) {
dvrWindowLength = Infinity;
}
// Start-over
const canSeek = XmlUtils.parseAttr(mss, 'CanSeek',
XmlUtils.parseBoolean, /* defaultValue= */ false);
if (dvrWindowLength === 0 && canSeek) {
dvrWindowLength = Infinity;
}
let segmentAvailabilityDuration = null;
if (dvrWindowLength && dvrWindowLength > 0) {
segmentAvailabilityDuration = dvrWindowLength / timescale;
}
// If it's live, we check for an override.
if (isLive && !isNaN(this.config_.availabilityWindowOverride)) {
segmentAvailabilityDuration = this.config_.availabilityWindowOverride;
}
// If it's null, that means segments are always available. This is always
// the case for VOD, and sometimes the case for live.
if (segmentAvailabilityDuration == null) {
segmentAvailabilityDuration = Infinity;
}
this.presentationTimeline_.setSegmentAvailabilityDuration(
segmentAvailabilityDuration);
// Duration in timescale units.
const duration = XmlUtils.parseAttr(mss, 'Duration',
XmlUtils.parseNonNegativeInt, Infinity);
goog.asserts.assert(duration && duration >= 0,
'Duration must be defined!');
if (!isLive) {
this.presentationTimeline_.setDuration(duration / timescale);
}
/** @type {!shaka.mss.MssParser.Context} */
const context = {
variants: [],
textStreams: [],
timescale: timescale,
duration: duration / timescale,
};
this.parseStreamIndexes_(mss, context);
// These steps are not done on manifest update.
if (!this.manifest_) {
this.manifest_ = {
presentationTimeline: this.presentationTimeline_,
variants: context.variants,
textStreams: context.textStreams,
imageStreams: [],
offlineSessionIds: [],
minBufferTime: 0,
sequenceMode: this.config_.mss.sequenceMode,
ignoreManifestTimestampsInSegmentsMode: false,
type: shaka.media.ManifestParser.MSS,
serviceDescription: null,
};
// This is the first point where we have a meaningful presentation start
// time, and we need to tell PresentationTimeline that so that it can
// maintain consistency from here on.
this.presentationTimeline_.lockStartTime();
} else {
// Just update the variants and text streams.
this.manifest_.variants = context.variants;
this.manifest_.textStreams = context.textStreams;
// Re-filter the manifest. This will check any configured restrictions on
// new variants, and will pass any new init data to DrmEngine to ensure
// that key rotation works correctly.
this.playerInterface_.filter(this.manifest_);
}
}
/**
* @param {!Element} mss
* @param {!shaka.mss.MssParser.Context} context
* @private
*/
parseStreamIndexes_(mss, context) {
const ContentProtection = shaka.mss.ContentProtection;
const XmlUtils = shaka.util.XmlUtils;
const ContentType = shaka.util.ManifestParserUtils.ContentType;
const protectionElems = XmlUtils.findChildren(mss, 'Protection');
const drmInfos = ContentProtection.parseFromProtection(
protectionElems, this.config_.mss.keySystemsBySystemId);
const audioStreams = [];
const videoStreams = [];
const textStreams = [];
const streamIndexes = XmlUtils.findChildren(mss, 'StreamIndex');
for (const streamIndex of streamIndexes) {
const qualityLevels = XmlUtils.findChildren(streamIndex, 'QualityLevel');
const timeline = this.createTimeline_(
streamIndex, context.timescale, context.duration);
// For each QualityLevel node, create a stream element
for (const qualityLevel of qualityLevels) {
const stream = this.createStream_(
streamIndex, qualityLevel, timeline, drmInfos, context);
if (!stream) {
// Skip unsupported stream
continue;
}
if (stream.type == ContentType.AUDIO &&
!this.config_.disableAudio) {
audioStreams.push(stream);
} else if (stream.type == ContentType.VIDEO &&
!this.config_.disableVideo) {
videoStreams.push(stream);
} else if (stream.type == ContentType.TEXT &&
!this.config_.disableText) {
textStreams.push(stream);
}
}
}
const variants = [];
for (const audio of (audioStreams.length > 0 ? audioStreams : [null])) {
for (const video of (videoStreams.length > 0 ? videoStreams : [null])) {
variants.push(this.createVariant_(audio, video));
}
}
context.variants = variants;
context.textStreams = textStreams;
}
/**
* @param {!Element} streamIndex
* @param {!Element} qualityLevel
* @param {!Array.<shaka.mss.MssParser.TimeRange>} timeline
* @param {!Array.<shaka.extern.DrmInfo>} drmInfos
* @param {!shaka.mss.MssParser.Context} context
* @return {?shaka.extern.Stream}
* @private
*/
createStream_(streamIndex, qualityLevel, timeline, drmInfos, context) {
const XmlUtils = shaka.util.XmlUtils;
const ContentType = shaka.util.ManifestParserUtils.ContentType;
const MssParser = shaka.mss.MssParser;
const type = streamIndex.getAttribute('Type');
const isValidType = type === 'audio' || type === 'video' ||
type === 'text';
if (!isValidType) {
shaka.log.alwaysWarn('Ignoring unrecognized type:', type);
return null;
}
const lang = streamIndex.getAttribute('Language');
const id = this.globalId_++;
const bandwidth = XmlUtils.parseAttr(
qualityLevel, 'Bitrate', XmlUtils.parsePositiveInt);
const width = XmlUtils.parseAttr(
qualityLevel, 'MaxWidth', XmlUtils.parsePositiveInt);
const height = XmlUtils.parseAttr(
qualityLevel, 'MaxHeight', XmlUtils.parsePositiveInt);
const channelsCount = XmlUtils.parseAttr(
qualityLevel, 'Channels', XmlUtils.parsePositiveInt);
const audioSamplingRate = XmlUtils.parseAttr(
qualityLevel, 'SamplingRate', XmlUtils.parsePositiveInt);
let duration = context.duration;
if (timeline.length) {
const start = timeline[0].start;
const end = timeline[timeline.length - 1].end;
duration = end - start;
}
const presentationDuration = this.presentationTimeline_.getDuration();
this.presentationTimeline_.setDuration(
Math.min(duration, presentationDuration));
/** @type {!shaka.extern.Stream} */
const stream = {
id: id,
originalId: streamIndex.getAttribute('Name') || String(id),
createSegmentIndex: () => Promise.resolve(),
closeSegmentIndex: () => Promise.resolve(),
segmentIndex: null,
mimeType: '',
codecs: '',
frameRate: undefined,
pixelAspectRatio: undefined,
bandwidth: bandwidth || 0,
width: width || undefined,
height: height || undefined,
kind: '',
encrypted: drmInfos.length > 0,
drmInfos: drmInfos,
keyIds: new Set(),
language: shaka.util.LanguageUtils.normalize(lang || 'und'),
originalLanguage: lang,
label: '',
type: '',
primary: false,
trickModeVideo: null,
emsgSchemeIdUris: [],
roles: [],
forced: false,
channelsCount: channelsCount,
audioSamplingRate: audioSamplingRate,
spatialAudio: false,
closedCaptions: null,
hdr: undefined,
tilesLayout: undefined,
matchedStreams: [],
mssPrivateData: {
duration: duration,
timescale: context.timescale,
codecPrivateData: null,
},
accessibilityPurpose: null,
external: false,
};
// This is specifically for text tracks.
const subType = streamIndex.getAttribute('Subtype');
if (subType) {
const role = MssParser.ROLE_MAPPING_[subType];
if (role) {
stream.roles.push(role);
}
if (role === 'main') {
stream.primary = true;
}
}
let fourCCValue = qualityLevel.getAttribute('FourCC');
// If FourCC not defined at QualityLevel level,
// then get it from StreamIndex level
if (fourCCValue === null || fourCCValue === '') {
fourCCValue = streamIndex.getAttribute('FourCC');
}
// If still not defined (optional for audio stream,
// see https://msdn.microsoft.com/en-us/library/ff728116%28v=vs.95%29.aspx),
// then we consider the stream is an audio AAC stream
if (!fourCCValue) {
if (type === 'audio') {
fourCCValue = 'AAC';
} else if (type === 'video') {
shaka.log.alwaysWarn('FourCC is not defined whereas it is required ' +
'for a QualityLevel element for a StreamIndex of type "video"');
return null;
}
}
// Check if codec is supported
if (!MssParser.SUPPORTED_CODECS_.includes(fourCCValue.toUpperCase())) {
shaka.log.alwaysWarn('Codec not supported:', fourCCValue);
return null;
}
const codecPrivateData = this.getCodecPrivateData_(
qualityLevel, type, fourCCValue, stream);
stream.mssPrivateData.codecPrivateData = codecPrivateData;
switch (type) {
case 'audio':
if (!codecPrivateData) {
shaka.log.alwaysWarn('Quality unsupported without CodecPrivateData',
type);
return null;
}
stream.type = ContentType.AUDIO;
// This mimetype is fake to allow the transmuxing.
stream.mimeType = 'mss/audio/mp4';
stream.codecs = this.getAACCodec_(
qualityLevel, fourCCValue, codecPrivateData);
break;
case 'video':
if (!codecPrivateData) {
shaka.log.alwaysWarn('Quality unsupported without CodecPrivateData',
type);
return null;
}
stream.type = ContentType.VIDEO;
// This mimetype is fake to allow the transmuxing.
stream.mimeType = 'mss/video/mp4';
stream.codecs = this.getH264Codec_(
qualityLevel, codecPrivateData);
break;
case 'text':
stream.type = ContentType.TEXT;
stream.mimeType = 'application/mp4';
if (fourCCValue === 'TTML' || fourCCValue === 'DFXP') {
stream.codecs = 'stpp';
}
break;
}
// Lazy-Load the segment index to avoid create all init segment at the
// same time
stream.createSegmentIndex = () => {
if (stream.segmentIndex) {
return Promise.resolve();
}
let initSegmentData;
if (this.initSegmentDataByStreamId_.has(stream.id)) {
initSegmentData = this.initSegmentDataByStreamId_.get(stream.id);
} else {
let videoNalus = [];
if (stream.type == ContentType.VIDEO) {
const codecPrivateData = stream.mssPrivateData.codecPrivateData;
videoNalus = codecPrivateData.split('00000001').slice(1);
}
/** @type {shaka.util.Mp4Generator.StreamInfo} */
const streamInfo = {
id: stream.id,
type: stream.type,
codecs: stream.codecs,
encrypted: stream.encrypted,
timescale: stream.mssPrivateData.timescale,
duration: stream.mssPrivateData.duration,
videoNalus: videoNalus,
audioConfig: new Uint8Array([]),
videoConfig: new Uint8Array([]),
data: null, // Data is not necessary for init segement.
stream: stream,
};
const mp4Generator = new shaka.util.Mp4Generator([streamInfo]);
initSegmentData = mp4Generator.initSegment();
this.initSegmentDataByStreamId_.set(stream.id, initSegmentData);
}
const initSegmentRef = new shaka.media.InitSegmentReference(
() => [],
/* startByte= */ 0,
/* endByte= */ null,
/* mediaQuality= */ null,
/* timescale= */ undefined,
initSegmentData);
const segments = this.createSegments_(initSegmentRef,
stream, streamIndex, timeline);
stream.segmentIndex = new shaka.media.SegmentIndex(segments);
return Promise.resolve();
};
stream.closeSegmentIndex = () => {
// If we have a segment index, release it.
if (stream.segmentIndex) {
stream.segmentIndex.release();
stream.segmentIndex = null;
}
};
return stream;
}
/**
* @param {!Element} qualityLevel
* @param {string} type
* @param {string} fourCCValue
* @param {!shaka.extern.Stream} stream
* @return {?string}
* @private
*/
getCodecPrivateData_(qualityLevel, type, fourCCValue, stream) {
const codecPrivateData = qualityLevel.getAttribute('CodecPrivateData');
if (codecPrivateData) {
return codecPrivateData;
}
if (type !== 'audio') {
return null;
}
// For the audio we can reconstruct the CodecPrivateData
// By default stereo
const channels = stream.channelsCount || 2;
// By default 44,1kHz.
const samplingRate = stream.audioSamplingRate || 44100;
const samplingFrequencyIndex = {
96000: 0x0,
88200: 0x1,
64000: 0x2,
48000: 0x3,
44100: 0x4,
32000: 0x5,
24000: 0x6,
22050: 0x7,
16000: 0x8,
12000: 0x9,
11025: 0xA,
8000: 0xB,
7350: 0xC,
};
const indexFreq = samplingFrequencyIndex[samplingRate];
if (fourCCValue === 'AACH') {
// High Efficiency AAC Profile
const objectType = 0x05;
// 4 bytes :
// XXXXX XXXX XXXX XXXX
// 'ObjectType' 'Freq Index' 'Channels value' 'Extens Sampl Freq'
// XXXXX XXX XXXXXXX
// 'ObjectType' 'GAS' 'alignment = 0'
const data = new Uint8Array(4);
// In HE AAC Extension Sampling frequence
// equals to SamplingRate * 2
const extensionSamplingFrequencyIndex =
samplingFrequencyIndex[samplingRate * 2];
// Freq Index is present for 3 bits in the first byte, last bit is in
// the second
data[0] = (objectType << 3) | (indexFreq >> 1);
data[1] = (indexFreq << 7) | (channels << 3) |
(extensionSamplingFrequencyIndex >> 1);
// Origin object type equals to 2 => AAC Main Low Complexity
data[2] = (extensionSamplingFrequencyIndex << 7) | (0x02 << 2);
// Slignment bits
data[3] = 0x0;
// Put the 4 bytes in an 16 bits array
const arr16 = new Uint16Array(2);
arr16[0] = (data[0] << 8) + data[1];
arr16[1] = (data[2] << 8) + data[3];
// Convert decimal to hex value
return arr16[0].toString(16) + arr16[1].toString(16);
} else {
// AAC Main Low Complexity
const objectType = 0x02;
// 2 bytes:
// XXXXX XXXX XXXX XXX
// 'ObjectType' 'Freq Index' 'Channels value' 'GAS = 000'
const data = new Uint8Array(2);
// Freq Index is present for 3 bits in the first byte, last bit is in
// the second
data[0] = (objectType << 3) | (indexFreq >> 1);
data[1] = (indexFreq << 7) | (channels << 3);
// Put the 2 bytes in an 16 bits array
const arr16 = new Uint16Array(1);
arr16[0] = (data[0] << 8) + data[1];
// Convert decimal to hex value
return arr16[0].toString(16);
}
}
/**
* @param {!Element} qualityLevel
* @param {string} fourCCValue
* @param {?string} codecPrivateData
* @return {string}
* @private
*/
getAACCodec_(qualityLevel, fourCCValue, codecPrivateData) {
let objectType = 0;
// Chrome problem, in implicit AAC HE definition, so when AACH is detected
// in FourCC set objectType to 5 => strange, it should be 2
if (fourCCValue === 'AACH') {
objectType = 0x05;
}
if (!codecPrivateData) {
// AAC Main Low Complexity => object Type = 2
objectType = 0x02;
if (fourCCValue === 'AACH') {
// High Efficiency AAC Profile = object Type = 5 SBR
objectType = 0x05;
}
} else if (objectType === 0) {
objectType = (parseInt(codecPrivateData.substr(0, 2), 16) & 0xF8) >> 3;
}
return 'mp4a.40.' + objectType;
}
/**
* @param {!Element} qualityLevel
* @param {?string} codecPrivateData
* @return {string}
* @private
*/
getH264Codec_(qualityLevel, codecPrivateData) {
// Extract from the CodecPrivateData field the hexadecimal representation
// of the following three bytes in the sequence parameter set NAL unit.
// => Find the SPS nal header
const nalHeader = /00000001[0-9]7/.exec(codecPrivateData);
if (!nalHeader.length) {
return '';
}
if (!codecPrivateData) {
return '';
}
// => Find the 6 characters after the SPS nalHeader (if it exists)
const avcoti = codecPrivateData.substr(
codecPrivateData.indexOf(nalHeader[0]) + 10, 6);
return 'avc1.' + avcoti;
}
/**
* @param {!shaka.media.InitSegmentReference} initSegmentRef
* @param {!shaka.extern.Stream} stream
* @param {!Element} streamIndex
* @param {!Array.<shaka.mss.MssParser.TimeRange>} timeline
* @return {!Array.<!shaka.media.SegmentReference>}
* @private
*/
createSegments_(initSegmentRef, stream, streamIndex, timeline) {
const ManifestParserUtils = shaka.util.ManifestParserUtils;
const url = streamIndex.getAttribute('Url');
goog.asserts.assert(url, 'Missing URL for segments');
const mediaUrl = url.replace('{bitrate}', String(stream.bandwidth));
const segments = [];
for (const time of timeline) {
const getUris = () => {
return ManifestParserUtils.resolveUris(this.manifestUris_,
[mediaUrl.replace('{start time}', String(time.unscaledStart))]);
};
segments.push(new shaka.media.SegmentReference(
time.start,
time.end,
getUris,
/* startByte= */ 0,
/* endByte= */ null,
initSegmentRef,
/* timestampOffset= */ 0,
/* appendWindowStart= */ 0,
/* appendWindowEnd= */ stream.mssPrivateData.duration));
}
return segments;
}
/**
* Expands a streamIndex into an array-based timeline. The results are in
* seconds.
*
* @param {!Element} streamIndex
* @param {number} timescale
* @param {number} duration The duration in seconds.
* @return {!Array.<shaka.mss.MssParser.TimeRange>}
* @private
*/
createTimeline_(streamIndex, timescale, duration) {
goog.asserts.assert(
timescale > 0 && timescale < Infinity,
'timescale must be a positive, finite integer');
goog.asserts.assert(
duration > 0, 'duration must be a positive integer');
const XmlUtils = shaka.util.XmlUtils;
const timePoints = XmlUtils.findChildren(streamIndex, 'c');
/** @type {!Array.<shaka.mss.MssParser.TimeRange>} */
const timeline = [];
let lastEndTime = 0;
for (let i = 0; i < timePoints.length; ++i) {
const timePoint = timePoints[i];
const next = timePoints[i + 1];
const t =
XmlUtils.parseAttr(timePoint, 't', XmlUtils.parseNonNegativeInt);
const d =
XmlUtils.parseAttr(timePoint, 'd', XmlUtils.parseNonNegativeInt);
const r = XmlUtils.parseAttr(timePoint, 'r', XmlUtils.parseInt);
if (!d) {
shaka.log.warning(
'"c" element must have a duration:',
'ignoring the remaining "c" elements.', timePoint);
return timeline;
}
let startTime = t != null ? t : lastEndTime;
let repeat = r || 0;
if (repeat < 0) {
if (next) {
const nextStartTime =
XmlUtils.parseAttr(next, 't', XmlUtils.parseNonNegativeInt);
if (nextStartTime == null) {
shaka.log.warning(
'An "c" element cannot have a negative repeat',
'if the next "c" element does not have a valid start time:',
'ignoring the remaining "c" elements.', timePoint);
return timeline;
} else if (startTime >= nextStartTime) {
shaka.log.warning(
'An "c" element cannot have a negative repeatif its start ',
'time exceeds the next "c" element\'s start time:',
'ignoring the remaining "c" elements.', timePoint);
return timeline;
}
repeat = Math.ceil((nextStartTime - startTime) / d) - 1;
} else {
if (duration == Infinity) {
// The MSS spec. actually allows the last "c" element to have a
// negative repeat value even when it has an infinite
// duration. No one uses this feature and no one ever should,
// ever.
shaka.log.warning(
'The last "c" element cannot have a negative repeat',
'if the Period has an infinite duration:',
'ignoring the last "c" element.', timePoint);
return timeline;
} else if (startTime / timescale >= duration) {
shaka.log.warning(
'The last "c" element cannot have a negative repeat',
'if its start time exceeds the duration:',
'igoring the last "c" element.', timePoint);
return timeline;
}
repeat = Math.ceil((duration * timescale - startTime) / d) - 1;
}
}
for (let j = 0; j <= repeat; ++j) {
const endTime = startTime + d;
const item = {
start: startTime / timescale,
end: endTime / timescale,
unscaledStart: startTime,
};
timeline.push(item);
startTime = endTime;
lastEndTime = endTime;
}
}
return timeline;
}
/**
* @param {?shaka.extern.Stream} audioStream
* @param {?shaka.extern.Stream} videoStream
* @return {!shaka.extern.Variant}
* @private
*/
createVariant_(audioStream, videoStream) {
const ContentType = shaka.util.ManifestParserUtils.ContentType;
goog.asserts.assert(!audioStream ||
audioStream.type == ContentType.AUDIO, 'Audio parameter mismatch!');
goog.asserts.assert(!videoStream ||
videoStream.type == ContentType.VIDEO, 'Video parameter mismatch!');
let bandwidth = 0;
if (audioStream && audioStream.bandwidth && audioStream.bandwidth > 0) {
bandwidth += audioStream.bandwidth;
}
if (videoStream && videoStream.bandwidth && videoStream.bandwidth > 0) {
bandwidth += videoStream.bandwidth;
}
return {
id: this.globalId_++,
language: audioStream ? audioStream.language : 'und',
disabledUntilTime: 0,
primary: (!!audioStream && audioStream.primary) ||
(!!videoStream && videoStream.primary),
audio: audioStream,
video: videoStream,
bandwidth: bandwidth,
allowedByApplication: true,
allowedByKeySystem: true,
decodingInfos: [],
};
}
};
/**
* Contains the minimum amount of time, in seconds, between manifest update
* requests.
*
* @private
* @const {number}
*/
shaka.mss.MssParser.MIN_UPDATE_PERIOD_ = 3;
/**
* @private
* @const {number}
*/
shaka.mss.MssParser.DEFAULT_TIME_SCALE_ = 1e7;
/**
* MSS supported codecs.
*
* @private
* @const {!Array.<string>}
*/
shaka.mss.MssParser.SUPPORTED_CODECS_ = [
'AAC',
'AACL',
'AACH',
'AACP',
'AVC1',
'H264',
'TTML',
'DFXP',
];
/**
* MPEG-DASH Role and accessibility mapping for text tracks according to
* ETSI TS 103 285 v1.1.1 (section 7.1.2)
*
* @const {!Object.<string, string>}
* @private
*/
shaka.mss.MssParser.ROLE_MAPPING_ = {
'CAPT': 'main',
'SUBT': 'alternate',
'DESC': 'main',
};
/**
* @typedef {{
* variants: !Array.<shaka.extern.Variant>,
* textStreams: !Array.<shaka.extern.Stream>,
* timescale: number,
* duration: number
* }}
*
* @property {!Array.<shaka.extern.Variant>} variants
* The presentation's Variants.
* @property {!Array.<shaka.extern.Stream>} textStreams
* The presentation's text streams.
* @property {number} timescale
* The presentation's timescale.
* @property {number} duration
* The presentation's duration.
*/
shaka.mss.MssParser.Context;
/**
* @typedef {{
* start: number,
* unscaledStart: number,
* end: number
* }}
*
* @description
* Defines a time range of a media segment. Times are in seconds.
*
* @property {number} start
* The start time of the range.
* @property {number} unscaledStart
* The start time of the range in representation timescale units.
* @property {number} end
* The end time (exclusive) of the range.
*/
shaka.mss.MssParser.TimeRange;
shaka.media.ManifestParser.registerParserByExtension(
'ism', () => new shaka.mss.MssParser());
shaka.media.ManifestParser.registerParserByMime(
'application/vnd.ms-sstr+xml', () => new shaka.mss.MssParser());