/**
* @license
* Copyright 2016 Google Inc.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
goog.provide('shaka.hls.HlsParser');
goog.require('goog.Uri');
goog.require('goog.asserts');
goog.require('shaka.hls.ManifestTextParser');
goog.require('shaka.hls.Playlist');
goog.require('shaka.hls.PlaylistType');
goog.require('shaka.hls.Tag');
goog.require('shaka.hls.Utils');
goog.require('shaka.log');
goog.require('shaka.media.DrmEngine');
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.net.DataUriPlugin');
goog.require('shaka.net.NetworkingEngine');
goog.require('shaka.text.TextEngine');
goog.require('shaka.util.DataViewReader');
goog.require('shaka.util.Error');
goog.require('shaka.util.Functional');
goog.require('shaka.util.LanguageUtils');
goog.require('shaka.util.ManifestParserUtils');
goog.require('shaka.util.MimeUtils');
goog.require('shaka.util.Mp4Parser');
goog.require('shaka.util.OperationManager');
/**
* Creates a new HLS parser.
*
* @struct
* @constructor
* @implements {shakaExtern.ManifestParser}
* @export
*/
shaka.hls.HlsParser = function() {
/** @private {?shakaExtern.ManifestParser.PlayerInterface} */
this.playerInterface_ = null;
/** @private {?shakaExtern.ManifestConfiguration} */
this.config_ = null;
/** @private {number} */
this.globalId_ = 1;
/**
* @private {!Map.<number, shaka.hls.HlsParser.StreamInfo>}
*/
// TODO: This is now only used for text codec detection, try to remove.
this.mediaTagsToStreamInfosMap_ = new Map();
/**
* The values are strings of the form "<VIDEO URI> - <AUDIO URI>",
* where the URIs are the verbatim media playlist URIs as they appeared in the
* master playlist.
*
* Used to avoid duplicates that vary only in their text stream.
*
* @private {!Set.<string>}
*/
this.variantUriSet_ = new Set();
/**
* A map from (verbatim) media playlist URI to stream infos representing the
* playlists.
*
* On update, used to iterate through and update from media playlists.
*
* On initial parse, used to iterate through and determine minimum timestamps,
* offsets, and to handle TS rollover.
*
* During parsing, used to avoid duplicates in the async methods
* createStreamInfoFromMediaTag_ and createStreamInfoFromVariantTag_.
*
* During parsing of updates, used by getStartTime_ to determine the start
* time of the first segment from existing segment references.
*
* @private {!Map.<string, shaka.hls.HlsParser.StreamInfo>}
*/
this.uriToStreamInfosMap_ = new Map();
/** @private {?shaka.media.PresentationTimeline} */
this.presentationTimeline_ = null;
/**
* The master playlist URI, after redirects.
*
* @private {string}
*/
this.masterPlaylistUri_ = '';
/** @private {shaka.hls.ManifestTextParser} */
this.manifestTextParser_ = new shaka.hls.ManifestTextParser();
/**
* The update period in seconds, or null for no updates.
* @private {?number}
*/
this.updatePeriod_ = null;
/** @private {?number} */
this.updateTimer_ = null;
/** @private {shaka.hls.HlsParser.PresentationType_} */
this.presentationType_ = shaka.hls.HlsParser.PresentationType_.VOD;
/** @private {?shakaExtern.Manifest} */
this.manifest_ = null;
/** @private {number} */
this.maxTargetDuration_ = 0;
/** @private {number} */
this.minTargetDuration_ = Infinity;
/** @private {!shaka.util.OperationManager} */
this.operationManager_ = new shaka.util.OperationManager();
/** @private {!Array.<!Array.<!shaka.media.SegmentReference>>} */
this.segmentsToNotifyByStream_ = [];
};
/**
* @typedef {{
* stream: !shakaExtern.Stream,
* segmentIndex: !shaka.media.SegmentIndex,
* drmInfos: !Array.<shakaExtern.DrmInfo>,
* verbatimMediaPlaylistUri: string,
* absoluteMediaPlaylistUri: string,
* minTimestamp: number,
* maxTimestamp: number,
* duration: number
* }}
*
* @description
* Contains a stream and information about it.
*
* @property {!shakaExtern.Stream} stream
* The Stream itself.
* @property {!shaka.media.SegmentIndex} segmentIndex
* SegmentIndex of the stream.
* @property {!Array.<shakaExtern.DrmInfo>} drmInfos
* DrmInfos of the stream. There may be multiple for multi-DRM content.
* @property {string} verbatimMediaPlaylistUri
* The verbatim media playlist URI, as it appeared in the master playlist.
* This has not been canonicalized into an absolute URI. This gives us a
* consistent key for this playlist, even if redirects cause us to update
* from different origins each time.
* @property {string} absoluteMediaPlaylistUri
* The absolute media playlist URI, resolved relative to the master playlist
* and updated to reflect any redirects.
* @property {number} minTimestamp
* The minimum timestamp found in the stream.
* @property {number} maxTimestamp
* The maximum timestamp found in the stream.
* @property {number} duration
* The duration of the playlist. Used for VOD only.
*/
shaka.hls.HlsParser.StreamInfo;
/**
* @override
* @exportInterface
*/
shaka.hls.HlsParser.prototype.configure = function(config) {
this.config_ = config;
};
/**
* @override
* @exportInterface
*/
shaka.hls.HlsParser.prototype.start = function(uri, playerInterface) {
goog.asserts.assert(this.config_, 'Must call configure() before start()!');
this.playerInterface_ = playerInterface;
return this.requestManifest_(uri).then(function(response) {
// Record the master playlist URI after redirects.
this.masterPlaylistUri_ = response.uri;
return this.parseManifest_(response.data).then(function() {
this.setUpdateTimer_(this.updatePeriod_);
return this.manifest_;
}.bind(this));
}.bind(this));
};
/**
* @override
* @exportInterface
*/
shaka.hls.HlsParser.prototype.stop = function() {
this.playerInterface_ = null;
this.config_ = null;
this.mediaTagsToStreamInfosMap_.clear();
this.variantUriSet_.clear();
this.uriToStreamInfosMap_.clear();
this.manifest_ = null;
return this.operationManager_.destroy();
};
/**
* @override
* @exportInterface
*/
shaka.hls.HlsParser.prototype.update = function() {
if (!this.isLive_()) {
return;
}
const promises = [];
for (const streamInfo of this.uriToStreamInfosMap_.values()) {
promises.push(this.updateStream_(streamInfo));
}
return Promise.all(promises);
};
/**
* Updates a stream.
*
* @param {!shaka.hls.HlsParser.StreamInfo} streamInfo
* @throws shaka.util.Error
* @private
*/
shaka.hls.HlsParser.prototype.updateStream_ = function(streamInfo) {
this.requestManifest_(streamInfo.absoluteMediaPlaylistUri).then(
function(response) {
const Utils = shaka.hls.Utils;
const PresentationType = shaka.hls.HlsParser.PresentationType_;
const playlist = this.manifestTextParser_.parsePlaylist(
response.data, response.uri);
if (playlist.type != shaka.hls.PlaylistType.MEDIA) {
throw new shaka.util.Error(
shaka.util.Error.Severity.CRITICAL,
shaka.util.Error.Category.MANIFEST,
shaka.util.Error.Code.HLS_INVALID_PLAYLIST_HIERARCHY);
}
let mediaSequenceTag = Utils.getFirstTagWithName(playlist.tags,
'EXT-X-MEDIA-SEQUENCE');
let startPosition = mediaSequenceTag ? Number(mediaSequenceTag.value) : 0;
let stream = streamInfo.stream;
this.createSegments_(streamInfo.verbatimMediaPlaylistUri, playlist,
startPosition, stream.mimeType, stream.codecs)
.then(function(segments) {
streamInfo.segmentIndex.replace(segments);
let newestSegment = segments[segments.length - 1];
goog.asserts.assert(newestSegment, 'Should have segments!');
// Once the last segment has been added to the playlist,
// #EXT-X-ENDLIST tag will be appended.
// If that happened, treat the rest of the EVENT presentation as VOD.
let endListTag = Utils.getFirstTagWithName(playlist.tags,
'EXT-X-ENDLIST');
if (endListTag) {
// Convert the presentation to VOD and set the duration to the last
// segment's end time.
this.setPresentationType_(PresentationType.VOD);
this.presentationTimeline_.setDuration(newestSegment.endTime);
}
}.bind(this));
}.bind(this));
};
/**
* @override
* @exportInterface
*/
shaka.hls.HlsParser.prototype.onExpirationUpdated = function(
sessionId, expiration) {
// No-op
};
/**
* Parses the manifest.
*
* @param {!ArrayBuffer} data
* @throws shaka.util.Error When there is a parsing error.
* @return {!Promise}
* @private
*/
shaka.hls.HlsParser.prototype.parseManifest_ = function(data) {
goog.asserts.assert(this.masterPlaylistUri_,
'Master playlist URI must be set before calling parseManifest_!');
const playlist = this.manifestTextParser_.parsePlaylist(
data, this.masterPlaylistUri_);
// We don't support directly providing a Media Playlist.
// See the error code for details.
if (playlist.type != shaka.hls.PlaylistType.MASTER) {
throw new shaka.util.Error(
shaka.util.Error.Severity.CRITICAL,
shaka.util.Error.Category.MANIFEST,
shaka.util.Error.Code.HLS_MASTER_PLAYLIST_NOT_PROVIDED);
}
return this.createPeriod_(playlist).then(function(period) {
// HLS has no notion of periods. We're treating the whole presentation as
// one period.
this.playerInterface_.filterAllPeriods([period]);
// Find the min and max timestamp of the earliest segment in all streams.
// Find the minimum duration of all streams as well.
let minFirstTimestamp = Infinity;
let maxFirstTimestamp = 0;
let maxLastTimestamp = 0;
let minDuration = Infinity;
for (const streamInfo of this.uriToStreamInfosMap_.values()) {
minFirstTimestamp =
Math.min(minFirstTimestamp, streamInfo.minTimestamp);
maxFirstTimestamp =
Math.max(maxFirstTimestamp, streamInfo.minTimestamp);
maxLastTimestamp =
Math.max(maxLastTimestamp, streamInfo.maxTimestamp);
if (streamInfo.stream.type != 'text') {
minDuration = Math.min(minDuration, streamInfo.duration);
}
}
goog.asserts.assert(this.presentationTimeline_ == null,
'Presentation timeline created early!');
this.createPresentationTimeline_(maxLastTimestamp);
if (this.isLive_()) {
// The HLS spec (RFC 8216) states in 6.3.3:
//
// "The client SHALL choose which Media Segment to play first ... the
// client SHOULD NOT choose a segment that starts less than three target
// durations from the end of the Playlist file. Doing so can trigger
// playback stalls."
//
// We accomplish this in our DASH-y model by setting a presentation delay
// of 3 segments. This will be the "live edge" of the presentation.
let threeSegmentDurations = this.maxTargetDuration_ * 3;
this.presentationTimeline_.setDelay(threeSegmentDurations);
// The HLS spec (RFC 8216) states in 6.3.4:
// "the client MUST wait for at least the target duration before
// attempting to reload the Playlist file again"
this.updatePeriod_ = this.minTargetDuration_;
// The spec says nothing much about seeking in live content, but Safari's
// built-in HLS implementation does not allow it. Therefore we will set
// the availability window equal to the presentation delay. The player
// will be able to buffer ahead three segments, but the seek window will
// be zero-sized.
const PresentationType = shaka.hls.HlsParser.PresentationType_;
if (this.presentationType_ == PresentationType.LIVE) {
let segmentAvailabilityDuration = threeSegmentDurations;
if (!isNaN(this.config_.availabilityWindowOverride)) {
segmentAvailabilityDuration = this.config_.availabilityWindowOverride;
}
this.presentationTimeline_.setSegmentAvailabilityDuration(
segmentAvailabilityDuration);
}
let rolloverSeconds =
shaka.hls.HlsParser.TS_ROLLOVER_ / shaka.hls.HlsParser.TS_TIMESCALE_;
let offset = 0;
while (maxFirstTimestamp >= rolloverSeconds) {
offset += rolloverSeconds;
maxFirstTimestamp -= rolloverSeconds;
}
if (offset) {
shaka.log.debug('Offsetting live streams by', offset,
'to compensate for rollover');
for (const streamInfo of this.uriToStreamInfosMap_.values()) {
if (streamInfo.minTimestamp < rolloverSeconds) {
shaka.log.v1('Offset applied to', streamInfo.stream.type);
// This is the offset that StreamingEngine must apply to align the
// actual segment times with the period.
streamInfo.stream.presentationTimeOffset = -offset;
// The segments were created with actual media times, rather than
// period-aligned times, so offset them all to period time.
streamInfo.segmentIndex.offset(offset);
} else {
shaka.log.v1('Offset NOT applied to', streamInfo.stream.type);
}
}
}
} else {
// For VOD/EVENT content, offset everything back to 0.
// Use the minimum timestamp as the offset for all streams.
// Use the minimum duration as the presentation duration.
this.presentationTimeline_.setDuration(minDuration);
// Use a negative offset to adjust towards 0.
this.presentationTimeline_.offset(-minFirstTimestamp);
for (const streamInfo of this.uriToStreamInfosMap_.values()) {
// This is the offset that StreamingEngine must apply to align the
// actual segment times with the period.
streamInfo.stream.presentationTimeOffset = minFirstTimestamp;
// The segments were created with actual media times, rather than
// period-aligned times, so offset them all now.
streamInfo.segmentIndex.offset(-minFirstTimestamp);
// Finally, fit the segments to the period duration.
streamInfo.segmentIndex.fit(minDuration);
}
}
this.manifest_ = {
presentationTimeline: this.presentationTimeline_,
periods: [period],
offlineSessionIds: [],
minBufferTime: 0
};
}.bind(this));
};
/**
* Parses a playlist into a Period object.
*
* @param {!shaka.hls.Playlist} playlist
* @return {!Promise.<!shakaExtern.Period>}
* @private
*/
shaka.hls.HlsParser.prototype.createPeriod_ = function(playlist) {
const Utils = shaka.hls.Utils;
const Functional = shaka.util.Functional;
let tags = playlist.tags;
let mediaTags = Utils.filterTagsByName(playlist.tags, 'EXT-X-MEDIA');
let textStreamTags = mediaTags.filter(function(tag) {
let type = shaka.hls.HlsParser.getRequiredAttributeValue_(tag, 'TYPE');
return type == 'SUBTITLES';
}.bind(this));
// TODO: CLOSED-CAPTIONS requires the parsing of CEA-608 from the video.
let textStreamPromises = textStreamTags.map(function(tag) {
return this.createTextStream_(tag, playlist);
}.bind(this));
return Promise.all(textStreamPromises).then(function(textStreams) {
// Create Variants for every 'EXT-X-STREAM-INF' tag. Do this after text
// streams have been created, so that we can push text codecs found on the
// variant tag back into the created text streams.
let variantTags = Utils.filterTagsByName(tags, 'EXT-X-STREAM-INF');
let variantsPromises = variantTags.map(function(tag) {
return this.createVariantsForTag_(tag, playlist);
}.bind(this));
return Promise.all(variantsPromises).then(function(allVariants) {
let variants = allVariants.reduce(Functional.collapseArrays, []);
return {
startTime: 0,
variants: variants,
textStreams: textStreams
};
}.bind(this));
}.bind(this));
};
/**
* @param {!shaka.hls.Tag} tag
* @param {!shaka.hls.Playlist} playlist
* @return {!Promise.<!Array.<!shakaExtern.Variant>>}
* @private
*/
shaka.hls.HlsParser.prototype.createVariantsForTag_ = function(tag, playlist) {
goog.asserts.assert(tag.name == 'EXT-X-STREAM-INF',
'Should only be called on variant tags!');
const ContentType = shaka.util.ManifestParserUtils.ContentType;
const HlsParser = shaka.hls.HlsParser;
const Utils = shaka.hls.Utils;
// These are the default codecs to assume if none are specified.
//
// The video codec is H.264, with baseline profile and level 3.0.
// http://blog.pearce.org.nz/2013/11/what-does-h264avc1-codecs-parameters.html
//
// The audio codec is "low-complexity" AAC.
const defaultCodecs = 'avc1.42E01E,mp4a.40.2';
const codecsString = tag.getAttributeValue('CODECS', defaultCodecs);
// Strip out internal whitespace while splitting on commas:
/** @type {!Array.<string>} */
let codecs = codecsString.split(/\s*,\s*/);
let resolutionAttr = tag.getAttribute('RESOLUTION');
let width = null;
let height = null;
let frameRate = tag.getAttributeValue('FRAME-RATE');
let bandwidth =
Number(HlsParser.getRequiredAttributeValue_(tag, 'BANDWIDTH'));
if (resolutionAttr) {
let resBlocks = resolutionAttr.value.split('x');
width = resBlocks[0];
height = resBlocks[1];
}
// After filtering, this is a list of the media tags we will process to
// combine with the variant tag (EXT-X-STREAM-INF) we are working on.
let mediaTags = Utils.filterTagsByName(playlist.tags, 'EXT-X-MEDIA');
// Do not create stream info from closed captions media tags, which are
// embedded in video streams.
mediaTags = mediaTags.filter((tag) => {
const type = HlsParser.getRequiredAttributeValue_(tag, 'TYPE');
return type != 'CLOSED-CAPTIONS';
});
// AUDIO or VIDEO tags without a URI attribute are valid.
// If there is no uri, it means that audio/video is embedded in the
// stream described by the Variant tag.
// Do not create stream from AUDIO/VIDEO EXT-X-MEDIA tags without URI
mediaTags = mediaTags.filter((tag) => {
const uri = tag.getAttributeValue('URI') || '';
const type = tag.getAttributeValue('TYPE') || '';
return type == 'SUBTITLES' || uri != '';
});
let audioGroupId = tag.getAttributeValue('AUDIO');
let videoGroupId = tag.getAttributeValue('VIDEO');
goog.asserts.assert(audioGroupId == null || videoGroupId == null,
'Unexpected: both video and audio described by media tags!');
// Find any associated audio or video groups and create streams for them.
if (audioGroupId) {
mediaTags = Utils.findMediaTags(mediaTags, 'AUDIO', audioGroupId);
} else if (videoGroupId) {
mediaTags = Utils.findMediaTags(mediaTags, 'VIDEO', videoGroupId);
}
// There may be a codec string for the text stream. We should identify it,
// add it to the appropriate stream, then strip it out of the variant to
// avoid confusing our multiplex detection below.
let textCodecs = this.guessCodecsSafe_(ContentType.TEXT, codecs);
if (textCodecs) {
// We found a text codec in the list, so look for an associated text stream.
let subGroupId = tag.getAttributeValue('SUBTITLES');
if (subGroupId) {
let textTags = Utils.findMediaTags(mediaTags, 'SUBTITLES', subGroupId);
goog.asserts.assert(textTags.length == 1,
'Exactly one text tag expected!');
if (textTags.length) {
// We found a text codec and text stream, so make sure the codec is
// attached to the stream.
const textStreamInfo =
this.mediaTagsToStreamInfosMap_.get(textTags[0].id);
textStreamInfo.stream.codecs = textCodecs;
}
}
// Remove this entry from the list of codecs that belong to audio/video.
codecs.splice(codecs.indexOf(textCodecs), 1);
}
let promises = mediaTags.map(function(tag) {
return this.createStreamInfoFromMediaTag_(tag, codecs);
}.bind(this));
let audioStreamInfos = [];
let videoStreamInfos = [];
return Promise.all(promises).then(function(data) {
if (audioGroupId) {
audioStreamInfos = data;
} else if (videoGroupId) {
videoStreamInfos = data;
}
// Make an educated guess about the stream type.
shaka.log.debug('Guessing stream type for', tag.toString());
let type;
let ignoreStream = false;
if (!audioStreamInfos.length && !videoStreamInfos.length) {
// There are no associated streams. This is either an audio-only stream,
// a video-only stream, or a multiplexed stream.
if (codecs.length == 1) {
// There is only one codec, so it shouldn't be multiplexed.
let videoCodecs = this.guessCodecsSafe_(ContentType.VIDEO, codecs);
if (resolutionAttr || frameRate || videoCodecs) {
// Assume video-only.
shaka.log.debug('Guessing video-only.');
type = ContentType.VIDEO;
} else {
// Assume audio-only.
shaka.log.debug('Guessing audio-only.');
type = ContentType.AUDIO;
}
} else {
// There are multiple codecs, so assume multiplexed content.
// Note that the default used when CODECS is missing assumes multiple
// (and therefore multiplexed).
// Recombine the codec strings into one so that MediaSource isn't
// lied to later. (That would trigger an error in Chrome.)
shaka.log.debug('Guessing multiplexed audio+video.');
type = ContentType.VIDEO;
codecs = [codecs.join(',')];
}
} else if (audioStreamInfos.length) {
let streamURI = HlsParser.getRequiredAttributeValue_(tag, 'URI');
let firstAudioStreamURI = audioStreamInfos[0].verbatimMediaPlaylistUri;
if (streamURI == firstAudioStreamURI) {
// The Microsoft HLS manifest generators will make audio-only variants
// that link to their URI both directly and through an audio tag.
// In that case, ignore the local URI and use the version in the
// AUDIO tag, so you inherit its language.
// As an example, see the manifest linked in issue #860.
shaka.log.debug('Guessing audio-only.');
type = ContentType.AUDIO;
ignoreStream = true;
} else {
// There are associated audio streams. Assume this is video.
shaka.log.debug('Guessing video.');
type = ContentType.VIDEO;
}
} else {
// There are associated video streams. Assume this is audio.
goog.asserts.assert(videoStreamInfos.length,
'No video streams! This should have been handled already!');
shaka.log.debug('Guessing audio.');
type = ContentType.AUDIO;
}
goog.asserts.assert(type, 'Type should have been set by now!');
if (ignoreStream) {
return Promise.resolve();
}
return this.createStreamInfoFromVariantTag_(tag, codecs, type);
}.bind(this)).then(function(streamInfo) {
if (streamInfo) {
if (streamInfo.stream.type == ContentType.AUDIO) {
audioStreamInfos = [streamInfo];
} else {
videoStreamInfos = [streamInfo];
}
}
goog.asserts.assert(videoStreamInfos || audioStreamInfos,
'We should have created a stream!');
if (videoStreamInfos) {
this.filterLegacyCodecs_(videoStreamInfos);
}
if (audioStreamInfos) {
this.filterLegacyCodecs_(audioStreamInfos);
}
return this.createVariants_(
audioStreamInfos,
videoStreamInfos,
bandwidth,
width,
height,
frameRate);
}.bind(this));
};
/**
* Filters out unsupported codec strings from an array of stream infos.
* @param {!Array.<shaka.hls.HlsParser.StreamInfo>} streamInfos
* @private
*/
shaka.hls.HlsParser.prototype.filterLegacyCodecs_ = function(streamInfos) {
streamInfos.forEach(function(streamInfo) {
let codecs = streamInfo.stream.codecs.split(',');
codecs = codecs.filter(function(codec) {
// mp4a.40.34 is a nonstandard codec string that is sometimes used in HLS
// for legacy reasons. It is not recognized by non-Apple MSE.
// See https://bugs.chromium.org/p/chromium/issues/detail?id=489520
// Therefore, ignore this codec string.
return codec != 'mp4a.40.34';
});
streamInfo.stream.codecs = codecs.join(',');
});
};
/**
* @param {!Array.<!shaka.hls.HlsParser.StreamInfo>} audioInfos
* @param {!Array.<!shaka.hls.HlsParser.StreamInfo>} videoInfos
* @param {number} bandwidth
* @param {?string} width
* @param {?string} height
* @param {?string} frameRate
* @return {!Array.<!shakaExtern.Variant>}
* @private
*/
shaka.hls.HlsParser.prototype.createVariants_ =
function(audioInfos, videoInfos, bandwidth, width, height, frameRate) {
const DrmEngine = shaka.media.DrmEngine;
videoInfos.forEach(function(info) {
this.addVideoAttributes_(info.stream, width, height, frameRate);
}.bind(this));
// In case of audio-only or video-only content, we create an array of
// one item containing a null. This way, the double-loop works for all
// kinds of content.
// NOTE: we currently don't have support for audio-only content.
if (!audioInfos.length) {
audioInfos = [null];
}
if (!videoInfos.length) {
videoInfos = [null];
}
let variants = [];
for (let i = 0; i < audioInfos.length; i++) {
for (let j = 0; j < videoInfos.length; j++) {
let audioStream = audioInfos[i] ? audioInfos[i].stream : null;
let videoStream = videoInfos[j] ? videoInfos[j].stream : null;
let audioDrmInfos = audioInfos[i] ? audioInfos[i].drmInfos : null;
let videoDrmInfos = videoInfos[j] ? videoInfos[j].drmInfos : null;
let drmInfos;
if (audioStream && videoStream) {
if (DrmEngine.areDrmCompatible(audioDrmInfos, videoDrmInfos)) {
drmInfos = DrmEngine.getCommonDrmInfos(audioDrmInfos, videoDrmInfos);
} else {
shaka.log.warning('Incompatible DRM info in HLS variant. Skipping.');
continue;
}
} else if (audioStream) {
drmInfos = audioDrmInfos;
} else if (videoStream) {
drmInfos = videoDrmInfos;
}
const videoStreamUri =
videoInfos[i] ? videoInfos[i].verbatimMediaPlaylistUri : '';
const audioStreamUri =
audioInfos[i] ? audioInfos[i].verbatimMediaPlaylistUri : '';
const variantUriKey = videoStreamUri + ' - ' + audioStreamUri;
if (this.variantUriSet_.has(variantUriKey)) {
// This happens when two variants only differ in their text streams.
shaka.log.debug('Skipping variant which only differs in text streams.');
continue;
}
let variant = this.createVariant_(
audioStream, videoStream, bandwidth, drmInfos);
variants.push(variant);
this.variantUriSet_.add(variantUriKey);
}
}
return variants;
};
/**
* @param {shakaExtern.Stream} audio
* @param {shakaExtern.Stream} video
* @param {number} bandwidth
* @param {!Array.<shakaExtern.DrmInfo>} drmInfos
* @return {!shakaExtern.Variant}
* @private
*/
shaka.hls.HlsParser.prototype.createVariant_ =
function(audio, video, bandwidth, drmInfos) {
const ContentType = shaka.util.ManifestParserUtils.ContentType;
// Since both audio and video are of the same type, this assertion will catch
// certain mistakes at runtime that the compiler would miss.
goog.asserts.assert(!audio || audio.type == ContentType.AUDIO,
'Audio parameter mismatch!');
goog.asserts.assert(!video || video.type == ContentType.VIDEO,
'Video parameter mismatch!');
return {
id: this.globalId_++,
language: audio ? audio.language : 'und',
primary: (!!audio && audio.primary) || (!!video && video.primary),
audio: audio,
video: video,
bandwidth: bandwidth,
drmInfos: drmInfos,
allowedByApplication: true,
allowedByKeySystem: true
};
};
/**
* Parses an EXT-X-MEDIA tag with TYPE="SUBTITLES" into a text stream.
*
* @param {!shaka.hls.Tag} tag
* @param {!shaka.hls.Playlist} playlist
* @return {!Promise.<?shakaExtern.Stream>}
* @private
*/
shaka.hls.HlsParser.prototype.createTextStream_ = function(tag, playlist) {
goog.asserts.assert(tag.name == 'EXT-X-MEDIA',
'Should only be called on media tags!');
let type = shaka.hls.HlsParser.getRequiredAttributeValue_(tag, 'TYPE');
goog.asserts.assert(type == 'SUBTITLES',
'Should only be called on tags with TYPE="SUBTITLES"!');
return this.createStreamInfoFromMediaTag_(tag, [])
.then(function(streamInfo) {
return streamInfo.stream;
});
};
/**
* Parse EXT-X-MEDIA media tag into a Stream object.
*
* @param {shaka.hls.Tag} tag
* @param {!Array.<string>} allCodecs
* @return {!Promise.<shaka.hls.HlsParser.StreamInfo>}
* @private
*/
shaka.hls.HlsParser.prototype.createStreamInfoFromMediaTag_ =
function(tag, allCodecs) {
goog.asserts.assert(tag.name == 'EXT-X-MEDIA',
'Should only be called on media tags!');
const HlsParser = shaka.hls.HlsParser;
const verbatimMediaPlaylistUri = HlsParser.getRequiredAttributeValue_(
tag, 'URI');
// Check if the stream has already been created as part of another Variant
// and return it if it has.
if (this.uriToStreamInfosMap_.has(verbatimMediaPlaylistUri)) {
return Promise.resolve(
this.uriToStreamInfosMap_.get(verbatimMediaPlaylistUri));
}
let type = HlsParser.getRequiredAttributeValue_(tag, 'TYPE').toLowerCase();
// Shaka recognizes the content types 'audio', 'video' and 'text'.
// The HLS 'subtitles' type needs to be mapped to 'text'.
const ContentType = shaka.util.ManifestParserUtils.ContentType;
if (type == 'subtitles') type = ContentType.TEXT;
const LanguageUtils = shaka.util.LanguageUtils;
const language = LanguageUtils.normalize(/** @type {string} */(
tag.getAttributeValue('LANGUAGE', 'und')));
const name = tag.getAttributeValue('NAME');
let defaultAttr = tag.getAttribute('DEFAULT');
let autoselectAttr = tag.getAttribute('AUTOSELECT');
// TODO: Should we take into account some of the currently ignored attributes:
// FORCED, INSTREAM-ID, CHARACTERISTICS, CHANNELS?
// Attribute descriptions: https://goo.gl/EpU48b
let channelsAttribute = tag.getAttributeValue('CHANNELS');
let channelsCount = type == 'audio' ?
this.getChannelCount_(channelsAttribute) : null;
let primary = !!defaultAttr || !!autoselectAttr;
return this.createStreamInfo_(
verbatimMediaPlaylistUri, allCodecs, type, language, primary,
name, channelsCount).then(function(streamInfo) {
// TODO: This check is necessary because of the possibility of multiple
// calls to createStreamInfoFromMediaTag_ before either has resolved.
if (this.uriToStreamInfosMap_.has(verbatimMediaPlaylistUri)) {
return this.uriToStreamInfosMap_.get(verbatimMediaPlaylistUri);
}
this.mediaTagsToStreamInfosMap_.set(tag.id, streamInfo);
this.uriToStreamInfosMap_.set(verbatimMediaPlaylistUri, streamInfo);
return streamInfo;
}.bind(this));
};
/**
* Get the channel count information for an HLS audio track.
*
* @param {?string} channels A string that specifies an ordered, "/" separated
* list of parameters. If the type is audio, the first parameter will be a
* decimal integer specifying the number of independent, simultaneous audio
* channels.
* No other channels parameters are currently defined.
* @return {?number} channelcount
* @private
*/
shaka.hls.HlsParser.prototype.getChannelCount_ = function(channels) {
if (!channels) return null;
let channelcountstring = channels.split('/')[0];
let count = parseInt(channelcountstring, 10);
return count;
};
/**
* Parse an EXT-X-STREAM-INF media tag into a Stream object.
*
* @param {!shaka.hls.Tag} tag
* @param {!Array.<string>} allCodecs
* @param {string} type
* @return {!Promise.<shaka.hls.HlsParser.StreamInfo>}
* @private
*/
shaka.hls.HlsParser.prototype.createStreamInfoFromVariantTag_ =
function(tag, allCodecs, type) {
goog.asserts.assert(tag.name == 'EXT-X-STREAM-INF',
'Should only be called on media tags!');
const HlsParser = shaka.hls.HlsParser;
const verbatimMediaPlaylistUri = HlsParser.getRequiredAttributeValue_(
tag, 'URI');
if (this.uriToStreamInfosMap_.has(verbatimMediaPlaylistUri)) {
return Promise.resolve(
this.uriToStreamInfosMap_.get(verbatimMediaPlaylistUri));
}
return this.createStreamInfo_(verbatimMediaPlaylistUri, allCodecs, type,
/* language */ 'und', /* primary */ false,
/* name */ null, /* channelcount */ null).then(
function(streamInfo) {
// TODO: This check is necessary because of the possibility of multiple
// calls to createStreamInfoFromVariantTag_ before either has resolved.
if (this.uriToStreamInfosMap_.has(verbatimMediaPlaylistUri)) {
return this.uriToStreamInfosMap_.get(verbatimMediaPlaylistUri);
}
this.uriToStreamInfosMap_.set(verbatimMediaPlaylistUri, streamInfo);
return streamInfo;
}.bind(this));
};
/**
* @param {string} verbatimMediaPlaylistUri
* @param {!Array.<string>} allCodecs
* @param {string} type
* @param {string} language
* @param {boolean} primary
* @param {?string} name
* @param {?number} channelsCount
* @return {!Promise.<shaka.hls.HlsParser.StreamInfo>}
* @throws shaka.util.Error
* @private
*/
shaka.hls.HlsParser.prototype.createStreamInfo_ = function(
verbatimMediaPlaylistUri, allCodecs, type, language, primary, name,
channelsCount) {
// TODO: Refactor, too many parameters
const Utils = shaka.hls.Utils;
const HlsParser = shaka.hls.HlsParser;
let absoluteMediaPlaylistUri = Utils.constructAbsoluteUri(
this.masterPlaylistUri_, verbatimMediaPlaylistUri);
/** @type {!shaka.hls.Playlist} */
let playlist;
/** @type {string} */
let codecs = '';
/** @type {string} */
let mimeType;
return this.requestManifest_(absoluteMediaPlaylistUri).then((response) => {
// Record the final URI after redirects.
absoluteMediaPlaylistUri = response.uri;
// Record the redirected, final URI of this media playlist when we parse it.
playlist = this.manifestTextParser_.parsePlaylist(
response.data, absoluteMediaPlaylistUri);
if (playlist.type != shaka.hls.PlaylistType.MEDIA) {
// EXT-X-MEDIA tags should point to media playlists.
throw new shaka.util.Error(
shaka.util.Error.Severity.CRITICAL,
shaka.util.Error.Category.MANIFEST,
shaka.util.Error.Code.HLS_INVALID_PLAYLIST_HIERARCHY);
}
goog.asserts.assert(playlist.segments != null,
'Media playlist should have segments!');
this.determinePresentationType_(playlist);
codecs = this.guessCodecs_(type, allCodecs);
return this.guessMimeType_(type, codecs, playlist);
}).then((mimeTypeArg) => {
mimeType = mimeTypeArg;
let mediaSequenceTag = Utils.getFirstTagWithName(playlist.tags,
'EXT-X-MEDIA-SEQUENCE');
let startPosition = mediaSequenceTag ? Number(mediaSequenceTag.value) : 0;
return this.createSegments_(
verbatimMediaPlaylistUri, playlist, startPosition, mimeType, codecs);
}).then((segments) => {
let minTimestamp = segments[0].startTime;
let lastEndTime = segments[segments.length - 1].endTime;
let duration = lastEndTime - minTimestamp;
let segmentIndex = new shaka.media.SegmentIndex(segments);
const initSegmentReference = this.createInitSegmentReference_(playlist);
let kind = undefined;
const ManifestParserUtils = shaka.util.ManifestParserUtils;
if (type == ManifestParserUtils.ContentType.TEXT) {
kind = ManifestParserUtils.TextStreamKind.SUBTITLE;
}
// TODO: CLOSED-CAPTIONS requires the parsing of CEA-608 from the video.
let drmTags = [];
playlist.segments.forEach(function(segment) {
let segmentKeyTags = Utils.filterTagsByName(segment.tags,
'EXT-X-KEY');
drmTags.push.apply(drmTags, segmentKeyTags);
});
let encrypted = false;
let drmInfos = [];
let keyId = null;
// TODO: May still need changes to support key rotation.
drmTags.forEach(function(drmTag) {
let method = HlsParser.getRequiredAttributeValue_(drmTag, 'METHOD');
if (method != 'NONE') {
encrypted = true;
let keyFormat =
HlsParser.getRequiredAttributeValue_(drmTag, 'KEYFORMAT');
let drmParser =
shaka.hls.HlsParser.KEYFORMATS_TO_DRM_PARSERS_[keyFormat];
let drmInfo = drmParser ? drmParser(drmTag) : null;
if (drmInfo) {
if (drmInfo.keyIds.length) {
keyId = drmInfo.keyIds[0];
}
drmInfos.push(drmInfo);
} else {
shaka.log.warning('Unsupported HLS KEYFORMAT', keyFormat);
}
}
});
if (encrypted && !drmInfos.length) {
throw new shaka.util.Error(
shaka.util.Error.Severity.CRITICAL,
shaka.util.Error.Category.MANIFEST,
shaka.util.Error.Code.HLS_KEYFORMATS_NOT_SUPPORTED);
}
let stream = {
id: this.globalId_++,
createSegmentIndex: Promise.resolve.bind(Promise),
findSegmentPosition: segmentIndex.find.bind(segmentIndex),
getSegmentReference: segmentIndex.get.bind(segmentIndex),
initSegmentReference: initSegmentReference,
presentationTimeOffset: 0,
mimeType: mimeType,
codecs: codecs,
kind: kind,
encrypted: encrypted,
keyId: keyId,
language: language,
label: name || null,
type: type,
primary: primary,
// TODO: trick mode
trickModeVideo: null,
containsEmsgBoxes: false,
frameRate: undefined,
width: undefined,
height: undefined,
bandwidth: undefined,
roles: [],
channelsCount: channelsCount
};
return {
stream: stream,
segmentIndex: segmentIndex,
drmInfos: drmInfos,
verbatimMediaPlaylistUri: verbatimMediaPlaylistUri,
absoluteMediaPlaylistUri: absoluteMediaPlaylistUri,
minTimestamp: minTimestamp,
maxTimestamp: lastEndTime,
duration: duration
};
});
};
/**
* @param {!shaka.hls.Playlist} playlist
* @private
*/
shaka.hls.HlsParser.prototype.determinePresentationType_ = function(playlist) {
const Utils = shaka.hls.Utils;
const PresentationType = shaka.hls.HlsParser.PresentationType_;
let presentationTypeTag = Utils.getFirstTagWithName(playlist.tags,
'EXT-X-PLAYLIST-TYPE');
let endListTag = Utils.getFirstTagWithName(playlist.tags, 'EXT-X-ENDLIST');
let isVod = (presentationTypeTag && presentationTypeTag.value == 'VOD') ||
endListTag;
let isEvent = presentationTypeTag && presentationTypeTag.value == 'EVENT' &&
!isVod;
let isLive = !isVod && !isEvent;
if (isVod) {
this.setPresentationType_(PresentationType.VOD);
} else {
// If it's not VOD, it must be presentation type LIVE or an ongoing EVENT.
if (isLive) {
this.setPresentationType_(PresentationType.LIVE);
} else {
this.setPresentationType_(PresentationType.EVENT);
}
let targetDurationTag = this.getRequiredTag_(playlist.tags,
'EXT-X-TARGETDURATION');
let targetDuration = Number(targetDurationTag.value);
// According to the HLS spec, updates should not happen more often than
// once in targetDuration. It also requires us to only update the active
// variant. We might implement that later, but for now every variant
// will be updated. To get the update period, choose the smallest
// targetDuration value across all playlists.
// Update the longest target duration if need be to use as a presentation
// delay later.
this.maxTargetDuration_ = Math.max(targetDuration, this.maxTargetDuration_);
// Update the shortest one to use as update period and segment availability
// time (for LIVE).
this.minTargetDuration_ = Math.min(targetDuration, this.minTargetDuration_);
}
};
/**
* @param {number} lastTimestamp
* @throws shaka.util.Error
* @private
*/
shaka.hls.HlsParser.prototype.createPresentationTimeline_ =
function(lastTimestamp) {
let presentationStartTime = null;
let delay = 0;
if (this.isLive_()) {
presentationStartTime = (Date.now() / 1000) - lastTimestamp;
// We should have a delay of at least 3 target durations.
delay = this.maxTargetDuration_ * 3;
}
this.presentationTimeline_ = new shaka.media.PresentationTimeline(
presentationStartTime, delay);
this.presentationTimeline_.setStatic(!this.isLive_());
this.notifySegments_();
};
/**
* @param {!shaka.hls.Playlist} playlist
* @return {shaka.media.InitSegmentReference}
* @private
* @throws {shaka.util.Error}
*/
shaka.hls.HlsParser.prototype.createInitSegmentReference_ = function(playlist) {
const Utils = shaka.hls.Utils;
let mapTags = Utils.filterTagsByName(playlist.tags, 'EXT-X-MAP');
// TODO: Support multiple map tags?
// For now, we don't support multiple map tags and will throw an error.
if (!mapTags.length) {
return null;
} else if (mapTags.length > 1) {
throw new shaka.util.Error(
shaka.util.Error.Severity.CRITICAL,
shaka.util.Error.Category.MANIFEST,
shaka.util.Error.Code.HLS_MULTIPLE_MEDIA_INIT_SECTIONS_FOUND);
}
// Map tag example: #EXT-X-MAP:URI="main.mp4",BYTERANGE="720@0"
let mapTag = mapTags[0];
const verbatimInitSegmentUri =
shaka.hls.HlsParser.getRequiredAttributeValue_(mapTag, 'URI');
const absoluteInitSegmentUri =
Utils.constructAbsoluteUri(playlist.absoluteUri, verbatimInitSegmentUri);
let startByte = 0;
let endByte = null;
let byterange = mapTag.getAttributeValue('BYTERANGE');
// If a BYTERANGE attribute is not specified, the segment consists
// of the entire resource.
if (byterange) {
let blocks = byterange.split('@');
let byteLength = Number(blocks[0]);
startByte = Number(blocks[1]);
endByte = startByte + byteLength - 1;
}
return new shaka.media.InitSegmentReference(
() => [absoluteInitSegmentUri],
startByte,
endByte);
};
/**
* Parses one shaka.hls.Segment object into a shaka.media.SegmentReference.
*
* @param {!shaka.hls.Playlist} playlist
* @param {shaka.media.SegmentReference} previousReference
* @param {!shaka.hls.Segment} hlsSegment
* @param {number} position
* @param {number} startTime
* @return {!shaka.media.SegmentReference}
* @private
*/
shaka.hls.HlsParser.prototype.createSegmentReference_ =
function(playlist, previousReference, hlsSegment, position, startTime) {
const Utils = shaka.hls.Utils;
const tags = hlsSegment.tags;
const absoluteSegmentUri = hlsSegment.absoluteUri;
let extinfTag = this.getRequiredTag_(tags, 'EXTINF');
// The EXTINF tag format is '#EXTINF:<duration>,[<title>]'.
// We're interested in the duration part.
let extinfValues = extinfTag.value.split(',');
let duration = Number(extinfValues[0]);
let endTime = startTime + duration;
let startByte = 0;
let endByte = null;
let byterange = Utils.getFirstTagWithName(tags, 'EXT-X-BYTERANGE');
// If BYTERANGE is not specified, the segment consists of the entire resource.
if (byterange) {
let blocks = byterange.value.split('@');
let byteLength = Number(blocks[0]);
if (blocks[1]) {
startByte = Number(blocks[1]);
} else {
goog.asserts.assert(previousReference,
'Cannot refer back to previous HLS segment!');
startByte = previousReference.endByte + 1;
}
endByte = startByte + byteLength - 1;
}
return new shaka.media.SegmentReference(
position,
startTime,
endTime,
() => [absoluteSegmentUri],
startByte,
endByte);
};
/** @private */
shaka.hls.HlsParser.prototype.notifySegments_ = function() {
// The presentation timeline may or may not be set yet.
// If it does not yet exist, hold onto the segments until it does.
if (!this.presentationTimeline_) {
return;
}
this.segmentsToNotifyByStream_.forEach((segments) => {
// HLS doesn't have separate periods, so it's always "the first period".
this.presentationTimeline_.notifySegments(segments, true);
});
this.segmentsToNotifyByStream_ = [];
};
/**
* Parses shaka.hls.Segment objects into shaka.media.SegmentReferences.
*
* @param {string} verbatimMediaPlaylistUri
* @param {!shaka.hls.Playlist} playlist
* @param {number} startPosition
* @param {string} mimeType
* @param {string} codecs
* @return {!Promise<!Array.<!shaka.media.SegmentReference>>}
* @private
*/
shaka.hls.HlsParser.prototype.createSegments_ = function(
verbatimMediaPlaylistUri, playlist, startPosition, mimeType, codecs) {
const hlsSegments = playlist.segments;
const references = [];
goog.asserts.assert(hlsSegments.length, 'Playlist should have segments!');
// We may need to look at the media itself to determine a segment start time.
const firstSegmentUri = hlsSegments[0].absoluteUri;
const firstSegmentRef =
this.createSegmentReference_(
playlist,
null /* previousReference */,
hlsSegments[0],
startPosition,
0 /* startTime, irrelevant */);
const initSegmentRef = this.createInitSegmentReference_(playlist);
return this.getStartTime_(verbatimMediaPlaylistUri, initSegmentRef,
firstSegmentRef, mimeType, codecs)
.then(function(firstStartTime) {
shaka.log.debug('First segment', firstSegmentUri.split('/').pop(),
'starts at', firstStartTime);
for (let i = 0; i < hlsSegments.length; ++i) {
let hlsSegment = hlsSegments[i];
let previousReference = references[references.length - 1];
let startTime = (i == 0) ? firstStartTime : previousReference.endTime;
let position = startPosition + i;
let reference = this.createSegmentReference_(
playlist,
previousReference,
hlsSegment,
position,
startTime);
references.push(reference);
}
this.segmentsToNotifyByStream_.push(references);
this.notifySegments_();
return references;
}.bind(this));
};
/**
* Try to fetch a partial segment, and fall back to a full segment if we have
* to.
*
* @param {!shaka.media.AnySegmentReference} segmentRef
* @return {!Promise.<shakaExtern.Response>}
* @throws {shaka.util.Error}
* @private
*/
shaka.hls.HlsParser.prototype.fetchPartialSegment_ = function(segmentRef) {
let networkingEngine = this.playerInterface_.networkingEngine;
const requestType = shaka.net.NetworkingEngine.RequestType.SEGMENT;
let request = shaka.net.NetworkingEngine.makeRequest(
segmentRef.getUris(), this.config_.retryParameters);
// Try to avoid fetching the entire segment, which can be quite large.
let partialSegmentHeaders = {};
let startByte = segmentRef.startByte;
let partialEndByte =
startByte + shaka.hls.HlsParser.PARTIAL_SEGMENT_SIZE_ - 1;
partialSegmentHeaders['Range'] = 'bytes=' + startByte + '-' + partialEndByte;
// Prepare a fallback to the entire segment.
let fullSegmentHeaders = {};
if ((startByte != 0) || (segmentRef.endByte != null)) {
let range = 'bytes=' + startByte + '-';
if (segmentRef.endByte != null) range += segmentRef.endByte;
fullSegmentHeaders['Range'] = range;
}
// Try a partial request first.
request.headers = partialSegmentHeaders;
let operation = networkingEngine.request(requestType, request);
this.operationManager_.manage(operation);
return operation.promise.catch((error) => {
// The partial request may fail for a number of reasons.
// Some servers do not support Range requests, and others do not support
// the OPTIONS request which must be made before any cross-origin Range
// request. Since this fallback is expensive, warn the app developer.
shaka.log.alwaysWarn('Unable to fetch a partial HLS segment! ' +
'Falling back to a full segment request, ' +
'which is expensive! Your server should ' +
'support Range requests and CORS preflights.',
request.uris[0]);
request.headers = fullSegmentHeaders;
let operation = networkingEngine.request(requestType, request);
this.operationManager_.manage(operation);
return operation.promise;
});
};
/**
* Gets the start time of a segment from the existing manifest (if possible) or
* by downloading it and parsing it otherwise.
*
* @param {string} verbatimMediaPlaylistUri
* @param {shaka.media.InitSegmentReference} initSegmentRef
* @param {!shaka.media.SegmentReference} segmentRef
* @param {string} mimeType
* @param {string} codecs
* @return {!Promise.<number>}
* @throws {shaka.util.Error}
* @private
*/
shaka.hls.HlsParser.prototype.getStartTime_ = function(
verbatimMediaPlaylistUri, initSegmentRef, segmentRef, mimeType, codecs) {
// If we are updating the manifest, we can usually skip fetching the segment
// by examining the references we already have. This won't be possible if
// there was some kind of lag or delay updating the manifest on the server,
// in which extreme case we would fall back to fetching a segment. This
// allows us to both avoid fetching segments when possible, and recover from
// certain server-side issues gracefully.
if (this.manifest_) {
const streamInfo = this.uriToStreamInfosMap_.get(verbatimMediaPlaylistUri);
const segmentIndex = streamInfo.segmentIndex;
const reference = segmentIndex.get(segmentRef.position);
if (reference) {
// We found it! Avoid fetching and parsing the segment.
shaka.log.v1('Found segment start time in previous manifest');
return Promise.resolve(reference.startTime);
}
shaka.log.debug('Unable to find segment start time in previous manifest!');
}
// TODO: Introduce a new tag to extend HLS and provide the first segment's
// start time. This will avoid the need for these fetches in content packaged
// with Shaka Packager. This web-friendly extension to HLS can then be
// proposed to Apple for inclusion in a future version of HLS.
// See https://github.com/google/shaka-packager/issues/294
shaka.log.v1('Fetching segment to find start time');
let fetches = [this.fetchPartialSegment_(segmentRef)];
if (mimeType == 'video/mp4' || mimeType == 'audio/mp4') {
// We also need the init segment to get the correct timescale.
if (initSegmentRef) {
fetches.push(this.fetchPartialSegment_(initSegmentRef));
} else {
// If the stream is self-initializing, use the same response for both.
fetches.push(fetches[0]);
}
}
return Promise.all(fetches).then(function(responses) {
if (mimeType == 'video/mp4' || mimeType == 'audio/mp4') {
return this.getStartTimeFromMp4Segment_(
responses[0].data, responses[1].data);
} else if (mimeType == 'audio/mpeg') {
// There is no standard way to embed a timestamp in an mp3 file, so the
// start time is presumably 0.
return 0;
} else if (mimeType == 'video/mp2t') {
return this.getStartTimeFromTsSegment_(responses[0].data);
} else if (mimeType == 'application/mp4' ||
mimeType.indexOf('text/') == 0) {
return this.getStartTimeFromTextSegment_(
mimeType, codecs, responses[0].data);
} else {
// TODO: Parse WebM?
// TODO: Parse raw AAC?
throw new shaka.util.Error(
shaka.util.Error.Severity.CRITICAL,
shaka.util.Error.Category.MANIFEST,
shaka.util.Error.Code.HLS_COULD_NOT_PARSE_SEGMENT_START_TIME);
}
}.bind(this));
};
/**
* Parses an mp4 segment to get its start time.
*
* @param {!ArrayBuffer} mediaData
* @param {!ArrayBuffer} initData
* @return {number}
* @throws {shaka.util.Error}
* @private
*/
shaka.hls.HlsParser.prototype.getStartTimeFromMp4Segment_ =
function(mediaData, initData) {
const Mp4Parser = shaka.util.Mp4Parser;
let timescale = 0;
new Mp4Parser()
.box('moov', Mp4Parser.children)
.box('trak', Mp4Parser.children)
.box('mdia', Mp4Parser.children)
.fullBox('mdhd', function(box) {
goog.asserts.assert(
box.version == 0 || box.version == 1,
'MDHD version can only be 0 or 1');
// Skip "creation_time" and "modification_time".
// They are 4 bytes each if the mdhd box is version 0, 8 bytes each if
// it is version 1.
box.reader.skip(box.version == 0 ? 8 : 16);
timescale = box.reader.readUint32();
box.parser.stop();
}).parse(initData, true /* partialOkay */);
if (!timescale) {
shaka.log.error('Unable to find timescale in init segment!');
throw new shaka.util.Error(
shaka.util.Error.Severity.CRITICAL,
shaka.util.Error.Category.MANIFEST,
shaka.util.Error.Code.HLS_COULD_NOT_PARSE_SEGMENT_START_TIME);
}
let startTime = 0;
let parsedMedia = false;
new Mp4Parser()
.box('moof', Mp4Parser.children)
.box('traf', Mp4Parser.children)
.fullBox('tfdt', function(box) {
goog.asserts.assert(
box.version == 0 || box.version == 1,
'TFDT version can only be 0 or 1');
let baseTime = (box.version == 0) ?
box.reader.readUint32() :
box.reader.readUint64();
startTime = baseTime / timescale;
parsedMedia = true;
box.parser.stop();
}).parse(mediaData, true /* partialOkay */);
if (!parsedMedia) {
throw new shaka.util.Error(
shaka.util.Error.Severity.CRITICAL,
shaka.util.Error.Category.MANIFEST,
shaka.util.Error.Code.HLS_COULD_NOT_PARSE_SEGMENT_START_TIME);
}
return startTime;
};
/**
* Parses a TS segment to get its start time.
*
* @param {!ArrayBuffer} data
* @return {number}
* @throws {shaka.util.Error}
* @private
*/
shaka.hls.HlsParser.prototype.getStartTimeFromTsSegment_ = function(data) {
let reader = new shaka.util.DataViewReader(
new DataView(data), shaka.util.DataViewReader.Endianness.BIG_ENDIAN);
const fail = function() {
throw new shaka.util.Error(
shaka.util.Error.Severity.CRITICAL,
shaka.util.Error.Category.MANIFEST,
shaka.util.Error.Code.HLS_COULD_NOT_PARSE_SEGMENT_START_TIME);
};
let packetStart = 0;
let syncByte = 0;
const skipPacket = function() {
// 188-byte packets are standard, so assume that.
reader.seek(packetStart + 188);
syncByte = reader.readUint8();
if (syncByte != 0x47) {
// We haven't found the sync byte, so try it as a 192-byte packet.
reader.seek(packetStart + 192);
syncByte = reader.readUint8();
}
if (syncByte != 0x47) {
// We still haven't found the sync byte, so try as a 204-byte packet.
reader.seek(packetStart + 204);
syncByte = reader.readUint8();
}
if (syncByte != 0x47) {
// We still haven't found the sync byte, so the packet was of a
// non-standard size.
fail();
}
// Put the sync byte back so we can read it in the next loop.
reader.rewind(1);
};
// eslint-disable-next-line no-constant-condition
while (true) {
// Format reference: https://goo.gl/wk6wwu
packetStart = reader.getPosition();
syncByte = reader.readUint8();
if (syncByte != 0x47) fail();
let flagsAndPacketId = reader.readUint16();
let hasPesPacket = flagsAndPacketId & 0x4000;
if (!hasPesPacket) fail();
let flags = reader.readUint8();
let adaptationFieldControl = (flags & 0x30) >> 4;
if (adaptationFieldControl == 0 /* reserved */ ||
adaptationFieldControl == 2 /* adaptation field, no payload */) {
fail();
}
if (adaptationFieldControl == 3) {
// Skip over adaptation field.
let length = reader.readUint8();
reader.skip(length);
}
// Now we come to the PES header (hopefully).
// Format reference: https://goo.gl/1166Mr
let startCode = reader.readUint32();
let startCodePrefix = startCode >> 8;
if (startCodePrefix != 1) {
// Not a PES packet yet. Skip this TS packet and try again.
skipPacket();
continue;
}
// Skip the 16-bit PES length and the first 8 bits of the optional header.
reader.skip(3);
// The next 8 bits contain flags about DTS & PTS.
let ptsDtsIndicator = reader.readUint8() >> 6;
if (ptsDtsIndicator == 0 /* no timestamp */ ||
ptsDtsIndicator == 1 /* forbidden */) {
fail();
}
let pesHeaderLengthRemaining = reader.readUint8();
if (pesHeaderLengthRemaining == 0) {
fail();
}
if (ptsDtsIndicator == 2 /* PTS only */) {
goog.asserts.assert(pesHeaderLengthRemaining == 5, 'Bad PES header?');
} else if (ptsDtsIndicator == 3 /* PTS and DTS */) {
goog.asserts.assert(pesHeaderLengthRemaining == 10, 'Bad PES header?');
}
let pts0 = reader.readUint8();
let pts1 = reader.readUint16();
let pts2 = reader.readUint16();
// Reconstruct 33-bit PTS from the 5-byte, padded structure.
let ptsHigh3 = (pts0 & 0x0e) >> 1;
let ptsLow30 = ((pts1 & 0xfffe) << 14) | ((pts2 & 0xfffe) >> 1);
// Reconstruct the PTS as a float. Avoid bitwise operations to combine
// because bitwise ops treat the values as 32-bit ints.
let pts = ptsHigh3 * (1 << 30) + ptsLow30;
return pts / shaka.hls.HlsParser.TS_TIMESCALE_;
}
};
/**
* Parses a text segment to get its start time.
*
* @param {string} mimeType
* @param {string} codecs
* @param {!ArrayBuffer} data
* @return {number}
* @throws {shaka.util.Error}
* @private
*/
shaka.hls.HlsParser.prototype.getStartTimeFromTextSegment_ =
function(mimeType, codecs, data) {
let fullMimeType = shaka.util.MimeUtils.getFullType(mimeType, codecs);
if (!shaka.text.TextEngine.isTypeSupported(fullMimeType)) {
// We won't be able to parse this, but it will be filtered out anyway.
// So we don't have to care about the start time.
return 0;
}
let textEngine = new shaka.text.TextEngine(/* displayer */ null);
textEngine.initParser(fullMimeType);
return textEngine.getStartTime(data);
};
/**
* Attempts to guess which codecs from the codecs list belong to a given content
* type. Does not assume a single codec is anything special, and does not throw
* if it fails to match.
*
* @param {string} contentType
* @param {!Array.<string>} codecs
* @return {?string} or null if no match is found
* @private
*/
shaka.hls.HlsParser.prototype.guessCodecsSafe_ = function(contentType, codecs) {
const ContentType = shaka.util.ManifestParserUtils.ContentType;
const HlsParser = shaka.hls.HlsParser;
let formats = HlsParser.CODEC_REGEXPS_BY_CONTENT_TYPE_[contentType];
for (let i = 0; i < formats.length; i++) {
for (let j = 0; j < codecs.length; j++) {
if (formats[i].test(codecs[j].trim())) {
return codecs[j].trim();
}
}
}
// Text does not require a codec string.
if (contentType == ContentType.TEXT) {
return '';
}
return null;
};
/**
* Attempts to guess which codecs from the codecs list belong to a given content
* type. Assumes that at least one codec is correct, and throws if none are.
*
* @param {string} contentType
* @param {!Array.<string>} codecs
* @return {string}
* @private
* @throws {shaka.util.Error}
*/
shaka.hls.HlsParser.prototype.guessCodecs_ = function(contentType, codecs) {
if (codecs.length == 1) {
return codecs[0];
}
let match = this.guessCodecsSafe_(contentType, codecs);
// A failure is specifically denoted by null; an empty string represents a
// valid match of no codec.
if (match != null) {
return match;
}
// Unable to guess codecs.
throw new shaka.util.Error(
shaka.util.Error.Severity.CRITICAL,
shaka.util.Error.Category.MANIFEST,
shaka.util.Error.Code.HLS_COULD_NOT_GUESS_CODECS,
codecs);
};
/**
* Attempts to guess stream's mime type based on content type and URI.
*
* @param {string} contentType
* @param {string} codecs
* @param {!shaka.hls.Playlist} playlist
* @return {!Promise.<string>}
* @private
* @throws {shaka.util.Error}
*/
shaka.hls.HlsParser.prototype.guessMimeType_ =
function(contentType, codecs, playlist) {
const ContentType = shaka.util.ManifestParserUtils.ContentType;
const HlsParser = shaka.hls.HlsParser;
goog.asserts.assert(playlist.segments.length,
'Playlist should have segments!');
const firstSegmentUri = playlist.segments[0].absoluteUri;
let parsedUri = new goog.Uri(firstSegmentUri);
let extension = parsedUri.getPath().split('.').pop();
let map = HlsParser.EXTENSION_MAP_BY_CONTENT_TYPE_[contentType];
let mimeType = map[extension];
if (mimeType) {
return Promise.resolve(mimeType);
}
if (contentType == ContentType.TEXT) {
// The extension map didn't work.
if (!codecs || codecs == 'vtt') {
// If codecs is 'vtt', it's WebVTT.
// If there was no codecs string, assume HLS text streams are WebVTT.
return Promise.resolve('text/vtt');
} else {
// Otherwise, assume MP4-embedded text, since text-based formats tend not
// to have a codecs string at all.
return Promise.resolve('application/mp4');
}
}
// If unable to guess mime type, request a segment and try getting it
// from the response.
let headRequest = shaka.net.NetworkingEngine.makeRequest(
[firstSegmentUri], this.config_.retryParameters);
headRequest.method = 'HEAD';
const requestType = shaka.net.NetworkingEngine.RequestType.SEGMENT;
let networkingEngine = this.playerInterface_.networkingEngine;
let operation = networkingEngine.request(requestType, headRequest);
this.operationManager_.manage(operation);
return operation.promise.then((response) => {
let mimeType = response.headers['content-type'];
if (!mimeType) {
throw new shaka.util.Error(
shaka.util.Error.Severity.CRITICAL,
shaka.util.Error.Category.MANIFEST,
shaka.util.Error.Code.HLS_COULD_NOT_GUESS_MIME_TYPE,
extension);
}
// Split the MIME type in case the server sent additional parameters.
return mimeType.split(';')[0];
});
};
/**
* Find the attribute and returns its value.
* Throws an error if attribute was not found.
*
* @param {shaka.hls.Tag} tag
* @param {string} attributeName
* @return {string}
* @private
* @throws {shaka.util.Error}
*/
shaka.hls.HlsParser.getRequiredAttributeValue_ = function(tag, attributeName) {
let attribute = tag.getAttribute(attributeName);
if (!attribute) {
throw new shaka.util.Error(
shaka.util.Error.Severity.CRITICAL,
shaka.util.Error.Category.MANIFEST,
shaka.util.Error.Code.HLS_REQUIRED_ATTRIBUTE_MISSING,
attributeName);
}
return attribute.value;
};
/**
* Returns a tag with a given name.
* Throws an error if tag was not found.
*
* @param {!Array.<shaka.hls.Tag>} tags
* @param {string} tagName
* @return {!shaka.hls.Tag}
* @private
* @throws {shaka.util.Error}
*/
shaka.hls.HlsParser.prototype.getRequiredTag_ = function(tags, tagName) {
const Utils = shaka.hls.Utils;
let tag = Utils.getFirstTagWithName(tags, tagName);
if (!tag) {
throw new shaka.util.Error(
shaka.util.Error.Severity.CRITICAL,
shaka.util.Error.Category.MANIFEST,
shaka.util.Error.Code.HLS_REQUIRED_TAG_MISSING, tagName);
}
return tag;
};
/**
* @param {shakaExtern.Stream} stream
* @param {?string} width
* @param {?string} height
* @param {?string} frameRate
* @private
*/
shaka.hls.HlsParser.prototype.addVideoAttributes_ =
function(stream, width, height, frameRate) {
if (stream) {
stream.width = Number(width) || undefined;
stream.height = Number(height) || undefined;
stream.frameRate = Number(frameRate) || undefined;
}
};
/**
* Makes a network request for the manifest and returns a Promise
* with the resulting data.
*
* @param {string} absoluteUri
* @return {!Promise.<!shakaExtern.Response>}
* @private
*/
shaka.hls.HlsParser.prototype.requestManifest_ = function(absoluteUri) {
const requestType = shaka.net.NetworkingEngine.RequestType.MANIFEST;
let request = shaka.net.NetworkingEngine.makeRequest(
[absoluteUri], this.config_.retryParameters);
let networkingEngine = this.playerInterface_.networkingEngine;
let operation = networkingEngine.request(requestType, request);
this.operationManager_.manage(operation);
return operation.promise;
};
/**
* A list of regexps to detect well-known video codecs.
*
* @const {!Array.<!RegExp>}
* @private
*/
shaka.hls.HlsParser.VIDEO_CODEC_REGEXPS_ = [
/^avc/,
/^hev/,
/^hvc/,
/^vp0?[89]/,
/^av1$/
];
/**
* A list of regexps to detect well-known audio codecs.
*
* @const {!Array.<!RegExp>}
* @private
*/
shaka.hls.HlsParser.AUDIO_CODEC_REGEXPS_ = [
/^vorbis$/,
/^opus$/,
/^flac$/,
/^mp4a/,
/^[ae]c-3$/
];
/**
* A list of regexps to detect well-known text codecs.
*
* @const {!Array.<!RegExp>}
* @private
*/
shaka.hls.HlsParser.TEXT_CODEC_REGEXPS_ = [
/^vtt$/,
/^wvtt/,
/^stpp/
];
/**
* @const {!Object.<string, !Array.<!RegExp>>}
* @private
*/
shaka.hls.HlsParser.CODEC_REGEXPS_BY_CONTENT_TYPE_ = {
'audio': shaka.hls.HlsParser.AUDIO_CODEC_REGEXPS_,
'video': shaka.hls.HlsParser.VIDEO_CODEC_REGEXPS_,
'text': shaka.hls.HlsParser.TEXT_CODEC_REGEXPS_
};
/**
* @const {!Object.<string, string>}
* @private
*/
shaka.hls.HlsParser.AUDIO_EXTENSIONS_TO_MIME_TYPES_ = {
'mp4': 'audio/mp4',
'm4s': 'audio/mp4',
'm4i': 'audio/mp4',
'm4a': 'audio/mp4',
// MPEG2-TS also uses video/ for audio: http://goo.gl/tYHXiS
'ts': 'video/mp2t'
};
/**
* @const {!Object.<string, string>}
* @private
*/
shaka.hls.HlsParser.VIDEO_EXTENSIONS_TO_MIME_TYPES_ = {
'mp4': 'video/mp4',
'm4s': 'video/mp4',
'm4i': 'video/mp4',
'm4v': 'video/mp4',
'ts': 'video/mp2t'
};
/**
* @const {!Object.<string, string>}
* @private
*/
shaka.hls.HlsParser.TEXT_EXTENSIONS_TO_MIME_TYPES_ = {
'mp4': 'application/mp4',
'm4s': 'application/mp4',
'm4i': 'application/mp4',
'vtt': 'text/vtt',
'ttml': 'application/ttml+xml'
};
/**
* @const {!Object.<string, !Object.<string, string>>}
* @private
*/
shaka.hls.HlsParser.EXTENSION_MAP_BY_CONTENT_TYPE_ = {
'audio': shaka.hls.HlsParser.AUDIO_EXTENSIONS_TO_MIME_TYPES_,
'video': shaka.hls.HlsParser.VIDEO_EXTENSIONS_TO_MIME_TYPES_,
'text': shaka.hls.HlsParser.TEXT_EXTENSIONS_TO_MIME_TYPES_
};
/**
* @typedef {function(!shaka.hls.Tag):?shakaExtern.DrmInfo}
* @private
*/
shaka.hls.HlsParser.DrmParser_;
/**
* @param {!shaka.hls.Tag} drmTag
* @return {?shakaExtern.DrmInfo}
* @private
*/
shaka.hls.HlsParser.widevineDrmParser_ = function(drmTag) {
const HlsParser = shaka.hls.HlsParser;
let method = HlsParser.getRequiredAttributeValue_(drmTag, 'METHOD');
// TODO: https://github.com/google/shaka-player/issues/1227
// Keep 'SAMPLE-AES-CENC' for backward compatibility. Deprecate it in a
// future release.
if (method != 'SAMPLE-AES-CENC' && method != 'SAMPLE-AES-CTR') {
shaka.log.error(
'Widevine in HLS is only supported with SAMPLE-AES-CTR and ' +
'SAMPLE-AES-CENC (deprecated), not', method);
return null;
}
let uri = HlsParser.getRequiredAttributeValue_(drmTag, 'URI');
let parsedData = shaka.net.DataUriPlugin.parse(uri);
// The data encoded in the URI is a PSSH box to be used as init data.
let pssh = new Uint8Array(parsedData.data);
let drmInfo = shaka.util.ManifestParserUtils.createDrmInfo(
'com.widevine.alpha', [
{initDataType: 'cenc', initData: pssh}
]);
let keyId = drmTag.getAttributeValue('KEYID');
if (keyId) {
// This value should begin with '0x':
goog.asserts.assert(keyId.substr(0, 2) == '0x', 'Incorrect KEYID format!');
// But the output should not contain the '0x':
drmInfo.keyIds = [keyId.substr(2).toLowerCase()];
}
return drmInfo;
};
/**
* Called when the update timer ticks.
*
* @private
*/
shaka.hls.HlsParser.prototype.onUpdate_ = function() {
goog.asserts.assert(this.updateTimer_, 'Should only be called by timer');
goog.asserts.assert(this.updatePeriod_ != null,
'There should be an update period');
shaka.log.info('Updating manifest...');
// Detect a call to stop()
if (!this.playerInterface_) {
return;
}
this.updateTimer_ = null;
this.update().then(function() {
this.setUpdateTimer_(this.updatePeriod_);
}.bind(this)).catch(function(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);
this.setUpdateTimer_(0);
}
}.bind(this));
};
/**
* Sets the update timer.
*
* @param {?number} time in seconds
* @private
*/
shaka.hls.HlsParser.prototype.setUpdateTimer_ = function(time) {
if (this.updatePeriod_ == null || time == null) {
return;
}
goog.asserts.assert(this.updateTimer_ == null,
'Timer should not be already set');
let callback = this.onUpdate_.bind(this);
this.updateTimer_ = window.setTimeout(callback, time * 1000);
};
/**
* @return {boolean}
* @private
*/
shaka.hls.HlsParser.prototype.isLive_ = function() {
const PresentationType = shaka.hls.HlsParser.PresentationType_;
return this.presentationType_ != PresentationType.VOD;
};
/**
* @param {shaka.hls.HlsParser.PresentationType_} type
* @private
*/
shaka.hls.HlsParser.prototype.setPresentationType_ = function(type) {
this.presentationType_ = type;
if (this.presentationTimeline_) {
this.presentationTimeline_.setStatic(!this.isLive_());
}
if (!this.isLive_()) {
if (this.updateTimer_ != null) {
window.clearTimeout(this.updateTimer_);
this.updateTimer_ = null;
this.updatePeriod_ = null;
}
}
};
/**
* @const {!Object.<string, shaka.hls.HlsParser.DrmParser_>}
* @private
*/
shaka.hls.HlsParser.KEYFORMATS_TO_DRM_PARSERS_ = {
/* TODO: https://github.com/google/shaka-player/issues/382
'com.apple.streamingkeydelivery':
shaka.hls.HlsParser.fairplayDrmParser_,
*/
'urn:uuid:edef8ba9-79d6-4ace-a3c8-27dcd51d21ed':
shaka.hls.HlsParser.widevineDrmParser_
};
/**
* @enum {string}
* @private
*/
shaka.hls.HlsParser.PresentationType_ = {
VOD: 'VOD',
EVENT: 'EVENT',
LIVE: 'LIVE'
};
/**
* @const {number}
* @private
*/
shaka.hls.HlsParser.TS_TIMESCALE_ = 90000;
/**
* At this value, timestamps roll over in TS content.
* @const {number}
* @private
*/
shaka.hls.HlsParser.TS_ROLLOVER_ = 0x200000000;
/**
* The amount of data from the start of a segment we will try to fetch when we
* need to know the segment start time. This allows us to avoid fetching the
* entire segment in many cases.
*
* @const {number}
* @private
*/
shaka.hls.HlsParser.PARTIAL_SEGMENT_SIZE_ = 2048;
shaka.media.ManifestParser.registerParserByExtension(
'm3u8', shaka.hls.HlsParser);
shaka.media.ManifestParser.registerParserByMime(
'application/x-mpegurl', shaka.hls.HlsParser);
shaka.media.ManifestParser.registerParserByMime(
'application/vnd.apple.mpegurl', shaka.hls.HlsParser);