/**
* @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.util.StreamUtils');
goog.require('goog.asserts');
goog.require('shaka.log');
goog.require('shaka.media.DrmEngine');
goog.require('shaka.media.MediaSourceEngine');
goog.require('shaka.text.TextEngine');
goog.require('shaka.util.ArrayUtils');
goog.require('shaka.util.Functional');
goog.require('shaka.util.LanguageUtils');
goog.require('shaka.util.ManifestParserUtils');
goog.require('shaka.util.MimeUtils');
/**
* @namespace shaka.util.StreamUtils
* @summary A set of utility functions for dealing with Streams and Manifests.
*/
/**
* @param {shakaExtern.Variant} variant
* @param {shakaExtern.Restrictions} restrictions
* Configured restrictions from the user.
* @param {{width: number, height: number}} maxHwRes
* The maximum resolution the hardware can handle.
* This is applied separately from user restrictions because the setting
* should not be easily replaced by the user's configuration.
* @return {boolean}
*/
shaka.util.StreamUtils.meetsRestrictions = function(
variant, restrictions, maxHwRes) {
var video = variant.video;
if (video) {
if (video.width < restrictions.minWidth ||
video.width > restrictions.maxWidth || video.width > maxHwRes.width ||
video.height < restrictions.minHeight ||
video.height > restrictions.maxHeight ||
video.height > maxHwRes.height ||
(video.width * video.height) < restrictions.minPixels ||
(video.width * video.height) > restrictions.maxPixels) {
return false;
}
}
if (variant.bandwidth < restrictions.minBandwidth ||
variant.bandwidth > restrictions.maxBandwidth) {
return false;
}
return true;
};
/**
* @param {shakaExtern.Period} period
* @param {shakaExtern.Restrictions} restrictions
* @param {{width: number, height: number}} maxHwRes
* @return {boolean} Whether the tracks changed.
*/
shaka.util.StreamUtils.applyRestrictions =
function(period, restrictions, maxHwRes) {
var tracksChanged = false;
period.variants.forEach(function(variant) {
var originalAllowed = variant.allowedByApplication;
variant.allowedByApplication = shaka.util.StreamUtils.meetsRestrictions(
variant, restrictions, maxHwRes);
if (originalAllowed != variant.allowedByApplication) {
tracksChanged = true;
}
});
return tracksChanged;
};
/**
* Alters the given Period to filter out any unplayable streams.
*
* @param {shaka.media.DrmEngine} drmEngine
* @param {!Object.<string, shakaExtern.Stream>} activeStreams
* @param {shakaExtern.Period} period
*/
shaka.util.StreamUtils.filterNewPeriod = function(
drmEngine, activeStreams, period) {
var StreamUtils = shaka.util.StreamUtils;
var ContentType = shaka.util.ManifestParserUtils.ContentType;
var activeVideo = activeStreams[ContentType.VIDEO];
var activeAudio = activeStreams[ContentType.AUDIO];
// Filter variants
for (var i = 0; i < period.variants.length; ++i) {
var variant = period.variants[i];
if (!StreamUtils.variantIsCompatible_(
variant, drmEngine, activeAudio, activeVideo)) {
shaka.log.debug('Dropping Variant (not compatible with key system, ' +
'platform, or active Variant)', variant);
period.variants.splice(i, 1);
--i;
continue;
}
}
// Filter text streams
for (var i = 0; i < period.textStreams.length; ++i) {
var stream = period.textStreams[i];
var fullMimeType = shaka.util.MimeUtils.getFullType(
stream.mimeType, stream.codecs);
if (!shaka.text.TextEngine.isTypeSupported(fullMimeType)) {
shaka.log.debug('Dropping text stream. Is not supported by the ' +
'platform.', stream);
period.textStreams.splice(i, 1);
--i;
}
}
};
/**
* Checks if a stream is compatible with the key system, platform,
* and active stream.
*
* @param {?shakaExtern.Stream} stream
* @param {shaka.media.DrmEngine} drmEngine
* @param {?shakaExtern.Stream} activeStream
* @return {boolean}
* @private
*/
shaka.util.StreamUtils.streamIsCompatible_ =
function(stream, drmEngine, activeStream) {
if (!stream) return true;
var ContentType = shaka.util.ManifestParserUtils.ContentType;
goog.asserts.assert(stream.type != ContentType.TEXT,
'Should not be called on a text stream!');
var drmSupportedMimeTypes = null;
if (drmEngine && drmEngine.initialized()) {
drmSupportedMimeTypes = drmEngine.getSupportedTypes();
}
// Check if stream can be played by the platform
var fullMimeType = shaka.util.MimeUtils.getFullType(
stream.mimeType, stream.codecs);
if (!shaka.media.MediaSourceEngine.isStreamSupported(stream))
return false;
// Check if stream can be handled by the key system.
// There's no need to check that the stream is supported by the
// chosen key system since the caller has already verified that.
if (drmSupportedMimeTypes && stream.encrypted &&
drmSupportedMimeTypes.indexOf(fullMimeType) < 0) {
return false;
}
// Lastly, check if active stream can switch to the stream
// Basic mime types and basic codecs need to match.
// For example, we can't adapt between WebM and MP4,
// nor can we adapt between mp4a.* to ec-3.
// We can switch between text types on the fly,
// so don't run this check on text.
if (activeStream) {
if (stream.mimeType != activeStream.mimeType ||
stream.codecs.split('.')[0] != activeStream.codecs.split('.')[0]) {
return false;
}
}
return true;
};
/**
* Checks if a variant is compatible with the key system, platform,
* and active stream.
*
* @param {!shakaExtern.Variant} variant
* @param {shaka.media.DrmEngine} drmEngine
* @param {shakaExtern.Stream} activeAudio
* @param {shakaExtern.Stream} activeVideo
* @return {boolean}
* @private
*/
shaka.util.StreamUtils.variantIsCompatible_ =
function(variant, drmEngine, activeAudio, activeVideo) {
var StreamUtils = shaka.util.StreamUtils;
if (drmEngine && drmEngine.initialized()) {
if (!drmEngine.isSupportedByKeySystem(variant)) return false;
}
return StreamUtils.streamIsCompatible_(variant.audio,
drmEngine,
activeAudio) &&
StreamUtils.streamIsCompatible_(variant.video, drmEngine, activeVideo);
};
/**
* Gets an array of Track objects for the given Period
*
* @param {shakaExtern.Period} period
* @param {?number} activeAudioId
* @param {?number} activeVideoId
* @return {!Array.<shakaExtern.Track>}
*/
shaka.util.StreamUtils.getVariantTracks =
function(period, activeAudioId, activeVideoId) {
var StreamUtils = shaka.util.StreamUtils;
var variants = StreamUtils.getPlayableVariants(period.variants);
var label = null;
var tracks = variants.map(function(variant) {
var isActive;
if (variant.video && variant.audio) {
isActive = activeVideoId == variant.video.id &&
activeAudioId == variant.audio.id;
} else {
isActive = (variant.video && activeVideoId == variant.video.id) ||
(variant.audio && activeAudioId == variant.audio.id);
}
var codecs = '';
if (variant.video) codecs += variant.video.codecs;
if (variant.audio) {
if (codecs != '') codecs += ', ';
codecs += variant.audio.codecs;
label = variant.audio.label;
}
var audioCodec = variant.audio ? variant.audio.codecs : null;
var videoCodec = variant.video ? variant.video.codecs : null;
var mimeType = null;
if (variant.video) mimeType = variant.video.mimeType;
else if (variant.audio) mimeType = variant.audio.mimeType;
var kind = null;
if (variant.audio) kind = variant.audio.kind;
else if (variant.video) kind = variant.video.kind;
var audioRoles = variant.audio ? variant.audio.roles : [];
var videoRoles = variant.video ? variant.video.roles : [];
var roles = shaka.util.ArrayUtils.removeDuplicates(
audioRoles.concat(videoRoles));
return {
id: variant.id,
active: isActive,
type: 'variant',
bandwidth: variant.bandwidth,
language: variant.language,
label: label,
kind: kind || null,
width: variant.video ? variant.video.width : null,
height: variant.video ? variant.video.height : null,
frameRate: variant.video ? variant.video.frameRate : undefined,
mimeType: mimeType,
codecs: codecs,
audioCodec: audioCodec,
videoCodec: videoCodec,
primary: variant.primary,
roles: roles,
videoId: variant.video ? variant.video.id : null,
audioId: variant.audio ? variant.audio.id : null,
channelsCount: variant.audio ? variant.audio.channelsCount : null,
audioBandwidth: (variant.audio && variant.audio.bandwidth) ?
variant.audio.bandwidth : null,
videoBandwidth: (variant.video && variant.video.bandwidth) ?
variant.video.bandwidth : null
};
});
return tracks;
};
/**
* Gets an array of text Track objects for the given Period.
*
* @param {shakaExtern.Period} period
* @param {?number} activeStreamId
* @return {!Array.<shakaExtern.Track>}
*/
shaka.util.StreamUtils.getTextTracks = function(period, activeStreamId) {
var ContentType = shaka.util.ManifestParserUtils.ContentType;
return period.textStreams.map(function(stream) {
return {
id: stream.id,
active: activeStreamId == stream.id,
type: ContentType.TEXT,
language: stream.language,
label: stream.label,
kind: stream.kind,
mimeType: stream.mimeType,
codecs: stream.codecs || null,
audioCodec: null,
videoCodec: null,
primary: stream.primary,
roles: stream.roles,
channelsCount: null,
audioBandwidth: null,
videoBandwidth: null
};
});
};
/**
* Find the Variant for the given track.
*
* @param {shakaExtern.Period} period
* @param {shakaExtern.Track} track
* @return {?shakaExtern.Variant}
*/
shaka.util.StreamUtils.findVariantForTrack = function(period, track) {
for (var i = 0; i < period.variants.length; i++) {
if (period.variants[i].id == track.id)
return period.variants[i];
}
return null;
};
/**
* Find the text stream for the given track.
*
* @param {shakaExtern.Period} period
* @param {shakaExtern.Track} track
* @return {?shakaExtern.Stream}
*/
shaka.util.StreamUtils.findTextStreamForTrack = function(period, track) {
for (var i = 0; i < period.textStreams.length; i++) {
if (period.textStreams[i].id == track.id)
return period.textStreams[i];
}
return null;
};
/**
* Determines if the given variant is playable.
* @param {!shakaExtern.Variant} variant
* @return {boolean}
*/
shaka.util.StreamUtils.isPlayable = function(variant) {
return variant.allowedByApplication && variant.allowedByKeySystem;
};
/**
* Filters out not playable variants.
* @param {!Array.<!shakaExtern.Variant>} variants
* @return {!Array.<!shakaExtern.Variant>}
*/
shaka.util.StreamUtils.getPlayableVariants = function(variants) {
return variants.filter(function(variant) {
return shaka.util.StreamUtils.isPlayable(variant);
});
};
/**
* Chooses variants according to the given config.
*
* @param {shakaExtern.Period} period
* @param {string} preferredLanguage
* @param {string} preferredRole
* @param {!Object=} opt_languageMatches
* @return {!Array.<!shakaExtern.Variant>}
*/
shaka.util.StreamUtils.filterVariantsByLanguageAndRole = function(
period, preferredLanguage, preferredRole, opt_languageMatches) {
var LanguageUtils = shaka.util.LanguageUtils;
var ContentType = shaka.util.ManifestParserUtils.ContentType;
var variants = shaka.util.StreamUtils.getPlayableVariants(period.variants);
// Start with the set of primary variants.
/** @type {!Array.<!shakaExtern.Variant>} */
var chosen = variants.filter(function(variant) {
return variant.primary;
});
// If there were no primary variants, go back to all variants.
if (!chosen.length) {
chosen = variants;
}
// Now reduce the set to one language. This covers both arbitrary language
// choice and the reduction of the "primary" variant set to one language.
var firstLanguage = chosen.length ? chosen[0].language : '';
chosen = chosen.filter(function(variant) {
return variant.language == firstLanguage;
});
// Now search for matches based on language preference. If any language match
// is found, it overrides the selection above. Favor exact matches, then base
// matches, finally different subtags. Execute in reverse order so the later
// steps override the previous ones.
if (preferredLanguage) {
var pref = LanguageUtils.normalize(preferredLanguage);
[LanguageUtils.MatchType.OTHER_SUB_LANGUAGE_OKAY,
LanguageUtils.MatchType.BASE_LANGUAGE_OKAY,
LanguageUtils.MatchType.EXACT]
.forEach(function(matchType) {
var betterLangMatchFound = false;
variants.forEach(function(variant) {
pref = LanguageUtils.normalize(pref);
var lang = LanguageUtils.normalize(variant.language);
if (LanguageUtils.match(matchType, pref, lang)) {
if (betterLangMatchFound) {
chosen.push(variant);
} else {
chosen = [variant];
betterLangMatchFound = true;
}
if (opt_languageMatches) {
opt_languageMatches[ContentType.AUDIO] = true;
}
}
}); // forEach(variant)
}); // forEach(matchType)
} // if (preferredLanguage)
// Now refine the choice based on role preference.
if (preferredRole) {
var roleMatches = shaka.util.StreamUtils.filterVariantsByRole_(
chosen, preferredRole);
if (roleMatches.length) {
return roleMatches;
} else {
shaka.log.warning('No exact match for the variant role could be found.');
}
}
// Either there was no role preference, or it could not be satisfied.
// Choose an arbitrary role, if there are any, and filter out any other roles.
// This ensures we never adapt between roles.
var allRoles = chosen.map(function(variant) {
var audioRoles = variant.audio ? variant.audio.roles : [];
var videoRoles = variant.video ? variant.video.roles : [];
return audioRoles.concat(videoRoles);
}).reduce(shaka.util.Functional.collapseArrays, []);
if (!allRoles.length) {
return chosen;
}
return shaka.util.StreamUtils.filterVariantsByRole_(chosen, allRoles[0]);
};
/**
* Chooses text streams according to the given config.
*
* @param {shakaExtern.Period} period
* @param {string} preferredLanguage
* @param {string} preferredRole
* @param {!Object=} opt_languageMatches
* @return {!Array.<!shakaExtern.Stream>}
*/
shaka.util.StreamUtils.filterTextStreamsByLanguageAndRole = function(
period, preferredLanguage, preferredRole, opt_languageMatches) {
var LanguageUtils = shaka.util.LanguageUtils;
var ContentType = shaka.util.ManifestParserUtils.ContentType;
var streams = period.textStreams;
// Start with the set of primary streams.
/** @type {!Array.<!shakaExtern.Stream>} */
var chosen = streams.filter(function(stream) {
return stream.primary;
});
// If there were no primary streams, go back to all streams.
if (!chosen.length) {
chosen = streams;
}
// Now reduce the set to one language. This covers both arbitrary language
// choice and the reduction of the "primary" stream set to one language.
var firstLanguage = chosen.length ? chosen[0].language : '';
chosen = chosen.filter(function(stream) {
return stream.language == firstLanguage;
});
// Now search for matches based on language preference. If any language match
// is found, it overrides the selection above. Favor exact matches, then base
// matches, finally different subtags. Execute in reverse order so the later
// steps override the previous ones.
if (preferredLanguage) {
var pref = LanguageUtils.normalize(preferredLanguage);
[LanguageUtils.MatchType.OTHER_SUB_LANGUAGE_OKAY,
LanguageUtils.MatchType.BASE_LANGUAGE_OKAY,
LanguageUtils.MatchType.EXACT]
.forEach(function(matchType) {
var betterLangMatchFound = false;
streams.forEach(function(stream) {
var lang = LanguageUtils.normalize(stream.language);
if (LanguageUtils.match(matchType, pref, lang)) {
if (betterLangMatchFound) {
chosen.push(stream);
} else {
chosen = [stream];
betterLangMatchFound = true;
}
if (opt_languageMatches)
opt_languageMatches[ContentType.TEXT] = true;
}
}); // forEach(stream)
}); // forEach(matchType)
} // if (preferredLanguage)
// Now refine the choice based on role preference.
if (preferredRole) {
var roleMatches = shaka.util.StreamUtils.filterTextStreamsByRole_(
chosen, preferredRole);
if (roleMatches.length) {
return roleMatches;
} else {
shaka.log.warning('No exact match for the text role could be found.');
}
}
// Either there was no role preference, or it could not be satisfied.
// Choose an arbitrary role, if there are any, and filter out any other roles.
// This ensures we never adapt between roles.
var allRoles = chosen.map(function(stream) {
return stream.roles;
}).reduce(shaka.util.Functional.collapseArrays, []);
if (!allRoles.length) {
return chosen;
}
return shaka.util.StreamUtils.filterTextStreamsByRole_(chosen, allRoles[0]);
};
/**
* Filter Variants by role.
*
* @param {!Array.<shakaExtern.Variant>} variants
* @param {string} preferredRole
* @return {!Array.<shakaExtern.Variant>}
* @private
*/
shaka.util.StreamUtils.filterVariantsByRole_ =
function(variants, preferredRole) {
return variants.filter(function(variant) {
return (variant.audio && variant.audio.roles.indexOf(preferredRole) >= 0) ||
(variant.video && variant.video.roles.indexOf(preferredRole) >= 0);
});
};
/**
* Filter text Streams by role.
*
* @param {!Array.<shakaExtern.Stream>} textStreams
* @param {string} preferredRole
* @return {!Array.<shakaExtern.Stream>}
* @private
*/
shaka.util.StreamUtils.filterTextStreamsByRole_ =
function(textStreams, preferredRole) {
return textStreams.filter(function(stream) {
return stream.roles.indexOf(preferredRole) >= 0;
});
};
/**
* Finds a Variant with given audio and video streams.
* Returns null if none was found.
*
* @param {?shakaExtern.Stream} audio
* @param {?shakaExtern.Stream} video
* @param {!Array.<!shakaExtern.Variant>} variants
* @return {?shakaExtern.Variant}
*/
shaka.util.StreamUtils.getVariantByStreams = function(audio, video, variants) {
for (var i = 0; i < variants.length; i++) {
if (variants[i].audio == audio && variants[i].video == video)
return variants[i];
}
return null;
};
/**
* Finds a Variant with the given video and audio streams, by stream ID.
* Returns null if none were found.
*
* @param {?number} audioId
* @param {?number} videoId
* @param {!Array.<shakaExtern.Variant>} variants
* @return {?shakaExtern.Variant}
*/
shaka.util.StreamUtils.getVariantByStreamIds = function(
audioId, videoId, variants) {
function matchesId(id, stream) {
if (id == null)
return stream == null;
else
return stream.id == id;
}
for (var i = 0; i < variants.length; i++) {
if (matchesId(audioId, variants[i].audio) &&
matchesId(videoId, variants[i].video)) {
return variants[i];
}
}
return null;
};
/**
* Gets the index of the Period that contains the given time.
* @param {shakaExtern.Manifest} manifest
* @param {number} time The time in seconds from the start of the presentation.
* @return {number}
*/
shaka.util.StreamUtils.findPeriodContainingTime = function(manifest, time) {
var threshold = shaka.util.ManifestParserUtils.GAP_OVERLAP_TOLERANCE_SECONDS;
for (var i = manifest.periods.length - 1; i > 0; --i) {
var period = manifest.periods[i];
// The last segment may end right before the end of the Period because of
// rounding issues.
if (time + threshold >= period.startTime)
return i;
}
return 0;
};
/**
* @param {shakaExtern.Manifest} manifest
* @param {shakaExtern.Stream} stream
* @return {number} The index of the Period which contains |stream|, or -1 if
* no Period contains |stream|.
*/
shaka.util.StreamUtils.findPeriodContainingStream = function(manifest, stream) {
var ContentType = shaka.util.ManifestParserUtils.ContentType;
for (var periodIdx = 0; periodIdx < manifest.periods.length; ++periodIdx) {
var period = manifest.periods[periodIdx];
if (stream.type == ContentType.TEXT) {
for (var j = 0; j < period.textStreams.length; ++j) {
var textStream = period.textStreams[j];
if (textStream == stream)
return periodIdx;
}
} else {
for (var j = 0; j < period.variants.length; ++j) {
var variant = period.variants[j];
if (variant.audio == stream || variant.video == stream ||
(variant.video && variant.video.trickModeVideo == stream)) {
return periodIdx;
}
}
}
}
return -1;
};
/**
* @param {shakaExtern.Manifest} manifest
* @param {shakaExtern.Variant} variant
* @return {number} The index of the Period which contains |stream|, or -1 if
* no Period contains |stream|.
*/
shaka.util.StreamUtils.findPeriodContainingVariant =
function(manifest, variant) {
for (var periodIdx = 0; periodIdx < manifest.periods.length; ++periodIdx) {
var period = manifest.periods[periodIdx];
for (var j = 0; j < period.variants.length; ++j) {
if (period.variants[j] == variant) {
return periodIdx;
}
}
}
return -1;
};
/**
* Gets the rebuffering goal from the manifest and configuration.
*
* @param {shakaExtern.Manifest} manifest
* @param {shakaExtern.StreamingConfiguration} config
* @param {number} scaleFactor
*
* @return {number}
*/
shaka.util.StreamUtils.getRebufferingGoal = function(
manifest, config, scaleFactor) {
return scaleFactor *
Math.max(manifest.minBufferTime || 0, config.rebufferingGoal);
};