Source: lib/util/stream_utils.js

  1. /*! @license
  2.  * Shaka Player
  3.  * Copyright 2016 Google LLC
  4.  * SPDX-License-Identifier: Apache-2.0
  5.  */
  7. goog.provide('shaka.util.StreamUtils');
  9. goog.require('goog.asserts');
  10. goog.require('shaka.log');
  11. goog.require('shaka.media.Capabilities');
  12. goog.require('shaka.text.TextEngine');
  13. goog.require('shaka.util.Functional');
  14. goog.require('shaka.util.LanguageUtils');
  15. goog.require('shaka.util.ManifestParserUtils');
  16. goog.require('shaka.util.MimeUtils');
  17. goog.require('shaka.util.MultiMap');
  18. goog.require('shaka.util.ObjectUtils');
  19. goog.require('shaka.util.Platform');
  20. goog.requireType('shaka.media.DrmEngine');
  23. /**
  24.  * @summary A set of utility functions for dealing with Streams and Manifests.
  25.  * @export
  26.  */
  27. shaka.util.StreamUtils = class {
  28.   /**
  29.    * In case of multiple usable codecs, choose one based on lowest average
  30.    * bandwidth and filter out the rest.
  31.    * Also filters out variants that have too many audio channels.
  32.    * @param {!shaka.extern.Manifest} manifest
  33.    * @param {!Array.<string>} preferredVideoCodecs
  34.    * @param {!Array.<string>} preferredAudioCodecs
  35.    * @param {!Array.<string>} preferredDecodingAttributes
  36.    */
  37.   static chooseCodecsAndFilterManifest(manifest, preferredVideoCodecs,
  38.       preferredAudioCodecs, preferredDecodingAttributes) {
  39.     const StreamUtils = shaka.util.StreamUtils;
  40.     const MimeUtils = shaka.util.MimeUtils;
  42.     let variants = manifest.variants;
  43.     // To start, choose the codecs based on configured preferences if available.
  44.     if (preferredVideoCodecs.length || preferredAudioCodecs.length) {
  45.       variants = StreamUtils.choosePreferredCodecs(variants,
  46.           preferredVideoCodecs, preferredAudioCodecs);
  47.     }
  49.     if (preferredDecodingAttributes.length) {
  50.       // group variants by resolution and choose preferred variants only
  51.       /** @type {!shaka.util.MultiMap.<shaka.extern.Variant>} */
  52.       const variantsByResolutionMap = new shaka.util.MultiMap();
  53.       for (const variant of variants) {
  54.         variantsByResolutionMap
  55.             .push(String(variant.video.width || 0), variant);
  56.       }
  57.       const bestVariants = [];
  58.       variantsByResolutionMap.forEach((width, variantsByResolution) => {
  59.         let highestMatch = 0;
  60.         let matchingVariants = [];
  61.         for (const variant of variantsByResolution) {
  62.           const matchCount = preferredDecodingAttributes.filter(
  63.               (attribute) => variant.decodingInfos[0][attribute],
  64.           ).length;
  65.           if (matchCount > highestMatch) {
  66.             highestMatch = matchCount;
  67.             matchingVariants = [variant];
  68.           } else if (matchCount == highestMatch) {
  69.             matchingVariants.push(variant);
  70.           }
  71.         }
  72.         bestVariants.push(...matchingVariants);
  73.       });
  74.       variants = bestVariants;
  75.     }
  77.     const audioStreamsSet = new Set();
  78.     const videoStreamsSet = new Set();
  79.     for (const variant of variants) {
  80.       if (variant.audio) {
  81.         audioStreamsSet.add(variant.audio);
  82.       }
  83.       if (variant.video) {
  84.         videoStreamsSet.add(variant.video);
  85.       }
  86.     }
  88.     const audioStreams = Array.from(audioStreamsSet).sort((v1, v2) => {
  89.       return v1.bandwidth - v2.bandwidth;
  90.     });
  91.     const validAudioIds = [];
  92.     const validAudioStreamsMap = new Map();
  93.     const getAudioId = (stream) => {
  94.       return stream.language + (stream.channelsCount || 0) +
  95.         (stream.audioSamplingRate || 0) + stream.roles.join(',') +
  96.         stream.label + stream.groupId + stream.fastSwitching;
  97.     };
  98.     for (const stream of audioStreams) {
  99.       const groupId = getAudioId(stream);
  100.       const validAudioStreams = validAudioStreamsMap.get(groupId) || [];
  101.       if (!validAudioStreams.length) {
  102.         validAudioStreams.push(stream);
  103.         validAudioIds.push(stream.id);
  104.       } else {
  105.         const previousStream = validAudioStreams[validAudioStreams.length - 1];
  106.         const previousCodec =
  107.           MimeUtils.getNormalizedCodec(previousStream.codecs);
  108.         const currentCodec =
  109.           MimeUtils.getNormalizedCodec(stream.codecs);
  110.         if (previousCodec == currentCodec) {
  111.           if (stream.bandwidth > previousStream.bandwidth) {
  112.             validAudioStreams.push(stream);
  113.             validAudioIds.push(stream.id);
  114.           }
  115.         }
  116.       }
  117.       validAudioStreamsMap.set(groupId, validAudioStreams);
  118.     }
  120.     const videoStreams = Array.from(videoStreamsSet)
  121.         .sort((v1, v2) => {
  122.           if (!v1.bandwidth || !v2.bandwidth) {
  123.             return v1.width - v2.width;
  124.           }
  125.           return v1.bandwidth - v2.bandwidth;
  126.         });
  128.     const isChangeTypeSupported =
  129.       shaka.media.Capabilities.isChangeTypeSupported();
  131.     const validVideoIds = [];
  132.     const validVideoStreamsMap = new Map();
  133.     const getVideoGroupId = (stream) => {
  134.       return Math.round(stream.frameRate || 0) + (stream.hdr || '') +
  135.           stream.fastSwitching;
  136.     };
  137.     for (const stream of videoStreams) {
  138.       const groupId = getVideoGroupId(stream);
  139.       const validVideoStreams = validVideoStreamsMap.get(groupId) || [];
  140.       if (!validVideoStreams.length) {
  141.         validVideoStreams.push(stream);
  142.         validVideoIds.push(stream.id);
  143.       } else {
  144.         const previousStream = validVideoStreams[validVideoStreams.length - 1];
  145.         if (!isChangeTypeSupported) {
  146.           const previousCodec =
  147.             MimeUtils.getNormalizedCodec(previousStream.codecs);
  148.           const currentCodec =
  149.             MimeUtils.getNormalizedCodec(stream.codecs);
  150.           if (previousCodec !== currentCodec) {
  151.             continue;
  152.           }
  153.         }
  154.         if (stream.width > previousStream.width ||
  155.           stream.height > previousStream.height) {
  156.           validVideoStreams.push(stream);
  157.           validVideoIds.push(stream.id);
  158.         } else if (stream.width == previousStream.width &&
  159.           stream.height == previousStream.height) {
  160.           const previousCodec =
  161.             MimeUtils.getNormalizedCodec(previousStream.codecs);
  162.           const currentCodec =
  163.             MimeUtils.getNormalizedCodec(stream.codecs);
  164.           if (previousCodec == currentCodec) {
  165.             if (stream.bandwidth > previousStream.bandwidth) {
  166.               validVideoStreams.push(stream);
  167.               validVideoIds.push(stream.id);
  168.             }
  169.           }
  170.         }
  171.       }
  172.       validVideoStreamsMap.set(groupId, validVideoStreams);
  173.     }
  175.     // Filter out any variants that don't match, forcing AbrManager to choose
  176.     // from a single video codec and a single audio codec possible.
  177.     manifest.variants = manifest.variants.filter((variant) => {
  178.       const audio = variant.audio;
  179.       const video = variant.video;
  180.       if (audio) {
  181.         if (!validAudioIds.includes(audio.id)) {
  182.           shaka.log.debug('Dropping Variant (better codec available)', variant);
  183.           return false;
  184.         }
  185.       }
  186.       if (video) {
  187.         if (!validVideoIds.includes(video.id)) {
  188.           shaka.log.debug('Dropping Variant (better codec available)', variant);
  189.           return false;
  190.         }
  191.       }
  192.       return true;
  193.     });
  194.   }
  196.   /**
  197.    * Choose the codecs by configured preferred audio and video codecs.
  198.    *
  199.    * @param {!Array<shaka.extern.Variant>} variants
  200.    * @param {!Array.<string>} preferredVideoCodecs
  201.    * @param {!Array.<string>} preferredAudioCodecs
  202.    * @return {!Array<shaka.extern.Variant>}
  203.    */
  204.   static choosePreferredCodecs(variants, preferredVideoCodecs,
  205.       preferredAudioCodecs) {
  206.     let subset = variants;
  207.     for (const videoCodec of preferredVideoCodecs) {
  208.       const filtered = subset.filter((variant) => {
  209.         return variant.video && variant.video.codecs.startsWith(videoCodec);
  210.       });
  211.       if (filtered.length) {
  212.         subset = filtered;
  213.         break;
  214.       }
  215.     }
  217.     for (const audioCodec of preferredAudioCodecs) {
  218.       const filtered = subset.filter((variant) => {
  219.         return variant.audio && variant.audio.codecs.startsWith(audioCodec);
  220.       });
  221.       if (filtered.length) {
  222.         subset = filtered;
  223.         break;
  224.       }
  225.     }
  226.     return subset;
  227.   }
  229.   /**
  230.    * Filter the variants in |manifest| to only include the variants that meet
  231.    * the given restrictions.
  232.    *
  233.    * @param {!shaka.extern.Manifest} manifest
  234.    * @param {shaka.extern.Restrictions} restrictions
  235.    * @param {shaka.extern.Resolution} maxHwResolution
  236.    */
  237.   static filterByRestrictions(manifest, restrictions, maxHwResolution) {
  238.     manifest.variants = manifest.variants.filter((variant) => {
  239.       return shaka.util.StreamUtils.meetsRestrictions(
  240.           variant, restrictions, maxHwResolution);
  241.     });
  242.   }
  244.   /**
  245.    * @param {shaka.extern.Variant} variant
  246.    * @param {shaka.extern.Restrictions} restrictions
  247.    *   Configured restrictions from the user.
  248.    * @param {shaka.extern.Resolution} maxHwRes
  249.    *   The maximum resolution the hardware can handle.
  250.    *   This is applied separately from user restrictions because the setting
  251.    *   should not be easily replaced by the user's configuration.
  252.    * @return {boolean}
  253.    * @export
  254.    */
  255.   static meetsRestrictions(variant, restrictions, maxHwRes) {
  256.     /** @type {function(number, number, number):boolean} */
  257.     const inRange = (x, min, max) => {
  258.       return x >= min && x <= max;
  259.     };
  261.     const video = variant.video;
  263.     // |video.width| and |video.height| can be undefined, which breaks
  264.     // the math, so make sure they are there first.
  265.     if (video && video.width && video.height) {
  266.       let videoWidth = video.width;
  267.       let videoHeight = video.height;
  268.       if (videoHeight > videoWidth) {
  269.         // Vertical video.
  270.         [videoWidth, videoHeight] = [videoHeight, videoWidth];
  271.       }
  273.       if (!inRange(videoWidth,
  274.           restrictions.minWidth,
  275.           Math.min(restrictions.maxWidth, maxHwRes.width))) {
  276.         return false;
  277.       }
  279.       if (!inRange(videoHeight,
  280.           restrictions.minHeight,
  281.           Math.min(restrictions.maxHeight, maxHwRes.height))) {
  282.         return false;
  283.       }
  285.       if (!inRange(video.width * video.height,
  286.           restrictions.minPixels,
  287.           restrictions.maxPixels)) {
  288.         return false;
  289.       }
  290.     }
  292.     // |variant.video.frameRate| can be undefined, which breaks
  293.     // the math, so make sure they are there first.
  294.     if (variant && variant.video && variant.video.frameRate) {
  295.       if (!inRange(variant.video.frameRate,
  296.           restrictions.minFrameRate,
  297.           restrictions.maxFrameRate)) {
  298.         return false;
  299.       }
  300.     }
  302.     // |variant.audio.channelsCount| can be undefined, which breaks
  303.     // the math, so make sure they are there first.
  304.     if (variant && variant.audio && variant.audio.channelsCount) {
  305.       if (!inRange(variant.audio.channelsCount,
  306.           restrictions.minChannelsCount,
  307.           restrictions.maxChannelsCount)) {
  308.         return false;
  309.       }
  310.     }
  312.     if (!inRange(variant.bandwidth,
  313.         restrictions.minBandwidth,
  314.         restrictions.maxBandwidth)) {
  315.       return false;
  316.     }
  318.     return true;
  319.   }
  322.   /**
  323.    * @param {!Array.<shaka.extern.Variant>} variants
  324.    * @param {shaka.extern.Restrictions} restrictions
  325.    * @param {shaka.extern.Resolution} maxHwRes
  326.    * @return {boolean} Whether the tracks changed.
  327.    */
  328.   static applyRestrictions(variants, restrictions, maxHwRes) {
  329.     let tracksChanged = false;
  331.     for (const variant of variants) {
  332.       const originalAllowed = variant.allowedByApplication;
  333.       variant.allowedByApplication = shaka.util.StreamUtils.meetsRestrictions(
  334.           variant, restrictions, maxHwRes);
  336.       if (originalAllowed != variant.allowedByApplication) {
  337.         tracksChanged = true;
  338.       }
  339.     }
  341.     return tracksChanged;
  342.   }
  345.   /**
  346.    * Alters the given Manifest to filter out any unplayable streams.
  347.    *
  348.    * @param {shaka.media.DrmEngine} drmEngine
  349.    * @param {shaka.extern.Manifest} manifest
  350.    * @param {!Array<string>=} preferredKeySystems
  351.    */
  352.   static async filterManifest(drmEngine, manifest, preferredKeySystems = []) {
  353.     await shaka.util.StreamUtils.filterManifestByMediaCapabilities(
  354.         drmEngine, manifest, manifest.offlineSessionIds.length > 0,
  355.         preferredKeySystems);
  356.     shaka.util.StreamUtils.filterTextStreams_(manifest);
  357.     await shaka.util.StreamUtils.filterImageStreams_(manifest);
  358.   }
  361.   /**
  362.    * Alters the given Manifest to filter out any streams unsupported by the
  363.    * platform via MediaCapabilities.decodingInfo() API.
  364.    *
  365.    * @param {shaka.media.DrmEngine} drmEngine
  366.    * @param {shaka.extern.Manifest} manifest
  367.    * @param {boolean} usePersistentLicenses
  368.    * @param {!Array<string>} preferredKeySystems
  369.    */
  370.   static async filterManifestByMediaCapabilities(
  371.       drmEngine, manifest, usePersistentLicenses, preferredKeySystems) {
  372.     goog.asserts.assert(navigator.mediaCapabilities,
  373.         'MediaCapabilities should be valid.');
  375.     await shaka.util.StreamUtils.getDecodingInfosForVariants(
  376.         manifest.variants, usePersistentLicenses, /* srcEquals= */ false,
  377.         preferredKeySystems);
  379.     let keySystem = null;
  380.     if (drmEngine) {
  381.       const drmInfo = drmEngine.getDrmInfo();
  382.       if (drmInfo) {
  383.         keySystem = drmInfo.keySystem;
  384.       }
  385.     }
  387.     const StreamUtils = shaka.util.StreamUtils;
  389.     manifest.variants = manifest.variants.filter((variant) => {
  390.       const supported = StreamUtils.checkVariantSupported_(variant, keySystem);
  391.       // Filter out all unsupported variants.
  392.       if (!supported) {
  393.         shaka.log.debug('Dropping variant - not compatible with platform',
  394.             StreamUtils.getVariantSummaryString_(variant));
  395.       }
  396.       return supported;
  397.     });
  398.   }
  401.   /**
  402.    * @param {!shaka.extern.Variant} variant
  403.    * @param {?string} keySystem
  404.    * @return {boolean}
  405.    * @private
  406.    */
  407.   static checkVariantSupported_(variant, keySystem) {
  408.     const ContentType = shaka.util.ManifestParserUtils.ContentType;
  409.     const Capabilities = shaka.media.Capabilities;
  410.     const ManifestParserUtils = shaka.util.ManifestParserUtils;
  411.     const MimeUtils = shaka.util.MimeUtils;
  412.     const StreamUtils = shaka.util.StreamUtils;
  414.     const isXboxOne = shaka.util.Platform.isXboxOne();
  415.     const isFirefoxAndroid = shaka.util.Platform.isFirefox() &&
  416.         shaka.util.Platform.isAndroid();
  418.     // See: https://github.com/shaka-project/shaka-player/issues/3860
  419.     const video = variant.video;
  420.     const videoWidth = (video && video.width) || 0;
  421.     const videoHeight = (video && video.height) || 0;
  423.     // See: https://github.com/shaka-project/shaka-player/issues/3380
  424.     // Note: it makes sense to drop early
  425.     if (isXboxOne && video && (videoWidth > 1920 || videoHeight > 1080) &&
  426.         (video.codecs.includes('avc1.') || video.codecs.includes('avc3.'))) {
  427.       return false;
  428.     }
  430.     if (video) {
  431.       let videoCodecs = StreamUtils.getCorrectVideoCodecs(video.codecs);
  432.       // For multiplexed streams. Here we must check the audio of the
  433.       // stream to see if it is compatible.
  434.       if (video.codecs.includes(',')) {
  435.         const allCodecs = video.codecs.split(',');
  437.         videoCodecs = ManifestParserUtils.guessCodecs(
  438.             ContentType.VIDEO, allCodecs);
  439.         videoCodecs = StreamUtils.getCorrectVideoCodecs(videoCodecs);
  440.         let audioCodecs = ManifestParserUtils.guessCodecs(
  441.             ContentType.AUDIO, allCodecs);
  442.         audioCodecs = StreamUtils.getCorrectAudioCodecs(
  443.             audioCodecs, video.mimeType);
  445.         const audioFullType = MimeUtils.getFullOrConvertedType(
  446.             video.mimeType, audioCodecs, ContentType.AUDIO);
  448.         if (!Capabilities.isTypeSupported(audioFullType)) {
  449.           return false;
  450.         }
  452.         // Update the codec string with the (possibly) converted codecs.
  453.         videoCodecs = [videoCodecs, audioCodecs].join(',');
  454.       }
  456.       const fullType = MimeUtils.getFullOrConvertedType(
  457.           video.mimeType, videoCodecs, ContentType.VIDEO);
  459.       if (!Capabilities.isTypeSupported(fullType)) {
  460.         return false;
  461.       }
  463.       // Update the codec string with the (possibly) converted codecs.
  464.       video.codecs = videoCodecs;
  465.     }
  467.     const audio = variant.audio;
  469.     // See: https://github.com/shaka-project/shaka-player/issues/6111
  470.     // It seems that Firefox Android reports that it supports
  471.     // Opus + Widevine, but it is not actually supported.
  472.     // It makes sense to drop early.
  473.     if (isFirefoxAndroid && audio && audio.encrypted &&
  474.         audio.codecs.toLowerCase().includes('opus')) {
  475.       return false;
  476.     }
  478.     if (audio) {
  479.       const codecs = StreamUtils.getCorrectAudioCodecs(
  480.           audio.codecs, audio.mimeType);
  481.       const fullType = MimeUtils.getFullOrConvertedType(
  482.           audio.mimeType, codecs, ContentType.AUDIO);
  484.       if (!Capabilities.isTypeSupported(fullType)) {
  485.         return false;
  486.       }
  488.       // Update the codec string with the (possibly) converted codecs.
  489.       audio.codecs = codecs;
  490.     }
  492.     return variant.decodingInfos.some((decodingInfo) => {
  493.       if (!decodingInfo.supported) {
  494.         return false;
  495.       }
  496.       if (keySystem) {
  497.         const keySystemAccess = decodingInfo.keySystemAccess;
  498.         if (keySystemAccess) {
  499.           if (keySystemAccess.keySystem != keySystem) {
  500.             return false;
  501.           }
  502.         }
  503.       }
  504.       return true;
  505.     });
  506.   }
  509.   /**
  510.    * Constructs a string out of an object, similar to the JSON.stringify method.
  511.    * Unlike that method, this guarantees that the order of the keys is
  512.    * alphabetical, so it can be used as a way to reliably compare two objects.
  513.    *
  514.    * @param {!Object} obj
  515.    * @return {string}
  516.    * @private
  517.    */
  518.   static alphabeticalKeyOrderStringify_(obj) {
  519.     const keys = [];
  520.     for (const key in obj) {
  521.       keys.push(key);
  522.     }
  523.     // Alphabetically sort the keys, so they will be in a reliable order.
  524.     keys.sort();
  526.     const terms = [];
  527.     for (const key of keys) {
  528.       const escapedKey = JSON.stringify(key);
  529.       const value = obj[key];
  530.       if (value instanceof Object) {
  531.         const stringifiedValue =
  532.             shaka.util.StreamUtils.alphabeticalKeyOrderStringify_(value);
  533.         terms.push(escapedKey + ':' + stringifiedValue);
  534.       } else {
  535.         const escapedValue = JSON.stringify(value);
  536.         terms.push(escapedKey + ':' + escapedValue);
  537.       }
  538.     }
  539.     return '{' + terms.join(',') + '}';
  540.   }
  543.   /**
  544.    * Queries mediaCapabilities for the decoding info for that decoding config,
  545.    * and assigns it to the given variant.
  546.    * If that query has been done before, instead return a cached result.
  547.    * @param {!shaka.extern.Variant} variant
  548.    * @param {!Array.<!MediaDecodingConfiguration>} decodingConfigs
  549.    * @private
  550.    */
  551.   static async getDecodingInfosForVariant_(variant, decodingConfigs) {
  552.     /**
  553.      * @param {?MediaCapabilitiesDecodingInfo} a
  554.      * @param {!MediaCapabilitiesDecodingInfo} b
  555.      * @return {!MediaCapabilitiesDecodingInfo}
  556.      */
  557.     const merge = (a, b) => {
  558.       if (!a) {
  559.         return b;
  560.       } else {
  561.         const res = shaka.util.ObjectUtils.shallowCloneObject(a);
  562.         res.supported = a.supported && b.supported;
  563.         res.powerEfficient = a.powerEfficient && b.powerEfficient;
  564.         res.smooth = a.smooth && b.smooth;
  565.         if (b.keySystemAccess && !res.keySystemAccess) {
  566.           res.keySystemAccess = b.keySystemAccess;
  567.         }
  568.         return res;
  569.       }
  570.     };
  572.     const StreamUtils = shaka.util.StreamUtils;
  573.     /** @type {?MediaCapabilitiesDecodingInfo} */
  574.     let finalResult = null;
  575.     const promises = [];
  576.     for (const decodingConfig of decodingConfigs) {
  577.       const cacheKey =
  578.           StreamUtils.alphabeticalKeyOrderStringify_(decodingConfig);
  580.       const cache = StreamUtils.decodingConfigCache_;
  581.       if (cache[cacheKey]) {
  582.         shaka.log.v2('Using cached results of mediaCapabilities.decodingInfo',
  583.             'for key', cacheKey);
  584.         finalResult = merge(finalResult, cache[cacheKey]);
  585.       } else {
  586.         // Do a final pass-over of the decoding config: if a given stream has
  587.         // multiple codecs, that suggests that it switches between those codecs
  588.         // at points of the go-through.
  589.         // mediaCapabilities by itself will report "not supported" when you
  590.         // put in multiple different codecs, so each has to be checked
  591.         // individually. So check each and take the worst result, to determine
  592.         // overall variant compatibility.
  593.         promises.push(StreamUtils
  594.             .checkEachDecodingConfigCombination_(decodingConfig).then((res) => {
  595.               /** @type {?MediaCapabilitiesDecodingInfo} */
  596.               let acc = null;
  597.               for (const result of (res || [])) {
  598.                 acc = merge(acc, result);
  599.               }
  600.               if (acc) {
  601.                 cache[cacheKey] = acc;
  602.                 finalResult = merge(finalResult, acc);
  603.               }
  604.             }));
  605.       }
  606.     }
  607.     await Promise.all(promises);
  608.     if (finalResult) {
  609.       variant.decodingInfos.push(finalResult);
  610.     }
  611.   }
  613.   /**
  614.    * @param {!MediaDecodingConfiguration} decodingConfig
  615.    * @return {!Promise.<?Array.<!MediaCapabilitiesDecodingInfo>>}
  616.    * @private
  617.    */
  618.   static checkEachDecodingConfigCombination_(decodingConfig) {
  619.     let videoCodecs = [''];
  620.     if (decodingConfig.video) {
  621.       videoCodecs = shaka.util.MimeUtils.getCodecs(
  622.           decodingConfig.video.contentType).split(',');
  623.     }
  624.     let audioCodecs = [''];
  625.     if (decodingConfig.audio) {
  626.       audioCodecs = shaka.util.MimeUtils.getCodecs(
  627.           decodingConfig.audio.contentType).split(',');
  628.     }
  629.     const promises = [];
  630.     for (const videoCodec of videoCodecs) {
  631.       for (const audioCodec of audioCodecs) {
  632.         const copy = shaka.util.ObjectUtils.cloneObject(decodingConfig);
  633.         if (decodingConfig.video) {
  634.           const mimeType = shaka.util.MimeUtils.getBasicType(
  635.               copy.video.contentType);
  636.           copy.video.contentType = shaka.util.MimeUtils.getFullType(
  637.               mimeType, videoCodec);
  638.         }
  639.         if (decodingConfig.audio) {
  640.           const mimeType = shaka.util.MimeUtils.getBasicType(
  641.               copy.audio.contentType);
  642.           copy.audio.contentType = shaka.util.MimeUtils.getFullType(
  643.               mimeType, audioCodec);
  644.         }
  645.         promises.push(new Promise((resolve, reject) => {
  646.           navigator.mediaCapabilities.decodingInfo(copy).then((res) => {
  647.             resolve(res);
  648.           }).catch(reject);
  649.         }));
  650.       }
  651.     }
  652.     return Promise.all(promises).catch((e) => {
  653.       shaka.log.info('MediaCapabilities.decodingInfo() failed.',
  654.           JSON.stringify(decodingConfig), e);
  655.       return null;
  656.     });
  657.   }
  660.   /**
  661.    * Get the decodingInfo results of the variants via MediaCapabilities.
  662.    * This should be called after the DrmEngine is created and configured, and
  663.    * before DrmEngine sets the mediaKeys.
  664.    *
  665.    * @param {!Array.<shaka.extern.Variant>} variants
  666.    * @param {boolean} usePersistentLicenses
  667.    * @param {boolean} srcEquals
  668.    * @param {!Array<string>} preferredKeySystems
  669.    * @exportDoc
  670.    */
  671.   static async getDecodingInfosForVariants(variants, usePersistentLicenses,
  672.       srcEquals, preferredKeySystems) {
  673.     const gotDecodingInfo = variants.some((variant) =>
  674.       variant.decodingInfos.length);
  675.     if (gotDecodingInfo) {
  676.       shaka.log.debug('Already got the variants\' decodingInfo.');
  677.       return;
  678.     }
  680.     // Try to get preferred key systems first to avoid unneeded calls to CDM.
  681.     for (const preferredKeySystem of preferredKeySystems) {
  682.       let keySystemSatisfied = false;
  683.       for (const variant of variants) {
  684.         /** @type {!Array.<!Array.<!MediaDecodingConfiguration>>} */
  685.         const decodingConfigs = shaka.util.StreamUtils.getDecodingConfigs_(
  686.             variant, usePersistentLicenses, srcEquals)
  687.             .filter((configs) => {
  688.               // All configs in a batch will have the same keySystem.
  689.               const config = configs[0];
  690.               const keySystem = config.keySystemConfiguration &&
  691.                 config.keySystemConfiguration.keySystem;
  692.               return keySystem === preferredKeySystem;
  693.             });
  695.         // The reason we are performing this await in a loop rather than
  696.         // batching into a `promise.all` is performance related.
  697.         // https://github.com/shaka-project/shaka-player/pull/4708#discussion_r1022581178
  698.         for (const configs of decodingConfigs) {
  699.           // eslint-disable-next-line no-await-in-loop
  700.           await shaka.util.StreamUtils.getDecodingInfosForVariant_(
  701.               variant, configs);
  702.         }
  703.         if (variant.decodingInfos.length) {
  704.           keySystemSatisfied = true;
  705.         }
  706.       } // for (const variant of variants)
  707.       if (keySystemSatisfied) {
  708.         // Return if any preferred key system is already satisfied.
  709.         return;
  710.       }
  711.     } // for (const preferredKeySystem of preferredKeySystems)
  713.     for (const variant of variants) {
  714.       /** @type {!Array.<!Array.<!MediaDecodingConfiguration>>} */
  715.       const decodingConfigs = shaka.util.StreamUtils.getDecodingConfigs_(
  716.           variant, usePersistentLicenses, srcEquals)
  717.           .filter((configs) => {
  718.             // All configs in a batch will have the same keySystem.
  719.             const config = configs[0];
  720.             const keySystem = config.keySystemConfiguration &&
  721.               config.keySystemConfiguration.keySystem;
  722.             // Avoid checking preferred systems twice.
  723.             return !keySystem || !preferredKeySystems.includes(keySystem);
  724.           });
  726.       // The reason we are performing this await in a loop rather than
  727.       // batching into a `promise.all` is performance related.
  728.       // https://github.com/shaka-project/shaka-player/pull/4708#discussion_r1022581178
  729.       for (const configs of decodingConfigs) {
  730.         // eslint-disable-next-line no-await-in-loop
  731.         await shaka.util.StreamUtils.getDecodingInfosForVariant_(
  732.             variant, configs);
  733.       }
  734.     }
  735.   }
  738.   /**
  739.    * Generate a batch of MediaDecodingConfiguration objects to get the
  740.    * decodingInfo results for each variant.
  741.    * Each batch shares the same DRM information, and represents the various
  742.    * fullMimeType combinations of the streams.
  743.    * @param {!shaka.extern.Variant} variant
  744.    * @param {boolean} usePersistentLicenses
  745.    * @param {boolean} srcEquals
  746.    * @return {!Array.<!Array.<!MediaDecodingConfiguration>>}
  747.    * @private
  748.    */
  749.   static getDecodingConfigs_(variant, usePersistentLicenses, srcEquals) {
  750.     const audio = variant.audio;
  751.     const video = variant.video;
  753.     const ContentType = shaka.util.ManifestParserUtils.ContentType;
  754.     const ManifestParserUtils = shaka.util.ManifestParserUtils;
  755.     const MimeUtils = shaka.util.MimeUtils;
  756.     const StreamUtils = shaka.util.StreamUtils;
  758.     const videoConfigs = [];
  759.     const audioConfigs = [];
  760.     if (video) {
  761.       for (const fullMimeType of video.fullMimeTypes) {
  762.         let videoCodecs = MimeUtils.getCodecs(fullMimeType);
  764.         // For multiplexed streams with audio+video codecs, the config should
  765.         // have AudioConfiguration and VideoConfiguration.
  766.         // We ignore the multiplexed audio when there is normal audio also.
  767.         if (videoCodecs.includes(',') && !audio) {
  768.           const allCodecs = videoCodecs.split(',');
  769.           const baseMimeType = MimeUtils.getBasicType(fullMimeType);
  771.           videoCodecs = ManifestParserUtils.guessCodecs(
  772.               ContentType.VIDEO, allCodecs);
  774.           let audioCodecs = ManifestParserUtils.guessCodecs(
  775.               ContentType.AUDIO, allCodecs);
  776.           audioCodecs = StreamUtils.getCorrectAudioCodecs(
  777.               audioCodecs, baseMimeType);
  779.           const audioFullType = MimeUtils.getFullOrConvertedType(
  780.               baseMimeType, audioCodecs, ContentType.AUDIO);
  782.           audioConfigs.push({
  783.             contentType: audioFullType,
  784.             channels: 2,
  785.             bitrate: variant.bandwidth || 1,
  786.             samplerate: 1,
  787.             spatialRendering: false,
  788.           });
  789.         }
  791.         videoCodecs = StreamUtils.getCorrectVideoCodecs(videoCodecs);
  792.         const fullType = MimeUtils.getFullOrConvertedType(
  793.             MimeUtils.getBasicType(fullMimeType), videoCodecs,
  794.             ContentType.VIDEO);
  796.         // VideoConfiguration
  797.         const videoConfig = {
  798.           contentType: fullType,
  800.           // NOTE: Some decoders strictly check the width and height fields and
  801.           // won't decode smaller than 64x64.  So if we don't have this info (as
  802.           // is the case in some of our simpler tests), assume a 64x64
  803.           // resolution to fill in this required field for MediaCapabilities.
  804.           //
  805.           // This became an issue specifically on Firefox on M1 Macs.
  806.           width: video.width || 64,
  807.           height: video.height || 64,
  809.           bitrate: video.bandwidth || variant.bandwidth || 1,
  810.           // framerate must be greater than 0, otherwise the config is invalid.
  811.           framerate: video.frameRate || 1,
  812.         };
  813.         if (video.hdr) {
  814.           switch (video.hdr) {
  815.             case 'SDR':
  816.               videoConfig.transferFunction = 'srgb';
  817.               break;
  818.             case 'PQ':
  819.               videoConfig.transferFunction = 'pq';
  820.               break;
  821.             case 'HLG':
  822.               videoConfig.transferFunction = 'hlg';
  823.               break;
  824.           }
  825.         }
  826.         if (video.colorGamut) {
  827.           videoConfig.colorGamut = video.colorGamut;
  828.         }
  829.         videoConfigs.push(videoConfig);
  830.       }
  831.     }
  832.     if (audio) {
  833.       for (const fullMimeType of audio.fullMimeTypes) {
  834.         const baseMimeType = MimeUtils.getBasicType(fullMimeType);
  835.         const codecs = StreamUtils.getCorrectAudioCodecs(
  836.             MimeUtils.getCodecs(fullMimeType), baseMimeType);
  837.         const fullType = MimeUtils.getFullOrConvertedType(
  838.             baseMimeType, codecs, ContentType.AUDIO);
  840.         // AudioConfiguration
  841.         audioConfigs.push({
  842.           contentType: fullType,
  843.           channels: audio.channelsCount || 2,
  844.           bitrate: audio.bandwidth || variant.bandwidth || 1,
  845.           samplerate: audio.audioSamplingRate || 1,
  846.           spatialRendering: audio.spatialAudio,
  847.         });
  848.       }
  849.     }
  851.     // Generate each combination of video and audio config as a separate
  852.     // MediaDecodingConfiguration, inside the main "batch".
  853.     /** @type {!Array.<!MediaDecodingConfiguration>} */
  854.     const mediaDecodingConfigBatch = [];
  855.     if (videoConfigs.length == 0) {
  856.       videoConfigs.push(null);
  857.     }
  858.     if (audioConfigs.length == 0) {
  859.       audioConfigs.push(null);
  860.     }
  861.     for (const videoConfig of videoConfigs) {
  862.       for (const audioConfig of audioConfigs) {
  863.         /** @type {!MediaDecodingConfiguration} */
  864.         const mediaDecodingConfig = {
  865.           type: srcEquals ? 'file' : 'media-source',
  866.         };
  867.         if (videoConfig) {
  868.           mediaDecodingConfig.video = videoConfig;
  869.         }
  870.         if (audioConfig) {
  871.           mediaDecodingConfig.audio = audioConfig;
  872.         }
  873.         mediaDecodingConfigBatch.push(mediaDecodingConfig);
  874.       }
  875.     }
  877.     const videoDrmInfos = variant.video ? variant.video.drmInfos : [];
  878.     const audioDrmInfos = variant.audio ? variant.audio.drmInfos : [];
  879.     const allDrmInfos = videoDrmInfos.concat(audioDrmInfos);
  881.     // Return a list containing the mediaDecodingConfig for unencrypted variant.
  882.     if (!allDrmInfos.length) {
  883.       return [mediaDecodingConfigBatch];
  884.     }
  886.     // A list of MediaDecodingConfiguration objects created for the variant.
  887.     const configs = [];
  889.     // Get all the drm info so that we can avoid using nested loops when we
  890.     // just need the drm info.
  891.     const drmInfoByKeySystems = new Map();
  892.     for (const info of allDrmInfos) {
  893.       if (!drmInfoByKeySystems.get(info.keySystem)) {
  894.         drmInfoByKeySystems.set(info.keySystem, []);
  895.       }
  896.       drmInfoByKeySystems.get(info.keySystem).push(info);
  897.     }
  899.     const persistentState =
  900.         usePersistentLicenses ? 'required' : 'optional';
  901.     const sessionTypes =
  902.         usePersistentLicenses ? ['persistent-license'] : ['temporary'];
  904.     for (const keySystem of drmInfoByKeySystems.keys()) {
  905.       const modifiedMediaDecodingConfigBatch = [];
  906.       for (const base of mediaDecodingConfigBatch) {
  907.         // Create a copy of the mediaDecodingConfig.
  908.         const config = /** @type {!MediaDecodingConfiguration} */
  909.             (Object.assign({}, base));
  911.         const drmInfos = drmInfoByKeySystems.get(keySystem);
  913.         /** @type {!MediaCapabilitiesKeySystemConfiguration} */
  914.         const keySystemConfig = {
  915.           keySystem: keySystem,
  916.           initDataType: 'cenc',
  917.           persistentState: persistentState,
  918.           distinctiveIdentifier: 'optional',
  919.           sessionTypes: sessionTypes,
  920.         };
  922.         for (const info of drmInfos) {
  923.           if (info.initData && info.initData.length) {
  924.             const initDataTypes = new Set();
  925.             for (const initData of info.initData) {
  926.               initDataTypes.add(initData.initDataType);
  927.             }
  928.             if (initDataTypes.size > 1) {
  929.               shaka.log.v2('DrmInfo contains more than one initDataType,',
  930.                   'and we use the initDataType of the first initData.',
  931.                   info);
  932.             }
  933.             keySystemConfig.initDataType = info.initData[0].initDataType;
  934.           }
  936.           if (info.distinctiveIdentifierRequired) {
  937.             keySystemConfig.distinctiveIdentifier = 'required';
  938.           }
  939.           if (info.persistentStateRequired) {
  940.             keySystemConfig.persistentState = 'required';
  941.           }
  942.           if (info.sessionType) {
  943.             keySystemConfig.sessionTypes = [info.sessionType];
  944.           }
  946.           if (audio) {
  947.             if (!keySystemConfig.audio) {
  948.               // KeySystemTrackConfiguration
  949.               keySystemConfig.audio = {
  950.                 encryptionScheme: info.encryptionScheme,
  951.                 robustness: info.audioRobustness,
  952.               };
  953.             } else {
  954.               keySystemConfig.audio.encryptionScheme =
  955.                   keySystemConfig.audio.encryptionScheme ||
  956.                   info.encryptionScheme;
  957.               keySystemConfig.audio.robustness =
  958.                   keySystemConfig.audio.robustness ||
  959.                   info.audioRobustness;
  960.             }
  961.             // See: https://github.com/shaka-project/shaka-player/issues/4659
  962.             if (keySystemConfig.audio.robustness == '') {
  963.               delete keySystemConfig.audio.robustness;
  964.             }
  965.           }
  967.           if (video) {
  968.             if (!keySystemConfig.video) {
  969.               // KeySystemTrackConfiguration
  970.               keySystemConfig.video = {
  971.                 encryptionScheme: info.encryptionScheme,
  972.                 robustness: info.videoRobustness,
  973.               };
  974.             } else {
  975.               keySystemConfig.video.encryptionScheme =
  976.                   keySystemConfig.video.encryptionScheme ||
  977.                   info.encryptionScheme;
  978.               keySystemConfig.video.robustness =
  979.                   keySystemConfig.video.robustness ||
  980.                   info.videoRobustness;
  981.             }
  982.             // See: https://github.com/shaka-project/shaka-player/issues/4659
  983.             if (keySystemConfig.video.robustness == '') {
  984.               delete keySystemConfig.video.robustness;
  985.             }
  986.           }
  987.         }
  988.         config.keySystemConfiguration = keySystemConfig;
  989.         modifiedMediaDecodingConfigBatch.push(config);
  990.       }
  991.       configs.push(modifiedMediaDecodingConfigBatch);
  992.     }
  993.     return configs;
  994.   }
  997.   /**
  998.    * Generates the correct audio codec for MediaDecodingConfiguration and
  999.    * for MediaSource.isTypeSupported.
  1000.    * @param {string} codecs
  1001.    * @param {string} mimeType
  1002.    * @return {string}
  1003.    */
  1004.   static getCorrectAudioCodecs(codecs, mimeType) {
  1005.     // According to RFC 6381 section 3.3, 'fLaC' is actually the correct
  1006.     // codec string. We still need to map it to 'flac', as some browsers
  1007.     // currently don't support 'fLaC', while 'flac' is supported by most
  1008.     // major browsers.
  1009.     // See https://bugs.chromium.org/p/chromium/issues/detail?id=1422728
  1010.     if (codecs.toLowerCase() == 'flac') {
  1011.       if (!shaka.util.Platform.isSafari()) {
  1012.         return 'flac';
  1013.       } else {
  1014.         return 'fLaC';
  1015.       }
  1016.     }
  1018.     // The same is true for 'Opus'.
  1019.     if (codecs.toLowerCase() === 'opus') {
  1020.       if (!shaka.util.Platform.isSafari()) {
  1021.         return 'opus';
  1022.       } else {
  1023.         if (shaka.util.MimeUtils.getContainerType(mimeType) == 'mp4') {
  1024.           return 'Opus';
  1025.         } else {
  1026.           return 'opus';
  1027.         }
  1028.       }
  1029.     }
  1031.     return codecs;
  1032.   }
  1035.   /**
  1036.    * Generates the correct video codec for MediaDecodingConfiguration and
  1037.    * for MediaSource.isTypeSupported.
  1038.    * @param {string} codec
  1039.    * @return {string}
  1040.    */
  1041.   static getCorrectVideoCodecs(codec) {
  1042.     if (codec.includes('avc1')) {
  1043.       // Convert avc1 codec string from RFC-4281 to RFC-6381 for
  1044.       // MediaSource.isTypeSupported
  1045.       // Example, convert avc1.66.30 to avc1.42001e (0x42 == 66 and 0x1e == 30)
  1046.       const avcdata = codec.split('.');
  1047.       if (avcdata.length == 3) {
  1048.         let result = avcdata.shift() + '.';
  1049.         result += parseInt(avcdata.shift(), 10).toString(16);
  1050.         result +=
  1051.             ('000' + parseInt(avcdata.shift(), 10).toString(16)).slice(-4);
  1052.         return result;
  1053.       }
  1054.     } else if (codec == 'vp9') {
  1055.       // MediaCapabilities supports 'vp09...' codecs, but not 'vp9'. Translate
  1056.       // vp9 codec strings into 'vp09...', to allow such content to play with
  1057.       // mediaCapabilities enabled.
  1058.       // This means profile 0, level 4.1, 8-bit color.  This supports 1080p @
  1059.       // 60Hz.  See https://en.wikipedia.org/wiki/VP9#Levels
  1060.       //
  1061.       // If we don't have more detailed codec info, assume this profile and
  1062.       // level because it's high enough to likely accommodate the parameters we
  1063.       // do have, such as width and height.  If an implementation is checking
  1064.       // the profile and level very strictly, we want older VP9 content to
  1065.       // still work to some degree.  But we don't want to set a level so high
  1066.       // that it is rejected by a hardware decoder that can't handle the
  1067.       // maximum requirements of the level.
  1068.       //
  1069.       // This became an issue specifically on Firefox on M1 Macs.
  1070.       return 'vp09.00.41.08';
  1071.     }
  1072.     return codec;
  1073.   }
  1076.   /**
  1077.    * Alters the given Manifest to filter out any streams uncompatible with the
  1078.    * current variant.
  1079.    *
  1080.    * @param {?shaka.extern.Variant} currentVariant
  1081.    * @param {shaka.extern.Manifest} manifest
  1082.    */
  1083.   static filterManifestByCurrentVariant(currentVariant, manifest) {
  1084.     const StreamUtils = shaka.util.StreamUtils;
  1085.     manifest.variants = manifest.variants.filter((variant) => {
  1086.       const audio = variant.audio;
  1087.       const video = variant.video;
  1088.       if (audio && currentVariant && currentVariant.audio) {
  1089.         if (!StreamUtils.areStreamsCompatible_(audio, currentVariant.audio)) {
  1090.           shaka.log.debug('Dropping variant - not compatible with active audio',
  1091.               'active audio',
  1092.               StreamUtils.getStreamSummaryString_(currentVariant.audio),
  1093.               'variant.audio',
  1094.               StreamUtils.getStreamSummaryString_(audio));
  1095.           return false;
  1096.         }
  1097.       }
  1099.       if (video && currentVariant && currentVariant.video) {
  1100.         if (!StreamUtils.areStreamsCompatible_(video, currentVariant.video)) {
  1101.           shaka.log.debug('Dropping variant - not compatible with active video',
  1102.               'active video',
  1103.               StreamUtils.getStreamSummaryString_(currentVariant.video),
  1104.               'variant.video',
  1105.               StreamUtils.getStreamSummaryString_(video));
  1106.           return false;
  1107.         }
  1108.       }
  1110.       return true;
  1111.     });
  1112.   }
  1114.   /**
  1115.    * Alters the given Manifest to filter out any unsupported text streams.
  1116.    *
  1117.    * @param {shaka.extern.Manifest} manifest
  1118.    * @private
  1119.    */
  1120.   static filterTextStreams_(manifest) {
  1121.     // Filter text streams.
  1122.     manifest.textStreams = manifest.textStreams.filter((stream) => {
  1123.       const fullMimeType = shaka.util.MimeUtils.getFullType(
  1124.           stream.mimeType, stream.codecs);
  1125.       const keep = shaka.text.TextEngine.isTypeSupported(fullMimeType);
  1127.       if (!keep) {
  1128.         shaka.log.debug('Dropping text stream. Is not supported by the ' +
  1129.                         'platform.', stream);
  1130.       }
  1132.       return keep;
  1133.     });
  1134.   }
  1137.   /**
  1138.    * Alters the given Manifest to filter out any unsupported image streams.
  1139.    *
  1140.    * @param {shaka.extern.Manifest} manifest
  1141.    * @private
  1142.    */
  1143.   static async filterImageStreams_(manifest) {
  1144.     const imageStreams = [];
  1145.     for (const stream of manifest.imageStreams) {
  1146.       let mimeType = stream.mimeType;
  1147.       if (mimeType == 'application/mp4' && stream.codecs == 'mjpg') {
  1148.         mimeType = 'image/jpg';
  1149.       }
  1150.       if (!shaka.util.StreamUtils.supportedImageMimeTypes_.has(mimeType)) {
  1151.         const minImage = shaka.util.StreamUtils.minImage_.get(mimeType);
  1152.         if (minImage) {
  1153.           // eslint-disable-next-line no-await-in-loop
  1154.           const res = await shaka.util.StreamUtils.isImageSupported_(minImage);
  1155.           shaka.util.StreamUtils.supportedImageMimeTypes_.set(mimeType, res);
  1156.         } else {
  1157.           shaka.util.StreamUtils.supportedImageMimeTypes_.set(mimeType, false);
  1158.         }
  1159.       }
  1161.       const keep =
  1162.           shaka.util.StreamUtils.supportedImageMimeTypes_.get(mimeType);
  1164.       if (!keep) {
  1165.         shaka.log.debug('Dropping image stream. Is not supported by the ' +
  1166.                         'platform.', stream);
  1167.       } else {
  1168.         imageStreams.push(stream);
  1169.       }
  1170.     }
  1171.     manifest.imageStreams = imageStreams;
  1172.   }
  1174.   /**
  1175.    * @param {string} minImage
  1176.    * @return {!Promise.<boolean>}
  1177.    * @private
  1178.    */
  1179.   static isImageSupported_(minImage) {
  1180.     return new Promise((resolve) => {
  1181.       const imageElement = /** @type {HTMLImageElement} */(new Image());
  1182.       imageElement.src = minImage;
  1183.       if ('decode' in imageElement) {
  1184.         imageElement.decode().then(() => {
  1185.           resolve(true);
  1186.         }).catch(() => {
  1187.           resolve(false);
  1188.         });
  1189.       } else {
  1190.         imageElement.onload = imageElement.onerror = () => {
  1191.           resolve(imageElement.height === 2);
  1192.         };
  1193.       }
  1194.     });
  1195.   }
  1197.   /**
  1198.    * @param {shaka.extern.Stream} s0
  1199.    * @param {shaka.extern.Stream} s1
  1200.    * @return {boolean}
  1201.    * @private
  1202.    */
  1203.   static areStreamsCompatible_(s0, s1) {
  1204.     // Basic mime types and basic codecs need to match.
  1205.     // For example, we can't adapt between WebM and MP4,
  1206.     // nor can we adapt between mp4a.* to ec-3.
  1207.     // We can switch between text types on the fly,
  1208.     // so don't run this check on text.
  1209.     if (s0.mimeType != s1.mimeType) {
  1210.       return false;
  1211.     }
  1213.     if (s0.codecs.split('.')[0] != s1.codecs.split('.')[0]) {
  1214.       return false;
  1215.     }
  1217.     return true;
  1218.   }
  1221.   /**
  1222.    * @param {shaka.extern.Variant} variant
  1223.    * @return {shaka.extern.Track}
  1224.    */
  1225.   static variantToTrack(variant) {
  1226.     /** @type {?shaka.extern.Stream} */
  1227.     const audio = variant.audio;
  1228.     /** @type {?shaka.extern.Stream} */
  1229.     const video = variant.video;
  1231.     /** @type {?string} */
  1232.     const audioMimeType = audio ? audio.mimeType : null;
  1233.     /** @type {?string} */
  1234.     const videoMimeType = video ? video.mimeType : null;
  1236.     /** @type {?string} */
  1237.     const audioCodec = audio ? audio.codecs : null;
  1238.     /** @type {?string} */
  1239.     const videoCodec = video ? video.codecs : null;
  1241.     /** @type {!Array.<string>} */
  1242.     const codecs = [];
  1243.     if (videoCodec) {
  1244.       codecs.push(videoCodec);
  1245.     }
  1246.     if (audioCodec) {
  1247.       codecs.push(audioCodec);
  1248.     }
  1250.     /** @type {!Array.<string>} */
  1251.     const mimeTypes = [];
  1252.     if (video) {
  1253.       mimeTypes.push(video.mimeType);
  1254.     }
  1255.     if (audio) {
  1256.       mimeTypes.push(audio.mimeType);
  1257.     }
  1258.     /** @type {?string} */
  1259.     const mimeType = mimeTypes[0] || null;
  1261.     /** @type {!Array.<string>} */
  1262.     const kinds = [];
  1263.     if (audio) {
  1264.       kinds.push(audio.kind);
  1265.     }
  1266.     if (video) {
  1267.       kinds.push(video.kind);
  1268.     }
  1269.     /** @type {?string} */
  1270.     const kind = kinds[0] || null;
  1272.     /** @type {!Set.<string>} */
  1273.     const roles = new Set();
  1274.     if (audio) {
  1275.       for (const role of audio.roles) {
  1276.         roles.add(role);
  1277.       }
  1278.     }
  1279.     if (video) {
  1280.       for (const role of video.roles) {
  1281.         roles.add(role);
  1282.       }
  1283.     }
  1285.     /** @type {shaka.extern.Track} */
  1286.     const track = {
  1287.       id: variant.id,
  1288.       active: false,
  1289.       type: 'variant',
  1290.       bandwidth: variant.bandwidth,
  1291.       language: variant.language,
  1292.       label: null,
  1293.       kind: kind,
  1294.       width: null,
  1295.       height: null,
  1296.       frameRate: null,
  1297.       pixelAspectRatio: null,
  1298.       hdr: null,
  1299.       colorGamut: null,
  1300.       videoLayout: null,
  1301.       mimeType: mimeType,
  1302.       audioMimeType: audioMimeType,
  1303.       videoMimeType: videoMimeType,
  1304.       codecs: codecs.join(', '),
  1305.       audioCodec: audioCodec,
  1306.       videoCodec: videoCodec,
  1307.       primary: variant.primary,
  1308.       roles: Array.from(roles),
  1309.       audioRoles: null,
  1310.       forced: false,
  1311.       videoId: null,
  1312.       audioId: null,
  1313.       channelsCount: null,
  1314.       audioSamplingRate: null,
  1315.       spatialAudio: false,
  1316.       tilesLayout: null,
  1317.       audioBandwidth: null,
  1318.       videoBandwidth: null,
  1319.       originalVideoId: null,
  1320.       originalAudioId: null,
  1321.       originalTextId: null,
  1322.       originalImageId: null,
  1323.       accessibilityPurpose: null,
  1324.       originalLanguage: null,
  1325.     };
  1327.     if (video) {
  1328.       track.videoId = video.id;
  1329.       track.originalVideoId = video.originalId;
  1330.       track.width = video.width || null;
  1331.       track.height = video.height || null;
  1332.       track.frameRate = video.frameRate || null;
  1333.       track.pixelAspectRatio = video.pixelAspectRatio || null;
  1334.       track.videoBandwidth = video.bandwidth || null;
  1335.       track.hdr = video.hdr || null;
  1336.       track.colorGamut = video.colorGamut || null;
  1337.       track.videoLayout = video.videoLayout || null;
  1338.     }
  1340.     if (audio) {
  1341.       track.audioId = audio.id;
  1342.       track.originalAudioId = audio.originalId;
  1343.       track.channelsCount = audio.channelsCount;
  1344.       track.audioSamplingRate = audio.audioSamplingRate;
  1345.       track.audioBandwidth = audio.bandwidth || null;
  1346.       track.spatialAudio = audio.spatialAudio;
  1347.       track.label = audio.label;
  1348.       track.audioRoles = audio.roles;
  1349.       track.accessibilityPurpose = audio.accessibilityPurpose;
  1350.       track.originalLanguage = audio.originalLanguage;
  1351.     }
  1353.     return track;
  1354.   }
  1357.   /**
  1358.    * @param {shaka.extern.Stream} stream
  1359.    * @return {shaka.extern.Track}
  1360.    */
  1361.   static textStreamToTrack(stream) {
  1362.     const ContentType = shaka.util.ManifestParserUtils.ContentType;
  1364.     /** @type {shaka.extern.Track} */
  1365.     const track = {
  1366.       id: stream.id,
  1367.       active: false,
  1368.       type: ContentType.TEXT,
  1369.       bandwidth: 0,
  1370.       language: stream.language,
  1371.       label: stream.label,
  1372.       kind: stream.kind || null,
  1373.       width: null,
  1374.       height: null,
  1375.       frameRate: null,
  1376.       pixelAspectRatio: null,
  1377.       hdr: null,
  1378.       colorGamut: null,
  1379.       videoLayout: null,
  1380.       mimeType: stream.mimeType,
  1381.       audioMimeType: null,
  1382.       videoMimeType: null,
  1383.       codecs: stream.codecs || null,
  1384.       audioCodec: null,
  1385.       videoCodec: null,
  1386.       primary: stream.primary,
  1387.       roles: stream.roles,
  1388.       audioRoles: null,
  1389.       forced: stream.forced,
  1390.       videoId: null,
  1391.       audioId: null,
  1392.       channelsCount: null,
  1393.       audioSamplingRate: null,
  1394.       spatialAudio: false,
  1395.       tilesLayout: null,
  1396.       audioBandwidth: null,
  1397.       videoBandwidth: null,
  1398.       originalVideoId: null,
  1399.       originalAudioId: null,
  1400.       originalTextId: stream.originalId,
  1401.       originalImageId: null,
  1402.       accessibilityPurpose: stream.accessibilityPurpose,
  1403.       originalLanguage: stream.originalLanguage,
  1404.     };
  1406.     return track;
  1407.   }
  1410.   /**
  1411.    * @param {shaka.extern.Stream} stream
  1412.    * @return {shaka.extern.Track}
  1413.    */
  1414.   static imageStreamToTrack(stream) {
  1415.     const ContentType = shaka.util.ManifestParserUtils.ContentType;
  1417.     let width = stream.width || null;
  1418.     let height = stream.height || null;
  1420.     // The stream width and height represent the size of the entire thumbnail
  1421.     // sheet, so divide by the layout.
  1422.     let reference = null;
  1423.     // Note: segmentIndex is built by default for HLS, but not for DASH, but
  1424.     // in DASH this information comes at the stream level and not at the
  1425.     // segment level.
  1426.     if (stream.segmentIndex) {
  1427.       reference = stream.segmentIndex.get(0);
  1428.     }
  1429.     let layout = stream.tilesLayout;
  1430.     if (reference) {
  1431.       layout = reference.getTilesLayout() || layout;
  1432.     }
  1433.     if (layout && width != null) {
  1434.       width /= Number(layout.split('x')[0]);
  1435.     }
  1436.     if (layout && height != null) {
  1437.       height /= Number(layout.split('x')[1]);
  1438.     }
  1439.     // TODO: What happens if there are multiple grids, with different
  1440.     // layout sizes, inside this image stream?
  1442.     /** @type {shaka.extern.Track} */
  1443.     const track = {
  1444.       id: stream.id,
  1445.       active: false,
  1446.       type: ContentType.IMAGE,
  1447.       bandwidth: stream.bandwidth || 0,
  1448.       language: '',
  1449.       label: null,
  1450.       kind: null,
  1451.       width,
  1452.       height,
  1453.       frameRate: null,
  1454.       pixelAspectRatio: null,
  1455.       hdr: null,
  1456.       colorGamut: null,
  1457.       videoLayout: null,
  1458.       mimeType: stream.mimeType,
  1459.       audioMimeType: null,
  1460.       videoMimeType: null,
  1461.       codecs: stream.codecs || null,
  1462.       audioCodec: null,
  1463.       videoCodec: null,
  1464.       primary: false,
  1465.       roles: [],
  1466.       audioRoles: null,
  1467.       forced: false,
  1468.       videoId: null,
  1469.       audioId: null,
  1470.       channelsCount: null,
  1471.       audioSamplingRate: null,
  1472.       spatialAudio: false,
  1473.       tilesLayout: layout || null,
  1474.       audioBandwidth: null,
  1475.       videoBandwidth: null,
  1476.       originalVideoId: null,
  1477.       originalAudioId: null,
  1478.       originalTextId: null,
  1479.       originalImageId: stream.originalId,
  1480.       accessibilityPurpose: null,
  1481.       originalLanguage: null,
  1482.     };
  1484.     return track;
  1485.   }
  1488.   /**
  1489.    * Generate and return an ID for this track, since the ID field is optional.
  1490.    *
  1491.    * @param {TextTrack|AudioTrack} html5Track
  1492.    * @return {number} The generated ID.
  1493.    */
  1494.   static html5TrackId(html5Track) {
  1495.     if (!html5Track['__shaka_id']) {
  1496.       html5Track['__shaka_id'] = shaka.util.StreamUtils.nextTrackId_++;
  1497.     }
  1498.     return html5Track['__shaka_id'];
  1499.   }
  1502.   /**
  1503.    * @param {TextTrack} textTrack
  1504.    * @return {shaka.extern.Track}
  1505.    */
  1506.   static html5TextTrackToTrack(textTrack) {
  1507.     const StreamUtils = shaka.util.StreamUtils;
  1509.     /** @type {shaka.extern.Track} */
  1510.     const track = StreamUtils.html5TrackToGenericShakaTrack_(textTrack);
  1511.     track.active = textTrack.mode != 'disabled';
  1512.     track.type = 'text';
  1513.     track.originalTextId = textTrack.id;
  1514.     if (textTrack.kind == 'captions') {
  1515.       // See: https://github.com/shaka-project/shaka-player/issues/6233
  1516.       track.mimeType = 'unknown';
  1517.     }
  1518.     if (textTrack.kind == 'subtitles') {
  1519.       track.mimeType = 'text/vtt';
  1520.     }
  1521.     if (textTrack.kind) {
  1522.       track.roles = [textTrack.kind];
  1523.     }
  1524.     if (textTrack.kind == 'forced') {
  1525.       track.forced = true;
  1526.     }
  1528.     return track;
  1529.   }
  1532.   /**
  1533.    * @param {AudioTrack} audioTrack
  1534.    * @return {shaka.extern.Track}
  1535.    */
  1536.   static html5AudioTrackToTrack(audioTrack) {
  1537.     const StreamUtils = shaka.util.StreamUtils;
  1539.     /** @type {shaka.extern.Track} */
  1540.     const track = StreamUtils.html5TrackToGenericShakaTrack_(audioTrack);
  1541.     track.active = audioTrack.enabled;
  1542.     track.type = 'variant';
  1543.     track.originalAudioId = audioTrack.id;
  1545.     if (audioTrack.kind == 'main') {
  1546.       track.primary = true;
  1547.     }
  1548.     if (audioTrack.kind) {
  1549.       track.roles = [audioTrack.kind];
  1550.       track.audioRoles = [audioTrack.kind];
  1551.       track.label = audioTrack.label;
  1552.     }
  1554.     return track;
  1555.   }
  1558.   /**
  1559.    * Creates a Track object with non-type specific fields filled out.  The
  1560.    * caller is responsible for completing the Track object with any
  1561.    * type-specific information (audio or text).
  1562.    *
  1563.    * @param {TextTrack|AudioTrack} html5Track
  1564.    * @return {shaka.extern.Track}
  1565.    * @private
  1566.    */
  1567.   static html5TrackToGenericShakaTrack_(html5Track) {
  1568.     const language = html5Track.language;
  1570.     /** @type {shaka.extern.Track} */
  1571.     const track = {
  1572.       id: shaka.util.StreamUtils.html5TrackId(html5Track),
  1573.       active: false,
  1574.       type: '',
  1575.       bandwidth: 0,
  1576.       language: shaka.util.LanguageUtils.normalize(language || 'und'),
  1577.       label: html5Track.label,
  1578.       kind: html5Track.kind,
  1579.       width: null,
  1580.       height: null,
  1581.       frameRate: null,
  1582.       pixelAspectRatio: null,
  1583.       hdr: null,
  1584.       colorGamut: null,
  1585.       videoLayout: null,
  1586.       mimeType: null,
  1587.       audioMimeType: null,
  1588.       videoMimeType: null,
  1589.       codecs: null,
  1590.       audioCodec: null,
  1591.       videoCodec: null,
  1592.       primary: false,
  1593.       roles: [],
  1594.       forced: false,
  1595.       audioRoles: null,
  1596.       videoId: null,
  1597.       audioId: null,
  1598.       channelsCount: null,
  1599.       audioSamplingRate: null,
  1600.       spatialAudio: false,
  1601.       tilesLayout: null,
  1602.       audioBandwidth: null,
  1603.       videoBandwidth: null,
  1604.       originalVideoId: null,
  1605.       originalAudioId: null,
  1606.       originalTextId: null,
  1607.       originalImageId: null,
  1608.       accessibilityPurpose: null,
  1609.       originalLanguage: language,
  1610.     };
  1612.     return track;
  1613.   }
  1616.   /**
  1617.    * Determines if the given variant is playable.
  1618.    * @param {!shaka.extern.Variant} variant
  1619.    * @return {boolean}
  1620.    */
  1621.   static isPlayable(variant) {
  1622.     return variant.allowedByApplication &&
  1623.         variant.allowedByKeySystem &&
  1624.         variant.disabledUntilTime == 0;
  1625.   }
  1628.   /**
  1629.    * Filters out unplayable variants.
  1630.    * @param {!Array.<!shaka.extern.Variant>} variants
  1631.    * @return {!Array.<!shaka.extern.Variant>}
  1632.    */
  1633.   static getPlayableVariants(variants) {
  1634.     return variants.filter((variant) => {
  1635.       return shaka.util.StreamUtils.isPlayable(variant);
  1636.     });
  1637.   }
  1640.   /**
  1641.    * Chooses streams according to the given config.
  1642.    * Works both for Stream and Track types due to their similarities.
  1643.    *
  1644.    * @param {!Array<!shaka.extern.Stream>|!Array<!shaka.extern.Track>} streams
  1645.    * @param {string} preferredLanguage
  1646.    * @param {string} preferredRole
  1647.    * @param {boolean} preferredForced
  1648.    * @return {!Array<!shaka.extern.Stream>|!Array<!shaka.extern.Track>}
  1649.    */
  1650.   static filterStreamsByLanguageAndRole(
  1651.       streams, preferredLanguage, preferredRole, preferredForced) {
  1652.     const LanguageUtils = shaka.util.LanguageUtils;
  1654.     /** @type {!Array<!shaka.extern.Stream>|!Array<!shaka.extern.Track>} */
  1655.     let chosen = streams;
  1657.     // Start with the set of primary streams.
  1658.     /** @type {!Array<!shaka.extern.Stream>|!Array<!shaka.extern.Track>} */
  1659.     const primary = streams.filter((stream) => {
  1660.       return stream.primary;
  1661.     });
  1663.     if (primary.length) {
  1664.       chosen = primary;
  1665.     }
  1667.     // Now reduce the set to one language.  This covers both arbitrary language
  1668.     // choice and the reduction of the "primary" stream set to one language.
  1669.     const firstLanguage = chosen.length ? chosen[0].language : '';
  1670.     chosen = chosen.filter((stream) => {
  1671.       return stream.language == firstLanguage;
  1672.     });
  1674.     // Find the streams that best match our language preference. This will
  1675.     // override previous selections.
  1676.     if (preferredLanguage) {
  1677.       const closestLocale = LanguageUtils.findClosestLocale(
  1678.           LanguageUtils.normalize(preferredLanguage),
  1679.           streams.map((stream) => stream.language));
  1681.       // Only replace |chosen| if we found a locale that is close to our
  1682.       // preference.
  1683.       if (closestLocale) {
  1684.         chosen = streams.filter((stream) => {
  1685.           const locale = LanguageUtils.normalize(stream.language);
  1686.           return locale == closestLocale;
  1687.         });
  1688.       }
  1689.     }
  1691.     // Filter by forced preference
  1692.     chosen = chosen.filter((stream) => {
  1693.       return stream.forced == preferredForced;
  1694.     });
  1696.     // Now refine the choice based on role preference.
  1697.     if (preferredRole) {
  1698.       const roleMatches = shaka.util.StreamUtils.filterStreamsByRole_(
  1699.           chosen, preferredRole);
  1700.       if (roleMatches.length) {
  1701.         return roleMatches;
  1702.       } else {
  1703.         shaka.log.warning('No exact match for the text role could be found.');
  1704.       }
  1705.     } else {
  1706.       // Prefer text streams with no roles, if they exist.
  1707.       const noRoleMatches = chosen.filter((stream) => {
  1708.         return stream.roles.length == 0;
  1709.       });
  1710.       if (noRoleMatches.length) {
  1711.         return noRoleMatches;
  1712.       }
  1713.     }
  1715.     // Either there was no role preference, or it could not be satisfied.
  1716.     // Choose an arbitrary role, if there are any, and filter out any other
  1717.     // roles. This ensures we never adapt between roles.
  1719.     const allRoles = chosen.map((stream) => {
  1720.       return stream.roles;
  1721.     }).reduce(shaka.util.Functional.collapseArrays, []);
  1723.     if (!allRoles.length) {
  1724.       return chosen;
  1725.     }
  1726.     return shaka.util.StreamUtils.filterStreamsByRole_(chosen, allRoles[0]);
  1727.   }
  1730.   /**
  1731.    * Filter Streams by role.
  1732.    * Works both for Stream and Track types due to their similarities.
  1733.    *
  1734.    * @param {!Array<!shaka.extern.Stream>|!Array<!shaka.extern.Track>} streams
  1735.    * @param {string} preferredRole
  1736.    * @return {!Array<!shaka.extern.Stream>|!Array<!shaka.extern.Track>}
  1737.    * @private
  1738.    */
  1739.   static filterStreamsByRole_(streams, preferredRole) {
  1740.     return streams.filter((stream) => {
  1741.       return stream.roles.includes(preferredRole);
  1742.     });
  1743.   }
  1746.   /**
  1747.    * Checks if the given stream is an audio stream.
  1748.    *
  1749.    * @param {shaka.extern.Stream} stream
  1750.    * @return {boolean}
  1751.    */
  1752.   static isAudio(stream) {
  1753.     const ContentType = shaka.util.ManifestParserUtils.ContentType;
  1754.     return stream.type == ContentType.AUDIO;
  1755.   }
  1758.   /**
  1759.    * Checks if the given stream is a video stream.
  1760.    *
  1761.    * @param {shaka.extern.Stream} stream
  1762.    * @return {boolean}
  1763.    */
  1764.   static isVideo(stream) {
  1765.     const ContentType = shaka.util.ManifestParserUtils.ContentType;
  1766.     return stream.type == ContentType.VIDEO;
  1767.   }
  1770.   /**
  1771.    * Get all non-null streams in the variant as an array.
  1772.    *
  1773.    * @param {shaka.extern.Variant} variant
  1774.    * @return {!Array.<shaka.extern.Stream>}
  1775.    */
  1776.   static getVariantStreams(variant) {
  1777.     const streams = [];
  1779.     if (variant.audio) {
  1780.       streams.push(variant.audio);
  1781.     }
  1782.     if (variant.video) {
  1783.       streams.push(variant.video);
  1784.     }
  1786.     return streams;
  1787.   }
  1790.   /**
  1791.    * Indicates if some of the variant's streams are fastSwitching.
  1792.    *
  1793.    * @param {shaka.extern.Variant} variant
  1794.    * @return {boolean}
  1795.    */
  1796.   static isFastSwitching(variant) {
  1797.     if (variant.audio && variant.audio.fastSwitching) {
  1798.       return true;
  1799.     }
  1800.     if (variant.video && variant.video.fastSwitching) {
  1801.       return true;
  1802.     }
  1803.     return false;
  1804.   }
  1807.   /**
  1808.    * Returns a string of a variant, with the attribute values of its audio
  1809.    * and/or video streams for log printing.
  1810.    * @param {shaka.extern.Variant} variant
  1811.    * @return {string}
  1812.    * @private
  1813.    */
  1814.   static getVariantSummaryString_(variant) {
  1815.     const summaries = [];
  1816.     if (variant.audio) {
  1817.       summaries.push(shaka.util.StreamUtils.getStreamSummaryString_(
  1818.           variant.audio));
  1819.     }
  1820.     if (variant.video) {
  1821.       summaries.push(shaka.util.StreamUtils.getStreamSummaryString_(
  1822.           variant.video));
  1823.     }
  1824.     return summaries.join(', ');
  1825.   }
  1827.   /**
  1828.    * Returns a string of an audio or video stream for log printing.
  1829.    * @param {shaka.extern.Stream} stream
  1830.    * @return {string}
  1831.    * @private
  1832.    */
  1833.   static getStreamSummaryString_(stream) {
  1834.     // Accepted parameters for Chromecast can be found (internally) at
  1835.     // go/cast-mime-params
  1837.     if (shaka.util.StreamUtils.isAudio(stream)) {
  1838.       return 'type=audio' +
  1839.              ' codecs=' + stream.codecs +
  1840.              ' bandwidth='+ stream.bandwidth +
  1841.              ' channelsCount=' + stream.channelsCount +
  1842.              ' audioSamplingRate=' + stream.audioSamplingRate;
  1843.     }
  1845.     if (shaka.util.StreamUtils.isVideo(stream)) {
  1846.       return 'type=video' +
  1847.              ' codecs=' + stream.codecs +
  1848.              ' bandwidth=' + stream.bandwidth +
  1849.              ' frameRate=' + stream.frameRate +
  1850.              ' width=' + stream.width +
  1851.              ' height=' + stream.height;
  1852.     }
  1854.     return 'unexpected stream type';
  1855.   }
  1858.   /**
  1859.    * Clears underlying decoding config cache.
  1860.    */
  1861.   static clearDecodingConfigCache() {
  1862.     shaka.util.StreamUtils.decodingConfigCache_ = {};
  1863.   }
  1864. };
  1867. /**
  1868.  * A cache of results from mediaCapabilities.decodingInfo, indexed by the
  1869.  * (stringified) decodingConfig.
  1870.  *
  1871.  * @type {Object.<(!string), (!MediaCapabilitiesDecodingInfo)>}
  1872.  * @private
  1873.  */
  1874. shaka.util.StreamUtils.decodingConfigCache_ = {};
  1877. /** @private {number} */
  1878. shaka.util.StreamUtils.nextTrackId_ = 0;
  1880. /**
  1881.  * @enum {string}
  1882.  */
  1883. shaka.util.StreamUtils.DecodingAttributes = {
  1884.   SMOOTH: 'smooth',
  1885.   POWER: 'powerEfficient',
  1886. };
  1888. /**
  1889.  * @private {!Map.<string, boolean>}
  1890.  */
  1891. shaka.util.StreamUtils.supportedImageMimeTypes_ = new Map()
  1892.     .set('image/svg+xml', true)
  1893.     .set('image/png', true)
  1894.     .set('image/jpeg', true)
  1895.     .set('image/jpg', true);
  1897. /**
  1898.  * @const {string}
  1899.  * @private
  1900.  */
  1901. shaka.util.StreamUtils.minWebPImage_ = 'data:image/webp;base64,UklGRjoAAABXRU' +
  1902.     'JQVlA4IC4AAACyAgCdASoCAAIALmk0mk0iIiIiIgBoSygABc6WWgAA/veff/0PP8bA//LwY' +
  1903.     'AAA';
  1905. /**
  1906.  * @const {string}
  1907.  * @private
  1908.  */
  1909. shaka.util.StreamUtils.minAvifImage_ = 'data:image/avif;base64,AAAAIGZ0eXBhdm' +
  1910.     'lmAAAAAGF2aWZtaWYxbWlhZk1BMUIAAADybWV0YQAAAAAAAAAoaGRscgAAAAAAAAAAcGljd' +
  1911.     'AAAAAAAAAAAAAAAAGxpYmF2aWYAAAAADnBpdG0AAAAAAAEAAAAeaWxvYwAAAABEAAABAAEA' +
  1912.     'AAABAAABGgAAAB0AAAAoaWluZgAAAAAAAQAAABppbmZlAgAAAAABAABhdjAxQ29sb3IAAAA' +
  1913.     'AamlwcnAAAABLaXBjbwAAABRpc3BlAAAAAAAAAAIAAAACAAAAEHBpeGkAAAAAAwgICAAAAA' +
  1914.     'xhdjFDgQ0MAAAAABNjb2xybmNseAACAAIAAYAAAAAXaXBtYQAAAAAAAAABAAEEAQKDBAAAA' +
  1915.     'CVtZGF0EgAKCBgANogQEAwgMg8f8D///8WfhwB8+ErK42A=';
  1917. /**
  1918.  * @const {!Map.<string, string>}
  1919.  * @private
  1920.  */
  1921. shaka.util.StreamUtils.minImage_ = new Map()
  1922.     .set('image/webp', shaka.util.StreamUtils.minWebPImage_)
  1923.     .set('image/avif', shaka.util.StreamUtils.minAvifImage_);