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refactor: extract duplicate code to getAndApplyDecodingInfosForVariant
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@CeilingFANC
CeilingFANC committed May 21, 2024
1 parent 07ca2ea commit f504712
Showing 1 changed file with 48 additions and 60 deletions.
108 changes: 48 additions & 60 deletions lib/util/stream_utils.js
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Original file line number Diff line number Diff line change
Expand Up @@ -704,10 +704,11 @@ shaka.util.StreamUtils = class {
} // for (const preferredKeySystem of preferredKeySystems)

/**
* For LR devices, polyfill is used, which calls isTypeSupported and
* For platforms which use the MediaCapabilities polyfill, calls to media
* capabilities are replaced with isTypeSupported and
* requestMediaKeySystemAccess instead.
* Group similar variants, and share results.
* Helpful for video with a lot of variants on LR.
* By grouping similar variants, we can improve performance for manifests
* with lots of variants.
*/
const enableCache = enableMediaCapabilitiesCache &&
!srcEquals && !shaka.util.Platform.isChromecast();
Expand All @@ -733,11 +734,7 @@ shaka.util.StreamUtils = class {
for (const videoFullMimeType of video.fullMimeTypes) {
for (const audioFullMimeType of audio.fullMimeTypes) {
cacheKeys.push(
`${videoFullMimeType}#${video.hdr}
#${audioFullMimeType}#${audio.spatialAudio}
#${audio.channelsCount}
#${keySystem}`);
// video.hdr + audio.spatialAudio + audio.channelsCount
`${videoFullMimeType}#${audioFullMimeType}#${keySystem}`);
}
}
}
Expand All @@ -747,52 +744,27 @@ shaka.util.StreamUtils = class {
// sort variants, so that high bandwidth checked first.
// High bandwidth tends to be less likely to be supported, or smooth
const sortedVariants = variants.sort((a, b) => b.bandwidth - a.bandwidth);
const keyToCheck = 'supported';

for (const variant of sortedVariants) {
const cacheKeys = buildCacheKey(variant);
const useCache = cacheKeys && cacheKeys.length &&
cacheKeys.reduce((hasCache, key) =>
(hasCache && decodeInfoCache[key] &&
// If not meet criteria, won't use cache.
decodeInfoCache[key][keyToCheck])
, true);
shaka.log.info('getDecodingInfosForVariants used cache.',
useCache, cacheKeys, variant);
cacheKeys.every((key) => {
return decodeInfoCache[key] && decodeInfoCache[key].supported;
});
if (useCache) {
variant.decodingInfos =
cacheKeys.map((key) => decodeInfoCache[key]);
continue;
}

/** @type {!Array.<!Array.<!MediaDecodingConfiguration>>} */
const decodingConfigs = shaka.util.StreamUtils.getDecodingConfigs_(
variant, usePersistentLicenses, srcEquals)
.filter((configs) => {
// All configs in a batch will have the same keySystem.
const config = configs[0];
const keySystem = config.keySystemConfiguration &&
config.keySystemConfiguration.keySystem;
// Avoid checking preferred systems twice.
return !keySystem || !preferredKeySystems.includes(keySystem);
});

// The reason we are performing this await in a loop rather than
// batching into a `promise.all` is performance related.
// https://github.com/shaka-project/shaka-player/pull/4708#discussion_r1022581178
for (let i = 0; i < decodingConfigs.length; i++) {
const configs = decodingConfigs[i];
// eslint-disable-next-line no-await-in-loop
await shaka.util.StreamUtils.getDecodingInfosForVariant_(
variant, configs);
// eslint-disable-next-line no-await-in-loop
await shaka.util.StreamUtils.getAndApplyDecodingInfosForVariant_(
variant, usePersistentLicenses, srcEquals, preferredKeySystems);

// getDecodingInfosForVariant_ could fail.
const result = variant.decodingInfos.length ?
variant.decodingInfos[i] : null;
if (cacheKeys && result) {
if (cacheKeys) {
for (let i = 0; i < variant.decodingInfos.length; i++) {
const cacheKey = cacheKeys[i];

decodeInfoCache[cacheKey] = result;
decodeInfoCache[cacheKey] = variant.decodingInfos[i];
delete decodeInfoCache[cacheKey]['configuration'];
}
}
Expand All @@ -801,26 +773,42 @@ shaka.util.StreamUtils = class {
}

for (const variant of variants) {
/** @type {!Array.<!Array.<!MediaDecodingConfiguration>>} */
const decodingConfigs = shaka.util.StreamUtils.getDecodingConfigs_(
variant, usePersistentLicenses, srcEquals)
.filter((configs) => {
// All configs in a batch will have the same keySystem.
const config = configs[0];
const keySystem = config.keySystemConfiguration &&
// eslint-disable-next-line no-await-in-loop
await shaka.util.StreamUtils.getAndApplyDecodingInfosForVariant_(
variant, usePersistentLicenses, srcEquals, preferredKeySystems);
}
}

/**
* Call mediaCapabilities
* Generate input for querying mediaCapabilities and call the API .
* @param {!shaka.extern.Variant} variant
* @param {boolean} usePersistentLicenses
* @param {boolean} srcEquals
* @param {!Array<string>=} preferredKeySystems
* @private
*/
static async getAndApplyDecodingInfosForVariant_(
variant, usePersistentLicenses, srcEquals, preferredKeySystems = []) {
/** @type {!Array.<!Array.<!MediaDecodingConfiguration>>} */
const decodingConfigs = shaka.util.StreamUtils.getDecodingConfigs_(
variant, usePersistentLicenses, srcEquals)
.filter((configs) => {
// All configs in a batch will have the same keySystem.
const config = configs[0];
const keySystem = config.keySystemConfiguration &&
config.keySystemConfiguration.keySystem;
// Avoid checking preferred systems twice.
return !keySystem || !preferredKeySystems.includes(keySystem);
});
// Avoid checking preferred systems twice.
return !keySystem || !preferredKeySystems.includes(keySystem);
});

// The reason we are performing this await in a loop rather than
// batching into a `promise.all` is performance related.
// https://github.com/shaka-project/shaka-player/pull/4708#discussion_r1022581178
for (const configs of decodingConfigs) {
// eslint-disable-next-line no-await-in-loop
await shaka.util.StreamUtils.getDecodingInfosForVariant_(
variant, configs);
}
// The reason we are performing this await in a loop rather than
// batching into a `promise.all` is performance related.
// https://github.com/shaka-project/shaka-player/pull/4708#discussion_r1022581178
for (const configs of decodingConfigs) {
// eslint-disable-next-line no-await-in-loop
await shaka.util.StreamUtils.getDecodingInfosForVariant_(
variant, configs);
}
}

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