61 lines
2.1 KiB
JavaScript
61 lines
2.1 KiB
JavaScript
// @flow
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import { CFG_LVL_TO_APP_QUALITY_LVL, VIDEO_QUALITY_LEVELS } from './constants';
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/**
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* Selects {@code VIDEO_QUALITY_LEVELS} for the given {@link availableHeight} and threshold to quality mapping.
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*
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* @param {number} availableHeight - The height to which a matching video quality level should be found.
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* @param {Map<number, number>} heightToLevel - The threshold to quality level mapping. The keys are sorted in the
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* ascending order.
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* @returns {number} The matching value from {@code VIDEO_QUALITY_LEVELS}.
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*/
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export function getReceiverVideoQualityLevel(availableHeight: number, heightToLevel: Map<number, number>): number {
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let selectedLevel = VIDEO_QUALITY_LEVELS.LOW;
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for (const [ levelThreshold, level ] of heightToLevel.entries()) {
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if (availableHeight >= levelThreshold) {
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selectedLevel = level;
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}
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}
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return selectedLevel;
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}
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/**
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* Converts {@code Object} passed in the config which represents height thresholds to vide quality level mapping to
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* a {@code Map}.
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*
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* @param {Object} minHeightForQualityLvl - The 'config.videoQuality.minHeightForQualityLvl' Object from
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* the configuration. See config.js for more details.
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* @returns {Map<number, number>|undefined} - A mapping of minimal thumbnail height required for given quality level or
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* {@code undefined} if the map contains invalid values.
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*/
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export function validateMinHeightForQualityLvl(minHeightForQualityLvl: Object): ?Map<number, number> {
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if (typeof minHeightForQualityLvl !== 'object'
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|| Object.keys(minHeightForQualityLvl).map(lvl => Number(lvl))
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.find(lvl => lvl === null || isNaN(lvl) || lvl < 0)) {
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return undefined;
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}
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const levelsSorted
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= Object.keys(minHeightForQualityLvl)
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.map(k => Number(k))
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.sort((a, b) => a - b);
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const map = new Map();
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for (const level of levelsSorted) {
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const configQuality = minHeightForQualityLvl[level];
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const appQuality = CFG_LVL_TO_APP_QUALITY_LVL[configQuality];
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if (!appQuality) {
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return undefined;
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}
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map.set(level, appQuality);
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}
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return map;
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}
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