# All files / src/controller cap-level-controller.js

22.03% Statements 13/59
27.66% Branches 13/47
21.43% Functions 3/14
22.03% Lines 13/59

    1
    2
    3
    4
    5
    6
    7
    8
    9
    10
    11
    12
    13
    14
    15
    16
    17
    18
    19
    20
    21
    22
    23
    24
    25
    26
    27
    28
    29
    30
    31
    32
    33
    34
    35
    36
    37
    38
    39
    40
    41
    42
    43
    44
    45
    46
    47
    48
    49
    50
    51
    52
    53
    54
    55
    56
    57
    58
    59
    60
    61
    62
    63
    64
    65
    66
    67
    68
    69
    70
    71
    72
    73
    74
    75
    76
    77
    78
    79
    80
    81
    82
    83
    84
    85
    86
    87
    88
    89
    90
    91
    92
    93
    94
    95
    96
    97
    98
    99
    100
    101
    102
    103
    104
    105
    106
    107
    108
    109
    110
    111
    112
    113
    114
    115
    116
    117
    118
    119
    120
    121
    122
    123
    124
    125
    126
    127
    128
    129
    130
    131
    132
    133
    134
    135
    136
    137
    138
    139
    140
    141
    142
    143
    144

    5x

    5x
    2x

    3x
    3x

    3x

    3x

    3x
    8x
    8x
    2x
    2x

    3x

     /*
     * cap stream level to media size dimension controller
    */

    import Event from '../events';
    import EventHandler from '../event-handler';

    class CapLevelController extends EventHandler {
    	constructor(hls) {
        super(hls,
          Event.FPS_DROP_LEVEL_CAPPING,
          Event.MEDIA_ATTACHING,
          Event.MANIFEST_PARSED);
    	}

    	destroy() {
        if (this.hls.config.capLevelToPlayerSize) {
          this.media = this.restrictedLevels = null;
          this.autoLevelCapping = Number.POSITIVE_INFINITY;
          if (this.timer) {
            this.timer = clearInterval(this.timer);
          }
        }
      }

      onFpsDropLevelCapping(data) {
    	  // Don't add a restricted level more than once
        if (CapLevelController.isLevelAllowed(data.droppedLevel, this.restrictedLevels)) {
          this.restrictedLevels.push(data.droppedLevel);
        }
      }

    	onMediaAttaching(data) {
        this.media = data.media instanceof HTMLVideoElement ? data.media : null;
      }

      onManifestParsed(data) {
        const hls = this.hls;
        this.restrictedLevels = [];
        if (hls.config.capLevelToPlayerSize) {
          this.autoLevelCapping = Number.POSITIVE_INFINITY;
          this.levels = data.levels;
          hls.firstLevel = this.getMaxLevel(data.firstLevel);
          clearInterval(this.timer);
          this.timer = setInterval(this.detectPlayerSize.bind(this), 1000);
          this.detectPlayerSize();
        }
      }

      detectPlayerSize() {
        if (this.media) {
          let levelsLength = this.levels ? this.levels.length : 0;
          if (levelsLength) {
            const hls = this.hls;
            hls.autoLevelCapping = this.getMaxLevel(levelsLength - 1);
            if (hls.autoLevelCapping > this.autoLevelCapping) {
              // if auto level capping has a higher value for the previous one, flush the buffer using nextLevelSwitch
              // usually happen when the user go to the fullscreen mode.
              hls.streamController.nextLevelSwitch();
            }
            this.autoLevelCapping = hls.autoLevelCapping;
          }
        }
      }

      /*
      * returns level should be the one with the dimensions equal or greater than the media (player) dimensions (so the video will be downscaled)
      */
      getMaxLevel(capLevelIndex) {
        if (!this.levels) {
          return -1;
        }

        const validLevels = this.levels.filter((level, index) =>
          CapLevelController.isLevelAllowed(index, this.restrictedLevels) && index <= capLevelIndex
        );

        return CapLevelController.getMaxLevelByMediaSize(validLevels, this.mediaWidth, this.mediaHeight);
      }

      get mediaWidth() {
        let width;
        const media = this.media;
        if (media) {
          width = media.width || media.clientWidth || media.offsetWidth;
          width *= CapLevelController.contentScaleFactor;
        }
        return width;
      }

      get mediaHeight() {
        let height;
        const media = this.media;
        if (media) {
          height = media.height || media.clientHeight || media.offsetHeight;
          height *= CapLevelController.contentScaleFactor;
        }
        return height;
      }

      static get contentScaleFactor() {
        let pixelRatio = 1;
        try {
          pixelRatio =  window.devicePixelRatio;
        } catch(e) {}
        return pixelRatio;
      }

      static isLevelAllowed(level, restrictedLevels = []) {
        return restrictedLevels.indexOf(level) === -1;
      }

      static getMaxLevelByMediaSize(levels, width, height) {
        if (!levels || (levels && !levels.length)) {
          return -1;
        }

        // Levels can have the same dimensions but differing bandwidths - since levels are ordered, we can look to the next
        // to determine whether we've chosen the greatest bandwidth for the media's dimensions
        const atGreatestBandiwdth = (curLevel, nextLevel) => {
          Iif (!nextLevel) {
            return true;
          }
          return curLevel.width !== nextLevel.width || curLevel.height !== nextLevel.height;
        };

        // If we run through the loop without breaking, the media's dimensions are greater than every level, so default to
        // the max level
        let maxLevelIndex = levels.length - 1;

        for (let i = 0; i < levels.length; i+= 1) {
          const level = levels[i];
          if ((level.width >= width || level.height >= height) && atGreatestBandiwdth(level, levels[i + 1])) {
            maxLevelIndex = i;
            break;
          }
        }

        return maxLevelIndex;
      }
    }

    export default CapLevelController;