LumiFlix Streaming

1class AdaptiveBitrateController {
2  constructor(player) {
3    this.player = player;
4    this.bandwidthSamples = [];
5  }
6  
7  selectQuality() {
8    const bandwidth = this.estimateBandwidth();
9    const qualities = this.player.getQualities();
10    
11    // Select quality with 20% safety margin
12    const targetBitrate = bandwidth * 0.8;
13    
14    return qualities.reduce((best, q) => {
15      if (q.bitrate <= targetBitrate && q.bitrate > best.bitrate) {
16        return q;
17      }
18      return best;
19    }, qualities[0]);
20  }
21  
22  estimateBandwidth() {
23    if (this.bandwidthSamples.length < 3) {
24      return 5000000; // Default 5Mbps
25    }
26    
27    // Use exponential weighted moving average
28    return this.bandwidthSamples.reduce((sum, sample, i) => {
29      const weight = Math.pow(0.8, this.bandwidthSamples.length - i - 1);
30      return sum + sample * weight;
31    }, 0);
32  }
33}