Quality Control & Adaptive Bitrate

interface Hls {
  /** Available quality levels (read-only) */
  readonly levels: Level[];
  
  /** Current quality level index (-1 for auto) */
  currentLevel: number;
  
  /** Next quality level to be loaded */
  nextLevel: number;
  
  /** Quality level for loading segments */
  loadLevel: number;
  
  /** Next load level to be used */
  nextLoadLevel: number;
  
  /** First level index to use */
  firstLevel: number;
  
  /** Starting level for playback */
  startLevel: number;
  
  /** Whether auto level selection is enabled (read-only) */
  readonly autoLevelEnabled: boolean;
  
  /** Manual level setting (-1 if auto) (read-only) */
  readonly manualLevel: number;
}

const hls = new Hls();

// Wait for manifest to be parsed
hls.on(Hls.Events.MANIFEST_PARSED, () => {
  console.log("Available levels:", hls.levels.length);
  
  // Print all quality levels
  hls.levels.forEach((level, index) => {
    console.log(`Level ${index}: ${level.width}x${level.height} @ ${level.bitrate}bps`);
  });
  
  // Set manual quality level
  hls.currentLevel = 2; // Select level 2
  
  // Enable auto quality selection
  hls.currentLevel = -1;
  
  // Set starting level for future streams
  hls.startLevel = 1;
});

// Listen for quality level changes
hls.on(Hls.Events.LEVEL_SWITCHING, (event, data) => {
  console.log(`Switching to level ${data.level}`);
});

hls.on(Hls.Events.LEVEL_SWITCHED, (event, data) => {
  console.log(`Switched to level ${data.level}`);
});

interface Hls {
  /** Current bandwidth estimate in bps */
  bandwidthEstimate: number;
  
  /** Default EWMA bandwidth estimate (read-only) */
  readonly abrEwmaDefaultEstimate: number;
  
  /** Time to first byte estimate (read-only) */
  readonly ttfbEstimate: number;
}

const hls = new Hls();

// Monitor bandwidth changes
hls.on(Hls.Events.FRAG_LOADED, () => {
  console.log("Current bandwidth estimate:", hls.bandwidthEstimate, "bps");
  console.log("TTFB estimate:", hls.ttfbEstimate, "ms");
});

// Set initial bandwidth estimate
hls.bandwidthEstimate = 2000000; // 2 Mbps

// Access default estimate
console.log("Default estimate:", hls.abrEwmaDefaultEstimate);

class AbrController {
  /**
   * Reset the bandwidth estimator
   * @param abrEwmaDefaultEstimate - Optional default estimate override
   */
  resetEstimator(abrEwmaDefaultEstimate?: number): void;
}

const hls = new Hls();

// Access ABR controller (after initialization)
hls.on(Hls.Events.MEDIA_ATTACHED, () => {
  // Reset bandwidth estimator
  (hls as any).abrController?.resetEstimator(1000000); // Reset to 1 Mbps
});

interface Hls {
  /** Auto level capping based on player size */
  autoLevelCapping: number;
  
  /** Maximum HDCP level supported */
  maxHdcpLevel: HdcpLevel;
}

const hls = new Hls({
  // Cap levels based on player size
  capLevelToPlayerSize: true,
  // Cap levels on FPS drops
  capLevelOnFPSDrop: true
});

// Monitor level capping
console.log("Auto level capping:", hls.autoLevelCapping);

// Set HDCP level limit
hls.maxHdcpLevel = "TYPE-1";

// Level switching events
hls.on(Hls.Events.LEVEL_SWITCHING, (event, data: { level: number }) => {
  // Called when starting to switch to a new level
});

hls.on(Hls.Events.LEVEL_SWITCHED, (event, data: { level: number }) => {
  // Called when switch to new level is complete
});

hls.on(Hls.Events.LEVEL_LOADING, (event, data: { level: number, url: string }) => {
  // Called when starting to load a level playlist
});

hls.on(Hls.Events.LEVEL_LOADED, (event, data: { 
  level: number,
  details: LevelDetails,
  stats: LoadStats 
}) => {
  // Called when level playlist is loaded
});

hls.on(Hls.Events.LEVEL_UPDATED, (event, data: {
  level: number,
  details: LevelDetails
}) => {
  // Called when level playlist is updated (live streams)
});

interface Level {
  /** Bitrate in bits per second */
  readonly bitrate: number;
  
  /** Video width in pixels */
  readonly width: number;
  
  /** Video height in pixels */  
  readonly height: number;
  
  /** Codec information string */
  readonly codecSet: string;
  
  /** Playlist URLs */
  readonly url: string[];
  
  /** Level details (after loading) */
  readonly details: LevelDetails | undefined;
  
  /** Frame rate */
  readonly frameRate: number | undefined;
  
  /** Video range (SDR, HDR10, etc.) */
  readonly videoRange: VideoRange | undefined;
  
  /** HDCP level requirement */
  readonly hdcpLevel: HdcpLevel | undefined;
}

interface LevelDetails {
  /** Total duration in seconds */
  readonly totalduration: number;
  
  /** Target duration for segments */
  readonly targetduration: number;
  
  /** Fragments in this level */
  readonly fragments: Fragment[];
  
  /** Live stream info */
  readonly live: boolean;
  
  /** Sequence number */
  readonly startSN: number;
  readonly endSN: number;
}

type HdcpLevel = "TYPE-0" | "TYPE-1" | null;

type VideoRange = "SDR" | "HDR10" | "HLG" | "HDR10+" | "DV";