Rename slidingStart > seekableStart

Add comments describing each field in `InterstitialsManager` API markdown

(cherry picked from commit bcb2db84d1ffba18befd658b284695fb0a69f7d4)

api-extractor/report/hls.js.api.md

@@ -4045,7 +4045,7 @@ export type PlayheadTimes = {
     bufferedEnd: number;
     currentTime: number;
     duration: number;
-    slidingStart: number;
+    seekableStart: number;
     seekTo: (time: number) => void;
 };
 

docs/API.md

@@ -1973,28 +1973,29 @@ Use `skip()` to skip the current interstitial. Use `primary`, `playout`, and `in
 
 ```ts
 interface InterstitialsManager {
-  events: InterstitialEvent[];
-  schedule: InterstitialScheduleItem[];
-  playerQueue: HlsAssetPlayer[];
-  bufferingPlayer: HlsAssetPlayer | null;
-  bufferingAsset: InterstitialAssetItem | null;
-  bufferingItem: InterstitialScheduleItem | null;
-  bufferingIndex: number;
-  playingAsset: InterstitialAssetItem | null;
-  playingItem: InterstitialScheduleItem | null;
-  playingIndex: number;
-  waitingIndex: number;
-  primary: PlayheadTimes;
-  playout: PlayheadTimes;
-  integrated: PlayheadTimes;
-  skip: () => void;
+  events: InterstitialEvent[]; // An array of Interstitials (events) parsed from the latest media playlist update
+  schedule: InterstitialScheduleItem[]; // An array of primary and event items with start and end times representing the scheduled program
+  playerQueue: HlsAssetPlayer[]; // And array of child Hls instances created to preload and stream Interstitial asset content
+  bufferingPlayer: HlsAssetPlayer | null; // The child Hls instance assigned to streaming media at the edge of the forward buffer
+  bufferingAsset: InterstitialAssetItem | null; // The Interstitial asset currently being streamed
+  bufferingItem: InterstitialScheduleItem | null; // The primary item or event item currently being streamed
+  bufferingIndex: number; // The index of `bufferingItem` in the `schedule` array
+  playingAsset: InterstitialAssetItem | null; // The Interstitial asset currently being streamed
+  playingItem: InterstitialScheduleItem | null; // The primary item or event item currently being played
+  playingIndex: number; // The index of `playingItem` in the `schedule` array
+  waitingIndex: number; // The index of the item whose asset list is being loaded in the `schedule` array
+  primary: PlayheadTimes; // playhead mapping and seekTo method based on the primary content
+  playout: PlayheadTimes; // playhead mapping and seekTo method based on playout of all items in the `schedule` array
+  integrated: PlayheadTimes; // playhead mapping and seekTo method that applies the X-TIMELINE-OCCUPIES attribute to each event item
+  skip: () => void; // A method for skipping the currently playing event item, provided it is not jump restricted
 }
 
 type PlayheadTimes = {
-  bufferedEnd: number;
-  currentTime: number;
-  duration: number;
-  seekTo: (time: number) => void;
+  bufferedEnd: number; // The buffer end time relative to the playhead in the scheduled program
+  currentTime: number; // The current playhead time in the scheduled program
+  duration: number; // The time at the end of the scheduled program
+  seekableStart: number; // The earliest available time where media is available (maps to the start of the first segment in primary media playlists)
+  seekTo: (time: number) => void; // A method for seeking to the designated time the scheduled program
 };
 ```
 

src/controller/interstitials-controller.ts

@@ -70,7 +70,7 @@ export type PlayheadTimes = {
   bufferedEnd: number;
   currentTime: number;
   duration: number;
-  slidingStart: number;
+  seekableStart: number;
   seekTo: (time: number) => void;
 };
 
@@ -494,7 +494,7 @@ export default class InterstitialsController
           get duration() {
             return getMappedDuration('primary');
           },
-          get slidingStart() {
+          get seekableStart() {
             return c.primaryDetails?.fragmentStart || 0;
           },
           seekTo: (time) => seekTo(time, 'primary'),
@@ -521,7 +521,7 @@ export default class InterstitialsController
           get duration() {
             return getMappedDuration('playout');
           },
-          get slidingStart() {
+          get seekableStart() {
             return findMappedTime(
               c.primaryDetails?.fragmentStart || 0,
               'playout',
@@ -551,7 +551,7 @@ export default class InterstitialsController
           get duration() {
             return getMappedDuration('integrated');
           },
-          get slidingStart() {
+          get seekableStart() {
             return findMappedTime(
               c.primaryDetails?.fragmentStart || 0,
               'integrated',