Fix regression that removed (unofficial) support for startLevel abo…

…ve max level index

Fixes #6172

(cherry picked from commit 88d54a9)

docs/API.md

@@ -737,7 +737,7 @@ Enable to use JavaScript version AES decryption for fallback of WebCrypto API.
 
 (default: `undefined`)
 
-When set, use this level as the default hls.startLevel. Keep in mind that the startLevel set with the API takes precedence over config.startLevel configuration parameter.
+When set, use this level as the default `hls.startLevel`. Keep in mind that the `startLevel` set with the API takes precedence over config.startLevel configuration parameter. `startLevel` should be set to value between 0 and the maximum index of `hls.levels`.
 
 ### `fragLoadingTimeOut` / `manifestLoadingTimeOut` / `levelLoadingTimeOut` (deprecated)
 

src/controller/abr-controller.ts

@@ -871,8 +871,9 @@ class AbrController extends Logger implements AbrComponentAPI {
   }
 
   public set nextAutoLevel(nextLevel: number) {
-    const value = Math.max(this.hls.minAutoLevel, nextLevel);
-    if (this._nextAutoLevel != value) {
+    const { maxAutoLevel, minAutoLevel } = this.hls;
+    const value = Math.min(Math.max(nextLevel, minAutoLevel), maxAutoLevel);
+    if (this._nextAutoLevel !== value) {
       this.nextAutoLevelKey = '';
       this._nextAutoLevel = value;
     }

src/controller/stream-controller.ts

@@ -134,7 +134,8 @@ export default class StreamController
         }
         // set new level to playlist loader : this will trigger start level load
         // hls.nextLoadLevel remains until it is set to a new value or until a new frag is successfully loaded
-        this.level = hls.nextLoadLevel = startLevel;
+        hls.nextLoadLevel = startLevel;
+        this.level = hls.loadLevel;
         this.loadedmetadata = false;
       }
       // if startPosition undefined but lastCurrentTime set, set startPosition to last currentTime