Fix level removal on key status error and optimize key-bytes comparison

Add "FIXME" comments for future MediaKeySessionContext multi-key handling improvements

Author: robwalch

src/controller/base-stream-controller.ts

@@ -2038,8 +2038,8 @@ export default class BaseStreamController
   }
 
   protected resetWhenMissingContext(chunkMeta: ChunkMetadata | Fragment) {
-    this.warn(
-      `The loading context changed while buffering fragment ${chunkMeta.sn} of ${this.playlistLabel()} ${chunkMeta.level}. This chunk will not be buffered.`,
+    this.log(
+      `Loading context changed while buffering sn ${chunkMeta.sn} of ${this.playlistLabel()} ${chunkMeta.level === -1 ? '<removed>' : chunkMeta.level}. This chunk will not be buffered.`,
     );
     this.removeUnbufferedFrags();
     this.resetStartWhenNotLoaded(this.levelLastLoaded);

src/controller/eme-controller.ts

@@ -55,9 +55,9 @@ interface KeySystemAccessPromises {
 export interface MediaKeySessionContext {
   keySystem: KeySystems;
   mediaKeys: MediaKeys;
-  decryptdata: LevelKey;
+  decryptdata: LevelKey; // FIXME: LevelKey has a URI which should be bound to the session, but is dependent one KeyId specifically. Session context should be allowed to adopt multiple level keys.
   mediaKeysSession: MediaKeySession;
-  keyStatus: MediaKeyStatus;
+  keyStatus: MediaKeyStatus; // FIXME: MediaKeySession can manage multiple keys with each with its own status
   licenseXhr?: XMLHttpRequest;
   _onmessage?: (this: MediaKeySession, ev: MediaKeyMessageEvent) => any;
   _onkeystatuseschange?: (this: MediaKeySession, ev: Event) => any;
@@ -376,7 +376,7 @@ class EMEController extends Logger implements ComponentAPI {
   ): Promise<void> {
     const keySession = mediaKeySessionContext.mediaKeysSession;
     this.log(
-      `Updating key-session "${keySession.sessionId}" for keyID ${arrayToHex(
+      `Updating key-session "${keySession.sessionId}" for keyId ${arrayToHex(
         mediaKeySessionContext.decryptdata.keyId || [],
       )}
       } (data length: ${data.byteLength})`,
@@ -791,7 +791,7 @@ class EMEController extends Logger implements ComponentAPI {
         return;
       }
       const initialStatus = context.keyStatus;
-      this.onKeyStatusChange(context, licenseStatus);
+      this.onKeyStatusChange(context);
       const status = context.keyStatus;
       if (status !== initialStatus) {
         licenseStatus.emit('keyStatus', status, context);
@@ -873,10 +873,7 @@ class EMEController extends Logger implements ComponentAPI {
       });
   }
 
-  private onKeyStatusChange(
-    mediaKeySessionContext: MediaKeySessionContext,
-    licenseStatus: EventEmitter<string | symbol, any>,
-  ) {
+  private onKeyStatusChange(mediaKeySessionContext: MediaKeySessionContext) {
     const sessionLevelKeyId = arrayToHex(
       new Uint8Array(mediaKeySessionContext.decryptdata.keyId || []),
     );
@@ -1371,10 +1368,11 @@ class EMEController extends Logger implements ComponentAPI {
   private removeSession(
     mediaKeySessionContext: MediaKeySessionContext,
   ): Promise<void> | void {
-    const { mediaKeysSession, licenseXhr } = mediaKeySessionContext;
-    if (mediaKeysSession as any) {
+    const { mediaKeysSession, licenseXhr, decryptdata } =
+      mediaKeySessionContext;
+    if (mediaKeysSession as MediaKeySession | undefined) {
       this.log(
-        `Remove licenses and keys and close session ${mediaKeysSession.sessionId}`,
+        `Remove licenses and keys and close session "${mediaKeysSession.sessionId}" keyId: ${arrayToHex((decryptdata as LevelKey | undefined)?.keyId || [])}`,
       );
       if (mediaKeySessionContext._onmessage) {
         mediaKeysSession.removeEventListener(

src/controller/error-controller.ts

@@ -496,7 +496,7 @@ export default class ErrorController
       return;
     }
     const { flags } = errorAction;
-    let nextAutoLevel = errorAction.nextAutoLevel;
+    const nextAutoLevel = errorAction.nextAutoLevel;
 
     switch (flags) {
       case ErrorActionFlags.None:
@@ -526,27 +526,20 @@ export default class ErrorController
         if (levelKey) {
           // Penalize all levels with key
           const levels = this.hls.levels;
-          let levelIndex = hls.loadLevel;
-          const removeLevels: number[] = [];
           for (let i = levels.length; i--; ) {
             if (this.variantHasKey(levels[i], levelKey)) {
               this.log(
-                `Banned key found in level ${i} or audio group "${levels[i].audioGroups?.join(',')}" (${data.frag?.type} fragment) ${arrayToHex(levelKey.keyId || [])}`,
+                `Banned key found in level ${i} (${levels[i].bitrate}bps) or audio group "${levels[i].audioGroups?.join(',')}" (${data.frag?.type} fragment) ${arrayToHex(levelKey.keyId || [])}`,
               );
               levels[i].fragmentError++;
               levels[i].loadError++;
-              levelIndex = i;
-              removeLevels.unshift(i);
-            }
-          }
-          const switchAction = this.getLevelSwitchAction(data, levelIndex);
-          nextAutoLevel = switchAction.nextAutoLevel;
-          for (let i = removeLevels.length; i--; ) {
-            if (nextAutoLevel !== i) {
               this.log(`Removing level ${i} with key error (${data.error})`);
               this.hls.removeLevel(i);
             }
           }
+          if (levels.length) {
+            errorAction.resolved = true;
+          }
         }
         break;
       }

src/loader/key-loader.ts

@@ -206,10 +206,6 @@ export default class KeyLoader extends Logger implements ComponentAPI {
             // Return the correct fragment with updated decryptdata key and loaded keyInfo
             const { keyInfo } = keyLoadedData;
             decryptdata.key = keyInfo.decryptdata.key;
-            // log key-status unblocking change for debugging only
-            // this.log(
-            //   `${frag.type} ${frag.level} key ${arrayToHex(decryptdata.keyId || [])} "${keyStatus}" session key ${keyInfo.decryptdata.keyId ? arrayToHex(keyInfo.decryptdata.keyId) : null}`,
-            // );
             return { frag, keyInfo };
           });
       }

src/loader/level-details.ts

@@ -97,7 +97,7 @@ export class LevelDetails {
         frag.setKeyFormat(levelKey.keyFormat as KeySystemFormats);
         decryptdata = frag.decryptdata;
       }
-      return decryptdata && levelKey.matches(decryptdata);
+      return !!decryptdata && levelKey.matches(decryptdata);
     });
   }
 

src/loader/level-key.ts

@@ -1,3 +1,4 @@
+import { arrayValuesMatch, optionalArrayValuesMatch } from '../utils/arrays';
 import { isFullSegmentEncryption } from '../utils/encryption-methods-util';
 import { hexToArrayBuffer } from '../utils/hex';
 import { convertDataUriToArrayBytes } from '../utils/keysystem-util';
@@ -63,9 +64,9 @@ export class LevelKey implements DecryptData {
       key.method === this.method &&
       key.encrypted === this.encrypted &&
       key.keyFormat === this.keyFormat &&
-      key.keyFormatVersions.join(',') === this.keyFormatVersions.join(',') &&
-      key.iv?.join(',') === this.iv?.join(',') &&
-      key.keyId?.join(',') === this.keyId?.join(',')
+      arrayValuesMatch(key.keyFormatVersions, this.keyFormatVersions) &&
+      optionalArrayValuesMatch(key.iv, this.iv) &&
+      optionalArrayValuesMatch(key.keyId, this.keyId)
     );
   }
 

src/utils/arrays.ts

@@ -0,0 +1,22 @@
+export function arrayValuesMatch(
+  a: (string | number)[] | Uint8Array,
+  b: (string | number)[] | Uint8Array,
+): boolean {
+  if (a.length === b.length) {
+    return !a.some((value: string | number, i: number) => value !== b[i]);
+  }
+  return false;
+}
+
+export function optionalArrayValuesMatch(
+  a: (string | number)[] | Uint8Array | null | undefined,
+  b: (string | number)[] | Uint8Array | null | undefined,
+): boolean {
+  if (!a && !b) {
+    return true;
+  }
+  if (!a || !b) {
+    return false;
+  }
+  return arrayValuesMatch(a, b);
+}