Backport 0.19 iOS HLS fixes (#24147)

web/src/components/player/dynamic/DynamicVideoController.ts

@@ -10,6 +10,10 @@ import { playWithTemporaryMuteFallback } from "@/utils/videoUtil.ts";
 
 type PlayerMode = "playback" | "scrubbing";
 
+// how long a seek may wait for its `seeked` event before playback starts
+// anyway; long enough that a normally completing seek always wins
+const SEEK_PLAY_FALLBACK_MS = 1000;
+
 export class DynamicVideoController {
   // main state
   public camera = "";
@@ -106,7 +110,10 @@ export class DynamicVideoController {
 
   waitAndPlay() {
     return new Promise((resolve) => {
+      let fallback: NodeJS.Timeout | undefined;
+
       const onSeekedHandler = () => {
+        clearTimeout(fallback);
         this.playerController.removeEventListener("seeked", onSeekedHandler);
         playWithTemporaryMuteFallback(this.playerController);
         resolve(undefined);
@@ -115,6 +122,12 @@ export class DynamicVideoController {
       this.playerController.addEventListener("seeked", onSeekedHandler, {
         once: true,
       });
+
+      // iOS ManagedMediaSource pauses hls.js buffering, so `seeked` may
+      // never fire; playing is what prompts WebKit to resume streaming
+      if ("ManagedMediaSource" in window) {
+        fallback = setTimeout(onSeekedHandler, SEEK_PLAY_FALLBACK_MS);
+      }
     });
   }