Merge branch 'patch/v1.4.x'

* patch/v1.4.x:
  Allow the odd empty segment to be skipped like a gap segment (#5676)
  Use input timescale when remuxing inband captions (#5675)

src/controller/base-stream-controller.ts

@@ -1702,8 +1702,15 @@ export default class BaseStreamController
       level.fragmentError = 0;
     } else if (this.transmuxer?.error === null) {
       const error = new Error(
-        `Found no media in fragment ${frag.sn} of level ${level.id} resetting transmuxer to fallback to playlist timing`
+        `Found no media in fragment ${frag.sn} of level ${frag.level} resetting transmuxer to fallback to playlist timing`
       );
+      if (level.fragmentError === 0) {
+        // Mark and track the odd empty segment as a gap to avoid reloading
+        level.fragmentError++;
+        frag.gap = true;
+        this.fragmentTracker.removeFragment(frag);
+        this.fragmentTracker.fragBuffered(frag, true);
+      }
       this.warn(error.message);
       this.hls.trigger(Events.ERROR, {
         type: ErrorTypes.MEDIA_ERROR,

src/controller/error-controller.ts

@@ -128,8 +128,17 @@ export default class ErrorController implements NetworkComponentAPI {
       case ErrorDetails.KEY_LOAD_TIMEOUT:
         data.errorAction = this.getFragRetryOrSwitchAction(data);
         return;
-      case ErrorDetails.FRAG_GAP:
       case ErrorDetails.FRAG_PARSING_ERROR:
+        // ignore empty segment errors marked as gap
+        if (data.frag?.gap) {
+          data.errorAction = {
+            action: NetworkErrorAction.DoNothing,
+            flags: ErrorActionFlags.None,
+          };
+          return;
+        }
+      // falls through
+      case ErrorDetails.FRAG_GAP:
       case ErrorDetails.FRAG_DECRYPT_ERROR: {
         // Switch level if possible, otherwise allow retry count to reach max error retries
         data.errorAction = this.getFragRetryOrSwitchAction(data);

src/controller/fragment-tracker.ts

@@ -185,7 +185,7 @@ export class FragmentTracker implements ComponentAPI {
 
     const fragKey = getFragmentKey(frag);
     const fragmentEntity = this.fragments[fragKey];
-    if (!fragmentEntity) {
+    if (!fragmentEntity || (fragmentEntity.buffered && frag.gap)) {
       return;
     }
     const isFragHint = !frag.relurl;