Only allow large gaps to be skipped if start gap or all fragments in …

…range are partial Fixes #5360
video-dev · Apr 5, 2023 · 25225c3 · 25225c3
1 parent dc67742
commit 25225c3
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Showing 8 changed files with 87 additions and 10 deletions.
diff --git a/api-extractor/report/hls.js.api.md b/api-extractor/report/hls.js.api.md
@@ -278,7 +278,7 @@ export class BaseSegment {
 //
 // @public (undocumented)
 export class BaseStreamController extends TaskLoop implements NetworkComponentAPI {
-    constructor(hls: Hls, fragmentTracker: FragmentTracker, keyLoader: KeyLoader, logPrefix: string);
+    constructor(hls: Hls, fragmentTracker: FragmentTracker, keyLoader: KeyLoader, logPrefix: string, playlistType: PlaylistLevelType);
     // (undocumented)
     protected afterBufferFlushed(media: Bufferable, bufferType: SourceBufferName, playlistType: PlaylistLevelType): void;
     // (undocumented)
@@ -412,6 +412,8 @@ export class BaseStreamController extends TaskLoop implements NetworkComponentAP
     // (undocumented)
     protected onvseeking: EventListener | null;
     // (undocumented)
+    protected playlistType: PlaylistLevelType;
+    // (undocumented)
     protected recoverWorkerError(data: ErrorData): void;
     // (undocumented)
     protected reduceLengthAndFlushBuffer(data: ErrorData): boolean;

diff --git a/src/controller/audio-stream-controller.ts b/src/controller/audio-stream-controller.ts
@@ -64,7 +64,13 @@ class AudioStreamController
     fragmentTracker: FragmentTracker,
     keyLoader: KeyLoader
   ) {
-    super(hls, fragmentTracker, keyLoader, '[audio-stream-controller]');
+    super(
+      hls,
+      fragmentTracker,
+      keyLoader,
+      '[audio-stream-controller]',
+      PlaylistLevelType.AUDIO
+    );
     this._registerListeners();
   }
 

diff --git a/src/controller/base-stream-controller.ts b/src/controller/base-stream-controller.ts
@@ -79,6 +79,7 @@ export default class BaseStreamController
   protected fragmentTracker: FragmentTracker;
   protected transmuxer: TransmuxerInterface | null = null;
   protected _state: string = State.STOPPED;
+  protected playlistType: PlaylistLevelType;
   protected media: HTMLMediaElement | null = null;
   protected mediaBuffer: Bufferable | null = null;
   protected config: HlsConfig;
@@ -107,9 +108,11 @@ export default class BaseStreamController
     hls: Hls,
     fragmentTracker: FragmentTracker,
     keyLoader: KeyLoader,
-    logPrefix: string
+    logPrefix: string,
+    playlistType: PlaylistLevelType
   ) {
     super();
+    this.playlistType = playlistType;
     this.logPrefix = logPrefix;
     this.log = logger.log.bind(logger, `${logPrefix}:`);
     this.warn = logger.warn.bind(logger, `${logPrefix}:`);
@@ -270,6 +273,16 @@ export default class BaseStreamController
     }
 
     if (media) {
+      // Remove gap fragments
+      if (this.lastCurrentTime > currentTime) {
+        this.fragmentTracker.removeFragmentsInRange(
+          currentTime,
+          this.lastCurrentTime,
+          this.playlistType,
+          true
+        );
+      }
+
       this.lastCurrentTime = currentTime;
     }
 

diff --git a/src/controller/fragment-tracker.ts b/src/controller/fragment-tracker.ts
@@ -220,7 +220,7 @@ export class FragmentTracker implements ComponentAPI {
     }
   }
 
-  public fragBuffered(frag: Fragment, force?: boolean) {
+  public fragBuffered(frag: Fragment, force?: true) {
     const fragKey = getFragmentKey(frag);
     let fragmentEntity = this.fragments[fragKey];
     if (!fragmentEntity && force) {
@@ -447,7 +447,8 @@ export class FragmentTracker implements ComponentAPI {
   public removeFragmentsInRange(
     start: number,
     end: number,
-    playlistType: PlaylistLevelType
+    playlistType: PlaylistLevelType,
+    withGap?: true
   ) {
     Object.keys(this.fragments).forEach((key) => {
       const fragmentEntity = this.fragments[key];

diff --git a/src/controller/gap-controller.ts b/src/controller/gap-controller.ts
@@ -1,6 +1,7 @@
 import type { BufferInfo } from '../utils/buffer-helper';
 import { BufferHelper } from '../utils/buffer-helper';
 import { ErrorTypes, ErrorDetails } from '../errors';
+import { PlaylistLevelType } from '../types/loader';
 import { Events } from '../events';
 import { logger } from '../utils/logger';
 import type Hls from '../hls';
@@ -256,7 +257,46 @@ export default class GapController {
       const bufferStarved = bufferInfo.len <= config.maxBufferHole;
       const waiting =
         bufferInfo.len > 0 && bufferInfo.len < 1 && media.readyState < 3;
-      if (currentTime < startTime && (bufferStarved || waiting)) {
+      const gapLength = startTime - currentTime;
+      if (gapLength > 0 && (bufferStarved || waiting)) {
+        // Only allow large gaps to be skipped if it is a start gap, or all fragments in skip range are partial
+        if (gapLength > config.maxBufferHole) {
+          const { fragmentTracker } = this;
+          let startGap = false;
+          if (currentTime === 0) {
+            const startFrag = fragmentTracker.getAppendedFrag(
+              0,
+              PlaylistLevelType.MAIN
+            );
+            if (startFrag && startTime < startFrag.end) {
+              startGap = true;
+            }
+          }
+          if (!startGap) {
+            const startProvisioned =
+              partial ||
+              fragmentTracker.getAppendedFrag(
+                currentTime,
+                PlaylistLevelType.MAIN
+              );
+            if (startProvisioned) {
+              let moreToLoad = false;
+              let pos = startProvisioned.end;
+              while (pos < startTime) {
+                const provisioned = fragmentTracker.getPartialFragment(pos);
+                if (provisioned) {
+                  pos += provisioned.duration;
+                } else {
+                  moreToLoad = true;
+                  break;
+                }
+              }
+              if (moreToLoad) {
+                return 0;
+              }
+            }
+          }
+        }
         const targetTime = Math.max(
           startTime + SKIP_BUFFER_RANGE_START,
           currentTime + SKIP_BUFFER_HOLE_STEP_SECONDS

diff --git a/src/controller/level-helper.ts b/src/controller/level-helper.ts
@@ -88,10 +88,13 @@ export function updateFragPTSDTS(
     endPTS = Math.max(endPTS, fragEndPts);
     endDTS = Math.max(endDTS, frag.endDTS);
   }
-  frag.duration = endPTS - startPTS;
 
   const drift = startPTS - frag.start;
-  frag.start = frag.startPTS = startPTS;
+  if (frag.start !== 0) {
+    frag.start = startPTS;
+  }
+  frag.duration = endPTS - frag.start;
+  frag.startPTS = startPTS;
   frag.maxStartPTS = maxStartPTS;
   frag.startDTS = startDTS;
   frag.endPTS = endPTS;

diff --git a/src/controller/stream-controller.ts b/src/controller/stream-controller.ts
@@ -62,7 +62,13 @@ export default class StreamController
     fragmentTracker: FragmentTracker,
     keyLoader: KeyLoader
   ) {
-    super(hls, fragmentTracker, keyLoader, '[stream-controller]');
+    super(
+      hls,
+      fragmentTracker,
+      keyLoader,
+      '[stream-controller]',
+      PlaylistLevelType.MAIN
+    );
     this._registerListeners();
   }
 

diff --git a/src/controller/subtitle-stream-controller.ts b/src/controller/subtitle-stream-controller.ts
@@ -49,7 +49,13 @@ export class SubtitleStreamController
     fragmentTracker: FragmentTracker,
     keyLoader: KeyLoader
   ) {
-    super(hls, fragmentTracker, keyLoader, '[subtitle-stream-controller]');
+    super(
+      hls,
+      fragmentTracker,
+      keyLoader,
+      '[subtitle-stream-controller]',
+      PlaylistLevelType.SUBTITLE
+    );
     this._registerListeners();
   }