From 6a502be3ca93092120e59512d483a55e190b2d5f Mon Sep 17 00:00:00 2001
From: altqx <al@altqx.com>
Date: Sat, 1 Aug 2026 19:26:15 +0700
Subject: [PATCH] fix hls offset and update libbitsub to v1.11.0

---
 package-lock.json                          | 28 +++++++++++++++++---
 package.json                               |  2 +-
 src/components/playback/playbackmanager.js | 30 +++-------------------
 src/plugins/htmlVideoPlayer/plugin.js      |  7 +++++
 4 files changed, 35 insertions(+), 32 deletions(-)

diff --git a/package-lock.json b/package-lock.json
index 3a3355fb8d..c9d1bf038e 100644
--- a/package-lock.json
+++ b/package-lock.json
@@ -49,7 +49,7 @@
         "jquery": "3.7.1",
         "jstree": "3.3.17",
         "libarchive.js": "2.0.2",
-        "libbitsub": "1.10.2",
+        "libbitsub": "1.11.0",
         "lodash-es": "4.18.1",
         "markdown-it": "14.2.0",
         "material-design-icons-iconfont": "6.7.0",
@@ -15019,15 +15019,35 @@
       }
     },
     "node_modules/libbitsub": {
-      "version": "1.10.2",
-      "resolved": "https://registry.npmjs.org/libbitsub/-/libbitsub-1.10.2.tgz",
-      "integrity": "sha512-cXD1ueeeXqJIaNvYRrkNZOZ0A5FMMv9+8Yp/lHJZXPvkim5h0yvF2G27lYr0vGN9HwZCaJhkz6GArRerieTtuw==",
+      "version": "1.11.0",
+      "resolved": "https://registry.npmjs.org/libbitsub/-/libbitsub-1.11.0.tgz",
+      "integrity": "sha512-1niXMUxtvShJSv36enD6kVR2QABXtjz6vAVtqcMooU9qefZomQDXYpV0pIEQS3fXDmH4xjl+xVJdgNpk6i/oRA==",
       "license": "MIT",
       "dependencies": {
         "@webgpu/types": "^0.1.71"
       },
       "engines": {
         "node": ">=18"
+      },
+      "peerDependencies": {
+        "hls.js": ">=1.0.0",
+        "react": ">=18.0.0",
+        "shaka-player": ">=4.0.0",
+        "video.js": ">=7.0.0"
+      },
+      "peerDependenciesMeta": {
+        "hls.js": {
+          "optional": true
+        },
+        "react": {
+          "optional": true
+        },
+        "shaka-player": {
+          "optional": true
+        },
+        "video.js": {
+          "optional": true
+        }
       }
     },
     "node_modules/lie": {
diff --git a/package.json b/package.json
index 0f49a24a4d..9ffc012168 100644
--- a/package.json
+++ b/package.json
@@ -117,7 +117,7 @@
     "jquery": "3.7.1",
     "jstree": "3.3.17",
     "libarchive.js": "2.0.2",
-    "libbitsub": "1.10.2",
+    "libbitsub": "1.11.0",
     "lodash-es": "4.18.1",
     "markdown-it": "14.2.0",
     "material-design-icons-iconfont": "6.7.0",
diff --git a/src/components/playback/playbackmanager.js b/src/components/playback/playbackmanager.js
index c715f4da21..4acf6b7a63 100644
--- a/src/components/playback/playbackmanager.js
+++ b/src/components/playback/playbackmanager.js
@@ -644,30 +644,6 @@ function showPlaybackInfoErrorMessage(instance, errorCode) {
     });
 }
 
-function isExternalGraphicalSubtitleStream(stream) {
-    if (!stream || stream.Type !== 'Subtitle' || stream.DeliveryMethod !== 'External') {
-        return false;
-    }
-
-    if (typeof stream.IsTextSubtitleStream === 'boolean') {
-        return !stream.IsTextSubtitleStream;
-    }
-
-    const codec = (stream.Codec || '').toLowerCase();
-    return codec === 'pgssub' || codec === 'dvdsub' || codec === 'vobsub';
-}
-
-function hasSelectedExternalGraphicalSubtitle(mediaSource) {
-    const selectedSubtitleIndices = [mediaSource.DefaultSubtitleStreamIndex, mediaSource.DefaultSecondarySubtitleStreamIndex]
-        .filter(index => typeof index === 'number' && index >= 0);
-
-    if (selectedSubtitleIndices.length === 0) {
-        return false;
-    }
-
-    return (mediaSource.MediaStreams || []).some(stream => selectedSubtitleIndices.includes(stream.Index) && isExternalGraphicalSubtitleStream(stream));
-}
-
 function normalizePlayOptions(playOptions) {
     playOptions.fullscreen = playOptions.fullscreen !== false;
 }
@@ -2899,10 +2875,10 @@ export class PlaybackManager {
                         contentType = 'application/x-mpegURL';
                     } else {
                         contentType = getMimeType(type.toLowerCase(), mediaSource.TranscodingContainer);
-                    }
 
-                    if (!(mediaSource.TranscodingSubProtocol === 'hls' && hasSelectedExternalGraphicalSubtitle(mediaSource))) {
-                        transcodingOffsetTicks = startPosition || 0;
+                        if (mediaUrl.toLowerCase().indexOf('copytimestamps=true') === -1) {
+                            transcodingOffsetTicks = startPosition || 0;
+                        }
                     }
                 }
             } else {
diff --git a/src/plugins/htmlVideoPlayer/plugin.js b/src/plugins/htmlVideoPlayer/plugin.js
index 8ecaafad3d..9b4db45281 100644
--- a/src/plugins/htmlVideoPlayer/plugin.js
+++ b/src/plugins/htmlVideoPlayer/plugin.js
@@ -452,6 +452,9 @@ export class HtmlVideoPlayer {
             video: videoElement,
             subUrl: getTextTrackUrl(track, item),
             timeOffset: getSubtitleTimeOffset(this._currentPlayOptions, this.#currentTrackOffset),
+            streamingLoad: true,
+            rangeRequests: true,
+            prefetchWindow: { before: 1, after: 2 },
             ...(displaySettings ? { displaySettings } : {}),
             onLoading: () => this.beginPendingSubtitleLoad(targetTextTrackIndex, loadToken),
             onLoaded: () => this.endPendingSubtitleLoad(targetTextTrackIndex, loadToken),
@@ -504,6 +507,10 @@ export class HtmlVideoPlayer {
 
         if (options.resetSubtitleOffset !== false) this.resetSubtitleOffset();
 
+        void import('libbitsub')
+            .then(({ warmup }) => warmup())
+            .catch((error) => console.warn('[libbitsub] worker prewarm failed; renderer fallback will be used', error));
+
         const elem = await this.createMediaElement(options);
         this.#applyAspectRatio(options.aspectRatio || this.getAspectRatio());