fix(subtitles): follow mpv sub-delay in mining, sidebar, and navigation (#302)

src/anki-integration.ts

@@ -45,6 +45,7 @@ import {
 } from './anki-field-config';
 import { createLogger } from './logger';
 import { captureLiveSubtitleMiningContext } from './core/services/mining';
+import { shiftSubtitleRangeToVideoClock } from './core/services/subtitle-clock';
 import {
   createUiFeedbackState,
   beginUpdateProgress,
@@ -1029,10 +1030,10 @@ export class AnkiIntegration {
       Number.isFinite(this.mpvClient.currentSubEnd) &&
       this.mpvClient.currentSubEnd > this.mpvClient.currentSubStart
     ) {
-      return {
-        startTime: this.mpvClient.currentSubStart,
-        endTime: this.mpvClient.currentSubEnd,
-      };
+      return shiftSubtitleRangeToVideoClock(
+        { startTime: this.mpvClient.currentSubStart, endTime: this.mpvClient.currentSubEnd },
+        this.mpvClient.currentSubDelay,
+      );
     }
 
     const currentTime = this.mpvClient.currentTimePos || 0;
@@ -1672,7 +1673,7 @@ export class AnkiIntegration {
           if (this.config.fields?.miscInfo) {
             result.miscInfoValue = this.formatMiscInfoPattern(
               audioFilename,
-              this.mpvClient.currentSubStart,
+              this.mpvClient.currentSubStart + this.mpvClient.currentSubDelay,
             );
           }
         }
@@ -1695,7 +1696,7 @@ export class AnkiIntegration {
           if (this.config.fields?.miscInfo && !result.miscInfoValue) {
             result.miscInfoValue = this.formatMiscInfoPattern(
               imageFilename,
-              this.mpvClient.currentSubStart,
+              this.mpvClient.currentSubStart + this.mpvClient.currentSubDelay,
             );
           }
         }

src/anki-integration/card-creation.ts

@@ -10,6 +10,7 @@ import {
   type MediaTimingReviewRequest,
   type WordCardKind,
 } from '../types/anki';
+import { shiftSubtitleRangeToVideoClock } from '../core/services/subtitle-clock';
 import { createLogger } from '../logger';
 import type { MediaInput } from '../media-input';
 import { SubtitleTimingTracker } from '../subtitle-timing-tracker';
@@ -428,10 +429,12 @@ export class CardCreationService {
         return;
       }
 
-      let startTime = mpvClient.currentSubStart;
-      let endTime = mpvClient.currentSubEnd;
+      let { startTime, endTime } = shiftSubtitleRangeToVideoClock(
+        { startTime: mpvClient.currentSubStart, endTime: mpvClient.currentSubEnd },
+        mpvClient.currentSubDelay,
+      );
 
-      if (startTime === undefined || endTime === undefined) {
+      if (mpvClient.currentSubStart === undefined || mpvClient.currentSubEnd === undefined) {
         const currentTime = mpvClient.currentTimePos || 0;
         const fallback = this.deps.getFallbackDurationSeconds() / 2;
         startTime = currentTime - fallback;

src/core/services/index.ts

@@ -55,6 +55,7 @@ export {
   subtitleCueListSeekTime,
   subtitleCueSeekTime,
 } from './subtitle-cue-navigation';
+export { shiftSubtitleRangeToVideoClock, toSubtitleClock, toVideoClock } from './subtitle-clock';
 export { createFrequencyDictionaryLookup } from './frequency-dictionary';
 export { createJlptVocabularyLookup } from './jlpt-vocab';
 export {

src/core/services/ipc.test.ts

@@ -89,6 +89,7 @@ function createSubtitleSidebarSnapshotFixture(): SubtitleSidebarSnapshot {
     cuesRevision: 1,
     cues: [],
     currentTimeSec: null,
+    subDelay: 0,
     currentSubtitle: { text: '', startTime: null, endTime: null },
     config: {
       enabled: false,

src/core/services/mining.test.ts

@@ -77,6 +77,7 @@ test('mineSentenceCard handles missing integration and disconnected mpv', async
         currentSubText: 'line',
         currentSubStart: 1,
         currentSubEnd: 2,
+        currentSubDelay: 0,
       },
       showMpvOsd: (text) => osd.push(text),
     }),
@@ -109,6 +110,7 @@ test('mineSentenceCard creates sentence card from mpv subtitle state', async ()
       currentSubText: 'subtitle line',
       currentSubStart: 10,
       currentSubEnd: 12,
+      currentSubDelay: 0,
       currentSecondarySubText: 'secondary line',
     },
     showMpvOsd: () => {},
@@ -148,6 +150,7 @@ test('mineSentenceCard prefers a canonical primary subtitle snapshot', async ()
       currentSubText: '今今今手手手',
       currentSubStart: 11.4,
       currentSubEnd: 11.8,
+      currentSubDelay: 0,
       currentSecondarySubText: 'English subtitle',
     },
     primarySubtitle: {
@@ -187,6 +190,7 @@ test('mineSentenceCard uses normalized secondary subtitle state instead of raw m
       currentSubText: '日本語字幕',
       currentSubStart: 10,
       currentSubEnd: 12,
+      currentSubDelay: 0,
       currentSecondarySubText: 'Your\nmosaic',
       requestProperty: async () => {
         requestedRawSecondaryText = true;
@@ -218,6 +222,7 @@ test('mineSentenceCard omits normalized secondary text that matches the primary
       currentSubText: '日本語字幕',
       currentSubStart: 10,
       currentSubEnd: 12,
+      currentSubDelay: 0,
       currentSecondarySubText: '日本語字幕',
     },
     showMpvOsd: () => {},
@@ -396,7 +401,7 @@ test('handleMineSentenceDigit joins per-entry secondary subtitles when available
 
 test('captureLiveSubtitleMiningContext snapshots the current line and timings', () => {
   const context = captureLiveSubtitleMiningContext(
-    { currentSubText: ' 食べる ', currentSubStart: 12.5, currentSubEnd: 15.25 },
+    { currentSubText: ' 食べる ', currentSubStart: 12.5, currentSubEnd: 15.25, currentSubDelay: 0 },
     () => 1234,
   );
 
@@ -409,6 +414,16 @@ test('captureLiveSubtitleMiningContext snapshots the current line and timings',
   });
 });
 
+test('captureLiveSubtitleMiningContext moves sub-delay retimed lines onto the video clock', () => {
+  const context = captureLiveSubtitleMiningContext(
+    { currentSubText: '食べる', currentSubStart: 5, currentSubEnd: 8, currentSubDelay: -1.5 },
+    () => 1234,
+  );
+
+  assert.equal(context?.startTime, 3.5);
+  assert.equal(context?.endTime, 6.5);
+});
+
 test('captureLiveSubtitleMiningContext rejects missing client, empty text and bad timings', () => {
   assert.equal(captureLiveSubtitleMiningContext(null), null);
   assert.equal(
@@ -416,6 +431,7 @@ test('captureLiveSubtitleMiningContext rejects missing client, empty text and ba
       currentSubText: '  ',
       currentSubStart: 1,
       currentSubEnd: 2,
+      currentSubDelay: 0,
     }),
     null,
   );
@@ -424,6 +440,7 @@ test('captureLiveSubtitleMiningContext rejects missing client, empty text and ba
       currentSubText: 'line',
       currentSubStart: 5,
       currentSubEnd: 5,
+      currentSubDelay: 0,
     }),
     null,
   );
@@ -432,6 +449,7 @@ test('captureLiveSubtitleMiningContext rejects missing client, empty text and ba
       currentSubText: 'line',
       currentSubStart: NaN,
       currentSubEnd: 2,
+      currentSubDelay: 0,
     }),
     null,
   );

src/core/services/mining.ts

@@ -1,5 +1,6 @@
 import type { SubtitleTimingBlock } from '../../subtitle-timing-tracker';
 import type { SubtitleMiningContext } from '../../types/subtitle';
+import { shiftSubtitleRangeToVideoClock } from './subtitle-clock';
 
 interface SubtitleTimingTrackerLike {
   getRecentBlocks: (count: number) => string[];
@@ -25,6 +26,7 @@ interface MpvClientLike {
   currentSubText: string;
   currentSubStart: number;
   currentSubEnd: number;
+  currentSubDelay: number;
   currentSecondarySubText?: string;
   requestProperty?: (name: string) => Promise<unknown>;
 }
@@ -62,7 +64,10 @@ export function handleMultiCopyDigit(
  * line is on screen by then; callers capture here at mining time instead.
  */
 export function captureLiveSubtitleMiningContext(
-  client: Pick<MpvClientLike, 'currentSubText' | 'currentSubStart' | 'currentSubEnd'> | null,
+  client: Pick<
+    MpvClientLike,
+    'currentSubText' | 'currentSubStart' | 'currentSubEnd' | 'currentSubDelay'
+  > | null,
   now: () => number = Date.now,
 ): SubtitleMiningContext | null {
   if (!client) {
@@ -73,7 +78,10 @@ export function captureLiveSubtitleMiningContext(
   if (!text || !Number.isFinite(startTime) || !Number.isFinite(endTime) || endTime <= startTime) {
     return null;
   }
-  return { source: 'overlay', text, startTime, endTime, capturedAtMs: now() };
+  return shiftSubtitleRangeToVideoClock<SubtitleMiningContext>(
+    { source: 'overlay', text, startTime, endTime, capturedAtMs: now() },
+    client.currentSubDelay,
+  );
 }
 
 export function copyCurrentSubtitle(deps: {
@@ -167,6 +175,7 @@ export async function markLastCardAsAudioCard(deps: {
 export async function mineSentenceCard(deps: {
   ankiIntegration: AnkiIntegrationLike | null;
   mpvClient: MpvClientLike | null;
+  /** Already on the video clock, like every `SubtitleMiningContext`. */
   primarySubtitle?: Pick<SubtitleMiningContext, 'text' | 'startTime' | 'endTime'>;
   showMpvOsd: (text: string) => void;
 }): Promise<boolean> {
@@ -185,10 +194,16 @@ export async function mineSentenceCard(deps: {
   }
 
   const secondarySubText = getCurrentSecondarySubTextForSentenceCard(mpvClient, primaryText);
+  const range =
+    deps.primarySubtitle ??
+    shiftSubtitleRangeToVideoClock(
+      { startTime: mpvClient.currentSubStart, endTime: mpvClient.currentSubEnd },
+      mpvClient.currentSubDelay,
+    );
   return await anki.createSentenceCard(
     primaryText,
-    deps.primarySubtitle?.startTime ?? mpvClient.currentSubStart,
-    deps.primarySubtitle?.endTime ?? mpvClient.currentSubEnd,
+    range.startTime,
+    range.endTime,
     secondarySubText,
   );
 }

src/core/services/mpv-properties.ts

@@ -38,6 +38,7 @@ const MPV_SUBTITLE_PROPERTY_OBSERVATIONS: string[] = [
   'path',
   'sub-start',
   'sub-end',
+  'sub-delay',
   'time-pos',
   'secondary-sub-text',
   'aid',

src/core/services/mpv-protocol.test.ts

@@ -73,6 +73,8 @@ function createDeps(overrides: Partial<MpvProtocolHandleMessageDeps> = {}): {
       getCurrentSubStart: () => 0,
       setCurrentSubEnd: () => {},
       getCurrentSubEnd: () => 0,
+      setCurrentSubDelay: () => {},
+      getCurrentSubDelay: () => 0,
       emitMediaPathChange: (payload) => {
         state.mediaPath = payload.path;
       },
@@ -131,6 +133,22 @@ test('dispatchMpvProtocolMessage emits subtitle text on property change', async
   assert.deepEqual(state.events, [{ text: '字幕', isOverlayVisible: false }]);
 });
 
+test('dispatchMpvProtocolMessage tracks sub-delay retiming', async () => {
+  const delays: number[] = [];
+  const { deps } = createDeps({ setCurrentSubDelay: (value) => delays.push(value) });
+
+  await dispatchMpvProtocolMessage(
+    { event: 'property-change', name: 'sub-delay', data: 1.5 },
+    deps,
+  );
+  await dispatchMpvProtocolMessage(
+    { event: 'property-change', name: 'sub-delay', data: null },
+    deps,
+  );
+
+  assert.deepEqual(delays, [1.5, 0]);
+});
+
 test('dispatchMpvProtocolMessage widens halfwidth katakana in subtitle text', async () => {
   const { deps, state } = createDeps();
 
@@ -379,6 +397,29 @@ test('dispatchMpvProtocolMessage pauses on sub-end when pendingPauseAtSubEnd is
   });
 });
 
+test('dispatchMpvProtocolMessage pauses at the sub-delay retimed sub-end', async () => {
+  let pauseAtTime: number | null = null;
+  let subDelay = 1.5;
+  const { deps } = createDeps({
+    getPendingPauseAtSubEnd: () => true,
+    getCurrentSubDelay: () => subDelay,
+    setCurrentSubDelay: (next) => {
+      subDelay = next;
+    },
+    getPauseAtTime: () => pauseAtTime,
+    setPauseAtTime: (next) => {
+      pauseAtTime = next;
+    },
+  });
+
+  await dispatchMpvProtocolMessage({ event: 'property-change', name: 'sub-end', data: 42 }, deps);
+  assert.equal(pauseAtTime, 43.5);
+
+  // Retiming before the replay reaches its end moves the pause with the line.
+  await dispatchMpvProtocolMessage({ event: 'property-change', name: 'sub-delay', data: 2 }, deps);
+  assert.equal(pauseAtTime, 44);
+});
+
 test('dispatchMpvProtocolMessage updates current time before emitting time-pos change', async () => {
   const calls: string[] = [];
   let currentTimePos = 0;

src/core/services/mpv-protocol.ts

@@ -1,6 +1,7 @@
 import { MpvSubtitleRenderMetrics } from '../../types';
 import { sanitizeMediaTitle } from '../../shared/media-identity';
 import { widenHalfwidthKana } from '../utils/halfwidth-kana';
+import { toVideoClock } from './subtitle-clock';
 
 export type MpvMessage = {
   event?: string;
@@ -64,6 +65,8 @@ export interface MpvProtocolHandleMessageDeps {
   getCurrentSubStart: () => number;
   setCurrentSubEnd: (value: number) => void;
   getCurrentSubEnd: () => number;
+  setCurrentSubDelay: (value: number) => void;
+  getCurrentSubDelay: () => number;
   emitMediaPathChange: (payload: { path: string }) => void;
   emitMediaTitleChange: (payload: { title: string | null }) => void;
   emitTimePosChange: (payload: { time: number }) => void;
@@ -263,7 +266,8 @@ export async function dispatchMpvProtocolMessage(
       const subEnd = (msg.data as number) || 0;
       deps.setCurrentSubEnd(subEnd);
       if (deps.getPendingPauseAtSubEnd() && subEnd > 0) {
-        deps.setPauseAtTime(subEnd);
+        // `sub-end` is on the subtitle clock; the pause check compares it with `time-pos`.
+        deps.setPauseAtTime(toVideoClock(subEnd, deps.getCurrentSubDelay()));
         deps.setPendingPauseAtSubEnd(false);
         deps.sendCommand({ command: ['set_property', 'pause', false] });
       }
@@ -272,6 +276,16 @@ export async function dispatchMpvProtocolMessage(
         start: deps.getCurrentSubStart(),
         end: deps.getCurrentSubEnd(),
       });
+    } else if (msg.name === 'sub-delay') {
+      const parsed = typeof msg.data === 'number' ? msg.data : Number(msg.data);
+      const delay = Number.isFinite(parsed) ? parsed : 0;
+      // A scheduled replay pause sits at the line's end on the video clock; retiming
+      // mid-replay moves that end, so the pause moves with it.
+      const pauseAtTime = deps.getPauseAtTime();
+      if (pauseAtTime !== null) {
+        deps.setPauseAtTime(pauseAtTime + delay - deps.getCurrentSubDelay());
+      }
+      deps.setCurrentSubDelay(delay);
     } else if (msg.name === 'secondary-sub-text') {
       const nextSubText = (msg.data as string) || '';
       deps.setCurrentSecondarySubText(nextSubText);

src/core/services/mpv.ts

@@ -160,6 +160,8 @@ export class MpvIpcClient implements MpvClient {
   public currentTimePos = 0;
   public currentSubStart = 0;
   public currentSubEnd = 0;
+  /** mpv `sub-delay`: seconds each primary line plays after its `sub-start`/`sub-end`. */
+  public currentSubDelay = 0;
   public currentSubText = '';
   public currentSecondarySubText = '';
   public currentAudioStreamIndex: number | null = null;
@@ -459,6 +461,10 @@ export class MpvIpcClient implements MpvClient {
         this.currentSubEnd = value;
       },
       getCurrentSubEnd: () => this.currentSubEnd,
+      setCurrentSubDelay: (value: number) => {
+        this.currentSubDelay = value;
+      },
+      getCurrentSubDelay: () => this.currentSubDelay,
       emitMediaPathChange: (payload) => {
         this.emit('media-path-change', payload);
       },

src/core/services/subtitle-clock.ts

@@ -0,0 +1,32 @@
+/**
+ * mpv's `sub-start`/`sub-end` and parsed cues carry the subtitle file's own timestamps
+ * (the subtitle clock), but mpv plays each line `sub-delay` seconds later (z/x retiming,
+ * `sub-step`). Playback position, seeks, and media cuts are on the video clock, so any
+ * value crossing between the two converts here.
+ */
+
+function finiteDelay(subDelay: number): number {
+  return Number.isFinite(subDelay) ? subDelay : 0;
+}
+
+/** Playback position (`time-pos`) on the subtitle clock, comparable with cue times. */
+export function toSubtitleClock(videoTimeSec: number, subDelay: number): number {
+  return videoTimeSec - finiteDelay(subDelay);
+}
+
+/** Subtitle-clock seconds on the video clock, for seeks. */
+export function toVideoClock(subtitleTimeSec: number, subDelay: number): number {
+  return subtitleTimeSec + finiteDelay(subDelay);
+}
+
+/** A subtitle-clock range on the video clock, for mining and media generation. */
+export function shiftSubtitleRangeToVideoClock<T extends { startTime: number; endTime: number }>(
+  range: T,
+  subDelay: number,
+): T {
+  const delay = finiteDelay(subDelay);
+  if (delay === 0) {
+    return range;
+  }
+  return { ...range, startTime: range.startTime + delay, endTime: range.endTime + delay };
+}

src/core/services/subtitle-cue-navigation.test.ts

@@ -26,7 +26,7 @@ test('next subtitle navigation skips generated ASS events and seeks to the next
     },
   ];
 
-  assert.deepEqual(resolveSanitizedSubtitleSeekCommand(['sub-seek', 1], cues, 10.2), [
+  assert.deepEqual(resolveSanitizedSubtitleSeekCommand(['sub-seek', 1], cues, 10.2, 0), [
     'seek',
     13.08,
     'absolute+exact',
@@ -41,7 +41,7 @@ test('next subtitle navigation treats simultaneous sanitized cues as one line bo
     { startTime: 13.02, endTime: 16, text: 'Next English' },
   ];
 
-  assert.deepEqual(resolveSanitizedSubtitleSeekCommand(['sub-seek', 1], cues, 10.1), [
+  assert.deepEqual(resolveSanitizedSubtitleSeekCommand(['sub-seek', 1], cues, 10.1, 0), [
     'seek',
     13.08,
     'absolute+exact',
@@ -55,7 +55,7 @@ test('next subtitle navigation advances past the latest overlapping lyric', () =
     { startTime: 16, endTime: 19, text: 'next lyric' },
   ];
 
-  assert.deepEqual(resolveSanitizedSubtitleSeekCommand(['sub-seek', 1], cues, 13.2), [
+  assert.deepEqual(resolveSanitizedSubtitleSeekCommand(['sub-seek', 1], cues, 13.2, 0), [
     'seek',
     16.08,
     'absolute+exact',
@@ -68,7 +68,7 @@ test('previous subtitle navigation leaves the current cue and seeks to the prior
     { startTime: 13, endTime: 16, text: 'current line' },
   ];
 
-  assert.deepEqual(resolveSanitizedSubtitleSeekCommand(['sub-seek', -1], cues, 14.5), [
+  assert.deepEqual(resolveSanitizedSubtitleSeekCommand(['sub-seek', -1], cues, 14.5, 0), [
     'seek',
     10.08,
     'absolute+exact',
@@ -78,8 +78,22 @@ test('previous subtitle navigation leaves the current cue and seeks to the prior
 test('subtitle navigation falls back when no sanitized destination exists', () => {
   const cues = [{ startTime: 10, endTime: 13, text: 'only line' }];
 
-  assert.equal(resolveSanitizedSubtitleSeekCommand(['sub-seek', 1], cues, 10.2), null);
-  assert.equal(resolveSanitizedSubtitleSeekCommand(['seek', 5], cues, 10.2), null);
+  assert.equal(resolveSanitizedSubtitleSeekCommand(['sub-seek', 1], cues, 10.2, 0), null);
+  assert.equal(resolveSanitizedSubtitleSeekCommand(['seek', 5], cues, 10.2, 0), null);
+});
+
+test('subtitle cue navigation finds and seeks cues on the sub-delay retimed timeline', () => {
+  const cues = [
+    { startTime: 10, endTime: 13, text: 'one' },
+    { startTime: 13, endTime: 16, text: 'two' },
+  ];
+
+  // At 14.5 with a 2s delay, mpv is showing "one" (12-15 on the video clock).
+  assert.deepEqual(resolveSanitizedSubtitleSeekCommand(['sub-seek', 1], cues, 14.5, 2), [
+    'seek',
+    15.08,
+    'absolute+exact',
+  ]);
 });
 
 test('sidebar cue seeks share the boundary-safe sanitized cue timestamp', () => {

src/core/services/subtitle-cue-navigation.ts

@@ -1,3 +1,4 @@
+import { toSubtitleClock, toVideoClock } from './subtitle-clock';
 import type { SubtitleCue } from './subtitle-cue-parser';
 
 const CUE_START_GROUP_TOLERANCE_SECONDS = 0.05;
@@ -80,8 +81,10 @@ export function subtitleCueListSeekTime(
 export function resolveSanitizedSubtitleSeekCommand(
   command: readonly (string | number)[],
   cues: readonly SubtitleCue[],
-  currentTimeSec: number,
+  videoTimeSec: number,
+  subDelay: number,
 ): (string | number)[] | null {
+  const currentTimeSec = toSubtitleClock(videoTimeSec, subDelay);
   if (
     command.length < 2 ||
     command[0] !== 'sub-seek' ||
@@ -124,5 +127,5 @@ export function resolveSanitizedSubtitleSeekCommand(
   if (!destination) {
     return null;
   }
-  return ['seek', subtitleCueSeekTime(destination.cue), 'absolute+exact'];
+  return ['seek', toVideoClock(subtitleCueSeekTime(destination.cue), subDelay), 'absolute+exact'];
 }

src/main.ts

@@ -328,9 +328,11 @@ import {
   setMpvSubVisibilityRuntime,
   setOverlayDebugVisualizationEnabledRuntime,
   setVisibleOverlayVisible as setVisibleOverlayVisibleCore,
+  shiftSubtitleRangeToVideoClock,
   showMpvOsdRuntime,
   JellyfinPlaybackReporter,
   tokenizeSubtitle as tokenizeSubtitleCore,
+  toSubtitleClock,
   triggerFieldGrouping as triggerFieldGroupingCore,
   upsertYomitanDictionarySettings,
   updateLastCardFromClipboard as updateLastCardFromClipboardCore,
@@ -1937,7 +1939,10 @@ let tokenizeSubtitleDeferred: ((text: string) => Promise<SubtitleData>) | null =
 function withCurrentSubtitleTiming(payload: SubtitleData): SubtitleData {
   const canonical = resolveCanonicalPrimarySubtitle({
     liveText: payload.text,
-    currentTimeSec: Number(appState.mpvClient?.currentTimePos),
+    currentTimeSec: toSubtitleClock(
+      Number(appState.mpvClient?.currentTimePos),
+      appState.mpvClient?.currentSubDelay ?? 0,
+    ),
     cues: appState.activeParsedSubtitleCues,
   });
   return {
@@ -1951,9 +1956,11 @@ function captureCurrentPrimarySubtitleMiningContext(): SubtitleMiningContext | n
   // Mine what the overlay shows, not raw mpv `sub-text`: the raw text lists every active
   // event, so a finished caption row lingering beside a fresh line would end up on the
   // card. The parsed view also carries the cue's own timings for the clip range.
+  // Cues sit on the subtitle clock, so the lookup undoes `sub-delay` first.
+  const subDelay = appState.mpvClient?.currentSubDelay ?? 0;
   const resolved = resolvePrimarySubtitle({
     liveText: appState.mpvClient?.currentSubText ?? '',
-    currentTimeSec: Number(appState.mpvClient?.currentTimePos),
+    currentTimeSec: toSubtitleClock(Number(appState.mpvClient?.currentTimePos), subDelay),
     cues: appState.activeParsedSubtitleCues,
   });
   // Same validity bar as the live capture path: an unusable resolved span must fall
@@ -1968,13 +1975,16 @@ function captureCurrentPrimarySubtitleMiningContext(): SubtitleMiningContext | n
   ) {
     return captureLiveSubtitleMiningContext(appState.mpvClient);
   }
-  return {
-    source: 'overlay',
-    text: resolvedText,
-    startTime: resolved.startTime,
-    endTime: resolved.endTime,
-    capturedAtMs: Date.now(),
-  };
+  return shiftSubtitleRangeToVideoClock<SubtitleMiningContext>(
+    {
+      source: 'overlay',
+      text: resolvedText,
+      startTime: resolved.startTime,
+      endTime: resolved.endTime,
+      capturedAtMs: Date.now(),
+    },
+    subDelay,
+  );
 }
 function emitSubtitlePayload(payload: SubtitleData, options?: { resumePrefetch?: boolean }): void {
   const timedPayload = withCurrentSubtitleTiming(payload);
@@ -2116,13 +2126,18 @@ function getSubtitleSidebarPlaybackState(): SubtitleSidebarPlaybackState {
     subtitleSidebarCuesRef = appState.activeParsedSubtitleCues;
     subtitleSidebarCuesRevision += 1;
   }
+  const subDelay = appState.mpvClient?.currentSubDelay ?? 0;
   return {
     sourceKey: JSON.stringify([
       appState.activeParsedSubtitleMediaPath,
       appState.activeParsedSubtitleSource,
     ]),
     cuesRevision: subtitleSidebarCuesRevision,
-    currentTimeSec: appState.mpvClient?.currentTimePos ?? null,
+    currentTimeSec:
+      appState.mpvClient?.currentTimePos === undefined
+        ? null
+        : toSubtitleClock(appState.mpvClient.currentTimePos, subDelay),
+    subDelay,
     currentSubtitle: {
       text: appState.currentSubText,
       startTime: appState.mpvClient?.currentSubStart ?? null,
@@ -2161,6 +2176,7 @@ function sendRendererMpvCommand(rawCommand: (string | number)[]): void {
       rawCommand,
       appState.activeParsedSubtitleCues,
       appState.mpvClient?.currentTimePos ?? Number.NaN,
+      appState.mpvClient?.currentSubDelay ?? 0,
     ) ?? rawCommand;
   if (isExplicitMpvSeekCommand(command)) {
     explicitSeekIntentExpiresAtMs = Date.now() + EXPLICIT_SEEK_INTENT_TTL_MS;
@@ -3115,7 +3131,10 @@ const mediaTimingReviewRuntime = createMediaTimingReviewRuntime({
   acquireMediaWindow: (source, range) => getSharedRemoteMediaWindowCache().acquire(source, range),
   getSubtitleContextLines: (range) =>
     collectMediaTimingContextLines({
-      cues: appState.activeParsedSubtitleCues,
+      // Review ranges and tracker entries are on the video clock; parsed cues are not.
+      cues: appState.activeParsedSubtitleCues.map((cue) =>
+        shiftSubtitleRangeToVideoClock(cue, appState.mpvClient?.currentSubDelay ?? 0),
+      ),
       fallbackPrevious: appState.subtitleTimingTracker?.getRecentEntries(40) ?? [],
       startTime: range.startTime,
       endTime: range.endTime,
@@ -6028,7 +6047,11 @@ const { registerIpcRuntimeHandlers } = composeIpcRuntimeHandlers({
       // live mpv sub timings at lookup time so media generation clips the mined line even
       // when extraction finishes long after playback has moved on.
       recordSubtitleMiningContext: (context) =>
-        recordSubtitleMiningContext(context ?? captureCurrentPrimarySubtitleMiningContext()),
+        recordSubtitleMiningContext(
+          context
+            ? shiftSubtitleRangeToVideoClock(context, appState.mpvClient?.currentSubDelay ?? 0)
+            : captureCurrentPrimarySubtitleMiningContext(),
+        ),
       tokenizeCurrentSubtitle: async () => {
         const tokenizeSubtitleForCurrent = tokenizeSubtitleDeferred;
         return resolveCurrentSubtitleForRenderer({

src/main/runtime/autoplay-subtitle-priming-runtime.ts

@@ -1,3 +1,4 @@
+import { toSubtitleClock } from '../../core/services/subtitle-clock';
 import type { SubtitleCue, SubtitleData } from '../../types';
 import { selectAutoplayStartupCue } from './autoplay-subtitle-primer';
 import { primeVisibleOverlaySubtitleFromMpv } from './current-subtitle-snapshot';
@@ -12,6 +13,7 @@ type AutoplaySubtitlePrimingMpvClient = {
   requestProperty: (name: string) => Promise<unknown>;
   currentVideoPath?: string;
   currentTimePos?: number;
+  currentSubDelay?: number;
   currentSubText?: string;
   currentSecondarySubText?: string;
   setCurrentSecondarySubText?: (text: string) => void;
@@ -156,7 +158,7 @@ export function createAutoplaySubtitlePrimingRuntime(deps: AutoplaySubtitlePrimi
     const currentTimeSec = Number(client?.currentTimePos ?? deps.getLastObservedTimePos());
     return resolvePrimarySubtitleText({
       liveText: text,
-      currentTimeSec,
+      currentTimeSec: toSubtitleClock(currentTimeSec, client?.currentSubDelay ?? 0),
       cues: deps.getActiveParsedSubtitleCues(),
     });
   }
@@ -270,7 +272,10 @@ export function createAutoplaySubtitlePrimingRuntime(deps: AutoplaySubtitlePrimi
     const currentTimeSeconds = Number(
       timePosRaw ?? client?.currentTimePos ?? deps.getLastObservedTimePos() ?? 0,
     );
-    const resolvedTimeSeconds = Number.isFinite(currentTimeSeconds) ? currentTimeSeconds : 0;
+    const resolvedTimeSeconds = toSubtitleClock(
+      Number.isFinite(currentTimeSeconds) ? currentTimeSeconds : 0,
+      client?.currentSubDelay ?? 0,
+    );
     const cue = selectAutoplayStartupCue(
       cues,
       resolvedTimeSeconds,

src/main/runtime/mpv-main-event-main-deps.test.ts

@@ -176,6 +176,21 @@ test('subtitle-track transitions ignore stale parsed cues until replacement cues
   assert.deepEqual(recordedStarts.slice(-1), [20]);
 });
 
+test('subtitle timing history records lines on the video clock under sub-delay', () => {
+  const timing: Array<{ text: string; start: number; end: number }> = [];
+  const { handlers } = buildMainDeps({
+    mpvClient: { currentSubDelay: 2 },
+    subtitleTimingTracker: {
+      recordSubtitle: (text: string, start: number, end: number) =>
+        timing.push({ text, start, end }),
+    },
+  });
+
+  handlers.recordSubtitleTiming('食べる', 5, 8);
+
+  assert.deepEqual(timing, [{ text: '食べる', start: 7, end: 10 }]);
+});
+
 test('canonical ASS cues replace live glyph spam for display, history, and immersion', () => {
   const immersion: Array<{ text: string; start: number; end: number }> = [];
   const timing: Array<{ text: string; start: number; end: number }> = [];

src/main/runtime/mpv-main-event-main-deps.ts

@@ -1,3 +1,4 @@
+import { toSubtitleClock } from '../../core/services/subtitle-clock';
 import { createSubtitleLineDedupGate } from '../../core/services/subtitle-line-dedup-gate';
 import type { MergedToken, SubtitleCue, SubtitleData } from '../../types';
 import {
@@ -23,6 +24,7 @@ export function createBuildBindMpvMainEventHandlersMainDepsHandler(deps: {
       currentSubText?: string;
       currentSecondarySubText?: string;
       currentTimePos?: number;
+      currentSubDelay?: number;
       requestProperty?: (name: string) => Promise<unknown>;
     } | null;
     immersionTracker: {
@@ -161,7 +163,10 @@ export function createBuildBindMpvMainEventHandlersMainDepsHandler(deps: {
     resolveSubtitleText: (liveText: string) =>
       resolvePrimarySubtitleText({
         liveText,
-        currentTimeSec: Number(deps.appState.mpvClient?.currentTimePos),
+        currentTimeSec: toSubtitleClock(
+          Number(deps.appState.mpvClient?.currentTimePos),
+          deps.appState.mpvClient?.currentSubDelay ?? 0,
+        ),
         cues: deps.appState.activeParsedSubtitleCues,
       }),
     getCurrentLiveSubtitleText: () => deps.appState.mpvClient?.currentSubText ?? '',
@@ -231,6 +236,9 @@ export function createBuildBindMpvMainEventHandlersMainDepsHandler(deps: {
     hasSubtitleTimingTracker: () => Boolean(deps.appState.subtitleTimingTracker),
     recordSubtitleTiming: (text: string, start: number, end: number) => {
       const secondaryText = deps.appState.mpvClient?.currentSecondarySubText || undefined;
+      // The tracker feeds multi-line mining, so it stores video-clock times: the subtitle
+      // timings plus the `sub-delay` in effect while the line was on screen.
+      const subDelay = deps.appState.mpvClient?.currentSubDelay ?? 0;
       const canonical = resolveCanonicalSample(text, start);
       if (!canonical) {
         const recordableText = resolveTextForRecording(text, start);
@@ -239,8 +247,8 @@ export function createBuildBindMpvMainEventHandlersMainDepsHandler(deps: {
         }
         deps.appState.subtitleTimingTracker?.recordSubtitle?.(
           recordableText,
-          start,
-          end,
+          start + subDelay,
+          end + subDelay,
           secondaryText,
         );
         return;
@@ -253,8 +261,8 @@ export function createBuildBindMpvMainEventHandlersMainDepsHandler(deps: {
         recordedTimingCanonicalKeys.add(key);
         deps.appState.subtitleTimingTracker?.recordSubtitle?.(
           cue.text,
-          cue.startTime,
-          cue.endTime,
+          cue.startTime + subDelay,
+          cue.endTime + subDelay,
           secondaryText,
         );
       }

src/renderer/modals/subtitle-sidebar-selection.electron-fixture.ts

@@ -28,6 +28,7 @@ export async function setup() {
     ],
     currentSubtitle: { text: '最初の台詞', startTime: 0, endTime: 1 },
     currentTimeSec: 0,
+    subDelay: 0,
     config: {
       ...SUBTITLE_DEFAULT_CONFIG.subtitleSidebar,
       enabled: true,

src/renderer/modals/subtitle-sidebar.test.ts

@@ -199,6 +199,7 @@ function createSidebarHarness(options: SidebarHarnessOptions = {}) {
     cues: options.cues ?? [{ startTime: 1, endTime: 2, text: 'first' }],
     currentSubtitle: options.currentSubtitle ?? { text: 'first', startTime: 1, endTime: 2 },
     currentTimeSec: 'currentTimeSec' in options ? (options.currentTimeSec ?? null) : 1.1,
+    subDelay: 0,
     config: { ...DEFAULT_SIDEBAR_CONFIG, ...options.config },
   };
   const requests = { snapshot: 0, playback: 0 };
@@ -226,8 +227,8 @@ function createSidebarHarness(options: SidebarHarnessOptions = {}) {
         },
         getSubtitleSidebarPlaybackState: async (): Promise<SubtitleSidebarPlaybackState> => {
           requests.playback += 1;
-          const { sourceKey, cuesRevision, currentTimeSec, currentSubtitle } = snapshot;
-          return { sourceKey, cuesRevision, currentTimeSec, currentSubtitle };
+          const { sourceKey, cuesRevision, currentTimeSec, subDelay, currentSubtitle } = snapshot;
+          return { sourceKey, cuesRevision, currentTimeSec, subDelay, currentSubtitle };
         },
         getPlaybackPaused: async () => false,
         sendMpvCommand: (command: MpvCommand) => {
@@ -528,6 +529,16 @@ test('subtitle sidebar seeks to the selected cue start using the overlap-aware s
   assert.deepEqual(h.mpvCommands.at(-1), ['seek', 3.48, 'absolute+exact']);
 });
 
+test('subtitle sidebar seeks to where mpv plays a sub-delay retimed cue', async () => {
+  const h = createSidebarHarness();
+  h.setSnapshot({ subDelay: 2 });
+  await h.modal.openSubtitleSidebarModal();
+
+  h.modal.seekToCue({ startTime: 1, endTime: 2, text: 'first' });
+
+  assert.deepEqual(h.mpvCommands.at(-1), ['seek', 3.08, 'absolute+exact']);
+});
+
 test('subtitle sidebar close reports hidden visibility and notifies the modal close', async () => {
   const h = createSidebarHarness();
   await h.modal.openSubtitleSidebarModal();

src/renderer/modals/subtitle-sidebar.ts

@@ -4,6 +4,7 @@ import type {
   SubtitleMiningContext,
   SubtitleSidebarSnapshot,
 } from '../../types';
+import { toVideoClock } from '../../core/services/subtitle-clock.js';
 import { subtitleCueListSeekTime } from '../../core/services/subtitle-cue-navigation.js';
 import type { ModalStateReader, RendererContext } from '../context';
 import { syncOverlayMouseIgnoreState } from '../overlay-mouse-ignore.js';
@@ -231,6 +232,8 @@ export function createSubtitleSidebarModal(
   let lastSubtitleSidebarLookupCueIndex = -1;
   let subtitleSourceKey: string | null = null;
   let subtitleCuesRevision: number | null = null;
+  // Latest mpv `sub-delay` from main; cue times plus this are where mpv plays the cue.
+  let subtitleSubDelay = 0;
 
   function restoreEmbeddedSidebarPassthrough(): void {
     syncOverlayMouseIgnoreState(ctx);
@@ -416,7 +419,7 @@ export function createSubtitleSidebarModal(
   function seekToCue(cue: SubtitleCue): void {
     window.electronAPI.sendMpvCommand([
       'seek',
-      subtitleCueListSeekTime(ctx.state.subtitleSidebarCues, cue),
+      toVideoClock(subtitleCueListSeekTime(ctx.state.subtitleSidebarCues, cue), subtitleSubDelay),
       'absolute+exact',
     ]);
   }
@@ -591,6 +594,7 @@ export function createSubtitleSidebarModal(
     const snapshot = await window.electronAPI.getSubtitleSidebarSnapshot();
     pollsSinceFullSnapshot = 0;
     subtitleCuesRevision = snapshot.cuesRevision;
+    subtitleSubDelay = snapshot.subDelay;
     if (snapshot.sourceKey !== subtitleSourceKey) {
       clearSubtitleSidebarSelection(ctx.dom.subtitleSidebarList);
       lastSubtitleSidebarLookupCueIndex = -1;
@@ -640,6 +644,7 @@ export function createSubtitleSidebarModal(
       await refreshSnapshot();
       return;
     }
+    subtitleSubDelay = playback.subDelay;
     updateActiveCue(playback.currentSubtitle, playback.currentTimeSec);
   }
 

src/types/runtime.ts

@@ -90,6 +90,8 @@ export interface MpvClient {
   currentTimePos: number;
   currentSubStart: number;
   currentSubEnd: number;
+  /** mpv `sub-delay`; `sub-start`/`sub-end` do not include it. */
+  currentSubDelay: number;
   currentAudioStreamIndex: number | null;
   requestProperty?: (name: string) => Promise<unknown>;
   send(command: { command: unknown[]; request_id?: number }): boolean;

src/types/subtitle.ts

@@ -235,7 +235,10 @@ export interface SubtitleSidebarPlaybackState {
   sourceKey: string | null;
   /** Bumps whenever main swaps in a different parsed cue array. */
   cuesRevision: number;
+  /** Playback position on the subtitle clock (`time-pos` minus `sub-delay`), like cue times. */
   currentTimeSec: number | null;
+  /** mpv `sub-delay`: cue times plus this give the video-clock seek target. */
+  subDelay: number;
   currentSubtitle: {
     text: string;
     startTime: number | null;
@@ -251,6 +254,7 @@ export interface SubtitleSidebarSnapshot extends SubtitleSidebarPlaybackState {
 export interface SubtitleMiningContext {
   source: 'subtitle-sidebar' | 'overlay';
   text: string;
+  /** Video-clock seconds: subtitle timings plus mpv `sub-delay` at capture time. */
   startTime: number;
   endTime: number;
   capturedAtMs?: number;