fix(anki): clip mined media on the sub-delay retimed timeline

mpv's sub-start/sub-end and parsed cues carry the subtitle file's own
timestamps; sub-delay (z/x, sub-step) only moves where mpv plays them.
Mining now shifts subtitle timings onto the video clock before media
generation, review, and MiscInfo timestamps.

changes/mining-respects-sub-delay.md

@@ -0,0 +1,4 @@
+type: fixed
+area: anki
+
+- Mined card audio, images, and timestamps now follow mpv's manual subtitle retiming (`sub-delay`, z/x), instead of clipping the subtitle file's original timing.

e2e/harness/fake-anki.ts

@@ -37,10 +37,12 @@ function isRecord(value: unknown): value is Record<string, unknown> {
   return typeof value === 'object' && value !== null && !Array.isArray(value);
 }
 
-// A recording AnkiConnect stand-in: an empty collection with one deck and one
-// Lapis-shaped note type. Scenarios assert on `requests`, not on stored notes.
+// A recording AnkiConnect stand-in: one deck and one Lapis-shaped note type.
+// Added notes are echoed back by `notesInfo` so the app can resolve their fields;
+// scenarios still assert on `requests`, not on stored notes.
 export async function startFakeAnki(): Promise<FakeAnki> {
   const requests: AnkiRequest[] = [];
+  const addedNotes = new Map<number, Record<string, unknown>>();
   let nextNoteId = 1000;
 
   const handle = (body: unknown): unknown => {
@@ -59,10 +61,33 @@ export async function startFakeAnki(): Promise<FakeAnki> {
         return [FAKE_ANKI_MODEL];
       case 'modelFieldNames':
         return MODEL_FIELDS;
-      case 'addNote':
-        return nextNoteId++;
+      case 'addNote': {
+        const noteId = nextNoteId++;
+        const note = isRecord(params.note) ? params.note : {};
+        addedNotes.set(noteId, isRecord(note.fields) ? note.fields : {});
+        return noteId;
+      }
+      case 'notesInfo': {
+        const ids = Array.isArray(params.notes) ? params.notes : [];
+        return ids.flatMap((id) => {
+          const fields = typeof id === 'number' ? addedNotes.get(id) : undefined;
+          if (!fields) return [];
+          return [
+            {
+              noteId: id,
+              modelName: FAKE_ANKI_MODEL,
+              tags: [],
+              fields: Object.fromEntries(
+                MODEL_FIELDS.map((name, order) => [
+                  name,
+                  { value: String(fields[name] ?? ''), order },
+                ]),
+              ),
+            },
+          ];
+        });
+      }
       case 'findNotes':
-      case 'notesInfo':
         return [];
       case 'storeMediaFile':
         return params.filename ?? null;

e2e/playback.e2e.test.ts

@@ -91,6 +91,14 @@ async function showCue(cue: (typeof FIXTURE_CUES)[number]): Promise<RenderedToke
     });
 }
 
+// Card-kind flags are written before media, so wait for the update carrying audio.
+function findMediaUpdate(session: E2eSession) {
+  return session.anki.requests.find(
+    (request) =>
+      request.action === 'updateNoteFields' && JSON.stringify(request.params).includes('[sound:'),
+  );
+}
+
 function hasToken(tokens: RenderedToken[], surface: string, headword: string): boolean {
   return tokens.some((token) => token.surface === surface && token.headword === headword);
 }
@@ -126,10 +134,10 @@ test(
     session.anki.requests.length = 0;
 
     await session.runAppCommand('--mine-sentence');
-    const update = await waitUntil(
-      () => session.anki.requests.find((request) => request.action === 'updateNoteFields'),
-      { description: 'media fields to be written to the mined note', timeoutMs: 30_000 },
-    );
+    const update = await waitUntil(() => findMediaUpdate(session), {
+      description: 'media fields to be written to the mined note',
+      timeoutMs: 30_000,
+    });
 
     const added = session.anki.requests.filter((request) => request.action === 'addNote');
     assert.equal(added.length, 1);
@@ -156,6 +164,38 @@ test(
   },
 );
 
+test(
+  'mining a line retimed with sub-delay clips it where mpv plays it',
+  { timeout: TEST_TIMEOUT_MS },
+  async () => {
+    const { session, overlay } = await useSession();
+    const cue = FIXTURE_CUES[1];
+    const delay = 2;
+    await session.mpv.command('set_property', 'sub-delay', delay);
+    try {
+      // Past the cue's own end, so the line is only on screen because of the delay.
+      await session.mpv.command('seek', cue.end + delay / 2, 'absolute+exact');
+      await overlay.waitFor(
+        `document.getElementById('subtitleRoot').textContent === ${JSON.stringify(cue.text)}`,
+        { description: 'overlay to show the delayed line' },
+      );
+      session.anki.requests.length = 0;
+
+      await session.runAppCommand('--mine-sentence');
+      await waitUntil(() => findMediaUpdate(session), {
+        description: 'media fields to be written to the mined note',
+        timeoutMs: 30_000,
+      });
+
+      // MiscInfo stamps the clip start: the cue's start on the video clock.
+      const written = JSON.stringify(session.anki.requests);
+      assert.ok(written.includes(`(00:00:0${cue.start + delay})`), written);
+    } finally {
+      await session.mpv.command('set_property', 'sub-delay', 0);
+    }
+  },
+);
+
 test(
   'open subtitle sidebar lists the parsed cues and follows playback',
   { timeout: TEST_TIMEOUT_MS },

src/anki-integration.ts

@@ -44,7 +44,10 @@ import {
   getPreferredWordValueFromExtractedFields,
 } from './anki-field-config';
 import { createLogger } from './logger';
-import { captureLiveSubtitleMiningContext } from './core/services/mining';
+import {
+  captureLiveSubtitleMiningContext,
+  shiftSubtitleRangeToVideoClock,
+} from './core/services/mining';
 import {
   createUiFeedbackState,
   beginUpdateProgress,
@@ -1029,10 +1032,10 @@ 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 +1675,7 @@ export class AnkiIntegration {
           if (this.config.fields?.miscInfo) {
             result.miscInfoValue = this.formatMiscInfoPattern(
               audioFilename,
-              this.mpvClient.currentSubStart,
+              this.mpvClient.currentSubStart + this.mpvClient.currentSubDelay,
             );
           }
         }
@@ -1695,7 +1698,7 @@ 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/mining';
 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

@@ -22,6 +22,7 @@ export {
   handleMultiCopyDigit,
   markLastCardAsAudioCard,
   mineSentenceCard,
+  shiftSubtitleRangeToVideoClock,
   triggerFieldGrouping,
   updateLastCardFromClipboard,
 } from './mining';

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

@@ -25,6 +25,7 @@ interface MpvClientLike {
   currentSubText: string;
   currentSubStart: number;
   currentSubEnd: number;
+  currentSubDelay: number;
   currentSecondarySubText?: string;
   requestProperty?: (name: string) => Promise<unknown>;
 }
@@ -55,6 +56,21 @@ export function handleMultiCopyDigit(
   }
 }
 
+/**
+ * mpv's `sub-start`/`sub-end` and parsed cues carry the subtitle file's own timestamps,
+ * but mpv plays each line `sub-delay` seconds later (z/x retiming). Media is cut from the
+ * video, so subtitle timings move onto the video clock before they reach mining.
+ */
+export function shiftSubtitleRangeToVideoClock<T extends { startTime: number; endTime: number }>(
+  range: T,
+  subDelay: number,
+): T {
+  if (!Number.isFinite(subDelay) || subDelay === 0) {
+    return range;
+  }
+  return { ...range, startTime: range.startTime + subDelay, endTime: range.endTime + subDelay };
+}
+
 /**
  * Snapshot the live mpv subtitle line and its timings as a mining context. Media
  * generation can run tens of seconds after the user mines (slow audio extraction),
@@ -62,7 +78,10 @@ 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 +92,10 @@ 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 +189,7 @@ 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 +208,16 @@ 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 +73,7 @@ function createDeps(overrides: Partial<MpvProtocolHandleMessageDeps> = {}): {
       getCurrentSubStart: () => 0,
       setCurrentSubEnd: () => {},
       getCurrentSubEnd: () => 0,
+      setCurrentSubDelay: () => {},
       emitMediaPathChange: (payload) => {
         state.mediaPath = payload.path;
       },
@@ -131,6 +132,22 @@ 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();
 

src/core/services/mpv-protocol.ts

@@ -64,6 +64,7 @@ export interface MpvProtocolHandleMessageDeps {
   getCurrentSubStart: () => number;
   setCurrentSubEnd: (value: number) => void;
   getCurrentSubEnd: () => number;
+  setCurrentSubDelay: (value: number) => void;
   emitMediaPathChange: (payload: { path: string }) => void;
   emitMediaTitleChange: (payload: { title: string | null }) => void;
   emitTimePosChange: (payload: { time: number }) => void;
@@ -272,6 +273,9 @@ export async function dispatchMpvProtocolMessage(
         start: deps.getCurrentSubStart(),
         end: deps.getCurrentSubEnd(),
       });
+    } else if (msg.name === 'sub-delay') {
+      const delay = typeof msg.data === 'number' ? msg.data : Number(msg.data);
+      deps.setCurrentSubDelay(Number.isFinite(delay) ? delay : 0);
     } 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 +461,9 @@ export class MpvIpcClient implements MpvClient {
         this.currentSubEnd = value;
       },
       getCurrentSubEnd: () => this.currentSubEnd,
+      setCurrentSubDelay: (value: number) => {
+        this.currentSubDelay = value;
+      },
       emitMediaPathChange: (payload) => {
         this.emit('media-path-change', payload);
       },

src/main.ts

@@ -328,6 +328,7 @@ import {
   setMpvSubVisibilityRuntime,
   setOverlayDebugVisualizationEnabledRuntime,
   setVisibleOverlayVisible as setVisibleOverlayVisibleCore,
+  shiftSubtitleRangeToVideoClock,
   showMpvOsdRuntime,
   JellyfinPlaybackReporter,
   tokenizeSubtitle as tokenizeSubtitleCore,
@@ -1951,9 +1952,11 @@ 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: Number(appState.mpvClient?.currentTimePos) - subDelay,
     cues: appState.activeParsedSubtitleCues,
   });
   // Same validity bar as the live capture path: an unusable resolved span must fall
@@ -1968,13 +1971,16 @@ 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);
@@ -3115,7 +3121,10 @@ 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 +6037,11 @@ 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/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

@@ -23,6 +23,7 @@ export function createBuildBindMpvMainEventHandlersMainDepsHandler(deps: {
       currentSubText?: string;
       currentSecondarySubText?: string;
       currentTimePos?: number;
+      currentSubDelay?: number;
       requestProperty?: (name: string) => Promise<unknown>;
     } | null;
     immersionTracker: {
@@ -231,6 +232,9 @@ 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 +243,8 @@ export function createBuildBindMpvMainEventHandlersMainDepsHandler(deps: {
         }
         deps.appState.subtitleTimingTracker?.recordSubtitle?.(
           recordableText,
-          start,
-          end,
+          start + subDelay,
+          end + subDelay,
           secondaryText,
         );
         return;
@@ -253,8 +257,8 @@ 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/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

@@ -251,6 +251,7 @@ 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;