fix(subtitles): preserve lyric selection and deduplicate secondary text

- Seek sidebar selections past overlapping karaoke exit spans
- Collapse duplicate long ASS lines and omit reconstructed sign grids

src/core/services/index.ts

@@ -52,6 +52,7 @@ export { syncYomitanDefaultAnkiServer } from './tokenizer/yomitan-parser-runtime
 export { createSubtitleProcessingController } from './subtitle-processing-controller';
 export {
   resolveSanitizedSubtitleSeekCommand,
+  subtitleCueListSeekTime,
   subtitleCueSeekTime,
 } from './subtitle-cue-navigation';
 export { createFrequencyDictionaryLookup } from './frequency-dictionary';

src/core/services/secondary-subtitle-line-identity.ts

@@ -0,0 +1,15 @@
+const MIN_FLATTENED_DUPLICATE_LENGTH = 16;
+const TERMINAL_SENTENCE_PUNCTUATION = /[.!?。！？…⋯]+$/gu;
+
+/**
+ * Identifies long lines that become duplicates when positioned ASS events are
+ * flattened into the secondary subtitle bar. Short dialogue stays distinct.
+ */
+export function flattenedSecondarySubtitleLineIdentity(text: string): string | null {
+  const identity = text
+    .normalize('NFKC')
+    .replace(/\s+/gu, '')
+    .replace(TERMINAL_SENTENCE_PUNCTUATION, '');
+
+  return identity.length >= MIN_FLATTENED_DUPLICATE_LENGTH ? identity : null;
+}

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

@@ -2,6 +2,7 @@ import assert from 'node:assert/strict';
 import test from 'node:test';
 import {
   resolveSanitizedSubtitleSeekCommand,
+  subtitleCueListSeekTime,
   subtitleCueSeekTime,
 } from './subtitle-cue-navigation';
 
@@ -85,3 +86,23 @@ test('sidebar cue seeks share the boundary-safe sanitized cue timestamp', () =>
   assert.equal(subtitleCueSeekTime({ startTime: 1, endTime: 2, text: 'line' }), 1.08);
   assert.equal(subtitleCueSeekTime({ startTime: 1, endTime: 1.04, text: 'short' }), 1.03);
 });
+
+test('sidebar cue selection clears an overlapping previous lyric', () => {
+  const cues = [
+    { startTime: 1, endTime: 3.4, text: 'previous lyric' },
+    { startTime: 3, endTime: 5, text: 'selected lyric' },
+  ];
+
+  assert.equal(subtitleCueListSeekTime(cues, cues[1]!), 3.48);
+});
+
+test('sidebar cue selection remains inside a short cue when overlap cannot be cleared', () => {
+  const cues = [
+    { startTime: 1, endTime: 3.4, text: 'previous lyric' },
+    { startTime: 3, endTime: 3.2, text: 'selected lyric' },
+  ];
+
+  const seekTime = subtitleCueListSeekTime(cues, cues[1]!);
+  assert.ok(seekTime >= 3.19);
+  assert.ok(seekTime < cues[1]!.endTime);
+});

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

@@ -42,6 +42,36 @@ export function subtitleCueSeekTime(cue: SubtitleCue): number {
   );
 }
 
+/**
+ * Choose a stable point inside a selected cue. Karaoke lines can overlap while the
+ * previous line animates out, so a sidebar selection should clear that overlap when
+ * the selected cue has enough time remaining.
+ */
+export function subtitleCueListSeekTime(
+  cues: readonly SubtitleCue[],
+  selectedCue: SubtitleCue,
+): number {
+  const groups = groupCueBoundaries(cues);
+  const selectedGroupIndex = groups.findIndex(
+    (group) =>
+      selectedCue.startTime >= group.startTime &&
+      selectedCue.startTime - group.startTime <= CUE_START_GROUP_TOLERANCE_SECONDS,
+  );
+  const previousGroupEndTime =
+    selectedGroupIndex > 0 ? groups[selectedGroupIndex - 1]?.endTime : undefined;
+  if (previousGroupEndTime === undefined || previousGroupEndTime <= selectedCue.startTime) {
+    return subtitleCueSeekTime(selectedCue);
+  }
+
+  return Math.max(
+    selectedCue.startTime,
+    Math.min(
+      selectedCue.endTime - CUE_END_GUARD_SECONDS,
+      previousGroupEndTime + CUE_BOUNDARY_SEEK_OFFSET_SECONDS,
+    ),
+  );
+}
+
 /**
  * Translate mpv subtitle-line navigation onto parsed cues. Generated ASS karaoke can
  * contain hundreds of subtitle events for one visible line, while the parsed list has

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

@@ -10,6 +10,7 @@ import { hasAssAnimationEvidence, mergeDuplicateCues } from './subtitle-cue-dedu
 
 export type AssCueLayout =
   | { kind: 'positioned'; sourceOrder: number; y: number }
+  | { kind: 'fragment-grid'; sourceOrder: number }
   | { kind: 'source-order'; sourceOrder: number };
 
 export interface SubtitleCue {
@@ -210,6 +211,7 @@ const MIN_FRAGMENT_LINE_EVENTS = 8;
 const MIN_FRAGMENT_LINE_PARTS = 4;
 const MAX_FRAGMENT_MEDIAN_LENGTH = 4;
 const MAX_FRAGMENT_LINE_TIMING_VARIANCE_SECONDS = 2;
+const MAX_FRAGMENT_LINE_VERTICAL_SPAN = 48;
 
 function parseAssTimestamp(raw: string): number | null {
   const match = ASS_TIMING_PATTERN.exec(raw.trim());
@@ -385,6 +387,30 @@ interface AssFragmentPart {
   text: string;
 }
 
+function reconstructedAssFragmentLayout(
+  parts: readonly AssFragmentPart[],
+  owner: AnnotatedSubtitleCue,
+): AssCueLayout | undefined {
+  let positionedPartCount = 0;
+  let minimumY = Infinity;
+  let maximumY = -Infinity;
+  for (const part of parts) {
+    const layout = part.cue.assLayout;
+    if (layout?.kind !== 'positioned') continue;
+    positionedPartCount += 1;
+    minimumY = Math.min(minimumY, layout.y);
+    maximumY = Math.max(maximumY, layout.y);
+  }
+
+  if (
+    positionedPartCount >= MIN_FRAGMENT_LINE_PARTS &&
+    maximumY - minimumY > MAX_FRAGMENT_LINE_VERTICAL_SPAN
+  ) {
+    return { kind: 'fragment-grid', sourceOrder: owner.order };
+  }
+  return owner.assLayout;
+}
+
 interface AssFragmentTimingCluster {
   events: AnnotatedSubtitleCue[];
   minStartTime: number;
@@ -515,6 +541,7 @@ function reconstructAssFragmentLine(
     source: 'reconstructed-ass',
     animationStartTime,
     animationEndTime,
+    assLayout: reconstructedAssFragmentLayout(parts, owner),
     overrides: [],
     overrideSignature: '',
   };

src/main/runtime/secondary-subtitle-track.test.ts

@@ -34,6 +34,44 @@ test('findActiveSubtitleText collapses whitespace variants of one ASS lyric', ()
   );
 });
 
+test('parsed secondary text collapses a positioned sign that repeats dialogue without punctuation', () => {
+  const ass = [
+    '[Events]',
+    'Format: Layer, Start, End, Style, Name, MarginL, MarginR, MarginV, Effect, Text',
+    'Dialogue: 10,0:03:58.49,0:04:00.34,GJM_Main_1080p,Nar,0,0,0,,{\\i1}A question veiled as an insult!',
+    'Dialogue: 1,0:03:58.59,0:04:00.34,iFanzSigns,,0,0,0,,{\\pos(960,75)}A question veiled as an insult',
+  ].join('\n');
+  const cues = parseSubtitleCues(ass, 'kaguya-s02e10.ass');
+
+  assert.equal(findActiveSubtitleText(cues, 238.48), '');
+  assert.equal(findActiveSubtitleText(cues, 238.5), 'A question veiled as an insult!');
+  assert.equal(findActiveSubtitleText(cues, 239), 'A question veiled as an insult!');
+  assert.equal(findActiveSubtitleText(cues, 240.34), '');
+});
+
+test('parsed secondary text drops a reconstructed grid of positioned sign fragments', () => {
+  const signFragment = (text: string, x: number, y: number) =>
+    `Dialogue: 1,0:00:01.00,0:00:03.00,Signs,,0,0,0,,{\\pos(${x},${y})\\t(0,100,\\fscx101)}${text}`;
+  const ass = [
+    '[Events]',
+    'Format: Layer, Start, End, Style, Name, MarginL, MarginR, MarginV, Effect, Text',
+    'Dialogue: 10,0:00:01.00,0:00:03.00,Default,Speaker,0,0,0,,Come on, wake up!',
+    signFragment('Timetable', 1700, 150),
+    signFragment('Mon', 1750, 230),
+    signFragment('Tue', 1850, 230),
+    signFragment('1', 1650, 320),
+    signFragment('2', 1650, 390),
+    signFragment('Civics', 1750, 320),
+    signFragment('Math', 1850, 390),
+    signFragment('PE', 1850, 460),
+  ].join('\n');
+
+  assert.equal(
+    findActiveSubtitleText(parseSubtitleCues(ass, 'kaguya-s02e11.ass'), 2),
+    'Come on, wake up!',
+  );
+});
+
 test('parsed secondary lyrics keep explicit ASS vertical order when durations alternate', () => {
   const lyric = (options: { start: string; end: string; style: string; y: number; text: string }) =>
     `Dialogue: 0,0:00:${options.start},0:00:${options.end},${options.style},,0,0,0,fx,{\\move(100,${options.y},120,${options.y})\\t(0,200,\\fscx110)}${options.text}\\N{\\p1}m 0 0 l 0 5`;

src/main/runtime/secondary-subtitle-track.ts

@@ -1,4 +1,5 @@
 import type { SubtitleCue } from '../../types/subtitle';
+import { flattenedSecondarySubtitleLineIdentity } from '../../core/services/secondary-subtitle-line-identity';
 
 type SecondarySubtitleMpvClient = {
   connected?: boolean;
@@ -110,6 +111,7 @@ export function findActiveSubtitleText(cues: readonly SubtitleCue[], timeSeconds
   const activeReconstructed = cues.filter(
     (cue) =>
       cue.source === 'reconstructed-ass' &&
+      cue.assLayout?.kind !== 'fragment-grid' &&
       cue.startTime <= timeSeconds &&
       cue.endTime > timeSeconds,
   );
@@ -135,7 +137,8 @@ export function findActiveSubtitleText(cues: readonly SubtitleCue[], timeSeconds
   }
   const selectedReconstructed = new Set(reconstructedByStyle.values());
 
-  const seen = new Set<string>();
+  const seenExact = new Set<string>();
+  const seenFlattened = new Set<string>();
   const activeText: string[] = [];
   const activeCues: IndexedSubtitleCue[] = [];
   cues.forEach((cue, index) => {
@@ -152,8 +155,12 @@ export function findActiveSubtitleText(cues: readonly SubtitleCue[], timeSeconds
   for (const { cue } of activeCues) {
     const text = cue.text.trim();
     const compactText = text.replace(/\s+/gu, '');
-    if (!compactText || seen.has(compactText)) continue;
-    seen.add(compactText);
+    if (!compactText || seenExact.has(compactText)) continue;
+    seenExact.add(compactText);
+
+    const flattenedIdentity = flattenedSecondarySubtitleLineIdentity(text);
+    if (flattenedIdentity && seenFlattened.has(flattenedIdentity)) continue;
+    if (flattenedIdentity) seenFlattened.add(flattenedIdentity);
     activeText.push(text);
   }
   return activeText.join('\n');

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

@@ -240,14 +240,15 @@ test('subtitle sidebar modal opens from snapshot and clicking cue seeks playback
 
   const snapshot: SubtitleSidebarSnapshot = {
     cues: [
-      { startTime: 1, endTime: 2, text: 'first' },
+      { startTime: 1, endTime: 3.4, text: 'first' },
       { startTime: 3, endTime: 4, text: 'second' },
     ],
     currentSubtitle: {
       text: 'second',
-      startTime: 3,
+      startTime: 3.5,
       endTime: 4,
     },
+    currentTimeSec: 3.5,
     config: {
       enabled: true,
       autoOpen: false,
@@ -361,6 +362,9 @@ test('subtitle sidebar modal opens from snapshot and clicking cue seeks playback
     modal.seekToCue(snapshot.cues[0]!);
     assert.deepEqual(mpvCommands.at(-1), ['seek', 1.08, 'absolute+exact']);
 
+    modal.seekToCue(snapshot.cues[1]!);
+    assert.deepEqual(mpvCommands.at(-1), ['seek', 3.48, 'absolute+exact']);
+
     modal.closeSubtitleSidebarModal();
     assert.deepEqual(visibilityChanges, [true, false]);
     assert.deepEqual(modalNotifications, ['open:subtitle-sidebar', 'close:subtitle-sidebar']);

src/renderer/modals/subtitle-sidebar.ts

@@ -4,7 +4,7 @@ import type {
   SubtitleMiningContext,
   SubtitleSidebarSnapshot,
 } from '../../types';
-import { subtitleCueSeekTime } from '../../core/services/subtitle-cue-navigation.js';
+import { subtitleCueListSeekTime } from '../../core/services/subtitle-cue-navigation.js';
 import type { ModalStateReader, RendererContext } from '../context';
 import { syncOverlayMouseIgnoreState } from '../overlay-mouse-ignore.js';
 import {
@@ -392,7 +392,11 @@ export function createSubtitleSidebarModal(
   }
 
   function seekToCue(cue: SubtitleCue): void {
-    window.electronAPI.sendMpvCommand(['seek', subtitleCueSeekTime(cue), 'absolute+exact']);
+    window.electronAPI.sendMpvCommand([
+      'seek',
+      subtitleCueListSeekTime(ctx.state.subtitleSidebarCues, cue),
+      'absolute+exact',
+    ]);
   }
 
   function getCueRowLabel(cue: SubtitleCue): string {

src/renderer/subtitle-render.test.ts

@@ -1454,6 +1454,15 @@ test('prepareSecondarySubtitleLines preserves repeated short dialogue without la
   assert.deepEqual(prepareSecondarySubtitleLines(dialogue.join('\\N')), dialogue);
 });
 
+test('prepareSecondarySubtitleLines collapses punctuation variants of a full-sentence fallback', () => {
+  const dialogue = 'A question veiled as an insult!';
+  const positionedSign = 'A question veiled as an insult';
+
+  assert.deepEqual(prepareSecondarySubtitleLines([dialogue, positionedSign].join('\\N')), [
+    dialogue,
+  ]);
+});
+
 test('prepareSecondarySubtitleLines preserves short simultaneous dialogue without repeats', () => {
   const dialogue = ['Wait', 'Go!', 'No!', 'Run!'];
 

src/renderer/subtitle-render.ts

@@ -6,6 +6,7 @@ import type {
   SubtitleRendererStyleConfig,
 } from '../types';
 import { assToPlainText, normalizePlainSubtitleText } from '../core/services/ass-text.js';
+import { flattenedSecondarySubtitleLineIdentity } from '../core/services/secondary-subtitle-line-identity.js';
 import type { RendererContext } from './context';
 import { PRIMARY_SUB_VISIBLE_ON_YOMITAN_POPUP_CLASS } from './yomitan-popup.js';
 
@@ -665,6 +666,17 @@ function isKaraokeLikeLineSet(lines: string[]): boolean {
   return median <= KARAOKE_MAX_MEDIAN_LINE_LENGTH;
 }
 
+function collapseFullLineFallbackCopies(lines: string[]): string[] {
+  const seen = new Set<string>();
+  return lines.filter((line) => {
+    const identity = flattenedSecondarySubtitleLineIdentity(line);
+    if (!identity) return true;
+    if (seen.has(identity)) return false;
+    seen.add(identity);
+    return true;
+  });
+}
+
 export function prepareSecondarySubtitleLines(text: string): string[] {
   // The one display-side ASS decode: secondary text also reaches the overlay from
   // websocket clients that forward their source line untouched, so unlike the primary
@@ -678,7 +690,7 @@ export function prepareSecondarySubtitleLines(text: string): string[] {
     .map((line) => line.trim())
     .filter((line) => line.length > 0);
   if (!isKaraokeLikeLineSet(lines)) {
-    return lines;
+    return collapseFullLineFallbackCopies(lines);
   }
 
   const seen = new Set<string>();