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

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);
   }