feat(subtitles): use loaded subtitles to guide generation timing (#249)

2026-09-19 05:16:27 -07:00 · 2026-09-18 00:24:42 -07:00
parent 186d4a0640
commit a8c16147ad
24 changed files with 965 additions and 75 deletions
@@ -0,0 +1,137 @@
+import assert from 'node:assert/strict';
+import { mkdtemp, rm, writeFile } from 'node:fs/promises';
+import { tmpdir } from 'node:os';
+import path from 'node:path';
+import test from 'node:test';
+import {
+  loadSubtitleGenerationReference,
+  readSubtitleGenerationReferences,
+  subtitleGenerationReferences,
+} from './subtitle-generation-reference';
+
+const embedded = { type: 'sub', codec: 'ass', 'ff-index': 2, lang: 'eng' };
+
+test('references exclude signs, songs, forced, bitmap and generated tracks even when selected', () => {
+  const excluded = [
+    'Signs & Songs',
+    'SignsSongs',
+    'Signs/Songs',
+    'S&S',
+    'S+S',
+    'Forced',
+    'Karaoke',
+    'OP',
+    'ED',
+    'English lyrics',
+    'Generated Japanese',
+  ];
+  assert.deepEqual(
+    subtitleGenerationReferences([
+      ...excluded.map((title) => ({ ...embedded, title, selected: true })),
+      { ...embedded, forced: true },
+      { ...embedded, codec: 'hdmv_pgs_subtitle' },
+      {
+        ...embedded,
+        title: 'English',
+        external: true,
+        'external-filename': '/subs/show.en.signs.ass',
+      },
+      { ...embedded, title: 'English Full' },
+    ]).map((reference) => reference.label),
+    ['English Full'],
+  );
+});
+
+test('references rank English dialogue first and resolve loaded external files against mpv cwd', () => {
+  const refs = subtitleGenerationReferences(
+    [
+      { ...embedded, title: 'French Full', lang: 'fra', selected: true },
+      { ...embedded, title: 'English' },
+      { type: 'sub', external: true, 'external-filename': 'subs/show.en.full.srt' },
+      { type: 'sub', external: true, 'external-filename': 'https://example.com/en.srt' },
+      { type: 'sub', 'ff-index': -1 },
+      null,
+    ],
+    '/mpv',
+  );
+  assert.deepEqual(
+    refs.map((ref) => ref.label),
+    ['show.en.full.srt', 'English', 'French Full'],
+  );
+  assert.deepEqual(refs[0]?.source, { kind: 'external', path: '/mpv/subs/show.en.full.srt' });
+  assert.deepEqual(
+    subtitleGenerationReferences([
+      { type: 'sub', external: true, 'external-filename': 'relative.en.srt' },
+    ]),
+    [],
+  );
+});
+
+test('reference discovery captures primary and secondary subtitle delays', async () => {
+  const properties: Record<string, unknown> = {
+    'working-directory': '/mpv',
+    sid: 1,
+    'secondary-sid': 2,
+    'sub-delay': 1.5,
+    'secondary-sub-delay': -2,
+  };
+  const refs = await readSubtitleGenerationReferences(
+    [
+      { ...embedded, id: 1 },
+      { ...embedded, id: 2 },
+      { ...embedded, id: 3 },
+    ],
+    async (name) => properties[name],
+  );
+  assert.deepEqual(
+    refs.map((ref) => ref.delaySeconds),
+    [1.5, -2, 0],
+  );
+});
+
+test('reference extraction retries unreadable tracks, restores audio offset and ignores marked lyrics', async () => {
+  const directory = await mkdtemp(path.join(tmpdir(), 'generation-reference-'));
+  try {
+    const ffmpegPath = path.join(directory, 'ffmpeg');
+    await writeFile(
+      ffmpegPath,
+      `#!${process.execPath}
+const args = process.argv.slice(2);
+if (args[args.indexOf('-map') + 1] === '0:2') process.exit(1);
+require('node:fs').writeFileSync(args.at(-1), '1\\n00:00:10,000 --> 00:00:12,000\\nHello\\n\\n2\\n00:00:20,000 --> 00:00:22,000\\n♪ Song ♪\\n\\n3\\n00:00:30,000 --> 00:00:32,000\\nWorld\\n');
+`,
+      { mode: 0o755 },
+    );
+    const refs = subtitleGenerationReferences([{ ...embedded }, { ...embedded, 'ff-index': 3 }]);
+    const hints = await loadSubtitleGenerationReference({
+      references: refs,
+      mediaPath: '/video.mkv',
+      ffmpegPath,
+      directory,
+      audioOffset: 2.5,
+    });
+    assert.deepEqual(hints, [7.5, 27.5]);
+    assert.deepEqual(
+      await loadSubtitleGenerationReference({
+        references: refs.slice(0, 1),
+        mediaPath: '/video.mkv',
+        ffmpegPath,
+        directory,
+        audioOffset: 0,
+      }),
+      [],
+    );
+    await assert.rejects(
+      loadSubtitleGenerationReference({
+        references: refs,
+        mediaPath: '/video.mkv',
+        ffmpegPath,
+        directory,
+        audioOffset: 0,
+        signal: AbortSignal.abort(),
+      }),
+    );
+  } finally {
+    await rm(directory, { recursive: true, force: true });
+  }
+});