Compact HE-AAC audio saves: server lane with fdkaac, shrink saved songs from Saved videos

server/media-cache.test.js

@@ -435,6 +435,39 @@ describe('media cache jobs', () => {
     expect(await again.filePath('stilAAAAAA1', after.gen, 'jpg')).toBeTruthy();
   }, 90000);
 
+  // Stand-in for fdkaac (not installed on dev machines): same CLI shape, reads
+  // WAV on stdin, writes a low-bitrate AAC .m4a to -o.
+  function fakeFdkaac() {
+    const p = join(root, 'fake-fdkaac.sh');
+    writeFileSync(p, '#!/bin/sh\nwhile [ "$1" != "-o" ]; do shift; done\nout="$2"\nexec ffmpeg -v error -nostdin -y -f wav -i - -c:a aac -b:a 24k -f mp4 "$out"\n');
+    spawnSync('chmod', ['+x', p]);
+    return p;
+  }
+
+  test('compact audio lane: HE-AAC copy is made once, gated, and kept with the copy', async () => {
+    await clearDb();
+    const { cache } = makeCache({ fixture: 'still40.mp4', duration: 40, fdkaac: fakeFdkaac() });
+    await cache.init();
+    expect((await cache.compactAudio('compAAAAAA1')).status).toBe('none');
+    await cache.ensureCached('compAAAAAA1', { priority: HIGH });
+    expect(await until(async () => ((await dbmod.getMedia('compAAAAAA1')).he_size || 0) > 0, 20000)).toBe(true);
+    const he = await cache.compactAudio('compAAAAAA1');
+    expect(he.status).toBe('ready');
+    const lc = await cache.filePath('compAAAAAA1', he.gen, 'm4a');
+    expect(he.size).toBeLessThan(readFileSync(lc).length * 0.85);
+    expect(he.sha256).toBe(await sha256File(he.path));
+    expect(await cache.filePath('compAAAAAA1', he.gen, 'he.m4a')).toBe(he.path);
+  }, 60000);
+
+  test('compact audio is off (never blocks saves) when fdkaac is missing', async () => {
+    await clearDb();
+    const { cache } = makeCache({ fdkaac: join(root, 'no-such-fdkaac') });
+    await cache.init();
+    await cache.ensureCached('nofdAAAAAA1', { priority: HIGH });
+    expect(await until(async () => (await cache.compactAudio('nofdAAAAAA1')).status === 'off', 15000)).toBe(true);
+    expect((await cache.stats()).compactAudio).toBe('fdkaac missing');
+  }, 30000);
+
   test('a moving copy already done by the HEVC lane is not re-encoded for rev 3', async () => {
     await clearDb();
     const seed = makeCache({ fixture: 'fat64.mp4', duration: 64,