Add JamesDSP playback controls and verification harness

frontend/app.js

@@ -675,10 +675,14 @@ const DEFAULT_SETTINGS = {
 };
 function normalizeJamesDspSettings(settings) {
   const saved = settings?.jamesDsp && typeof settings.jamesDsp === 'object' ? settings.jamesDsp : {};
+  const params = saved.params && typeof saved.params === 'object' && !Array.isArray(saved.params) ? { ...saved.params } : {};
+  // Impulse-response PCM is intentionally session-only; do not re-enable the
+  // convolver on a later boot without its uploaded audio buffer.
+  delete params['convolver.enabled'];
   settings.jamesDsp = {
     enabled: saved.enabled === true,
     preset: typeof saved.preset === 'string' ? saved.preset : 'flat',
-    params: saved.params && typeof saved.params === 'object' && !Array.isArray(saved.params) ? { ...saved.params } : {},
+    params,
   };
   return settings;
 }
@@ -3346,6 +3350,20 @@ function openMoreActions() {
     row.onclick = () => { closeModal(); setTimeout(() => src.click(), 0); };
     list.appendChild(row);
   }
+  if (data.settings?.jamesDsp?.enabled && EQ.state().jamesDsp?.active) {
+    const row = document.createElement('button');
+    row.type = 'button'; row.className = 'more-row';
+    const bypassed = !!EQ.state().jamesDsp?.bypassed;
+    row.innerHTML = '<span class="more-ico" aria-hidden="true">A/B</span><span class="more-txt"><b></b><small>Temporarily compare with the unprocessed signal</small></span><span class="more-go">›</span>';
+    row.querySelector('b').textContent = bypassed ? 'Resume JamesDSP' : 'Bypass JamesDSP';
+    row.setAttribute('aria-label', row.querySelector('b').textContent);
+    row.onclick = async () => {
+      closeModal();
+      const next = await EQ.toggleDspBypass();
+      toast(next ? 'JamesDSP bypassed' : 'JamesDSP active');
+    };
+    list.appendChild(row);
+  }
   if (!list.children.length) { toast('No more actions for this video'); return; }
   showModal('More actions', list, [{ label: 'Close', onClick: closeModal }]);
 }
@@ -5521,7 +5539,7 @@ const EQ = (() => {
   const isIOS = /iPad|iPhone|iPod/.test(navigator.userAgent) || (navigator.platform === 'MacIntel' && navigator.maxTouchPoints > 1);
   const AC = window.AudioContext || window.webkitAudioContext;
   const st = { ctx: null, filters: null, levelDb: 0 };
-  let dspController = null, dspControllerPromise = null;
+  let dspController = null, dspControllerPromise = null, dspRequest = 0;
   // Web Audio is off on iOS (it silences playback when the screen locks)
   // unless the user opted in through "Level volume" (Settings → Playback).
   // Live Web Audio is off on iOS (it silences playback when the screen locks)
@@ -5554,6 +5572,8 @@ const EQ = (() => {
   function dspFailed(error) {
     if (!data.settings.jamesDsp?.enabled) return;
     data.settings.jamesDsp.enabled = false;
+    if ($('setSoundEngine')) $('setSoundEngine').value = 'standard';
+    if ($('jamesDspControls')) $('jamesDspControls').hidden = true;
     persist();
     toast(`JamesDSP unavailable; Standard sound is active. ${error?.message || ''}`.trim());
     apply();
@@ -5562,15 +5582,19 @@ const EQ = (() => {
 
   async function getDspController() {
     if (dspController) return dspController;
-    if (!dspControllerPromise) dspControllerPromise = Lazy.load('feature:jamesdsp').then(() => {
-      dspController = JamesDSPFeature.createController({ graph: AudioGraph, prepareGraph: prepareDspGraph, onError: dspFailed });
+    if (!dspControllerPromise) dspControllerPromise = Lazy.load('feature:jamesdsp').then(async () => {
+      dspController = await JamesDSPFeature.createController({ graph: AudioGraph, prepareGraph: prepareDspGraph, onError: dspFailed });
       return dspController;
     }).catch(error => { dspControllerPromise = null; throw error; });
     return dspControllerPromise;
   }
 
   function startDsp() {
-    getDspController().then(controller => controller.enable(data.settings.jamesDsp, st.levelDb)).catch(dspFailed);
+    const request = ++dspRequest;
+    getDspController().then(controller => {
+      if (request !== dspRequest || !data.settings.jamesDsp?.enabled) return controller.disable();
+      return controller.enable(data.settings.jamesDsp, st.levelDb);
+    }).catch(dspFailed);
   }
 
   function build() {
@@ -5620,7 +5644,9 @@ const EQ = (() => {
       renderButton();
       return;
     }
+    dspRequest++;
     if (dspController) dspController.disable().catch(() => {});
+    else if (dspControllerPromise) dspControllerPromise.then(controller => controller.disable()).catch(() => {});
     if (!available()) return;
     if (!st.ctx && isFlat() && EqParameters.amount(data.settings.vocalLevel ?? 100) === 100 && EqParameters.width(data.settings.stereoWidth) === 0) return;
     if (!build()) return;
@@ -5733,8 +5759,22 @@ const EQ = (() => {
     return true;
   }
 
+  async function toggleDspBypass() {
+    if (!dspController?.active) return false;
+    try { return await dspController.toggleBypass(); }
+    catch (error) { dspFailed(error); return false; }
+  }
+
+  async function loadDspIR(file) {
+    if (!data.settings.jamesDsp?.enabled || !dspController?.active) throw new Error('Turn on JamesDSP before importing an impulse response.');
+    const context = st.ctx;
+    if (!context?.decodeAudioData) throw new Error('Audio decoding is unavailable on this device.');
+    const audioBuffer = await context.decodeAudioData(await file.arrayBuffer());
+    return dspController.loadIR(audioBuffer);
+  }
+
   return { open, apply, renderButton, available, analyser, setLevel, gains, bands: EQ_BANDS, isIOS: () => isIOS, state: () => ({ wired: !!st.ctx, ctx: st.ctx && st.ctx.state, gains: st.filters ? st.filters.map((f) => f.gain.value) : null,
-    levelDb: st.level ? Math.round(200 * Math.log10(Math.max(1e-6, st.level.gain.value))) / 10 : null }) };
+    levelDb: st.level ? Math.round(200 * Math.log10(Math.max(1e-6, st.level.gain.value))) / 10 : null, jamesDsp: dspController?.state() || null }), toggleDspBypass, loadDspIR };
 })();
 
 // ============================================================================