v82: trimStartBlob через AudioContext+OfflineRenderer — обрезка 0.2с для Whisper

js/audio.js

@@ -321,13 +321,28 @@ function encodeWAV(samples, sampleRate) {
 
 // Обрезает первые cutSec секунд, возвращает WAV Blob (для Groq)
 async function trimStartBlob(blob, cutSec = 0.2) {
-  const ctx = new OfflineAudioContext(1, 1, 44100);
-  const ab = await blob.arrayBuffer();
-  const buf = await ctx.decodeAudioData(ab);
-  const sr = buf.sampleRate;
-  const data = buf.getChannelData(0);
-  const cutSamples = Math.floor(sr * cutSec);
-  const trimmed = data.slice(cutSamples);
-  const wav = encodeWAV(trimmed, sr);
-  return new Blob([wav], { type: 'audio/wav' });
+  try {
+    const ab = await blob.arrayBuffer();
+    const actx = new AudioContext();
+    const rawBuf = await actx.decodeAudioData(ab);
+    const sr = rawBuf.sampleRate;
+    const cutSamples = Math.floor(sr * cutSec);
+    const newLen = rawBuf.length - cutSamples;
+    if (newLen < sr * 0.05) { actx.close(); return blob; }
+
+    // Render trimmed via OfflineAudioContext (надёжнее ручного slice)
+    const offline = new OfflineAudioContext(1, newLen, sr);
+    const src = offline.createBufferSource();
+    src.buffer = rawBuf;
+    src.connect(offline.destination);
+    src.start(0, cutSec / sr);
+    const rendered = await offline.startRendering();
+    actx.close();
+
+    const wav = encodeWAV(rendered.getChannelData(0), sr);
+    return new Blob([wav], { type: 'audio/wav' });
+  } catch(e) {
+    console.log('[trimStartBlob] fallback to raw:', e);
+    return blob;
+  }
 }