初始化项目

utils/audioUtils.ts

@@ -0,0 +1,80 @@
+
+export const base64ToUint8Array = (base64: string) => {
+  const binaryString = atob(base64);
+  const len = binaryString.length;
+  const bytes = new Uint8Array(len);
+  for (let i = 0; i < len; i++) {
+    bytes[i] = binaryString.charCodeAt(i);
+  }
+  return bytes;
+};
+
+export const uint8ArrayToBase64 = (bytes: Uint8Array) => {
+  let binary = '';
+  const len = bytes.byteLength;
+  for (let i = 0; i < len; i++) {
+    binary += String.fromCharCode(bytes[i]);
+  }
+  return btoa(binary);
+};
+
+export const triggerDownload = (blob: Blob, filename: string) => {
+  const url = URL.createObjectURL(blob);
+  const a = document.createElement('a');
+  a.href = url;
+  a.download = filename;
+  document.body.appendChild(a);
+  a.click();
+  document.body.removeChild(a);
+  URL.revokeObjectURL(url);
+};
+
+export const createWavFileFromPcm = (pcmData: Uint8Array, sampleRate: number = 24000, numChannels: number = 1): Blob => {
+  const header = new ArrayBuffer(44);
+  const view = new DataView(header);
+  
+  const writeString = (view: DataView, offset: number, string: string) => {
+    for (let i = 0; i < string.length; i++) {
+      view.setUint8(offset + i, string.charCodeAt(i));
+    }
+  };
+
+  writeString(view, 0, 'RIFF');
+  view.setUint32(4, 36 + pcmData.length, true);
+  writeString(view, 8, 'WAVE');
+  writeString(view, 12, 'fmt ');
+  view.setUint32(16, 16, true);
+  view.setUint16(20, 1, true);
+  view.setUint16(22, numChannels, true);
+  view.setUint32(24, sampleRate, true);
+  view.setUint32(28, sampleRate * numChannels * 2, true);
+  view.setUint16(32, numChannels * 2, true);
+  view.setUint16(34, 16, true);
+  writeString(view, 36, 'data');
+  view.setUint32(40, pcmData.length, true);
+
+  return new Blob([view, pcmData], { type: 'audio/wav' });
+};
+
+export const processAndDownloadAudio = (base64Data: string, filename: string) => {
+  try {
+    // Check for RIFF header (WAV)
+    // Some base64 strings might have newlines, strip them if necessary, 
+    // but generally atob handles it or we assume clean base64.
+    const binaryString = atob(base64Data.substring(0, 50).replace(/\s/g, ''));
+    const isWav = binaryString.startsWith('RIFF');
+    
+    if (isWav) {
+       const bytes = base64ToUint8Array(base64Data);
+       const blob = new Blob([bytes], { type: 'audio/wav' });
+       triggerDownload(blob, filename);
+    } else {
+       // Assume Raw PCM 24kHz 16-bit Mono (Gemini Flash TTS default)
+       const bytes = base64ToUint8Array(base64Data);
+       const blob = createWavFileFromPcm(bytes, 24000, 1);
+       triggerDownload(blob, filename);
+    }
+  } catch (e) {
+    console.error("Error downloading audio", e);
+  }
+};