先看效果
1、打开页面
2、点击开始录音，弹出权限提示，点击“仅这次访问时允许”
3、录完后，点击停止
4、文件自动下载到默认目录
上代码
js 部分
document.addEventListener('DOMContentLoaded', () => {const startBtn = document.getElementById('startBtn');const stopBtn = document.getElementById('stopBtn');const audioPlayback = document.getElementById('audioPlayback');let mediaRecorder;let audioChunks = [];startBtn.addEventListener('click', async () => {try {// Request access to the microphoneconst stream = await navigator.mediaDevices.getUserMedia({ audio: { channelCount: 1, sampleRate: 16000 } });if (!stream) {throw new Error('No media stream received.');}// Create a MediaRecorder instance with specific settingsmediaRecorder = new MediaRecorder(stream, {mimeType: 'audio/webm'});mediaRecorder.ondataavailable = event => {audioChunks.push(event.data);};mediaRecorder.onstop = () => {const audioBlob = new Blob(audioChunks, { type: 'audio/webm' });convertWebmToWav(audioBlob);audioChunks = [];};mediaRecorder.start();startBtn.disabled = true;stopBtn.disabled = false;} catch (err) {console.error('Error accessing microphone:', err);alert('Error accessing microphone: ' + err.message);}});stopBtn.addEventListener('click', () => {if (mediaRecorder && mediaRecorder.state !== 'inactive') {mediaRecorder.stop();}startBtn.disabled = false;stopBtn.disabled = true;});function convertWebmToWav(webmBlob) {const reader = new FileReader();reader.onloadend = () => {const arrayBuffer = reader.result;const audioContext = new AudioContext();audioContext.decodeAudioData(arrayBuffer, audioBuffer => {const samples = audioBuffer.getChannelData(0);const buffer = createWav(samples, audioBuffer.sampleRate);const blob = new Blob([buffer], { type: 'audio/wav' });const audioUrl = URL.createObjectURL(blob);audioPlayback.src = audioUrl;// Save or download the blob as a WAV fileconst link = document.createElement('a');link.href = audioUrl;link.download = 'recorded_audio.wav';document.body.appendChild(link);link.click();document.body.removeChild(link);}, error => {console.error('Error decoding audio data:', error);});};reader.readAsArrayBuffer(webmBlob);}function createWav(samples, sampleRate) {const buffer = new ArrayBuffer(44 + samples.length * 2);const view = new DataView(buffer);// RIFF identifierwriteString(view, 0, 'RIFF');// file length minus RIFF identifier length and file description lengthview.setUint32(4, 36 + samples.length * 2, true);// RIFF typewriteString(view, 8, 'WAVE');// format chunk identifierwriteString(view, 12, 'fmt ');// format chunk lengthview.setUint32(16, 16, true);// sample format (raw)view.setUint16(20, 1, true);// channel countview.setUint16(22, 1, true);// sample rateview.setUint32(24, sampleRate, true);// byte rate (sample rate * block align)view.setUint32(28, sampleRate * 2, true);// block align (channel count * bytes per sample)view.setUint16(32, 2, true);// bits per sampleview.setUint16(34, 16, true);// data chunk identifierwriteString(view, 36, 'data');// data chunk lengthview.setUint32(40, samples.length * 2, true);floatTo16BitPCM(view, 44, samples);return buffer;}function floatTo16BitPCM(output, offset, input) {for (let i = 0; i < input.length; i++, offset += 2) {const s = Math.max(-1, Math.min(1, input[i]));output.setInt16(offset, s < 0 ? s * 0x8000 : s * 0x7FFF, true);}}function writeString(view, offset, string) {for (let i = 0; i < string.length; i++) {view.setUint8(offset + i, string.charCodeAt(i));}}
});html部分
<!DOCTYPE html>
<html lang="en">
<head><meta charset="UTF-8"><meta name="viewport" content="width=device-width, initial-scale=1.0"><title>Audio Recorder</title>
</head>
<body><h1>Audio Recorder</h1><button id="startBtn">Start Recording</button><button id="stopBtn" disabled>Stop Recording</button><br><br><audio id="audioPlayback" controls></audio><script src="recorder.js"></script>
</body>
</html>
、队列(Queue)、双端队列(Deque) —— 有码有图有真相)
