【音频可视化】通过canvas绘制音频波形图

前言

这两天写项目刚好遇到Ai对话相关的需求，需要录音功能，绘制录制波形图，写了一个函数用canvas实现可视化，保留分享一下，有需要的直接粘贴即可，使用时传入一个1024长的，0-255大小的Uint8Array类型音频数据源

<canvas ref="canvasRef" width="800" height="200"></canvas>

const drawWaveform = (audioArray) => {const canvas = canvasRef.value;if (!canvas || !audioArray) return;const ctx = canvas.getContext('2d');if (!ctx) return;const width = canvas.width;const height = canvas.height;const bufferLength = audioArray.length;// 清除画布ctx.clearRect(0, 0, width, height);// 设置线条样式ctx.strokeStyle = '#4f35b5';ctx.lineWidth = 2;ctx.beginPath();const sliceWidth = width / bufferLength;let x = 0;for (let i = 0; i < bufferLength; i++) {const value = audioArray[i] / 255.0;  // 将0-255的值归一化为0-1const y = value * height;if (i === 0) {ctx.moveTo(x, y);} else {ctx.lineTo(x, y);}x += sliceWidth;}ctx.stroke();
};

通过requestAnimationFrame调用即可

示例：

// 持续更新波形
const updateWaveform = () => {ensureRecorder(() => {audioArray.value = recorder!.getRecordAnalyseData();drawWaveform(audioArray.value);animationFrameId = requestAnimationFrame(updateWaveform);});
};