017-audio-wave/audio wave.html at main · JIEJOE-WEB-Tutorial/017-audio-wave · GitHub

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<!DOCTYPE html>
<html lang="en">

<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>audio wave</title>
</head>
<style>
    * {
        margin: 0;
        padding: 0;
        font-size: 1vmin;
    }

    div {
        display: flex;
    }

    body {
        display: flex;
        justify-content: center;
        align-items: center;
        width: 100%;
        height: 100vh;
        background-color: #171717;
    }

    .line {
        position: absolute;
        justify-content: center;
        align-items: start;
        width: 50rem;
        height: 50rem;
    }

    .line::after {
        content: "";
        position: relative;
        width: 0.2rem;
        height: 8rem;
        background-color: #17f700;
        transform: scale(var(--s));
        transition: transform 0.3s ease;
    }
</style>

<body>
</body>
<script>
    // JIEJOE produce
    // b站主页：https://space.bilibili.com/3546390319860710
    const audio_wave = {
        waves_data: null,
        lines_total: 200,
        lines: [],
        timer: null,
        current_wave_index: 0,
        async init() {
            for (let i = 0; i < this.lines_total; i++) {
                const line = document.createElement("div");
                line.className = "line";
                line.style.transform = `rotate(${360 / this.lines_total * i}deg)`;
                line.style.setProperty("--s", 0);
                document.body.appendChild(line);
                this.lines.push(line);
            }
            this.waves_data = await this.get_waves_data(0.3, this.lines_total);
            this.run();
        },
        async get_waves_data(segment_length, points) {
            const response = await fetch("audio.mp3");
            const array_buffer = await response.arrayBuffer();
            const audio_buffer = await new AudioContext().decodeAudioData(array_buffer);
            const rate = audio_buffer.sampleRate;
            const duration = audio_buffer.duration;
            const channel_data = audio_buffer.getChannelData(0);
            const result = [];
            const segments = Math.ceil(duration / segment_length);
            for (let seg = 0; seg < segments; seg++) {
                const start_time = seg * segment_length;
                const end_time = Math.min(start_time + segment_length, duration);
                if (start_time >= duration) break;
                const start_sample = Math.floor(start_time * rate);
                const end_sample = Math.floor(end_time * rate);
                const point_samples = Math.floor((end_sample - start_sample) / points);
                const points_data = [];
                for (let i = 0; i < points; i++) {
                    const start_seg = start_sample + i * point_samples;
                    const end_seg = start_seg + point_samples;
                    let sum = 0;
                    for (let j = start_seg; j < end_seg; j++) {
                        sum += Math.abs(channel_data[j] || 0);
                    }
                    points_data.push(sum / point_samples);
                }
                result.push(points_data);
            }
            return result;
        },
        run() {
            this.timer = setInterval(() => {
                this.current_wave_index = (this.current_wave_index + 1) % (this.waves_data.length - 1);
                this.lines.forEach((line, i) => {
                    line.style.setProperty("--s", this.waves_data[this.current_wave_index][i]);
                })
            }, 300);
        }
    }
    audio_wave.init();
</script>

</html>