我花了一些时间来破解 wavesurfer js 代码,以找出如何在不加载歌曲的情况下使其绘制:P
在后端变量中设置峰值并调用drawBuffer就达到了目的,将其与一些播放按钮逻辑相结合,我们得到以下代码:
//Create new wavesurfer
wavesurfer = WaveSurfer.create({
container: '#waveform',
backend: 'MediaElement',
mediaType:'audio',
normalize: true,
barWidth: 3
});
//Set song
wavesurfer.song = "http://www.stephaniequinn.com/Music/Allegro%20from%20Duet%20in%20C%20Major.mp3"
//Set peaks
wavesurfer.backend.peaks = [0.0218, 0.0183, 0.0165, 0.0198, 0.2137, 0.2888, 0.2313, 0.15, 0.2542, 0.2538, 0.2358, 0.1195, 0.1591, 0.2599, 0.2742, 0.1447, 0.2328, 0.1878, 0.1988, 0.1645, 0.1218, 0.2005, 0.2828, 0.2051, 0.1664, 0.1181, 0.1621, 0.2966, 0.189, 0.246, 0.2445, 0.1621, 0.1618, 0.189, 0.2354, 0.1561, 0.1638, 0.2799, 0.0923, 0.1659, 0.1675, 0.1268, 0.0984, 0.0997, 0.1248, 0.1495, 0.1431, 0.1236, 0.1755, 0.1183, 0.1349, 0.1018, 0.1109, 0.1833, 0.1813, 0.1422, 0.0961, 0.1191, 0.0791, 0.0631, 0.0315, 0.0157, 0.0166, 0.0108];
//Draw peaks
wavesurfer.drawBuffer();
//Variable to check if song is loaded
wavesurfer.loaded = false;
//Load song when play is pressed
wavesurfer.on("play", function () {
if(!wavesurfer.loaded) {
wavesurfer.load(wavesurfer.song, wavesurfer.backend.peaks);
}
});
//Start playing after song is loaded
wavesurfer.on("ready", function () {
if(!wavesurfer.loaded) {
wavesurfer.loaded = true;
wavesurfer.play();
}
});
确保删除不必要的<audio>
来自 html 的标签,浏览器似乎会在加载时下载这些标签中的所有音频文件和属性,例如preload=false
好像被忽略了……