用Tone.js实现弦频连续变化
用Tone.js实现弦频连续变化
提问于 2021-04-01 06:46:19
如何用tone.js实现吉他和弦基频的连续交互改变？
显然，将Tone.Sampler与可能命名为"pitchBend“或"pitchShift”的接口一起使用是一种可行的方法，但我不确定实际的选择。换言之，如何制作“投诉警察课滑块”？
我为一组振荡器(每个振荡器对应一个吉他弦)的本机window.AudioContext解决了这个问题，这些振荡器使用滑块中的频率进行更新，如下所示：
oscillator.frequency.setValueAtTime(频率，context.currentTime )；
它很好地改变了所有弦的音调，而振荡器仍然活着并在演奏。
但1)音色不完全是吉他的默认正弦声音波形和2)弦有时会干扰或混响，使声音太不自然。
也许tone.js平台之外的其他平台可以做到这一点？
谢谢。
回答 1
Stack Overflow用户
发布于 2021-04-04 07:47:34
我做了更多的研究，现在看起来原生WebAudio应用程序接口解决了这个问题，但还不清楚有多可靠和精确。我确实加载了吉他弦乐样本，并使滑块改变他们的速度比例来重新调整。代码如下：
<!DOCTYPE html>
<html>
<head>
<title>Continuous chord. Capo effect.</title>
<meta charset="utf-8">
<meta name="viewport"
content="width=device-width, initial-scale=1.0, maximum-scale=1.0, minimum-scale=1.0">
<script>
window.onload = function () {
//==================================================
// //\\ configures sound parameters
//==================================================
// //\\ scale constants
/*
var logStep = Math.log( 2 ) / 12;
var semitone = Math.exp( logStep );
console.log( semitone );
var semi2 = semitone * semitone;
var semi4 = semi2 * semi2;
var semi7 = semi2 * semitone;
*/
// \\// scale constants
//E3, A3, C3#,
//165, 220, 277
var initSpeed = 1;
var clipStart = 0; //0.65; //0.7;
var clipLenOriginal = 3.2; //0.43;
var doLoop = false; //true;
//speed raise
//if it is expected only one url for all tones in chord,
//adjust here speeds to generate different tones according to
//frequency ratios,
var clipLenSpeeds = [
//minor
/*
var smR0 = 1;
var smR1 = 262/220;
var smR2 = 330/220;
*/
//major
1,
1, // 277/220, //220/165
1, // 330/220, //277/165
];
var clipLengs = clipLenSpeeds.map( sp => clipLenOriginal*sp );
var clipLenSpeeds = clipLenSpeeds.map( sp => initSpeed*sp );
var dataPath = 'data';
//data are from this path:
//var dataPath = 'https://github.com/nbrosowsky/tonejs-instruments/tree/master/samples/guitar-acoustic';
var urls = [
dataPath + '/' + 'A3.wav',
dataPath + '/' + 'E3.wav',
dataPath + '/' + 'Cs3.wav',
];
//var fname = 'second-line-captured.mkv.mp3';
//var urls = clipLenSpeeds.map( el => fname );
//==================================================
// \\// configures sound parameters
//==================================================
//==================================================
// //\\ loads and prepares sourceNodes
//==================================================
let audioContext = new AudioContext();
var sourceNodes = [];
var audioBuffers = [];
Promise.all(
clipLenSpeeds.map( ( el, ix ) =>
getSample( ix )
)
).then(
( values ) => {
//console.log( 'values from last promise-then:', values );
button.removeAttribute( 'disabled' );
},
).catch( (err) => {
console.log( err );
});
//==================================================
// \\// loads and prepares sourceNodes
//==================================================
//==================================================
// //\\ GUI
//==================================================
const button = document.querySelector( '.run' );
const playbackControl = document.querySelector( '.playback-rate-control' );
const playbackValue = document.querySelector( '.playback-rate-value' );
button.setAttribute( 'disabled', 'disabled' );
button.addEventListener( 'click', () => {
audioBuffers.forEach( (val,vix) =>
startLoopByIx( vix )
);
});
playbackControl.oninput = function() {
playbackValue.innerHTML = playbackControl.value;
sourceNodes.forEach( (sn,i) => {
sn.playbackRate.value = clipLenSpeeds[i] * playbackControl.value;
});
}
//==================================================
// \\// GUI
//==================================================
return;
///part of the load and initation of audio buffer,
///returns promise from the last ".then"
function getSample( ix )
{
return fetch( urls[ ix ] )
.then( response => response.arrayBuffer() )
.then( arrayBuffer => audioContext.decodeAudioData( arrayBuffer ) )
.then( audioBuffer => {
audioBuffers[ ix ] = audioBuffer;
//if uncommented, this returned value populates
//values in Promise.all.then first param,
//return audioBuffer;
})
;
}
///fires up loop belonging to sourceNode[ ix ],
///options: either doLoop or one-time play,
function startLoopByIx( ix )
{
var audioBuffer = audioBuffers[ ix ];
var clipLen = clipLengs[ ix ];
var rate = clipLenSpeeds[ ix ];
var pan = 0; //stereo channels balance
let sourceNode = audioContext.createBufferSource();
let pannerNode = audioContext.createStereoPanner();
sourceNode.buffer = audioBuffer;
sourceNode.loop = doLoop;
sourceNode.loopStart = clipStart;
sourceNode.loopEnd = clipStart + clipLen;
sourceNode.playbackRate.value = rate; //does retuning
pannerNode.pan.value = pan;
sourceNode.connect( pannerNode );
pannerNode.connect( audioContext.destination );
if( doLoop ) {
sourceNode.start( 0, clipStart, );
} else {
sourceNode.start( 0, clipStart, clipLen );
}
sourceNodes[ ix ] = sourceNode;
}
};
</script>
</head>
<body>
<button class="run">Run samples</button><br>
<h2>Set playback rate</h2>
<input class="playback-rate-control" type="range" min="0.25" max="3" step="0.05" value="1">
<span class="playback-rate-value">1.0</span>
</body>
</html>页面原文内容由Stack Overflow提供。腾讯云小微IT领域专用引擎提供翻译支持
原文链接：
https://stackoverflow.com/questions/66896251
复制相关文章
相似问题
腾讯云开发者
Copyright © 2013 - 2026 Tencent Cloud. All Rights Reserved. 腾讯云 版权所有
深圳市腾讯计算机系统有限公司 ICP备案/许可证号：粤B2-20090059 
粤公网安备44030502008569号
腾讯云计算（北京）有限责任公司 京ICP证150476号 | 京ICP备11018762号