关于使用声音数据来移动东西，我跟着这个tut。
直到现在它正常工作，它播放声音，这是代码：
/* Hoist some variables. */
var audio,
context = new (window.AudioContext ||
window.webAudioContext ||
window.webkitAudioContext)(),
/* Create a script processor node with a `bufferSize` of 1024. */
processor = context.createScriptProcessor(1024),
/* Create an analyser node */
analyser = context.createAnalyser();
/* Wire the processor into our audio context. */
processor.connect(context.destination);
/* Wire the analyser into the processor */
analyser.connect(processor);
/* Define a Uint8Array to receive the analysers data. */
var data = new Uint8Array(analyser.frequencyBinCount);
/* Try instantiating a new AudioContext, throw an error if it fails. */
try {
/* Setup an AudioContext. */
context = new AudioContext();
} catch(e) {
throw new Error('The Web Audio API is unavailable');
}
/* Define a `Sound` Class */
var Sound = {
/* Give the sound an element property initially undefined. */
element: undefined,
/* Define a class method of play which instantiates a new Media Element
* Source each time the file plays, once the file has completed disconnect
* and destroy the media element source. */
play: function() {
var sound = context.createMediaElementSource(this.element);
this.element.onended = function() {
sound.disconnect();
sound = null;
}
sound.connect(context.destination);
/* Call `play` on the MediaElement. */
this.element.play();
}
};
/* Create an async function which returns a promise of a playable audio element. */
function loadAudioElement(url) {
return new Promise(function(resolve, reject) {
var audio = new Audio();
audio.addEventListener('canplay', function() {
/* Resolve the promise, passing through the element. */
resolve(audio);
});
/* Reject the promise on an error. */
audio.addEventListener('error', reject);
audio.src = url;
});
}
/* Let's load our file. */
loadAudioElement('/audio/shorter.mp3').then(function(elem) {
/* Instantiate the Sound class into our hoisted variable. */
audio = Object.create(Sound);
/* Set the element of `audio` to our MediaElement. */
audio.element = elem;
/* Immediately play the file. */
audio.play();
}, function(elem) {
/* Let's throw an the error from the MediaElement if it fails. */
throw elem.error;
});
但我想用音频分析仪数据移动东西......
所以我必须修改声音类，而不是仅将音频媒体元素源连接到音频上下文中，它现在也应该连接分析器。
但是当我添加此代码时，声音停止播放......
/* Removed for brevity... */
play: function() {
var sound = context.createMediaElementSource(this.element);
this.element.onended = function() {
sound.disconnect();
sound = null;
/* Noop the audioprocess handler when the file finishes. */
processor.onaudioprocess = function() {};
}
/* Add the following line to wire into the analyser. */
sound.connect(analyser);
sound.connect(context.destination);
processor.onaudioprocess = function() {
/* Populate the data array with the frequency data. */
analyser.getByteTimeDomainData(data);
};
/* Call `play` on the MediaElement. */
this.element.play();
}
这是停止工作的完整代码：
/* Hoist some variables. */
var audio,
context = new (window.AudioContext ||
window.webAudioContext ||
window.webkitAudioContext)(),
/* Create a script processor node with a `bufferSize` of 1024. */
processor = context.createScriptProcessor(1024),
/* Create an analyser node */
analyser = context.createAnalyser();
/* Wire the processor into our audio context. */
processor.connect(context.destination);
/* Wire the analyser into the processor */
analyser.connect(processor);
/* Define a Uint8Array to receive the analysers data. */
var data = new Uint8Array(analyser.frequencyBinCount);
/* Try instantiating a new AudioContext, throw an error if it fails. */
try {
/* Setup an AudioContext. */
context = new AudioContext();
} catch(e) {
throw new Error('The Web Audio API is unavailable');
}
/* Define a `Sound` Class */
var Sound = {
/* Give the sound an element property initially undefined. */
element: undefined,
/* Define a class method of play which instantiates a new Media Element
* Source each time the file plays, once the file has completed disconnect
* and destroy the media element source. */
/* Removed for brevity... */
play: function() {
var sound = context.createMediaElementSource(this.element);
this.element.onended = function() {
sound.disconnect();
sound = null;
/* Noop the audioprocess handler when the file finishes. */
processor.onaudioprocess = function() {};
}
/* Add the following line to wire into the analyser. */
sound.connect(analyser);
sound.connect(context.destination);
processor.onaudioprocess = function() {
/* Populate the data array with the frequency data. */
analyser.getByteTimeDomainData(data);
};
/* Call `play` on the MediaElement. */
this.element.play();
}
};
/* Create an async function which returns a promise of a playable audio element. */
function loadAudioElement(url) {
return new Promise(function(resolve, reject) {
var audio = new Audio();
audio.addEventListener('canplay', function() {
/* Resolve the promise, passing through the element. */
resolve(audio);
});
/* Reject the promise on an error. */
audio.addEventListener('error', reject);
audio.src = url;
});
}
/* Let's load our file. */
loadAudioElement('/audio/shorter.mp3').then(function(elem) {
/* Instantiate the Sound class into our hoisted variable. */
audio = Object.create(Sound);
/* Set the element of `audio` to our MediaElement. */
audio.element = elem;
/* Immediately play the file. */
audio.play();
}, function(elem) {
/* Let's throw an the error from the MediaElement if it fails. */
throw elem.error;
});
有什么想法吗？
答案 0 :(得分：1)
您应该将分析仪连接到目的地以使其正常工作。
sound.connect(analyser);
analyser.connect(context.destination);