我想合并音频片段，将它们叠加在一起，以便它们同步播放并保存在一个新的音频文件中。任何帮助将非常感激。我在网上做了一些挖掘，但找不到关于 Javascript 音频编辑库(例如 Mix.js)的许多可用工具是否有能力的明确答案。
最佳答案
是的，可以使用 OfflineAudioContext() 或 AudioContext.createChannelMerger()并创建一个 MediaStream .参见 Phonegap mixing audio files , Web Audio API .
您可以使用 fetch()或 XMLHttpRequest()以 ArrayBuffer 形式检索音频资源, AudioContext.decodeAudioData()创建一个 AudioBufferSourceNode来自回应； OfflineAudioContext()呈现合并的音频，AudioContext , AudioContext.createBufferSource() , AudioContext.createMediaStreamDestination() , MediaRecorder()记录流； Promise.all() , Promise()构造函数，.then()处理对 fetch() 的异步请求, AudioContext.decodeAudioData() ，传递生成的混合音频 Blob在 stop MediaRecorder的事件.
连接每个AudioContext AudioBufferSourceNode至 OfflineAudioContext.destination , 调用 .start()在每个节点上；调用OfflineAudioContext.startRendering() ;新建 AudioContext节点，连接 renderedBuffer ;调用.createMediaStreamDestination()在 AudioContext创建一个 MediaStream从合并的音频缓冲区中，传递 .stream至 MediaRecorder() , 在 stop MediaRecorder的事件, 创建 Blob URL的 Blob与 URL.createObjectURL() 混合录制的音频，可以使用 <a> 下载带有 download 的元素属性和 href设置为 Blob URL .
var sources = ["https://upload.wikimedia.org/wikipedia/commons/b/be/"
+ "Hidden_Tribe_-_Didgeridoo_1_Live.ogg"
, "https://upload.wikimedia.org/wikipedia/commons/6/6e/"
+ "Micronesia_National_Anthem.ogg"];
var description = "HiddenTribeAnthem";
var context;
var recorder;
var div = document.querySelector("div");
var duration = 60000;
var chunks = [];
var audio = new AudioContext();
var mixedAudio = audio.createMediaStreamDestination();
var player = new Audio();
player.controls = "controls";
function get(src) {
return fetch(src)
.then(function(response) {
return response.arrayBuffer()
})
}
function stopMix(duration, ...media) {
setTimeout(function(media) {
media.forEach(function(node) {
node.stop()
})
}, duration, media)
}
Promise.all(sources.map(get)).then(function(data) {
var len = Math.max.apply(Math, data.map(function(buffer) {
return buffer.byteLength
}));
context = new OfflineAudioContext(2, len, 44100);
return Promise.all(data.map(function(buffer) {
return audio.decodeAudioData(buffer)
.then(function(bufferSource) {
var source = context.createBufferSource();
source.buffer = bufferSource;
source.connect(context.destination);
return source.start()
})
}))
.then(function() {
return context.startRendering()
})
.then(function(renderedBuffer) {
return new Promise(function(resolve) {
var mix = audio.createBufferSource();
mix.buffer = renderedBuffer;
mix.connect(audio.destination);
mix.connect(mixedAudio);
recorder = new MediaRecorder(mixedAudio.stream);
recorder.start(0);
mix.start(0);
div.innerHTML = "playing and recording tracks..";
// stop playback and recorder in 60 seconds
stopMix(duration, mix, recorder)
recorder.ondataavailable = function(event) {
chunks.push(event.data);
};
recorder.onstop = function(event) {
var blob = new Blob(chunks, {
"type": "audio/ogg; codecs=opus"
});
console.log("recording complete");
resolve(blob)
};
})
})
.then(function(blob) {
console.log(blob);
div.innerHTML = "mixed audio tracks ready for download..";
var audioDownload = URL.createObjectURL(blob);
var a = document.createElement("a");
a.download = description + "." + blob.type.replace(/.+\/|;.+/g, "");
a.href = audioDownload;
a.innerHTML = a.download;
document.body.appendChild(a);
a.insertAdjacentHTML("afterend", "<br>");
player.src = audioDownload;
document.body.appendChild(player);
})
})
.catch(function(e) {
console.log(e)
});<!DOCTYPE html>
<html>
<head>
</head>
<body>
<div>loading audio tracks.. please wait</div>
</body>
</html>您也可以使用 AudioContext.createChannelMerger() , AudioContext.createChannelSplitter()
var sources = ["/path/to/audoi1", "/path/to/audio2"];
var description = "mix";
var chunks = [];
var channels = [[0, 1], [1, 0]];
var audio = new AudioContext();
var player = new Audio();
var merger = audio.createChannelMerger(2);
var splitter = audio.createChannelSplitter(2);
var mixedAudio = audio.createMediaStreamDestination();
var duration = 60000;
var context;
var recorder;
var audioDownload;
player.controls = "controls";
function get(src) {
return fetch(src)
.then(function(response) {
return response.arrayBuffer()
})
}
function stopMix(duration, ...media) {
setTimeout(function(media) {
media.forEach(function(node) {
node.stop()
})
}, duration, media)
}
Promise.all(sources.map(get)).then(function(data) {
return Promise.all(data.map(function(buffer, index) {
return audio.decodeAudioData(buffer)
.then(function(bufferSource) {
var channel = channels[index];
var source = audio.createBufferSource();
source.buffer = bufferSource;
source.connect(splitter);
splitter.connect(merger, channel[0], channel[1]);
return source
})
}))
.then(function(audionodes) {
merger.connect(mixedAudio);
merger.connect(audio.destination);
recorder = new MediaRecorder(mixedAudio.stream);
recorder.start(0);
audionodes.forEach(function(node) {
node.start(0)
});
stopMix(duration, ...audionodes, recorder);
recorder.ondataavailable = function(event) {
chunks.push(event.data);
};
recorder.onstop = function(event) {
var blob = new Blob(chunks, {
"type": "audio/ogg; codecs=opus"
});
audioDownload = URL.createObjectURL(blob);
var a = document.createElement("a");
a.download = description + "." + blob.type.replace(/.+\/|;.+/g, "");
a.href = audioDownload;
a.innerHTML = a.download;
player.src = audioDownload;
document.body.appendChild(a);
document.body.appendChild(player);
};
})
})
.catch(function(e) {
console.log(e)
});
关于javascript - 是否可以最好使用 javascript 将多个音频文件叠加在一起，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/40570114/