【发布时间】：2019-03-12 00:11:15
【问题描述】：
关于录制的一切都很顺利，然后当您停止录制器时，文件会提供一个链接，您可以在其中上传。我的问题是当您点击停止按钮并且代码准备 BLOB 时，有没有办法将 BLOB wav 文件传输到 Wavesurfer-JS，以便它可以显示刚刚记录的波形文件，您可以编辑 wav 和亲眼所见？
我假设在“函数 createDownloadLink(blob)”部分下，我将捕获文件以发送到 Wavesurfer 以实时显示 Wav 文件？谢谢。
//App.JS
//webkitURL is deprecated but nevertheless
URL = window.URL || window.webkitURL;
var gumStream; //stream from getUserMedia()
var rec; //Recorder.js object
var input; //MediaStreamAudioSourceNode we'll be recording
// shim for AudioContext when it's not avb.
var AudioContext = window.AudioContext || window.webkitAudioContext;
var audioContext //audio context to help us record
var recordButton = document.getElementById("recordButton");
var stopButton = document.getElementById("stopButton");
var pauseButton = document.getElementById("pauseButton");
//add events to those 2 buttons
recordButton.addEventListener("click", startRecording);
stopButton.addEventListener("click", stopRecording);
pauseButton.addEventListener("click", pauseRecording);
function startRecording() {
console.log("recordButton clicked");
/*
Simple constraints object, for more advanced audio features see
https://addpipe.com/blog/audio-constraints-getusermedia/
*/
var constraints = { audio: true, video:false }
/*
Disable the record button until we get a success or fail from getUserMedia()
*/
recordButton.disabled = true;
stopButton.disabled = false;
pauseButton.disabled = false
/*
We're using the standard promise based getUserMedia()
https://developer.mozilla.org/en-US/docs/Web/API/MediaDevices/getUserMedia
*/
navigator.mediaDevices.getUserMedia(constraints).then(function(stream) {
console.log("getUserMedia() success, stream created, initializing Recorder.js ...");
/*
create an audio context after getUserMedia is called
sampleRate might change after getUserMedia is called, like it does on macOS when recording through AirPods
the sampleRate defaults to the one set in your OS for your playback device
*/
audioContext = new AudioContext();
//update the format
document.getElementById("formats").innerHTML="Format: 1 channel pcm @ "+audioContext.sampleRate/1000+"kHz"
/* assign to gumStream for later use */
gumStream = stream;
/* use the stream */
input = audioContext.createMediaStreamSource(stream);
/*
Create the Recorder object and configure to record mono sound (1 channel)
Recording 2 channels will double the file size
*/
rec = new Recorder(input,{numChannels:1})
//start the recording process
rec.record()
console.log("Recording started");
}).catch(function(err) {
//enable the record button if getUserMedia() fails
recordButton.disabled = false;
stopButton.disabled = true;
pauseButton.disabled = true
});
}
function pauseRecording(){
console.log("pauseButton clicked rec.recording=",rec.recording );
if (rec.recording){
//pause
rec.stop();
pauseButton.innerHTML="Resume";
}else{
//resume
rec.record()
pauseButton.innerHTML="Pause";
}
}
function stopRecording() {
console.log("stopButton clicked");
//disable the stop button, enable the record too allow for new recordings
stopButton.disabled = true;
recordButton.disabled = false;
pauseButton.disabled = true;
//reset button just in case the recording is stopped while paused
pauseButton.innerHTML="Pause";
//tell the recorder to stop the recording
rec.stop();
//stop microphone access
gumStream.getAudioTracks()[0].stop();
//create the wav blob and pass it on to createDownloadLink
rec.exportWAV(createDownloadLink);
}
function createDownloadLink(blob) {
var url = URL.createObjectURL(blob);
var au = document.createElement('audio');
var li = document.createElement('li');
var link = document.createElement('a');
//name of .wav file to use during upload and download (without extendion)
var filename = new Date().toISOString();
//add controls to the <audio> element
au.controls = true;
au.src = url;
//save to disk link
link.href = url;
link.download = filename+".wav"; //download forces the browser to donwload the file using the filename
//add the new audio element to li
li.appendChild(au);
//add the filename to the li
li.appendChild(document.createTextNode(filename+".wav "))
//add the save to disk link to li
li.appendChild(link);
//upload link
var upload = document.createElement('a');
upload.href="#";
upload.innerHTML = "Upload to server";
upload.addEventListener("click", function(event){
var xhr=new XMLHttpRequest();
xhr.onload=function(e) {
if(this.readyState === 4) {
console.log("Server returned: ",e.target.responseText);
}
};
var wavesurfer = WaveSurfer.create({
container: '#waveform',
waveColor: 'violet',
progressColor: 'purple'
});
wavesurfer.load(blob);
var fd=new FormData();
fd.append("audio_data",blob, filename);
xhr.open("POST","upload.php",true);
xhr.send(fd);
})
li.appendChild(document.createTextNode (" "))//add a space in between
li.appendChild(upload)//add the upload link to li
//add the li element to the ol
recordingsList.appendChild(li);
}<!DOCTYPE html>
<html>
<head>
<meta charset="UTF-8">
<title>Simple Recorder.js demo with record, stop and pause</title>
<meta name="viewport" content="width=device-width, initial-scale=1.0">
<link rel="stylesheet" type="text/css" href="style.css">
</head>
<body>
<h1>Tester</h1>
<br>
<div id="controls">
<button id="recordButton">Record</button>
<button id="pauseButton" disabled>Pause</button>
<button id="stopButton" disabled>Stop</button>
</div>
<div id="formats">Format: start recording to see sample rate</div>
<h3>Recordings</h3>
<br>
<ol id="recordingsList"></ol>
<br>
<div id="waveform"></div>
<!-- inserting these scripts at the end to be able to use all the elements in the DOM -->
<script src="https://cdn.rawgit.com/mattdiamond/Recorderjs/08e7abd9/dist/recorder.js"></script>
<script src="js/app.js"></script>
<script src="https://unpkg.com/wavesurfer.js"></script>
</body>
</html>【问题讨论】：
标签： javascript html