根据最新更新,什么是捕获麦克风和扬声器音频以在后台js中进行实时音频处理的正确方法。我被困在这里,我尝试了所有媒体记录器api,record js api和chrome桌面捕获,但是它们都返回了麦克风音频。他们都将无法捕获扬声器音频。请提出一种实现这种情况的方法
下面是捕获麦克风但不捕获扬声器的示例代码:
var audioChunks;
startRecord.onclick = e => {
startRecord.disabled = true;
stopRecord.disabled=false;
// This will prompt for permission if not allowed earlier
navigator.mediaDevices.getUserMedia({audio:true})
.then(stream => {
audioChunks = [];
rec = new MediaRecorder(stream);
rec.ondataavailable = e => {
audioChunks.push(e.data);
if (rec.state == "inactive"){
let blob = new Blob(audioChunks,{type:'audio/x-mpeg-3'});
recordedAudio.src = URL.createObjectURL(blob);
recordedAudio.controls=true;
recordedAudio.autoplay=true;
audioDownload.href = recordedAudio.src;
audioDownload.download = 'mp3';
audioDownload.innerHTML = 'download';
}
}
rec.start();
})
.catch(e=>console.log(e));
}
stopRecord.onclick = e => {
startRecord.disabled = false;
stopRecord.disabled=true;
rec.stop();
}
答案 0 :(得分:6)
当您首次拨打getUserMedia
的电话时,您可用的设备将只有音频(意味着麦克风)和摄像头(默认网络摄像头)。但是,如果您致电enumerateDevices
,则会返回所有可用音频设备的列表。然后,您可以指定音频卡的特定ID,如下所示:
navigator.mediaDevices.getUserMedia({audio:{deviceId:{exact: deviceId}}})
这需要两次调用getUserMedia并在其中等待才能正常工作。另外,我应注意,devicechange
的事件不会在Chromium浏览器中触发。这将使检测配置更改更加困难。
对于背景扩展,我认为您必须花点时间才能使其正常工作。您可以向用户显示设备列表,然后让他们选择,但是这会将一些消息传递到您的前端脚本,然后再返回,使设置复杂化。
答案 1 :(得分:-1)
这是示例代码,列出了所有可用的设备。
navigator.mediaDevices.enumerateDevices()
.then((devicesInfo)) => {
// Expect devices of kind `audioinput`, `audiooutput`, `videoinput` and other media cards available.
// Internal default speakers would fall under `audiooutput` and internal default microphone would fall under `audioinput`.
const select = document.createElement('select');
devicesInfo.forEach((device, index) => {
const option = document.createElement('option');
option.value = deviceInfo.deviceId;
if(deviceInfo.kind === 'audioinput')
option.text = deviceInfo.label;
select.appendChild(option);
})
document.body.appendChild(select);
...
// Let user make the selection of device. Once selected, start the recording.
...
// select.value has the selected deviceId. Use `onChange` event of select to capture the value.
const constraints = {
audio: {deviceId: select.value ? {exact: select.value} : undefined}
};
var audioChunks = [];
navigator.mediaDevices.getUserMedia(constraints)
.then((stream) => {
window.stream = stream; // make stream available to console
var rec = new MediaRecorder(stream);
rec.ondataavailable = (e) => {
audioChunks.push(e.data);
if (rec.state == "inactive"){
let blob = new Blob(audioChunks,{type:'audio/x-mpeg-3'});
const recording = document.createElement('audio');
recording.id = "recording";
recording.src = URL.createObjectURL(blob);
recording.controls=true;
recording.autoplay=true;
document.body.removeChild(document.getElementById('recording'));
document.body.appendChild(downloadLink);
const downloadLink = document.createElement('a');
downloadLink.id = "downloadLink";
downloadLink.href = recordedAudio.src;
downloadLink.download = 'mp3';
downloadLink.innerHTML = 'download';
document.body.removeChild(document.getElementById('downloadLink'));
document.body.appendChild(downloadLink);
};
// Start recording whenever user prefers to start.
rec.start();
...
...
// Stop recording whenever user prefers to stop.
rec.stop();
}
})
}
让我们知道这是否是您想要的。