guest271314
commented
2 years ago Describe the feature
Route system or specific application audio output through a dedicated audio context intended to be utilized for this purpose.
Is there a prototype? Yes. https://github.com/guest271314/captureSystemAudio/tree/master/native_messaging/capture_system_audio.
In pertinent part re Notification
async function nativeMessageStream() {
return new Promise(async (resolve) => {
let permission = await navigator.permissions.query({
name: 'notifications',
});
if (permission.state !== 'granted') {
permission = await Notification.requestPermission();
}
if (permission.state === 'granted' || permission === 'granted') {
const captureSystemActionNotification = new Notification('Save file?', {
body: `Click "Activate" to capture system audio.`,
});
captureSystemActionNotification.onclick = async (e) => {
onmessage = (e) => {
if (e.origin === this.src.origin) {
if (!this.source) {
this.source = e.source;
}
if (e.data === 1) {
this.source.postMessage(
{ type: 'start', message: this.stdin },
'*'
);
}
if (e.data === 0) {
document
.querySelectorAll(`[src="${this.src.href}"]`)
.forEach((iframe) => {
document.body.removeChild(iframe);
});
onmessage = null;
}
if (e.data instanceof ReadableStream) {
this.stdout = e.data;
resolve(this.captureSystemAudio());
}
}
};
this.transferableWindow = document.createElement('iframe');
this.transferableWindow.style.display = 'none';
this.transferableWindow.name = location.href;
this.transferableWindow.src = this.src.href;
document.body.appendChild(this.transferableWindow);
};
}
}).catch((err) => {
throw err;
});
}Describe the feature in more detail
User performs user action, e.g., clicking a Notification to capture system audio output. Entire system audio output is routed through a dedicated MediaStreamAudioDestinationNode or dedicated AudioWorkletProcessor.
User calls stop() on MedisStreamAudioDestinationNode or return false in process() to stop system audio capture.
Prior feature request in we-baudio-api-v2 https://github.com/WebAudio/web-audio-api-v2/issues/106.
https://github.com/WebAudio/web-audio-api-v2/issues/106#issuecomment-904246686
@PaulFidika
capture user-audio on this machine, then stream or record it let users select in their browser what audio device they want their music to play out of These two requests are different; the latter is being tracked by #10 and the WG's response to the former request is laid out in https://github.com/WebAudio/web-audio-api-v2/issues/106#issuecomment-846093297. However, please feel free to open a new issue if you have different thoughts.
This is implementable on Linux, Windows, and macOS https://www.buildtoconnect.com/help/how-to-record-system-audio.
No movements elsewhere to implement this. Only piecemeal issues here and there that become circular references, e.g., https://github.com/w3c/mediacapture-output/issues/125.
I added the Notification to the beginning of the code to demonstrate such a requirement is trivial to implement at the implementer source code level.
Thus, there should be no issue specifying and implementing an AudioOutputContext. Whether or not browser source code authors implement the specification is a separate matter. The technology exists to achieve the requirement .
hoch
padenot
AudioWG virtual F2F:
Originally posted by @padenot in https://github.com/WebAudio/web-audio-api-v2/issues/106#issuecomment-846093297