[Webkit-unassigned] [Bug 237523] New: WebRTC / HTMLMediaElement - calling getDisplayMedia "unmutes" getUserMedia stream on muted video element

Mon Mar 7 04:36:56 PST 2022

https://bugs.webkit.org/show_bug.cgi?id=237523

            Bug ID: 237523
           Summary: WebRTC / HTMLMediaElement - calling getDisplayMedia
                    "unmutes" getUserMedia stream on muted video element
           Product: WebKit
           Version: Safari 15
          Hardware: Mac (Intel)
                OS: macOS 12
            Status: NEW
          Severity: Normal
          Priority: P2
         Component: WebRTC
          Assignee: webkit-unassigned at lists.webkit.org
          Reporter: ajdalshov at icloud.com
                CC: youennf at gmail.com

The sample code below starts a local stream with getUserMedia and adds the stream to a muted video element (muted prop set on user video element to prevent audio feedback), audio is muted as expected, but after calling getDisplayMedia (allowing the request), the video element with the user media stream will unmute and cause audio feedback. It's not even needed to add the display media stream to the other video element, calling getDisplayMedia alone is sufficient.

Note that document.getElementById("user").muted will still return true even if audio feedback is clearly present. 

Tested with:

Safari Version 15.3 (17612.4.9.1.8) / macOS 12.2.1
Safari Technology Preview Release 141 (Safari 15.4, WebKit 17614.1.3.8) / macOS 12.2.1

---
<html>
<head></head>
<body>
        <button onclick="startScreenSharing()">Start screen sharing</button>
        <video id="user" playsinline autoplay muted></video>
        <video id="display" playsinline autoplay></video>
        <script>
                window.onload = function() {
                        navigator.mediaDevices.getUserMedia({audio: true, video: true})
                        .then((stream) => {
                                document.getElementById("user").srcObject = stream;
                        });
                };
                this.startScreenSharing = () => {
                        navigator.mediaDevices.getDisplayMedia({video: true})
                        .then((stream) => {
                                document.getElementById("display").srcObject = stream;
                        });
                };
        </script>
</body>
</html>

-- 
You are receiving this mail because:
You are the assignee for the bug.
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.webkit.org/pipermail/webkit-unassigned/attachments/20220307/1559b74c/attachment.htm>