1865744 - flip.com experiences poor audio recording (AEC handling of echo from loopback)

Status: NEW

(Web Compatibility :: Site Reports, defect, P1)

Description

[Jim Mathies [:jimm]]

STR:

You'll need a Windows 11 pc with a camera and microphone. I am testing on a Mozilla workstation with an external USB based camera and mic. I have not tested on a windows 11 laptop with built-in camera and mic.

1. sign up for flip.com. You can use an MS or Google account. Site is generally safe (education based)
2. Once signed up and logged in, from the main interface, click on the camera option on the upper left, which will take you to the recording interface.
3. Click the record button in the bottom middle of the video
4. Speak
5. Stop recording and click Next on the lower right
6. Replay your recording

In Firefox, the audio is severely degraded and 'echoy'. Doing the same on the same pc using Chrome produces clear audio.

Site doesn't appear to be using webrtc for camera and mic access. I'm guessing media recorder based?

Fx 121.0a1 (2023-11-20) (64-bit)

Comment 1

[Jim Mathies [:jimm]]

https://www.tribute.co/ may be impacted as well.

Also testing in Release, the issue exists there as well.

Comment 2

[Jim Mathies [:jimm]]

This is specific to flip.com. On other Media Recorder test pages audio is fine. (https://webrtc.github.io/samples/src/content/getusermedia/record/)

Comment 3

[Andreas Pehrson [:pehrsons]]

This is an AEC problem, unrelated to MediaRecorder.

Flip does an odd thing in that they play the captured audio straight to speakers, and records it. This is a loopback setup, and one of the hardest scenarios for an AEC, because with a low latency loop the input and the output look very similar. Really the symptom of the reported degraded audio is that the input stream volume oscillates up and down. It makes some sense: imagine the AEC detects the short loopback feedback loop and lowers the volume of the input. The lower volume means there is no more echo so it increases the volume again. Rinse and repeat...

We can keep this for tuning and improving the AEC, but it's not really a real-world scenario that we should prioritize optimizing for.

Comment 4

[Vicky Chin [:vchin]]

Does Flip process the audio differently on Chrome? It is not usable at all on Firefox so there is a very real-world scenario that doesn't currently work.

Comment 5

[Andreas Pehrson [:pehrsons]]

Indeed on Chrome they do not play back the captured microphone directly to speakers. It should be a trivial bug to fix for them.

Comment 6

[Andrew Overholt [:overholt]]

(In reply to Andreas Pehrson [:pehrsons] from comment #5)

Indeed on Chrome they do not play back the captured microphone directly to speakers. It should be a trivial bug to fix for them.

Dennis, do you have any contacts at Flip?

Comment 7

[Dennis Schubert [:denschub]]

We don't have any direct contacts, but it's a Microsoft property, so the general contact channels might work well enough. I sent an email just now, and will update this bug if we hear anything back.

Given comment 3, I'm not sure if we want to do any engineering work here. If not, feel free to move this to the Web Compatibility :: Site Reports component.