1687368 - Noticeable stuttering on both video and audio on MacOS

Status: RESOLVED INVALID

(Core :: Audio/Video: cubeb, defect, P3)

Description

[Alastor Wu [:alwu]]

I can reproduce this issue on Firefox Release 84 and Nightly 86. I'm using MacOS 10.14.6.

STR.

1. go to https://tdj.zlongame.com/
2. click site information panel, and select Allow audio and video for autoplay
3. refresh the page

Expect.
4. both audio and video play without any stuttering

Actual.
4. Noticeable stuttering happens around every 2 seconds

Here is the profiled result, there are a lot of jank in MediaDecoderStateMachine thread. Most of them happened inside CoreAudio, which were called from cubeb callstack.

Eg.
<cubeb_coreaudio::backend::AudioUnitStream as core::ops::drop::Drop>::drop -> .... -> mach_msg_trap

Comment 1

[Alastor Wu [:alwu]]

In addition, I couldn't reproduce this issue on my another MacOS 11.0.1. And I was also not able to reproduce this issue on Windows 10 and Ubuntu 20.04.

Comment 2

[Paul Adenot (:padenot)]

Well the real problem is that Gecko is telling cubeb to shutdown and restart the audio stream every two seconds, why is that ?

Also what audio output device is that, any non-standard configuration? Destroying and creating and audio stream doesn't take hundreds of milliseconds on my macbook pros.

Comment 3

[Alastor Wu [:alwu]]

Attachment: about:support

Here is the information from my about:support page. In addittion, hold NI to investigate why we were telling cubeb to shutdown and restart.

Comment 4

[Paul Adenot (:padenot)]

What's this ZoomAudioDevice thing you have ? Can you still repro this?

Comment 5

[Paul Adenot (:padenot)]

It's seeking here, and that's what's causing cubeb to re-init, but it should be faster than that. Can you still repro this, can you give us the raw data of about:config ?

Comment 6

[Alastor Wu [:alwu]]

I'm not able to reproduce this anymore, the website has been changed. So close this bug.