Hi Varkha@,

I tried playing a youtube video , local video file and a video file in google drive in samus on 9334.5.0 build , open the the status tray and navigate to Bluetooth page and listen to music over BT headset.

I didn't see any bad audio. Can you please attach any recording and logs of the machine?

Yes, I can still repro this with arbitrary YT video as well with the same Sennheiser Momentum 2 BT headset (https://goo.gl/8JdGPY available from https://goo.gl/TLsGXR). See https://goo.gl/photos/C6aLTMyMKdRyaJVx6 for how it sounds.
I'll attach net logs in a bit.

Attaching a log. The recording should be about 30 seconds and I have opened and closed the Bluetooth details page twice while playing a YT video.

Deleted: net-internals-log-bt-audio-stutter.json 2.9 MB

net-internals-log-bt-audio-stutter.json 2.9 MB View Download

I can also reproduce this with another samus I have in M-56 using an old test dev build (56.0.2924.109 / 9000.89.0) both with ash-md flag enabled or disabled. So this is not a regression, at least not a recent one and is not specific to MD UI.

Hi varkha@,
Can you reproduce the issue when you discover the devices from Settings?
(e.g. chrome://md-settings/bluetoothDevices on ToT)

If it occurs only on system menu, it might be caused by inefficient algorithm to refresh the device list.
It re-creates the whole list on every refresh, and I saw that the list refresh occurs 5 times in one second on samus.

Yes, it seems same in chrome://md-settings/bluetoothDevices. The cycle seems to be about 16 seconds during which there is about 10 seconds of stuttering and then 5-6 seconds of clear audio; then the cycle repeats until you close the BT settings page or navigate away from the details page in the menu.
It is also reproducible for audio-only playback (Play Music).

It sounds like this is probably related to Bluetooth scanning which we do when either the system tray or the Settings UI is open.

Is this a regression or always happened?

#9, I have only noticed this recently (in M-58) but I went as far back as M-56 and it is reproducible there.

Additionally (possibly a separate bug as of 58.0.3029.18):
After opening a browser window and navigating to chrome://md-settings, the Bluetooth gets immediately disabled system-wide (seems like the page load currently forces BT off). After re-enabling BT and closing this page the stutter does not stop. Could it be that the BT scanning is not stopped when the page is navigated away from? There is probably some way to stop scanning but I could not find a way other than restarting the OS.

varkha@ - That would definitely be a bug, would you mind confirming that and filing a separate issue for the MD Settings behavior? There is code that is intended to ensure that scanning is stopped regardless of how the window is closed, but it is certainly possible that is broken? We certainly should not be forcing Bluetooth to off!

Hi Miao,
According to the bug description and comment #7, it seems BT audio playback stutters while the Bluetooth adapter is discovering devices on samus.
Could you take a look at this issue?

#12, filed bugs:
 bug 703694  (initial state on chrome://md-settings)
 bug 703698  (scanning does not stop when closing chrome://md-settings)

I have this exact same issue on a Toshiba Chromebook 2. Once I opened the Bluetooth settings after pairing my headphones (Bose QC35), it started stuttering and won't stop. I've rebooted and unpaired and repaired the headphones. It causes the video to visibly stutter with it. I can attach any logs that would be useful.

#17, tried with 61.0.3159.8. Stuttering (constant and quite bad) is there while BT discovery is active (this bug) but it goes away after closing the BT details page in system menu or chrome://settings ( bug 703698  that I can see was fixed in M-59) with no need for reboot or re-pairing.