Sound issue between TurboVNC and Slack

[Torsten Kupke]

Hi,

currently I still use TurboVNC 2.2.7 (server on Ubuntu and native
Windows viewer). When I'm running the viewer in fullscreen mode, I
cannot hear any sounds from my Slack App (message ticks and calling
sounds). In lucky cases I can see a corresponding message displayed by
the Slack instance running on the remote host desktop. When I switch off
the fullscreen mode of the viewer, I can hear all Slack sounds again. I
think, Slack assumes, that I'm a gamer and don't want to be disturbed,
when my local display is in fullscreen mode. I reported this as bug to
Slack already. But they seem to be unable to fix it (may be because too
few users have the same issue). Is there any chance to fix this issue on
TurboVNC side? Or another question: Is TurboVNC able to transfer any
sounds from the remote host to the viewer in any way? Is TurboVNC 3 able
to achieve this?

BR

tkansgar

[DRC]

Does this happen with the Windows/Java TurboVNC Viewer as well?

Mostly, there is nothing special about the TurboVNC Viewer's full-screen
mode on Windows. The viewer simply removes the decorations from its
main window and resizes the window so that it will fill all available
screen real estate. However, the (now deprecated) native Windows
TurboVNC Viewer from TurboVNC 2.2.x and prior sets the HWND_TOPMOST hint
in full-screen mode, which instructs Windows to keep the window in front
of all other windows. Maybe Slack is detecting that.

Slack may also be detecting that the TurboVNC Viewer grabbed the
keyboard in full-screen mode. Try setting the keyboard grabbing mode to
"Manual" and leaving/re-entering full-screen mode. (You can tell that
the keyboard is ungrabbed by the fact that you will be able to Alt-Tab
away from the TurboVNC Viewer. If the keyboard is grabbed, then Alt-Tab
will be passed to the VNC server instead.)

The results of those tests (whether the issue is observed with the
Windows/Java TurboVNC Viewer and without keyboard grabbing) will give me
a clue as to what is causing Slack to trigger, but there is still
probably very little I can do about it.

Also, I would suggest upgrading to the 3.0.x TurboVNC Viewer. 2.2.x is
currently at the Maintenance support level
(https://turbovnc.org/DeveloperInfo/Versioning) and will transition to
Extended (critical fixes only) once TurboVNC 3.1 is released.

TurboVNC does not have built-in audio support. See:
https://github.com/TurboVNC/turbovnc/issues/178

[Torsten Kupke]

Am 14.03.2023 um 18:57 schrieb 'DRC' via TurboVNC User Discussion/Support:
> Does this happen with the Windows/Java TurboVNC Viewer as well?

With the Windows/Java TurboVNC Viewer the behaviour of Slack is exactly
the same. Without running the viewer in fullscreen mode I can hear
Slack's sounds, in fullscreen mode I cannot.

I will now try to switch off keyboard grabbing of the viewer in
fullscreen mode.

[Torsten Kupke]

Am 17.03.2023 um 20:10 schrieb Torsten Kupke:
> Am 14.03.2023 um 18:57 schrieb 'DRC' via TurboVNC User
> Discussion/Support:
>> Does this happen with the Windows/Java TurboVNC Viewer as well?
>
> With the Windows/Java TurboVNC Viewer the behaviour of Slack is
> exactly the same. Without running the viewer in fullscreen mode I can
> hear Slack's sounds, in fullscreen mode I cannot.
>
> I will now try to switch off keyboard grabbing of the viewer in
> fullscreen mode.
>
>>
>> Mostly, there is nothing special about the TurboVNC Viewer's
>> full-screen mode on Windows.  The viewer simply removes the
>> decorations from its main window and resizes the window so that it
>> will fill all available screen real estate.  However, the (now
>> deprecated) native Windows TurboVNC Viewer from TurboVNC 2.2.x and
>> prior sets the HWND_TOPMOST hint in full-screen mode, which instructs
>> Windows to keep the window in front of all other windows.  Maybe
>> Slack is detecting that.
>>
>> Slack may also be detecting that the TurboVNC Viewer grabbed the
>> keyboard in full-screen mode.  Try setting the keyboard grabbing mode
>> to "Manual" and leaving/re-entering full-screen mode.  (You can tell
>> that the keyboard is ungrabbed by the fact that you will be able to
>> Alt-Tab away from the TurboVNC Viewer.  If the keyboard is grabbed,
>> then Alt-Tab will be passed to the VNC server instead.)

Therefore I saved a new .vnc file with "grabkeyboard=2" and started this
one. With that I'm able to Alt-Tab away from the TurboVNC Viewer, but
Slack still is silent, when the viewer is set to fullscreen mode.

So there seems to be not any chance to run the TurboVNC Viewer in
fullscreen mode and hear any sounds from Slack.

[DRC]

On 3/17/23 2:36 PM, Torsten Kupke wrote:
> Therefore I saved a new .vnc file with "grabkeyboard=2" and started
> this one. With that I'm able to Alt-Tab away from the TurboVNC Viewer,
> but Slack still is silent, when the viewer is set to fullscreen mode.
>
> So there seems to be not any chance to run the TurboVNC Viewer in
> fullscreen mode and hear any sounds from Slack.

If Slack is so poorly written that it silences its output whenever a
full-screen window is active, then this issue will affect all remote
desktop software, not just TurboVNC.  In short, it's their bug, and
there is nothing we can do about it.  As a workaround, automatic desktop
resizing and automatic screen scaling make it easier to use the TurboVNC
Viewer in windowed mode.