#1386 sound bug after pressing alt+shift+F12 several times

[Thomas Witek]

start x64sc.exe, press alt+shift+F12 several times. After 5-25 presses, "pop" sounds are produced in irregular invervals. Same "pop" sound you hear when starting x64sc.exe. To stop the sounds you have to restart x64sc.exe

[dqh]

Is that the GTK3 or SDL2 version?

[dqh]

Does pausing then unpausing fix the audio? What about changing buffer or fragment size in the audio settings?

[Thomas Witek]

It's the official download link version: GTK3VICE-3.5-win64.
Pausing and unpausing reduces the number of "pop" sounds, but they don't go away.
Fragment size medium/very small/very large: no change.
Changing buffer size to 10ms changes the pitch and the length of the "pop" sounds. It's much longer and sounds very metallic.

[dqh]

Based on your other report, I'm guessing that at 30ms + this problem goes away for you. The other thing i'd be interested in is if there is any difference when you switch to 48000 samples per second. Would also be interested to know what sample rate Windows has your audio device running at.

[Thomas Witek]

This was tested at default 100ms.
Buffer 30ms to 150ms: "pop" sounds appear.
Changing the sample rate when "pop" sounds already appeared does not get rid of them.
Setting to 48k / 30ms: "pop" sounds appear.

Windows setting for "Loudspeaker" / Advanced / Standardformat:
24bit, 48000 Hz
Changed it to 16 bit, 44100 Hz for testing:
buffer 150ms, 44.1kHz: "pop" sounds appear.

[dqh]

so no matter what, you have popping sounds. Are all other settings at default? Can you try resetting all settings and testing from there? FYI 100ms is no longer the default, 26ms is the default, so i'm wondering what else is not default.

[Thomas Witek]

I found a vice.ini in "C:\Users\user\AppData\Roaming\vice"
After deleting it, the default was 26ms, with the effect of slowdown as explained in the other ticket. But the "pop" sounds were gone.

The source of the "pop" sounds is in Settings / Display / VIC-II / "Audio leak emulation".
When enabled, the "pop" sounds can be "enabled" again with alt+shift+F12.

[gpz]

if "Audio leak emulation" is enabled, then its not a bug IMHO - the same will happen with a CRT monitor (which is what this option simulates)

[Thomas Witek]

Is there any documentation about this "Audio leak emulation"?
There are no "pop" sound after starting x64sc. Only after pressing alt+shift+f12 several times. And they are gone after pausing the emulator or resetting the audio otherwise.

[gpz]

"audio leak emulation" simulates various forms of "crosstalk" between video and audio. Like when you have a real C64 connected to a TV, you will also hear a "pop sound" when turning on the C64.
So, if you can confirm the problem is gone when you disable this option, this is not a bug :)

[gpz]

so can this be closed?

[Thomas Witek]

go ahead and close it