Am 29.03.23 um 21:20 schrieb BALATON Zoltan:
On Tue, 28 Mar 2023, Volker Rümelin wrote:
it seems your Mac uses a 48kHz sample rate, although QEMU requested a
44.1kHz sample rate. Could you add -audiodev
coreaudio,id=audio0,out.frequency=48000 to your command line and test if
the playback speed and pitch is now correct?
I guess you could also set the sampling rate in the guest to match the host
but if that results it to do resampling then it may use more CPU that way.
With default settings QEMU resamples the selected guest rate to
out.frequency.
The default for out.frequency is 44100.
I think ALSA and Pulseaudio may also default to 48kHz. I remember
configuring ALSA to 44.1 kHz on my machine to avoid resampling in the more
common case of playing music. So is this a general problem or something
with the coreadio backend? Should this somehow detect the host sampling
rate and do something about it?
Querying the host sample rate and using the host sample rate instead of
out.frequency seems easy. It gets difficult when someone changes the host
sample rate when QEMU is running. Current QEMU code can't change the sample
rate for an established audio stream.