Failed to create the audio driver

[jedker999]

Im using macOS big sur and have installed fluidsynth v 2.1.7. When I want to start it I get an error:

fluidsynth: error: Error setting the audio callback. Status=-66748
Failed to create the audio driver

any ideas how to fix it?

[derselbst]

Same issue as https://lists.nongnu.org/archive/html/fluid-dev/2021-02/msg00003.html

No idea how to fix it. Pls. verify that when using the portaudio driver fluidsynth -a portaudio it fails as well. If it does fail, it's not a fluidsynth issue.

[jedker999]

Same issue as https://lists.nongnu.org/archive/html/fluid-dev/2021-02/msg00003.html

No idea how to fix it. Pls. verify that when using the portaudio driver fluidsynth -a portaudio it fails as well. If it does fail, it's not a fluidsynth issue.

unfortunately throws error as well:
||PaMacCore (AUHAL)|| Error on line 1316: err='-66748', msg=Unknown Error
fluidsynth: error: Error opening PortAudio stream: Internal PortAudio error
Failed to create the audio driver

[derselbst]

This error is printed when the call to AudioUnitSetProperty fails. According to www.osstatus.com the returned error is kAudioComponentErr_NotPermitted. You'll probably be more lucky trying to reach out in a Mac Forum.

[jedker999]

This error is printed when the call to AudioUnitSetProperty fails. According to www.osstatus.com the returned error is kAudioComponentErr_NotPermitted. You'll probably be more lucky trying to reach out in a Mac Forum.

Thanks for response.

[giona69]

@jedker999 any luck on solving this problem? I have it too ...

[mawe42]

Just an idea (coming from somebody who doesn't use Macs): According to this, the kAudioComponentErr_NotPermitted error might point to insufficient privileges:

@constant kAudioComponentErr_NotPermitted
app needs "inter-app-audio" entitlement or host app needs "audio" in its UIBackgroundModes. Or app is trying to register a component not declared in its Info.plist.

Could you try giving fluidsynth more permissions under System Preferences / Security & Privacy / Privacy? The following might be interesting:

• Microphone
• Media & Apple Music

But maybe there are even more audio related permissions?

[ringoz]

@jedker999 can you reopen this issue?

fluidsynth just doesn't work on macOS currently.

[ringoz]

quote from debug output:

This application, or a library it uses, is using the deprecated Component Manager for hosting Audio Components. This is not supported when rebuilding against the 11.00 or later SDK. Also, this makes the host incompatible with version 3 audio units. Please transition to the API's in AudioComponent.h.

[derselbst]

Wow, I would have never guessed that kAudioComponentErr_NotPermitted is due to a deprecated API. @ringoz Thank you very much! Does the debug output you've posted show up automatically, or do you have to set some environment variables or something?

[ringoz]

Fortunately, this debug output was shown by OS automatically.
It is not stdout or stderr, but NSLog & os_log kind of output.

[derselbst]

Ok, thanks.

@giona69 @jedker999 I've just applied the fix to master. Pls. let me know if it works for you, so I can backport this to 2.1.x .

[mawe42]

Great that this was fixed! And funny that PortAudio had the exact same problem: PortAudio/portaudio#338

[justinpage]

For those on macOS Big Sur who download fluidsynth via homebrew: you have version 2.1.8 installed.

I was seeing the same issue described in this thread and the following command did the trick:

fluidsynth -g 2 -p fluidsynth -o midi.driver=coremidi -o audio.driver=portaudio \
	-o audio.coreaudio.device=default -o audio.period-size=256 \
	soundfont.sf2

In other words, running audio.driver=portaudio instead of audio.driver=coreaudio worked for me.

Keep in mind that Homebrew has an open pull request to make the latest version number available:
Homebrew/homebrew-core#74428

Hope this helps!