Problems with setAudioDeviceSetup of AudioDeviceManager

General JUCE discussion
1

Hi,
I have problems using setAudioDeviceSetup (const AudioDeviceSetup &newSetup, bool treatAsChosenDevice)
It always return error. The returned strings are “Can’t open the audio device! This may be because another application is currently using the same device - if so, you should close any other applications and try again!” or “Couldn’t open the input device!”

I am writing a simple audioserver, so I want to remotely control the behaviour of the soundcard.
My server creates the AudioDeviceManager and initialise it, playTestSound() produces sound (I call it remotely using a JSON message) so I think the audio system is working properly.
Now the client says “Server change buffer_size 512”, the server calls getAudioDeviceSetup (AudioDeviceSetup &setup) to obtain the actual config, then tweaks the bufferSize param and calls setAudioDeviceSetup (const AudioDeviceSetup &newSetup, bool treatAsChosenDevice)

Looking at the code of AudioDeviceSelectorComponent it seems to me to do the same thing but probably not as my app doesn’t work… :slight_smile:
instead AudioDemo works perfectly!

Hope someone could help me,
bye

Andrea

2

You should debug the process of opening the device, and see how far it gets.

3

Debugging I noticed where things go wrong but I cannot find a solution:

I have initialised with

Then I ask the audioDeviceManager to change to 2nd output device (as an example)

audioDeviceManager->getAudioDeviceSetup(actualSetup); actualSetup.outputDeviceName = "mySecondOutputDevice"; actualSetup.useDefaultOutputChannels = true; audioDeviceManager->setAudioDeviceSetup(actualSetup, false);
Now in juce_AudioDeviceManager.cpp (line 386)

returns nullptr

In particular device.initialise() in juce_win32_WASAPI.cpp (line 1035) fails.
initialise() calls createDevice(), the 1st condition is verified

so it return false…

After that… I continue not to understand why when the audioEngine starts I can listen sound but I cannot change anything…

4

Well, if the OS can’t even create an instance of the device enumerator, then something is pretty screwed-up! I’ve no idea what you’d have to do to make that fail!

You’re calling it from the main message thread, right?

5

mmm, maybe not:
audioDeviceManager is a member variable of MyClass_ServiceHandler.

MyClass_ServiceHandler has a method called “handleMessage” that is called by MyClass_Connection::messageReceived(const MemoryBlock &message)
so the operation on audioDeviceManager is executed by the thread of MyClass_Connection.

The interaction is something like:
MyClass_Connection (inherits from InterprocessConnection) when receives a message calls MyClass_ServiceHandler::handleMessage that based on the message could calls audioDeviceManager to tweak the soundcard.

6

Well WASAPI uses COM objects, so it’ll fail if you try to call it on a thread that hasn’t had CoInitialize called.

7

My knowledge stops here… :frowning:
How to call CoInitialize(0) in the thread of connection? I have tried to add that in the constructor of MyClass_Connection but obviously it is not accepted as it is not a method of MyClass_Connection, InterprocessConnection, Thread…

8

If you’re using an InterprocessConnection, why not just set it to use the message thread? It’s an option in the constructor.

9

You are my idol !!!
It is great when only changing a param from “false” to “true” makes everything to work!

Thank you!

Andrea