CODEWITHSUNDEEP
objective-ccocoamacosaudio
Jaliborc
Jaliborc

Reputation: 353

Setting sound output/input

I've been looking all over the web, but I don't know if it is possible: can a Cocoa Mac OS X app change the sound input/output device? If so, how come?

Upvotes: 1

Views: 1901

Answers (2)

Carlitos Ruiz
Carlitos Ruiz

Reputation: 21

I know this is an old post but I've been struggling these days trying to find a way of changing the sound input/output device using code and I finally found how to do it. In case someone else runs into the same problem, here's the answer!

There's a command line utility called SwitchAudio-OSX (https://code.google.com/p/switchaudio-osx/) that allows you to switch the audio source from the terminal. It is open-source and you can find the latest version here: https://github.com/deweller/switchaudio-osx.

Anyway, you can use these lines to change the sound input/output device:

UInt32 propertySize = sizeof(UInt32);
AudioHardwareSetProperty(kAudioHardwarePropertyDefaultInputDevice, propertySize, &newDeviceID); // To change the input device
AudioHardwareSetProperty(kAudioHardwarePropertyDefaultOutputDevice, propertySize, &newDeviceID); // To change the output device
AudioHardwareSetProperty(kAudioHardwarePropertyDefaultSystemOutputDevice, propertySize, &newDeviceID); // To change the system output device

Where newDeviceID is an instance of AudioDeviceID and represents the id of the device you want to select. Also, a list of all available devices can be obtained using this code:

AudioDeviceID dev_array[64];
AudioHardwareGetProperty(kAudioHardwarePropertyDevices, &propertySize, dev_array);
int numberOfDevices = (propertySize / sizeof(AudioDeviceID));

Upvotes: 2

Peter Hosey
Peter Hosey

Reputation: 96323

can a Cocoa Mac OS X app change the sound input/output device?

Yes, by setting the relevant Audio System Object property.

If so, how come?

Probably because the user might want to change the default input or output device from within an application, rather than having to jump over to the Sound prefpane before and after or use the Sound menu extra.

Upvotes: 2

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