Question

I am trying to write a C++ program which plays real-time processed audio. I have decided to use RtAudio but cannot make the test programs play audio.

I am using Mac OS X, so I compiled with ./configure --with-core and make. After compiling the files in the test directory, I ran ./audioprobe to return this list.

Compiled APIs:
  OS-X Core Audio

Current API: OS-X Core Audio

Found 3 device(s) ...

Device Name = Apple Inc.: Built-in Microphone
Probe Status = Successful
Output Channels = 0
Input Channels = 2
Duplex Channels = 0
This is NOT the default output device.
This is NOT the default input device.
Natively supported data formats:
  32-bit float
Supported sample rates = 44100 48000 88200 96000 

Device Name = Apple Inc.: Built-in Input
Probe Status = Successful
Output Channels = 0
Input Channels = 2
Duplex Channels = 0
This is NOT the default output device.
This is the default input device.
Natively supported data formats:
  32-bit float
Supported sample rates = 44100 48000 88200 96000 

Device Name = Apple Inc.: Built-in Output
Probe Status = Successful
Output Channels = 2
Input Channels = 0
Duplex Channels = 0
This is the default output device.
This is NOT the default input device.
Natively supported data formats:
  32-bit float
Supported sample rates = 44100 48000 88200 96000 

Since the Built-in Output device is index 2, I then ran ./playsaw 2 44100 2, but an error occurred:

RtApiCore::probeDeviceOpen: system error (kAudioHardwareUnknownPropertyError)
    getting stream format for device (2).

How can this be fixed?

Answer 1

Are you on Lion (10.7)? I am seeing the same problem, on older systems (10.6.x) RtAudio work fine for me.

Perhaps you can downgrade to RtAudio 4.0.6, this worked for me on Lion, but there’s still a bug lurking around with device names which got fixed in 4.0.8.