私はしばらくの間これを行う方法に頭をぶつけて、最終的にそれを理解しました:
BOOL isMic = NO;
BOOL isSpeaker = NO;
AudioDeviceID device = audioDevices[i];
// Determine direction of the device by asking for the number of input or
// output streams.
propertyAddress.mSelector = kAudioDevicePropertyStreams;
propertyAddress.mScope = kAudioDevicePropertyScopeInput;
UInt32 dataSize = 0;
OSStatus status = AudioObjectGetPropertyDataSize(device,
&propertyAddress,
0,
NULL,
&dataSize);
UInt32 streamCount = dataSize / sizeof(AudioStreamID);
if (streamCount > 0)
{
isMic = YES;
}
propertyAddress.mScope = kAudioDevicePropertyScopeOutput;
dataSize = 0;
status = AudioObjectGetPropertyDataSize(device,
&propertyAddress,
0,
NULL,
&dataSize);
streamCount = dataSize / sizeof(AudioStreamID);
if (streamCount > 0)
{
isSpeaker = YES;
}
ご覧のとおり、重要な部分はScopeInput/ScopeOutputパラメーター値を使用することです。