For example: defaults write srcWCamId 'HD Webcam C525” Type defaults write srcWCamId ' webcam-userid', where webcam-userid is the user ID of the preferred webcam, which you obtained from the Real-Time Audio-Video log file. In Terminal ( /Applications/Utilities/Terminal.app), use the defaults write command to set the preferred webcam or microphone.For example, the user ID of the internal face time camera is FaceTime HD Camera (Built-in) and the user ID of the internal microphone is Built-in Microphone. The user ID appears after the string UserId= in the log file. Find the webcam or microphone that you prefer in the Real-Time Audio-Video log file and make a note of its user ID.T12:18:17.404Z| vthread-3| I120: RTAV: static void AudioCaptureBase::LogDevEnum() - Index=255 Name=Built-in Input UserId=Built-in Input#AppleHDAEngineInput:1B,0,1,1:2 SystemId=AppleHDAEngineInput:1B,0,1,1:2

T12:18:17.404Z| vthread-3| I120: RTAV: static void AudioCaptureBase::LogDevEnum() - Index=255 Name=Built-in Microphone UserId=Built-in Microphone#AppleHDAEngineInput:1B,0,1,0:1 SystemId=AppleHDAEngineInput:1B,0,1,0:1 T12:18:17.404Z| vthread-3| I120: RTAV: static void AudioCaptureBase::LogDevEnum() - 2 Device(s) found T12:18:17.404Z| vthread-3| I120: RTAV: int AVCaptureEnumerateAudioDevices(MMDev::DeviceList&). T12:18:17.404Z| vthread-3| I120: RTAV: static void VideoInputBase::LogDevEnum() - Name=FaceTime HD Camera (Built-in) UserId=FaceTime HD Camera (Built-in)#0xfa20000005ac8509 SystemId=0xfa20000005ac8509The following example shows how microphone entries might appear in the Real-Time Audio-Video log file:

T12:18:17.404Z| vthread-3| I120: RTAV: static void VideoInputBase::LogDevEnum() - 1 Device(s) found The following example shows how webcam entries might appear in the Real-Time Audio-Video log file:

Use external camera on mac