The type of media to request capture of, such as AVMediaTypeAudio. See Media Types.
The position of capture device to request relative to system hardware (front- or back-facing). Pass AVCaptureDevicePositionUnspecified to search for devices regardless of position.
The system default device for the specified combination of device type, media type, and position, or nil if no currently available device satisfies the specified criteria.
Use this method to easily select the system default capture device for a given scenario. For example, to obtain the dual camera on supported hardware and fall back to the standard wide-angle camera otherwise, call this method twice, as shown below.