frameworks/av/services/camera/libcameraservice/api1/CameraClient.cpp

Android 中对于摄像头处理分为前置摄像头和后置摄像头

1、Camera.CameraInfo.CAMERA_FACING_FRONT ：前置摄像头

2、Camera.CameraInfo.CAMERA_FACING_BACK：后置摄像头

base/core/java/android/hardware/Camera.java