Front/Back camera semantic support added to Android VideoCapture back-end.

modules/androidcamera/camera_wrapper/camera_wrapper.cpp

@@ -362,6 +362,9 @@ CameraHandler* CameraHandler::initCameraConnect(const CameraCallback& callback,
     typedef sp<Camera> (*Android23ConnectFuncType)(int);
     typedef sp<Camera> (*Android3DConnectFuncType)(int, int);
 
+    const int BACK_CAMERA_INDEX = 99;
+    const int FRONT_CAMERA_INDEX = 98;
+
     enum {
     CAMERA_SUPPORT_MODE_2D = 0x01, /* Camera Sensor supports 2D mode. */
     CAMERA_SUPPORT_MODE_3D = 0x02, /* Camera Sensor supports 3D mode. */
@@ -373,7 +376,51 @@ CameraHandler* CameraHandler::initCameraConnect(const CameraCallback& callback,
     const char Android23ConnectName[] = "_ZN7android6Camera7connectEi";
     const char Android3DConnectName[] = "_ZN7android6Camera7connectEii";
 
-    LOGD("CameraHandler::initCameraConnect(%p, %d, %p, %p)", callback, cameraId, userData, prevCameraParameters);
+    int localCameraIndex = cameraId;
+
+#if !defined(ANDROID_r2_2_0)
+    if (cameraId == BACK_CAMERA_INDEX)
+    {
+        LOGD("Back camera selected");
+        for (int i = 0; i < Camera::getNumberOfCameras(); i++)
+        {
+            CameraInfo info;
+            Camera::getCameraInfo(i, &info);
+            if (info.facing == CAMERA_FACING_BACK)
+            {
+                localCameraIndex = i;
+                break;
+            }
+        }
+    }
+    else if (cameraId == FRONT_CAMERA_INDEX)
+    {
+        LOGD("Front camera selected");
+        for (int i = 0; i < Camera::getNumberOfCameras(); i++)
+        {
+            CameraInfo info;
+            Camera::getCameraInfo(i, &info);
+            if (info.facing == CAMERA_FACING_FRONT)
+            {
+                localCameraIndex = i;
+                break;
+            }
+        }
+    }
+
+    if (localCameraIndex == BACK_CAMERA_INDEX)
+    {
+        LOGE("Back camera not found!");
+        return NULL;
+    }
+    else if (localCameraIndex == FRONT_CAMERA_INDEX)
+    {
+        LOGE("Front camera not found!");
+        return NULL;
+    }
+#endif
+
+    LOGD("CameraHandler::initCameraConnect(%p, %d, %p, %p)", callback, localCameraIndex, userData, prevCameraParameters);
 
     sp<Camera> camera = 0;
 
@@ -396,12 +443,12 @@ CameraHandler* CameraHandler::initCameraConnect(const CameraCallback& callback,
     else if (Android23ConnectFuncType Android23Connect = (Android23ConnectFuncType)dlsym(CameraHALHandle, Android23ConnectName))
     {
         LOGD("Connecting to CameraService v 2.3");
-    camera = Android23Connect(cameraId);
+        camera = Android23Connect(localCameraIndex);
     }
     else if (Android3DConnectFuncType Android3DConnect = (Android3DConnectFuncType)dlsym(CameraHALHandle, Android3DConnectName))
     {
         LOGD("Connecting to CameraService v 3D");
-    camera = Android3DConnect(cameraId, CAMERA_SUPPORT_MODE_2D);
+        camera = Android3DConnect(localCameraIndex, CAMERA_SUPPORT_MODE_2D);
     }
     else
     {
@@ -422,7 +469,7 @@ CameraHandler* CameraHandler::initCameraConnect(const CameraCallback& callback,
     camera->setListener(handler);
 
     handler->camera = camera;
-    handler->cameraId = cameraId;
+    handler->cameraId = localCameraIndex;
 
     if (prevCameraParameters != 0)
     {

modules/highgui/include/opencv2/highgui/highgui_c.h

@@ -305,6 +305,8 @@ enum
     CV_CAP_OPENNI_ASUS =910,   // OpenNI (for Asus Xtion)
 
     CV_CAP_ANDROID  =1000,  // Android
+    CV_CAP_ANDROID_BACK =CV_CAP_ANDROID+99, // Android back camera
+    CV_CAP_ANDROID_FRONT =CV_CAP_ANDROID+98, // Android front camera
 
     CV_CAP_XIAPI    =1100,   // XIMEA Camera API