Made changes in Android camera classes: now we can get list of possible preview…

Made changes in Android camera classes: now we can get list of possible preview resolutions of Android camera (as string).
Also now work of Android camera is more accurate in the case when the size of grabbed frame buffer does not consist with the expected frame size.

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

@@ -354,6 +354,7 @@ enum
     CV_CAP_PROP_WHITE_BALANCE_RED_V =26,
     CV_CAP_PROP_MAX_DC1394    =27,
     CV_CAP_PROP_AUTOGRAB      =1024, // property for highgui class CvCapture_Android only
+    CV_CAP_PROP_SUPPORTED_PREVIEW_SIZES_STRING=1025, // tricky property, returns cpnst char* indeed
 	// OpenNI map generators
     CV_CAP_OPENNI_DEPTH_GENERATOR = 0,
     CV_CAP_OPENNI_IMAGE_GENERATOR = 1 << 31,

modules/highgui/src/cap_android.cpp

@@ -145,9 +145,6 @@ public:
 
                 m_capture->setFrame(buffer, bufferSize);
 
-		m_capture->m_dataState = CvCapture_Android::CVCAPTURE_ANDROID_STATE_HAS_NEW_FRAME_UNGRABBED;
-                m_capture->m_waitingNextFrame = false;//set flag that no more frames required at this moment
-
                 pthread_cond_broadcast(&m_capture->m_nextFrameCond);
                 pthread_mutex_unlock(&m_capture->m_nextFrameMutex);
             }
@@ -255,6 +252,9 @@ double CvCapture_Android::getProperty( int propIdx )
         return (double)m_activity->getFrameWidth();
     case CV_CAP_PROP_FRAME_HEIGHT:
         return (double)m_activity->getFrameHeight();
+
+    case CV_CAP_PROP_SUPPORTED_PREVIEW_SIZES_STRING:
+	return (double)m_activity->getProperty(ANDROID_CAMERA_PROPERTY_SUPPORTED_PREVIEW_SIZES_STRING);
     default:
         CV_Error( CV_StsOutOfRange, "Failed attempt to GET unsupported camera property." );
         break;
@@ -296,8 +296,10 @@ bool CvCapture_Android::setProperty( int propIdx, double propValue )
 
 bool CvCapture_Android::grabFrame()
 {
-    if( !isOpened() )
+    if( !isOpened() ) {
+	    LOGE("CvCapture_Android::grabFrame(): camera is not opened");
 	    return false;
+    }
 
     bool res=false;
     pthread_mutex_lock(&m_nextFrameMutex);
@@ -314,6 +316,7 @@ bool CvCapture_Android::grabFrame()
     }
 
     if (m_dataState == CVCAPTURE_ANDROID_STATE_HAS_NEW_FRAME_UNGRABBED) {
+	    LOGD("CvCapture_Android::grabFrame: get new frame");
 	    //swap current and new frames
 	    unsigned char* tmp = m_frameYUV420i;
 	    m_frameYUV420i = m_frameYUV420inext;
@@ -327,8 +330,11 @@ bool CvCapture_Android::grabFrame()
 	    m_framesGrabbed++;
 
 	    res=true;
+    } else {
+	    LOGE("CvCapture_Android::grabFrame: NO new frame");
     }
 
+
     int res_unlock=pthread_mutex_unlock(&m_nextFrameMutex);
     if (res_unlock) {
 	    LOGE("Error in CvCapture_Android::grabFrame: pthread_mutex_unlock returned %d --- probably, this object has been destroyed", res_unlock);
@@ -394,6 +400,7 @@ void CvCapture_Android::setFrame(const void* buffer, int bufferSize)
 
     //copy data
     memcpy(m_frameYUV420inext, buffer, bufferSize);
+    LOGD("CvCapture_Android::setFrame -- memcpy is done");
 
 #if 0 //moved this part of code into grabFrame
     //swap current and new frames
@@ -405,22 +412,31 @@ void CvCapture_Android::setFrame(const void* buffer, int bufferSize)
     m_hasGray = false;
     m_hasColor = false;
 #endif
+
+    m_dataState = CVCAPTURE_ANDROID_STATE_HAS_NEW_FRAME_UNGRABBED;
+    m_waitingNextFrame = false;//set flag that no more frames required at this moment
 }
 
+//Attention: this method should be called inside pthread_mutex_lock(m_nextFrameMutex) only
 void CvCapture_Android::prepareCacheForYUV420i(int width, int height)
 {
     if (width != m_width || height != m_height)
     {
+	LOGD("CvCapture_Android::prepareCacheForYUV420i: Changing size of buffers: from width=%d height=%d to width=%d height=%d", m_width, m_height, width, height);
         m_width = width;
         m_height = height;
         unsigned char *tmp = m_frameYUV420inext;
         m_frameYUV420inext = new unsigned char [width * height * 3 / 2];
+	if (tmp != NULL) {
 		delete[] tmp;
+	}
 
         tmp = m_frameYUV420i;
         m_frameYUV420i = new unsigned char [width * height * 3 / 2];
+	if (tmp != NULL) {
 		delete[] tmp;
 	}
+    }
 }
 
 inline unsigned char clamp(int value)