diff --git a/src/plugins/gstreamer/camerabin/camerabinsession.cpp b/src/plugins/gstreamer/camerabin/camerabinsession.cpp
index 23cbd608..87d9e2fd 100644
--- a/src/plugins/gstreamer/camerabin/camerabinsession.cpp
+++ b/src/plugins/gstreamer/camerabin/camerabinsession.cpp
@@ -143,6 +143,7 @@ CameraBinSession::CameraBinSession(GstElementFactory *sourceFactory, QObject *pa
      m_sourceFactory(sourceFactory),
      m_viewfinderHasChanged(true),
      m_inputDeviceHasChanged(true),
+     m_inputDeviceHasChangedAndOpened(false),
      m_usingWrapperCameraBinSrc(false),
      m_viewfinderProbe(this),
      m_audioSrc(0),
@@ -153,6 +154,9 @@ CameraBinSession::CameraBinSession(GstElementFactory *sourceFactory, QObject *pa
      m_videoEncoder(0),
      m_muxer(0)
 {
+#if CAMERABIN_DEBUG
+    qDebug() << "CameraBin Constructing...";
+#endif
     if (m_sourceFactory)
         gst_object_ref(GST_OBJECT(m_sourceFactory));
     m_camerabin = gst_element_factory_make(QT_GSTREAMER_CAMERABIN_ELEMENT_NAME, "camerabin");
@@ -196,10 +200,17 @@ CameraBinSession::CameraBinSession(GstElementFactory *sourceFactory, QObject *pa
 
     g_object_set(G_OBJECT(m_camerabin), PREVIEW_CAPS_PROPERTY, previewCaps, NULL);
     gst_caps_unref(previewCaps);
+#if CAMERABIN_DEBUG
+    qDebug() << "CameraBin Constructed.";
+#endif
 }
 
 CameraBinSession::~CameraBinSession()
 {
+#if CAMERABIN_DEBUG
+    qDebug() << "CameraBin Destructing...";
+#endif
+
     if (m_camerabin) {
         if (m_viewfinderInterface)
             m_viewfinderInterface->stopRenderer();
@@ -220,6 +231,10 @@ CameraBinSession::~CameraBinSession()
 
     if (m_videoSrc)
         gst_object_unref(GST_OBJECT(m_videoSrc));
+
+#if CAMERABIN_DEBUG
+    qDebug() << "CameraBin Destructed.";
+#endif
 }
 
 #if QT_CONFIG(gstreamer_photography)
@@ -477,6 +492,24 @@ GstElement *CameraBinSession::buildCameraSource()
     m_inputDeviceHasChanged = false;
     m_usingWrapperCameraBinSrc = false;
 
+    if (m_inputDeviceHasChangedAndOpened) {
+        m_inputDeviceHasChangedAndOpened = false;
+#if CAMERABIN_DEBUG
+        qDebug().noquote() << QString("CameraBinSession: deviceChangedAndOpened. camera=0x%1 ref=%2") \
+            .arg((quintptr)m_cameraSrc, QT_POINTER_SIZE * 2, 16, QChar('0')) \
+            .arg(GST_OBJECT_REFCOUNT_VALUE(GST_OBJECT_CAST(m_cameraSrc)));
+#endif
+        // m_videoSrcがm_cameraSrcを握っているかもしれないのでunrefしてみる
+        if (m_videoSrc) {
+            gst_object_unref(GST_OBJECT(m_videoSrc));
+            m_videoSrc = 0;
+        }
+        if (m_cameraSrc) {
+            gst_object_unref(GST_OBJECT(m_cameraSrc));
+            m_cameraSrc = 0;
+        }
+    }
+
     GstElement *camSrc = 0;
     g_object_get(G_OBJECT(m_camerabin), CAMERA_SOURCE_PROPERTY, &camSrc, NULL);
 
@@ -489,6 +522,9 @@ GstElement *CameraBinSession::buildCameraSource()
 
     if (m_cameraSrc) {
 #if CAMERABIN_DEBUG
+        qDebug().noquote() << QString("CameraBinSession: set camera... camera=0x%1 ref=%2") \
+            .arg((quintptr)m_cameraSrc, QT_POINTER_SIZE * 2, 16, QChar('0')) \
+            .arg(GST_OBJECT_REFCOUNT_VALUE(GST_OBJECT_CAST(m_cameraSrc)));
         qDebug() << "set camera device" << m_inputDevice;
 #endif
         m_usingWrapperCameraBinSrc = qstrcmp(qt_gst_element_get_factory_name(m_cameraSrc), "wrappercamerabinsrc") == 0;
@@ -556,6 +592,11 @@ GstElement *CameraBinSession::buildCameraSource()
             }
         }
     }
+#if CAMERABIN_DEBUG
+    qDebug().noquote() << QString("CameraBinSession: set_src... camera=0x%1 ref=%2") \
+        .arg((quintptr)m_cameraSrc, QT_POINTER_SIZE * 2, 16, QChar('0')) \
+        .arg(GST_OBJECT_REFCOUNT_VALUE(GST_OBJECT_CAST(m_cameraSrc)));
+#endif
 
     if (m_cameraSrc != camSrc) {
         g_object_set(G_OBJECT(m_camerabin), CAMERA_SOURCE_PROPERTY, m_cameraSrc, NULL);
@@ -564,6 +605,11 @@ GstElement *CameraBinSession::buildCameraSource()
             gst_object_unref(GST_OBJECT(camSrc));
     }
 
+#if CAMERABIN_DEBUG
+    qDebug().noquote() << QString("CameraBinSession: build end. camera=0x%1 ref=%2") \
+        .arg((quintptr)m_cameraSrc, QT_POINTER_SIZE * 2, 16, QChar('0')) \
+        .arg(GST_OBJECT_REFCOUNT_VALUE(GST_OBJECT_CAST(m_cameraSrc)));
+#endif
     return m_cameraSrc;
 }
 
@@ -625,6 +671,9 @@ void CameraBinSession::setDevice(const QString &device)
     if (m_inputDevice != device) {
         m_inputDevice = device;
         m_inputDeviceHasChanged = true;
+        if (m_cameraSrc) {
+            m_inputDeviceHasChangedAndOpened = true;
+        }
     }
 }
 
diff --git a/src/plugins/gstreamer/camerabin/camerabinsession.h b/src/plugins/gstreamer/camerabin/camerabinsession.h
index 999398fa..e6603c56 100644
--- a/src/plugins/gstreamer/camerabin/camerabinsession.h
+++ b/src/plugins/gstreamer/camerabin/camerabinsession.h
@@ -258,6 +258,7 @@ private:
     GstElementFactory *m_sourceFactory;
     bool m_viewfinderHasChanged;
     bool m_inputDeviceHasChanged;
+    bool m_inputDeviceHasChangedAndOpened;
     bool m_usingWrapperCameraBinSrc;
 
     class ViewfinderProbe : public QGstreamerVideoProbeControl {