Migrate to categorized logging in Quick 2 video output

Enable qt.multimedia.video to get the logs. Also enhance the printing
when creating the video node implementation. It is essential to have
an easy way to figure out what handle and formats the node in use
supports.

Change-Id: Idf3a9f076ba03b5e613c19f2347204c841850b45
Reviewed-by: Andy Nichols <andy.nichols@theqtcompany.com>

src/qtmultimediaquicktools/qdeclarativevideooutput.cpp

@@ -39,11 +39,12 @@
 #include <QtMultimedia/qmediaobject.h>
 #include <QtMultimedia/qmediaservice.h>
 #include <private/qmediapluginloader_p.h>
-
-//#define DEBUG_VIDEOITEM
+#include <QtCore/qloggingcategory.h>
 
 QT_BEGIN_NAMESPACE
 
+Q_LOGGING_CATEGORY(qLcVideo, "qt.multimedia.video")
+
 /*!
     \qmltype VideoOutput
     \instantiates QDeclarativeVideoOutput
@@ -154,9 +155,7 @@ QDeclarativeVideoOutput::~QDeclarativeVideoOutput()
 
 void QDeclarativeVideoOutput::setSource(QObject *source)
 {
-#ifdef DEBUG_VIDEOITEM
-    qDebug() << Q_FUNC_INFO << source;
-#endif
+    qCDebug(qLcVideo) << "source is" << source;
 
     if (source == m_source.data())
         return;
@@ -273,9 +272,7 @@ void QDeclarativeVideoOutput::_q_updateMediaObject()
     if (m_source)
         mediaObject = qobject_cast<QMediaObject*>(m_source.data()->property("mediaObject").value<QObject*>());
 
-#ifdef DEBUG_VIDEOITEM
-    qDebug() << Q_FUNC_INFO << mediaObject;
-#endif
+    qCDebug(qLcVideo) << "media object is" << mediaObject;
 
     if (m_mediaObject.data() == mediaObject)
         return;