Fixing a dead lock problem when launching more than one render in the same session

This also fix the crash when clicking on play without any media loaded

src/Workflow/ClipWorkflow.cpp

@@ -67,7 +67,7 @@ void    ClipWorkflow::lock( ClipWorkflow* clipWorkflow, void** pp_ret )
 
     //In any case, we give vlc a buffer to render in...
     //If we don't, segmentation fault will catch us and eat our brain !! ahem...
-//    qDebug() << "Locking in ClipWorkflow::lock";
+    qDebug() << "Locking in ClipWorkflow::lock";
     *pp_ret = clipWorkflow->m_buffer;
 }
 
@@ -89,6 +89,7 @@ void    ClipWorkflow::unlock( ClipWorkflow* clipWorkflow )
         }
         clipWorkflow->m_waitCond->wait( clipWorkflow->m_condMutex );
     }
+//    qDebug() << "UnLocking in ClipWorkflow::unlock";
 }
 
 void    ClipWorkflow::setRenderComplete()

src/Workflow/MainWorkflow.cpp

@@ -29,7 +29,10 @@ MainWorkflow::MainWorkflow() : m_renderStarted( false )
 {
     m_tracks = new TrackWorkflow*[NB_TRACKS];
     for (unsigned int i = 0; i < NB_TRACKS; ++i)
+    {
         m_tracks[i] = new TrackWorkflow;
+        connect( m_tracks[i], SIGNAL( endReached() ), this, SLOT( __endReached() ) );
+    }
 }
 
 void    MainWorkflow::addClip( Clip* clip, unsigned int trackId, qint64 start )
@@ -74,3 +77,8 @@ qint64      MainWorkflow::getLength() const
 {
     return m_length;
 }
+
+void        MainWorkflow::__endReached()
+{
+    emit endReached();
+}

src/Workflow/MainWorkflow.h

@@ -63,6 +63,9 @@ class   MainWorkflow : public QObject
         qint64                  m_currentFrame;
         qint64                  m_length;
 
+    private slots:
+        void                    __endReached();
+
     signals:
         /**
          *  \brief Used to notify a change to the timeline cursor
@@ -72,6 +75,8 @@ class   MainWorkflow : public QObject
           * \brief Used to nofify a change to the PreviewWidget
           */
         void                    positionChanged( float pos );
+
+        void                    endReached();
 };
 
 #endif // MAINWORKFLOW_H

src/Workflow/TrackWorkflow.cpp

@@ -50,6 +50,9 @@ void    TrackWorkflow::addClip( Clip* clip, qint64 start )
 void    TrackWorkflow::startRender()
 {
     m_current = m_clips.end();
+
+    if ( m_clips.size() <= 0)
+        return ;
     //If the first frame is to be render soon, we should play it now.
     if ( m_clips.begin().key() < TrackWorkflow::nbFrameBeforePreload )
     {
@@ -75,6 +78,9 @@ bool                TrackWorkflow::checkNextClip( qint64 currentFrame )
     //Picking next clip :
     if ( m_current == m_clips.end() )
     {
+        //Checking if there is a clip in the first place...
+        if ( m_clips.count() == 0 )
+            return false;
         next = m_clips.begin();
     }
     else
@@ -123,10 +129,15 @@ unsigned char*      TrackWorkflow::getOutput( qint64 currentFrame )
 
     QReadLocker     lock( m_currentLock );
 
-//    qDebug() << "Frame nb" << m_currentFrame;
+//    qDebug() << "Frame nb" << currentFrame;
     clipsRemaining = checkNextClip( currentFrame );
     if ( m_current == m_clips.end() )
     {
+        if ( clipsRemaining == false )
+        {
+//            qDebug() << "End Reached";
+            emit endReached();
+        }
 //        qDebug() << "Stil no clip at this time, going to the next frame";
         return ret;
     }
@@ -139,7 +150,10 @@ unsigned char*      TrackWorkflow::getOutput( qint64 currentFrame )
     else
     {
         if ( clipsRemaining == false )
-            return NULL;
+        {
+//            qDebug() <<"End reached";
+            emit endReached();
+        }
     }
     return ret;
 }

src/Workflow/TrackWorkflow.h

@@ -96,6 +96,9 @@ class   TrackWorkflow : public QObject
 
     public:
         void            addClip( Clip*, qint64 start );
+
+    signals:
+        void            endReached();
 };
 
 #endif // TRACKWORKFLOW_H

src/gui/GenericPreviewWidget.h

@@ -47,7 +47,6 @@ public:
 
     virtual void                    startPreview( Media* media ) = 0;
     virtual void                    setPosition( float newPos ) = 0;
-    virtual void                    togglePlayPause( bool forcePause = false ) = 0;
 
 protected:
     LibVLCpp::MediaPlayer*          m_mediaPlayer;
@@ -58,6 +57,9 @@ public slots:
     virtual void                    __videoPlaying() = 0;
     virtual void                    __endReached() = 0;
 
+    //For meta invoking
+    virtual void                    togglePlayPause( bool forcePause = false ) = 0;
+
 signals:
     void                    stopped();
     void                    paused();

src/gui/PreviewWidget.cpp

@@ -23,6 +23,7 @@
 
 #include <QUrl>
 #include <QtDebug>
+#include <QMetaMethod>
 
 #include "ui_PreviewWidget.h"
 #include "gui/PreviewWidget.h"
@@ -177,6 +178,10 @@ void PreviewWidget::on_pushButtonPlay_clicked()
 {
     if ( m_previewStopped == true )
         m_previewStopped = false;
+//    int     methodIndex = m_currentPreviewRenderer->metaObject()->indexOfMethod("togglePlayPause(bool)");
+//    qDebug() << methodIndex;
+//    QMetaMethod method = m_currentPreviewRenderer->metaObject()->method( methodIndex );
+//    qDebug() << method.invoke( m_currentPreviewRenderer, Qt::QueuedConnection, Q_ARG(bool, false) );
     m_currentPreviewRenderer->togglePlayPause();
 }
 

src/gui/RenderPreviewWidget.cpp

@@ -21,6 +21,7 @@
  *****************************************************************************/
 
 #include <QtDebug>
+#include <QThread>
 
 #include "RenderPreviewWidget.h"
 
@@ -50,6 +51,7 @@ RenderPreviewWidget::RenderPreviewWidget( MainWorkflow* mainWorkflow, QWidget* r
 
     connect( m_mediaPlayer, SIGNAL( playing() ), this, SLOT( __videoPlaying() ) );
     connect( m_mediaPlayer, SIGNAL( paused() ), this, SLOT( __videoPaused() ) );
+    connect( m_mainWorkflow, SIGNAL( endReached() ), this, SLOT( __endReached() ) );
     connect( m_mainWorkflow, SIGNAL( positionChanged( float ) ), this, SLOT( __positionChanged( float ) ) );
 }
 
@@ -64,12 +66,6 @@ void*   RenderPreviewWidget::lock( void* datas )
 //    qDebug() << "Locking invmem";
     RenderPreviewWidget* self = reinterpret_cast<RenderPreviewWidget*>( datas);
     void* ret = self->m_mainWorkflow->getOutput();
-    if ( ret == NULL )
-    {
-        //maybe we should display a black screen here to really emphasize
-        //the end of the render
-        self->m_mediaPlayer->stop();
-    }
     return ret;
 }
 
@@ -78,6 +74,13 @@ void    RenderPreviewWidget::unlock( void*  )
 //    qDebug() << "Unlocking invmem";
 }
 
+void        RenderPreviewWidget::stopPreview()
+{
+    m_mediaPlayer->stop();
+    m_isRendering = false;
+    qDebug() << "Stopped";
+}
+
 void        RenderPreviewWidget::startPreview( Media* )
 {
     m_mainWorkflow->startRender();
@@ -109,7 +112,8 @@ void        RenderPreviewWidget::togglePlayPause( bool /*forcePause*/ )
 
 void        RenderPreviewWidget::__endReached()
 {
-    qDebug() << "RenderPreviewWidget::__endReached : unimplemented";
+//    qDebug() << "Stopping preview";
+    stopPreview();
 }
 
 void        RenderPreviewWidget::__positionChanged()

src/gui/RenderPreviewWidget.h

@@ -40,6 +40,7 @@ class   RenderPreviewWidget : public GenericPreviewWidget
         ~RenderPreviewWidget();
 
         virtual void        startPreview( Media* );
+        void                stopPreview();
 
         /**
             \brief          Set the preview position
@@ -58,12 +59,12 @@ class   RenderPreviewWidget : public GenericPreviewWidget
         LibVLCpp::Media*    m_media;
         bool                m_isRendering;
 
-public slots:
-    void                    __positionChanged();
-    void                    __positionChanged( float pos );
-    void                    __videoPaused();
-    void                    __videoPlaying();
-    void                    __endReached();
+    public slots:
+        void                    __positionChanged();
+        void                    __positionChanged( float pos );
+        void                    __videoPaused();
+        void                    __videoPlaying();
+        void                    __endReached();
 };
 
 #endif // RENDERPREVIEWWIDGET_H