filterContextType, filter opacity. FilterContext in AVThread can be null

TODO:
  do not check FilterContext in public api

src/Filter.cpp

@@ -40,12 +40,6 @@ void Filter::process(FilterContext *context, Statistics *statistics)
     Q_UNUSED(statistics);
 }
 
-void Filter::process(QByteArray &data)
-{
-    Q_UNUSED(data);
-}
-
-
 void Filter::setEnabled(bool enabled)
 {
     DPTR_D(Filter);
@@ -58,4 +52,20 @@ bool Filter::isEnabled() const
     return d.enabled;
 }
 
+void Filter::setOpacity(qreal o)
+{
+    DPTR_D(Filter);
+    d.opacity = o;
+}
+
+qreal Filter::opacity() const
+{
+    return d_func().opacity;
+}
+
+FilterContext::Type Filter::contextType() const
+{
+    return FilterContext::None;
+}
+
 } //namespace QtAV

src/FilterContext.cpp

@@ -46,6 +46,12 @@ VideoFilterContext::VideoFilterContext():
 {
 }
 
+QPainterFilterContext::QPainterFilterContext():
+    painter(0)
+{
+
+}
+
 FilterContext::Type QPainterFilterContext::type() const
 {
     return FilterContext::QtPainter;

src/OSDFilter.cpp

@@ -43,13 +43,31 @@ OSDFilterImpl<QPainterFilterContext>::OSDFilterImpl():
 }
 
 template<>
-void OSFilterQPainter::process(FilterContext *context, Statistics *statistics)
+void OSDFilterQPainter::process(FilterContext *context, Statistics *statistics)
 {
     if (mShowType == ShowNone)
         return;
+    if (!context || context->type() != contextType()) {
+        if (context && context->type() != contextType()) {
+            qDebug("incompatible context type");
+            delete context;
+            context = 0;
+        } else {
+            qDebug("null context");
+        }
+        context = FilterContext::create(FilterContext::QtPainter);
+        QPainterFilterContext* ctx = static_cast<QPainterFilterContext*>(context);
+        ctx->painter = new QPainter();
+    }
     QPainterFilterContext* ctx = static_cast<QPainterFilterContext*>(context);
-    if (!ctx->painter)
+    if (!ctx->painter) {
+        //qWarning("null QPainter in OSDFilterQPainter!");
         return;
+    }
+    if (!ctx->painter->isActive()) {
+        qWarning("QPainter in OSDFilterQPainter is not active");
+        return;
+    }
     QPainter *p = ctx->painter;
     p->save(); //TODO: move outside?
     p->setFont(mFont);
@@ -57,5 +75,11 @@ void OSFilterQPainter::process(FilterContext *context, Statistics *statistics)
     p->drawText(ctx->rect.topLeft(), text(statistics));
     p->restore(); //TODO: move outside?
 }
-
+/*
+template<>
+FilterContext::Type OSDFilterQPainter::contextType() const
+{
+    return FilterContext::QtPainter;
+}
+*/
 } //namespace QtAV

src/QPainterRenderer.cpp

@@ -31,7 +31,7 @@ QPainterRenderer::QPainterRenderer()
 {
     DPTR_D(QPainterRenderer);
     d.filter_context = FilterContext::create(FilterContext::QtPainter);
-    d.osd_filter = new OSFilterQPainter();
+    d.osd_filter = new OSDFilterQPainter();
     d.filters.append(d.osd_filter);
 }
 
@@ -39,7 +39,7 @@ QPainterRenderer::QPainterRenderer(QPainterRendererPrivate &d)
     :VideoRenderer(d)
 {
     d.filter_context = FilterContext::create(FilterContext::QtPainter);
-    d.osd_filter = new OSFilterQPainter();
+    d.osd_filter = new OSDFilterQPainter();
     d.filters.append(d.osd_filter);
 }
 

src/QtAV/Filter.h

@@ -42,18 +42,23 @@ class Q_EXPORT Filter
 public:
     virtual ~Filter() = 0;
     //isEnabled() then setContext
-    virtual void process(FilterContext* context, Statistics* statistics);
+    /*!
+     * if context is null, or contextType() != context->type(), then create a right one and assign it to context.
+     */
+    virtual void process(FilterContext *context, Statistics* statistics);
     //TODO: parameter FrameContext
     void setEnabled(bool enabled); //AVComponent.enabled
     bool isEnabled() const;
 
-    FilterContext::Type contextType() const;
+    qreal opacity() const;
+    void setOpacity(qreal o);
+
+    virtual FilterContext::Type contextType() const;
 
 protected:
     /*
      * If the filter is in AVThread, it's safe to operate on ref.
      */
-    virtual void process(QByteArray& data);
     Filter(FilterPrivate& d);
 
     friend class AVThread;

src/QtAV/FilterContext.h

@@ -48,7 +48,7 @@ public:
     static FilterContext* create(Type t);
     virtual ~FilterContext();
     virtual Type type() const = 0;
-    QByteArray data;
+    QByteArray data; //TODO: initialize() on data
     //QPainter, paintdevice, surface etc. contains all of them here?
 };
 
@@ -59,14 +59,23 @@ public:
     QRect rect;
 };
 
+//TODO: font, pen, brush etc?
 class Q_EXPORT QPainterFilterContext : public VideoFilterContext
 {
 public:
+    QPainterFilterContext();
     QPainter *painter;
     virtual Type type() const; //QtPainter
 };
 
 
+template<class T> struct TypeTrait {};
+template<> struct TypeTrait<QPainterFilterContext> {
+    enum {
+        type = FilterContext::QtPainter
+    };
+};
+
 } //namespace QtAV
 
 #endif // QTAV_FILTERCONTEXT_H

src/QtAV/OSDFilter.h

@@ -42,10 +42,13 @@ class OSDFilterImpl : public OSDFilter
 public:
     OSDFilterImpl();
     ~OSDFilterImpl() {}
-    virtual void process(FilterContext* context, Statistics* statistics);
+    virtual void process(FilterContext *context, Statistics* statistics);
+    FilterContext::Type contextType() const {
+        return (FilterContext::Type)TypeTrait<Context>::type;
+    }
 };
 
-typedef OSDFilterImpl<QPainterFilterContext> OSFilterQPainter;
+typedef OSDFilterImpl<QPainterFilterContext> OSDFilterQPainter;
 
 } //namespace QtAV
 

src/QtAV/private/AVThread_p.h

@@ -25,6 +25,7 @@
 #include <QtCore/QMutex>
 #include <QtCore/QMutexLocker>
 #include <QtCore/QWaitCondition>
+
 #include <QtAV/Packet.h>
 #include <QtAV/QtAV_Global.h>
 
@@ -67,7 +68,7 @@ public:
     QMutex mutex;
     QWaitCondition cond; //pause
     qreal delay;
-    FilterContext *filter_context;
+    FilterContext *filter_context;//TODO: use own smart ptr. QSharedPointer "=" is ugly
     QList<Filter*> filters;
     Statistics *statistics; //not obj. Statistics is unique for the player, which is in AVPlayer
 };

src/QtAV/private/Filter_p.h

@@ -34,11 +34,13 @@ public:
     FilterPrivate():
         enabled(true)
       , context(0)
+      , opacity(1)
     {}
     virtual ~FilterPrivate() {}
 
     bool enabled;
     FilterContext *context; //used only when is necessary
+    qreal opacity;
 };
 
 } //namespace QtAV

src/VideoThread.cpp

@@ -91,8 +91,6 @@ void VideoThread::run()
     Q_ASSERT(d.clock != 0);
     VideoDecoder *dec = static_cast<VideoDecoder*>(d.dec);
     VideoRenderer* vo = static_cast<VideoRenderer*>(d.writer);
-    //TODO: do not init filter_context
-    d.filter_context = FilterContext::create(FilterContext::QtPainter); //vo->filterContextType()
     while (!d.stop) {
         //TODO: why put it at the end of loop then playNextFrame() not work?
         if (tryPause()) { //DO NOT continue, or playNextFrame() will fail
@@ -162,7 +160,7 @@ void VideoThread::run()
             if (!d.conv->convert(d.decoded_data.constData(), d.image.bits())) {
             }*/
             QByteArray data = dec->data();
-            if (d.statistics && d.filter_context) {
+            if (d.statistics) {
                 d.statistics->video.current_time = QTime().addMSecs(int(pkt.pts * 1000.0)); //TODO: is it expensive?
                 foreach (Filter *filter, d.filters) {
                     filter->process(d.filter_context, d.statistics);