diff --git a/.travis.yml b/.travis.yml
new file mode 100644
index 0000000..e7a3db6
--- /dev/null
+++ b/.travis.yml
@@ -0,0 +1,31 @@
+
+language: cpp
+os: linux
+sudo: false
+dist: trusty
+compiler:
+  - gcc
+  - clang
+
+cache:
+  directories:
+    - ~/.ccache
+    - qt5
+
+install:
+  - mkdir -p qt5
+  - if [ ! -d qt5/.git ] ; then rm qt5 -Rf ; git clone --branch=5.10 git://code.qt.io/qt/qt5.git ; fi
+  - pushd qt5
+  - if [ ! -d qtbase/.git ] ; then perl init-repository --module-subset=qtbase,qtimageformats,qtmultimedia,qttools ; fi
+  - if [ ! -f config.summary ] ; then ./configure -prefix `pwd`/build -opensource -confirm-license -nomake examples -nomake tests ; fi
+  - if [ ! -d build ] ; then make -j2 > /dev/null && make install ; fi
+  - popd
+  - ccache -s
+
+script:
+  - mkdir -p build
+  - pushd build
+  - ../qt5/build/bin/qmake CONFIG+=ccache .. -config release
+  - make -j2
+  - make install
+  - popd
diff --git a/osciwidget.cpp b/osciwidget.cpp
index 6a049eb..9193440 100644
--- a/osciwidget.cpp
+++ b/osciwidget.cpp
@@ -47,6 +47,8 @@ void OsciWidget::renderSamples(const SamplePair *begin, const SamplePair *end)
 {
     m_callbacksCounter++;
 
+    m_samplesCounter += std::distance(begin, end);
+
     m_buffer.insert(m_buffer.end(), begin, end);
 }
 
@@ -57,9 +59,10 @@ void OsciWidget::paintEvent(QPaintEvent *event)
     m_frameCounter++;
     if (m_statsTimer.hasExpired(1000))
     {
-        emit statusUpdate(QString("%0FPS (%1 audio callbacks)").arg(m_frameCounter).arg(m_callbacksCounter));
+        emit statusUpdate(QString("%0FPS (%1 callbacks, %2 samples, %3 avg per callback)").arg(m_frameCounter).arg(m_callbacksCounter).arg(m_samplesCounter).arg(m_callbacksCounter>0?m_samplesCounter/m_callbacksCounter:0));
         m_frameCounter = 0;
         m_callbacksCounter = 0;
+        m_samplesCounter = 0;
         m_statsTimer.restart();
     }
 
@@ -73,7 +76,10 @@ void OsciWidget::updateFrameBuffer()
     if(m_buffer.empty()) return;
 
     if (m_pixmap.size() != size())
+    {
         m_pixmap = QPixmap(size());
+        m_pixmap.fill(Qt::black);
+    }
 
     QPainter painter(&m_pixmap);
 
diff --git a/osciwidget.h b/osciwidget.h
index 9403099..7b32068 100644
--- a/osciwidget.h
+++ b/osciwidget.h
@@ -50,7 +50,7 @@ private:
 
     std::vector<SamplePair> m_buffer;
 
-    int m_frameCounter{0}, m_callbacksCounter{0};
+    int m_frameCounter{0}, m_callbacksCounter{0}, m_samplesCounter{0};
     QElapsedTimer m_statsTimer;
 
     int m_redrawTimerId;