fix sigfpe on timecode function if the timebase isn't valid

app/common/timecodefunctions.cpp

@@ -33,15 +33,14 @@ QString olive::timestamp_to_timecode(const int64_t &timestamp,
                                      const TimecodeDisplay& display,
                                      bool show_plus_if_positive)
 {
+  if (timebase.isNull()) {
+    return QString();
+  }
+
   double timestamp_dbl = (rational(timestamp) * timebase).toDouble();
 
   switch (display) {
   case kTimecodeNonDropFrame:
-    // Convert timestamp from drop frame to non-drop frame
-    if (timebase.numerator() == 1001) {
-      timestamp_dbl = timestamp_dbl / timebase.flipped().toDouble() * (static_cast<double>(timebase.denominator())/1000.0);
-    }
-    /* fall-through */
   case kTimecodeDropFrame:
   case kTimecodeSeconds:
   {

app/node/block/transition/crossdissolve/crossdissolvetransition.cpp

@@ -0,0 +1,6 @@
+#include "crossdissolvetransition.h"
+
+CrossDissolveTransition::CrossDissolveTransition()
+{
+
+}

app/node/block/transition/crossdissolve/crossdissolvetransition.h

@@ -0,0 +1,11 @@
+#ifndef CROSSDISSOLVETRANSITION_H
+#define CROSSDISSOLVETRANSITION_H
+
+
+class CrossDissolveTransition
+{
+public:
+  CrossDissolveTransition();
+};
+
+#endif // CROSSDISSOLVETRANSITION_H

app/node/block/transition/diptoblack/diptoblacktransition.cpp

@@ -0,0 +1,6 @@
+#include "diptoblacktransition.h"
+
+DipToBlackTransition::DipToBlackTransition()
+{
+
+}

app/node/block/transition/diptoblack/diptoblacktransition.h

@@ -0,0 +1,11 @@
+#ifndef DIPTOBLACKTRANSITION_H
+#define DIPTOBLACKTRANSITION_H
+
+
+class DipToBlackTransition
+{
+public:
+  DipToBlackTransition();
+};
+
+#endif // DIPTOBLACKTRANSITION_H