viewer: implement playback resolution option

app/render/videoparams.cpp

@@ -200,6 +200,15 @@ int VideoParams::GetBytesPerPixel(VideoParams::Format format, int channels)
   return GetBytesPerChannel(format) * channels;
 }
 
+QString VideoParams::GetNameForDivider(int div)
+{
+  if (div == 1) {
+    return QCoreApplication::translate("VideoParams", "Full");
+  } else {
+    return QCoreApplication::translate("VideoParams", "1/%1").arg(div);
+  }
+}
+
 bool VideoParams::FormatIsFloat(VideoParams::Format format)
 {
   switch (format) {

app/render/videoparams.h

@@ -231,6 +231,8 @@ public:
     return GetBufferSize(width_, height_, format_, channel_count_);
   }
 
+  static QString GetNameForDivider(int div);
+
   static bool FormatIsFloat(Format format);
 
   static QString GetFormatName(Format format);