References #1227. Better approximation for ValidVideoFrames.

This just returns the number of frames in the typical full vo buffer.
In practice this means that NVP::IsReallyNearEnd() uses only the
RingBuffer buffer fill and block size to detect the end of file when
doing PVR-350 video output.



git-svn-id: http://svn.mythtv.org/svn/trunk@8884 7dbf422c-18fa-0310-86e9-fd20926502f2

mythtv/libs/libmythtv/videoout_ivtv.cpp

@@ -160,6 +160,11 @@ int VideoOutputIvtv::GetRefreshRate(void)
     return 0;
 }
 
+int VideoOutputIvtv::ValidVideoFrames(void) const
+{
+    return 131; // approximation for when output buffer is full...
+}
+
 bool VideoOutputIvtv::Init(int width, int height, float aspect, 
                            WId winid, int winx, int winy, int winw, 
                            int winh, WId embedid)

mythtv/libs/libmythtv/videoout_ivtv.h

@@ -59,6 +59,9 @@ class VideoOutputIvtv: public VideoOutput
         (void) allow_unsafe;
         return NULL;
     }
+
+    int ValidVideoFrames(void) const;
+
   private:
     typedef enum
     {

mythtv/libs/libmythtv/videooutbase.h

@@ -215,7 +215,8 @@ class VideoOutput
     bool WaitForAvailable(uint w) { return vbuffers.WaitForAvailable(w); }
 
     /// \brief Returns number of frames that are fully decoded.
-    int ValidVideoFrames(void) { return vbuffers.ValidVideoFrames(); }
+    virtual int ValidVideoFrames(void) const
+        { return vbuffers.ValidVideoFrames(); }
     /// \brief Returns number of frames available for decoding onto.
     int FreeVideoFrames(void) { return vbuffers.FreeVideoFrames(); }
     /// \brief Returns true iff enough frames are available to decode onto.