add get_fps to Monitor and use it to adjust the # of frames to cache before writing to db

src/zm_event.cpp

@@ -582,7 +582,8 @@ Debug(3, "Writing video");
     static char sql[ZM_SQL_MED_BUFSIZ];
 
     frame_data.push( new Frame(id, frames, frame_type, timestamp, delta_time, score ) );
-    if ( frame_data.size() > 10 ) {
+    // The idea is to write out 1/sec
+    if ( frame_data.size() > (int)monitor->get_fps() ) {
       WriteDbFrames();
       Debug(1, "Adding 10 frames to DB");
       last_db_frame = frames;

src/zm_monitor.cpp

@@ -1689,18 +1689,19 @@ Error("Creating new event when one exists");
                   event->AddFrame( snap_image, *timestamp, score );
               }
             } else {
+              if ( state == ALARM ) {
+                if ( config.record_event_stats ) {
                   for( int i = 0; i < n_zones; i++ ) {
                     if ( zones[i]->Alarmed() ) {
-                  if ( config.record_event_stats && state == ALARM ) {
                       zones[i]->RecordStats( event );
                     }
                   }
                 }
-              if ( state == PREALARM )
-                Event::AddPreAlarmFrame( snap_image, *timestamp, score );
-              else
                 event->AddFrame( snap_image, *timestamp, score );
+              } else { // ( state == PREALARM )
+                Event::AddPreAlarmFrame( snap_image, *timestamp, score );
               }
+            } // end if analysis_images
             if ( event && noteSetMap.size() > 0 )
               event->updateNotes( noteSetMap );
           } else if ( state == ALERT ) {

src/zm_monitor.h

@@ -530,6 +530,9 @@ public:
 #if HAVE_LIBAVCODEC
   //void StreamMpeg( const char *format, int scale=100, int maxfps=10, int bitrate=100000 );
 #endif // HAVE_LIBAVCODEC
+  double get_fps( ) const {
+    return fps;
+  }
 };
 
 #define MOD_ADD( var, delta, limit ) (((var)+(limit)+(delta))%(limit))