Quick fix for precision issue

sprokit/processes/core/downsample_process.cxx

@@ -324,7 +324,12 @@ ::make_config()
 int downsample_process::priv
 ::target_frame_count( double time_seconds )
 {
-  return static_cast< int >( std::floor( time_seconds * target_frame_rate_ + 1e-10 ) );
+  // 1e-6 constant is a quick hack because the time value reported by
+  // kwiver timestamps is only valid up to microsecond precision and
+  // floating point arithmetic using this lack of precision for the
+  // below equation leads to some ill-defined behaviour when attempting
+  // to downsample to the target frame rate without this usec addition
+  return static_cast< int >( std::floor( ( time_seconds + 1e-6 ) * target_frame_rate_ ) );
 }
 
 sprokit::datum_t downsample_process::priv