- xmlNewProp( child, _x("in"), _x(mlt_properties_get_time( properties, "in", context->time_format )) );
- xmlNewProp( child, _x("out"), _x(mlt_properties_get_time( properties, "out", context->time_format )) );
+ if ( mlt_properties_get_position( properties, "in" ) >= 0 )
+ xmlNewProp( child, _x("in"), _x(mlt_properties_get_time( properties, "in", context->time_format )) );
+ if ( mlt_properties_get_position( properties, "out" ) >= 0 )
+ xmlNewProp( child, _x("out"), _x(mlt_properties_get_time( properties, "out", context->time_format )) );