//printf("VWindow::change_source %d %p\n", __LINE__, mwindow->edl->get_vwindow_edl(edl_number));
if( edl_number >= 0 && edl_number < mwindow->edl->total_vwindow_edls() &&
mwindow->edl->get_vwindow_edl(edl_number) )
//printf("VWindow::change_source %d %p\n", __LINE__, mwindow->edl->get_vwindow_edl(edl_number));
if( edl_number >= 0 && edl_number < mwindow->edl->total_vwindow_edls() &&
mwindow->edl->get_vwindow_edl(edl_number) )