if ( !p_es->b_empty )
{
i_numpics ++;
- if( p_sys->i_order_length && p_es->psz_id != 0 )
+ if( p_sys->i_order_length && p_es->psz_id != NULL )
{
/* We also want to leave slots for images given in
* mosaic-order that are not available in p_vout_picture */