Do not use p_demux->p_parent to get the p_input

(Use vlc_find_object(PARENT)

modules/demux/mp4/mp4.c

@@ -2212,11 +2212,14 @@ static void MP4_TrackSetELST( demux_t *p_demux, mp4_track_t *tk,
 static vlc_bool_t FindItem( demux_t *p_demux, playlist_t *p_playlist,
                             playlist_item_t **pp_item )
 {
+    input_thread_t *p_input = (input_thread_t *)vlc_object_find( p_demux, VLC_OBJECT_INPUT, FIND_PARENT );
     vlc_bool_t b_play = var_CreateGetBool( p_demux, "playlist-autostart" );
 
+    *pp_item = NULL;
+    if( p_input )
+    {
         if( b_play && p_playlist->status.p_item &&
-             p_playlist->status.p_item->p_input ==
-                input_GetItem((input_thread_t *)p_demux->p_parent))
+            p_playlist->status.p_item->p_input == input_GetItem(p_input) )
         {
             msg_Dbg( p_playlist, "starting playlist playback" );
             *pp_item = p_playlist->status.p_item;
@@ -2224,16 +2227,17 @@ static vlc_bool_t FindItem( demux_t *p_demux, playlist_t *p_playlist,
         }
         else
         {
-         input_item_t *p_current = input_GetItem(
-                                    (input_thread_t*)p_demux->p_parent);
+            input_item_t *p_current = input_GetItem( p_input );
+
             *pp_item = playlist_ItemGetByInput( p_playlist, p_current, VLC_FALSE );
             if( !*pp_item )
-         {
                 msg_Dbg( p_playlist, "unable to find item in playlist");
-         }
+
             msg_Dbg( p_playlist, "not starting playlist playback");
             b_play = VLC_FALSE;
         }
+        vlc_object_release( p_input );
+    }
     return b_play;
 }
 

modules/demux/ogg.c

@@ -179,6 +179,7 @@ static void Ogg_ReadAnnodexHeader( vlc_object_t *, logical_stream_t *, ogg_packe
 static int Open( vlc_object_t * p_this )
 {
     demux_t *p_demux = (demux_t *)p_this;
+    input_thread_t *p_input;
     demux_sys_t    *p_sys;
     uint8_t        *p_peek;
 
@@ -203,17 +204,20 @@ static int Open( vlc_object_t * p_this )
     p_sys->i_eos = 0;
 
 
-    if( ((input_thread_t* )(p_demux->p_parent ))->b_preparsing == VLC_TRUE )
+    p_input = (input_thread_t *)vlc_object_find( p_demux, VLC_OBJECT_INPUT, FIND_PARENT );
+    if( p_input && p_input->b_preparsing )
     {
         module_t *p_meta = module_Need( p_demux, "meta reader", NULL, 0 );
         if( p_meta )
         {
-            vlc_meta_Merge( input_GetItem((input_thread_t* )(p_demux->p_parent ))->p_meta,
-                                (vlc_meta_t*)(p_demux->p_private ) );
+            vlc_meta_Merge( input_GetItem(p_input)->p_meta, (vlc_meta_t*)(p_demux->p_private ) );
             module_Unneed( p_demux, p_meta );
         }
+        vlc_object_release( p_input );
         return VLC_SUCCESS;
     }
+    if( p_input )
+        vlc_object_release( p_input );
 
     /* Initialize the Ogg physical bitstream parser */
     ogg_sync_init( &p_sys->oy );