Do not use private vout fields in atmo filter.

It breaks a bit atmo filter features (ie crop parameters aren't retreive correctly
anymore, at least until the core does set them for video filter2).
But it fixes potential segfaults due to the way the crop-update callback
is (un)registered.

modules/video_filter/atmo/atmo.cpp

@@ -67,12 +67,6 @@ static void DelStateVariableCallback( filter_t *);
 static int StateCallback(vlc_object_t *, char const *,
                          vlc_value_t, vlc_value_t, void *);
 
-/* callback for variable crop-update */
-static void AddCropVariableCallback( filter_t *);
-static void DelCropVariableCallback( filter_t *);
-static int CropCallback(vlc_object_t *, char const *,
-                        vlc_value_t, vlc_value_t, void *);
-
 /* callback for atmo settings variables whose change
    should be immediately realized and applied to output
 */
@@ -1711,16 +1705,6 @@ static void Atmo_SetupParameters(filter_t *p_filter)
         p_sys->pf_extract_mini_image = NULL;
     }
 
-    p_sys->i_crop_x_offset  = 0;
-    p_sys->i_crop_y_offset  = 0;
-    p_sys->i_crop_width     = p_filter->fmt_in.video.i_visible_width;
-    p_sys->i_crop_height    = p_filter->fmt_in.video.i_visible_height;
-
-    msg_Dbg( p_filter, "set default crop %d,%d %dx%d",p_sys->i_crop_x_offset,
-        p_sys->i_crop_y_offset,
-        p_sys->i_crop_width,
-        p_sys->i_crop_height );
-
     /*
     for debugging purpose show the samplinggrid on each frame as
     white dots
@@ -1922,8 +1906,6 @@ static int CreateFilter( vlc_object_t *p_this )
 
     AddStateVariableCallback(p_filter);
 
-    AddCropVariableCallback(p_filter);
-
     AddAtmoSettingsVariablesCallbacks(p_filter);
 
     Atmo_SetupParameters(p_filter);
@@ -1948,7 +1930,7 @@ static void DestroyFilter( vlc_object_t *p_this )
     msg_Dbg( p_filter, "Destroy Atmo Filter");
 
     DelStateVariableCallback(p_filter);
-    DelCropVariableCallback(p_filter);
+
     DelAtmoSettingsVariablesCallbacks(p_filter);
 
     Atmo_Shutdown(p_filter);
@@ -2276,6 +2258,11 @@ static picture_t * Filter( filter_t *p_filter, picture_t *p_pic )
         (p_sys->pf_extract_mini_image != NULL) &&
         (p_sys->b_pause_live == false))
     {
+        p_sys->i_crop_x_offset  = p_filter->fmt_in.video.i_x_offset;
+        p_sys->i_crop_y_offset  = p_filter->fmt_in.video.i_y_offset;
+        p_sys->i_crop_width     = p_filter->fmt_in.video.i_visible_width;
+        p_sys->i_crop_height    = p_filter->fmt_in.video.i_visible_height;
+
         CreateMiniImage(p_filter, p_pic);
     }
 
@@ -2516,71 +2503,6 @@ static void DelStateVariableCallback( filter_t *p_filter )
     }
 }
 
-
-static int CropCallback(vlc_object_t *p_this, char const *psz_cmd,
-                        vlc_value_t oldval, vlc_value_t newval,
-                        void *p_data)
-{
-    vout_thread_t *p_vout = (vout_thread_t *)p_this;
-    filter_t *p_filter = (filter_t *)p_data;
-    filter_sys_t *p_sys = (filter_sys_t *)p_filter->p_sys;
-
-    /*
-    //if the handler is attache to crop variable directly!
-    int i_visible_width, i_visible_height, i_x_offset, i_y_offset;
-    atmo_parse_crop(newval.psz_string, p_vout->fmt_render,
-    p_vout->fmt_render,
-    i_visible_width, i_visible_height,
-    i_x_offset, i_y_offset);
-    p_sys->i_crop_x_offset  = i_x_offset;
-    p_sys->i_crop_y_offset  = i_y_offset;
-    p_sys->i_crop_width     = i_visible_width;
-    p_sys->i_crop_height    = i_visible_height;
-    */
-
-    p_sys->i_crop_x_offset  = p_vout->fmt_in.i_x_offset;
-    p_sys->i_crop_y_offset  = p_vout->fmt_in.i_y_offset;
-    p_sys->i_crop_width     = p_vout->fmt_in.i_visible_width;
-    p_sys->i_crop_height    = p_vout->fmt_in.i_visible_height;
-
-    msg_Dbg(p_filter, "cropping picture %ix%i to %i,%i,%ix%i",
-        p_vout->fmt_in.i_width,
-        p_vout->fmt_in.i_height,
-        p_sys->i_crop_x_offset,
-        p_sys->i_crop_y_offset,
-        p_sys->i_crop_width,
-        p_sys->i_crop_height
-        );
-
-    return VLC_SUCCESS;
-}
-
-
-static void AddCropVariableCallback( filter_t *p_filter)
-{
-    vout_thread_t *p_vout = (vout_thread_t *)vlc_object_find( p_filter,
-        VLC_OBJECT_VOUT,
-        FIND_ANYWHERE );
-    if( p_vout )
-    {
-        var_AddCallback( p_vout, "crop-update", CropCallback, p_filter );
-        vlc_object_release( p_vout );
-    }
-}
-
-static void DelCropVariableCallback( filter_t *p_filter)
-{
-    vout_thread_t *p_vout = (vout_thread_t *)vlc_object_find( p_filter,
-        VLC_OBJECT_VOUT,
-        FIND_ANYWHERE );
-    if( p_vout )
-    {
-        var_DelCallback( p_vout, "crop-update", CropCallback, p_filter );
-        vlc_object_release( p_vout );
-    }
-}
-
-
 /****************************************************************************
 * StateCallback: Callback for the inputs variable "State" to get notified
 * about Pause and Continue Playback events.