diff --git a/gst/gstcaps.c b/gst/gstcaps.c
index 0b9be9fad3..5b94d88682 100644
--- a/gst/gstcaps.c
+++ b/gst/gstcaps.c
@@ -241,8 +241,10 @@ void gst_caps_append_structure (GstCaps *caps, GstStructure *structure)
   g_return_if_fail(caps != NULL);
 
   if (structure){
+#if 0 /* disable this, since too many plugins rely on undefined behavior */
 #ifdef USE_POISONING
     STRUCTURE_POISON (structure);
+#endif
 #endif
     g_ptr_array_add (caps->structs, structure);
   }
@@ -578,7 +580,9 @@ GstCaps *gst_caps_intersect (const GstCaps *caps1, const GstCaps *caps2)
   GstStructure *struct1;
   GstStructure *struct2;
   GstCaps *dest;
-  //GstCaps *caps;
+#if 0
+  GstCaps *caps;
+#endif
 
   g_return_val_if_fail (caps1 != NULL, NULL);
   g_return_val_if_fail (caps2 != NULL, NULL);
@@ -750,8 +754,10 @@ GstCaps *gst_caps_load_thyself (xmlNodePtr parent)
 /* utility */
 void gst_caps_replace (GstCaps **caps, GstCaps *newcaps)
 {
+#if 0 /* disable this, since too many plugins rely on undefined behavior */
 #ifdef USE_POISONING
-  if (newcaps) CAPS_POISON (newcaps);
+  //if (newcaps) CAPS_POISON (newcaps);
+#endif
 #endif
   if (*caps) gst_caps_free(*caps);
   *caps = newcaps;
diff --git a/gst/gstinfo.c b/gst/gstinfo.c
index f5effd1e10..8e530b6626 100644
--- a/gst/gstinfo.c
+++ b/gst/gstinfo.c
@@ -70,6 +70,7 @@ extern gchar *_gst_progname;
 static void	gst_debug_reset_threshold	(gpointer category,
 						 gpointer unused);
 static void	gst_debug_reset_all_thresholds	(void);
+static void     gst_debug_set_log_function_level (GstLogFunction func, gpointer data, GstDebugLevel level);
 
 /* list of all name/level pairs from --gst-debug and GST_DEBUG */
 static GStaticMutex __level_name_mutex = G_STATIC_MUTEX_INIT;
@@ -87,10 +88,13 @@ static GSList *__categories = NULL;
 typedef struct {
   GstLogFunction	func;
   gpointer		user_data;
+  GstDebugLevel         max_level;
 } LogFuncEntry;
 static GStaticMutex __log_func_mutex = G_STATIC_MUTEX_INIT;
 static GSList *__log_functions = NULL;
+static GstDebugLevel __log_level;
 
+static GstDebugLevel _gst_debug_max_threshold;
 static GstAtomicInt __default_level;
 static GstAtomicInt __use_color;
 gboolean __gst_debug_enabled = TRUE;
@@ -287,14 +291,16 @@ void gst_debug_log_valist (GstDebugCategory *category, GstDebugLevel level,
   g_return_if_fail (function != NULL);
   g_return_if_fail (format != NULL);
 
-  message = g_strdup_vprintf (format, args);
-  handler = __log_functions;
-  while (handler) {
-    entry = handler->data;
-    handler = g_slist_next (handler);
-    entry->func (category, level, file, function, line, object, message, entry->user_data);
+  if (level <= __log_level) {
+    message = g_strdup_vprintf (format, args);
+    handler = __log_functions;
+    while (handler) {
+      entry = handler->data;
+      handler = g_slist_next (handler);
+      entry->func (category, level, file, function, line, object, message, entry->user_data);
+    }
+    g_free (message);
   }
-  g_free (message);
 }
 /**
  * gst_debug_construct_term_color:
@@ -440,6 +446,8 @@ gst_debug_add_log_function (GstLogFunction func, gpointer data)
   entry = g_new (LogFuncEntry, 1);
   entry->func = func;
   entry->user_data = data;
+  //entry->max_level = GST_LEVEL_LOG;
+  entry->max_level = 0;
   /* FIXME: we leak the old list here - other threads might access it right now
    * in gst_debug_logv. Another solution is to lock the mutex in gst_debug_logv,
    * but that is waaay costly.
@@ -449,11 +457,35 @@ gst_debug_add_log_function (GstLogFunction func, gpointer data)
   g_static_mutex_lock (&__log_func_mutex);
   list = g_slist_copy (__log_functions);
   __log_functions = g_slist_prepend (list, entry);
+  __log_level = MAX (__log_level, entry->max_level);
   g_static_mutex_unlock (&__log_func_mutex);
 
   GST_DEBUG ("prepended log function %p (user data %p) to log functions",
              func, data);
 }
+
+static void
+gst_debug_set_log_function_level (GstLogFunction func, gpointer data, GstDebugLevel level)
+{
+  LogFuncEntry *entry;
+  GSList *list;
+  GstDebugLevel new_level;
+
+  g_static_mutex_lock (&__log_func_mutex);
+  list = __log_functions;
+  new_level = 0;
+  while (list) {
+    entry = list->data;
+    if (entry->func == func && entry->user_data == data) {
+      entry->max_level = level;
+    }
+    new_level = MAX (new_level, entry->max_level);
+    list = g_slist_next (list);
+  }
+  __log_level = new_level;
+  g_static_mutex_unlock (&__log_func_mutex);
+}
+
 static gint
 gst_debug_compare_log_function_by_func (gconstpointer entry, gconstpointer func)
 {
@@ -468,12 +500,16 @@ gst_debug_compare_log_function_by_data (gconstpointer entry, gconstpointer data)
   
   return (entrydata < data) ? -1 : (entrydata > data) ? 1 : 0;
 }
+
 static guint
 gst_debug_remove_with_compare_func (GCompareFunc func, gpointer data)
 {
   GSList *found;
   GSList *new;
   guint removals = 0;
+  GstDebugLevel new_level;
+  GSList *handler;
+
   g_static_mutex_lock (&__log_func_mutex);
   new = __log_functions;
   while ((found = g_slist_find_custom (new, data, func))) {
@@ -485,12 +521,21 @@ gst_debug_remove_with_compare_func (GCompareFunc func, gpointer data)
     new = g_slist_delete_link (new, found);
     removals++;
   }
+  new_level = 0;
+  handler = new;
+  while (handler) {
+    LogFuncEntry *entry = handler->data;
+    new_level = MAX (entry->max_level, new_level);
+    handler = g_slist_next (handler);
+  }
+  __log_level = new_level;
   /* FIXME: We leak the old list here. See _add_log_function for why. */
   __log_functions = new;
   g_static_mutex_unlock (&__log_func_mutex);
 
   return removals;
 }
+
 /**
  * gst_debug_remove_log_function:
  * @func: the log function to remove
@@ -512,6 +557,7 @@ gst_debug_remove_log_function (GstLogFunction func)
 
   return removals;
 }
+
 /**
  * gst_debug_remove_log_function_by_data:
  * @data: user data of the log function to remove
@@ -531,6 +577,7 @@ gst_debug_remove_log_function_by_data (gpointer data)
 
   return removals;
 }
+
 /**
  * gst_debug_set_colored:
  * @colored: Whether to use colored output or not
@@ -606,6 +653,23 @@ gst_debug_get_default_threshold (void)
 {	
   return (GstDebugLevel) gst_atomic_int_read (&__default_level);
 }
+
+static void
+gst_debug_recalculate_max_threshold (void)
+{
+  GSList *walk;
+  GstDebugLevel new_threshold = 0;
+  walk = __categories;
+  while (walk) {
+    GstDebugCategory *cat = walk->data;
+    new_threshold = MAX (gst_atomic_int_read (cat->threshold), new_threshold);
+    walk = g_slist_next (walk);
+  }
+  _gst_debug_max_threshold = new_threshold;
+  gst_debug_set_log_function_level (gst_debug_log_default, NULL,
+      _gst_debug_max_threshold);
+}
+
 static void
 gst_debug_reset_threshold (gpointer category, gpointer unused)
 {
@@ -627,8 +691,10 @@ gst_debug_reset_threshold (gpointer category, gpointer unused)
   gst_debug_category_set_threshold (cat, gst_debug_get_default_threshold ());
 
 exit:
+  gst_debug_recalculate_max_threshold ();
   g_static_mutex_unlock (&__level_name_mutex);
 }
+
 static void
 gst_debug_reset_all_thresholds (void)
 {
@@ -673,6 +739,7 @@ gst_debug_set_threshold_for_name (const gchar *name, GstDebugLevel level)
   g_static_mutex_unlock (&__level_name_mutex);
   g_static_mutex_lock (&__cat_mutex);
   g_slist_foreach (__categories, for_each_threshold_by_entry, entry);
+  gst_debug_recalculate_max_threshold ();
   g_static_mutex_unlock (&__cat_mutex);
 }
 /**
@@ -703,6 +770,7 @@ gst_debug_unset_threshold_for_name (const gchar *name)
       walk = __level_name;
     }
   }
+  gst_debug_recalculate_max_threshold ();
   g_static_mutex_unlock (&__level_name_mutex);
   g_pattern_spec_free (pat);
   gst_debug_reset_all_thresholds ();
diff --git a/gst/gstinfo.h b/gst/gstinfo.h
index 7d7e6922cd..009f7f44f4 100644
--- a/gst/gstinfo.h
+++ b/gst/gstinfo.h
@@ -104,6 +104,14 @@ struct _GstDebugCategory {
 
 /********** some convenience macros for debugging **********/
 
+#define GST_TEMP_STRING(str, statement) G_STMT_START { \
+  char * str = NULL; \
+  statement; \
+  g_free( str ); \
+} G_STMT_END
+
+
+
 /* This is needed in printf's if a char* might be NULL. Solaris crashes then */
 #define GST_STR_NULL(str) ((str) ? (str) : "(NULL)")
 
@@ -162,6 +170,16 @@ void		gst_debug_log			(GstDebugCategory *	category,
 						 GObject *		object,
 						 gchar *		format,
 						 ...)  G_GNUC_PRINTF (7, 8) G_GNUC_NO_INSTRUMENT;
+void		gst_debug_log_callback		(GstDebugCategory *	category,
+						 GstDebugLevel		level,
+						 const gchar *		file,
+						 const gchar *		function,
+						 gint			line,
+						 GObject *		object,
+                                                 char *                 (*callback)(gpointer callback_arg),
+                                                 gpointer               callback_arg,
+						 gchar *		format,
+						 ...)  G_GNUC_PRINTF (9, 10) G_GNUC_NO_INSTRUMENT;
 void		gst_debug_log_valist  		(GstDebugCategory *	category,
 						 GstDebugLevel		level,
 						 const gchar *		file,