bpy.app.handlers.frame_change_pre/post handlers.

source/blender/blenkernel/intern/scene.c

@@ -56,6 +56,7 @@
 #include "BLI_math.h"
 #include "BLI_blenlib.h"
 #include "BLI_utildefines.h"
+#include "BLI_callbacks.h"
 
 #include "BKE_anim.h"
 #include "BKE_animsys.h"
@@ -1022,6 +1023,9 @@ void scene_update_for_newframe(Main *bmain, Scene *sce, unsigned int lay)
 	float ctime = BKE_curframe(sce);
 	Scene *sce_iter;
 
+	/* keep this first */
+	BLI_exec_cb(bmain, (ID *)sce, BLI_CB_EVT_FRAME_CHANGE_PRE);
+
 	sound_set_cfra(sce->r.cfra);
 	
 	/* clear animation overrides */
@@ -1048,6 +1052,9 @@ void scene_update_for_newframe(Main *bmain, Scene *sce, unsigned int lay)
 
 	/* object_handle_update() on all objects, groups and sets */
 	scene_update_tagged_recursive(bmain, sce, sce);
+
+	/* keep this last */
+	BLI_exec_cb(bmain, (ID *)sce, BLI_CB_EVT_FRAME_CHANGE_POST);
 }
 
 /* return default layer, also used to patch old files */

source/blender/blenlib/BLI_callbacks.h

@@ -40,6 +40,8 @@ struct Main;
 struct ID;
 
 typedef enum {
+	BLI_CB_EVT_FRAME_CHANGE_PRE,
+	BLI_CB_EVT_FRAME_CHANGE_POST,
 	BLI_CB_EVT_RENDER_PRE,
 	BLI_CB_EVT_RENDER_POST,
 	BLI_CB_EVT_RENDER_STATS,

source/blender/python/intern/bpy_app_handlers.c

@@ -40,6 +40,8 @@ void bpy_app_generic_callback(struct Main *main, struct ID *id, void *arg);
 static PyTypeObject BlenderAppCbType;
 
 static PyStructSequence_Field app_cb_info_fields[]= {
+    {(char *)"frame_change_pre", NULL},
+	{(char *)"frame_change_post", NULL},
 	{(char *)"render_pre", NULL},
 	{(char *)"render_post", NULL},
 	{(char *)"render_stats", NULL},