Index: include/BIF_drawseq.h
===================================================================
--- include/BIF_drawseq.h	(revision 11922)
+++ include/BIF_drawseq.h	(working copy)
@@ -36,6 +36,7 @@
 struct ScrArea;
 struct Sequence;
 
+void drawprefetchseqspace(struct ScrArea *sa, void *spacedata);
 void drawseqspace(struct ScrArea *sa, void *spacedata);
 void set_special_seq_update(int val);
 
Index: include/BSE_sequence.h
===================================================================
--- include/BSE_sequence.h	(revision 11922)
+++ include/BSE_sequence.h	(working copy)
@@ -60,6 +60,15 @@
 struct ImBuf *give_ibuf_seq(int rectx, int recty, int cfra, int chansel); 
 /* chansel: render this channel. Default=0 (renders end result)*/
 
+/* sequence prefetch API */
+void seq_start_threads();
+void seq_stop_threads();
+void give_ibuf_prefetch_request(int rectx, int recty, int cfra, int chanshown);
+void seq_wait_for_prefetch_ready();
+struct ImBuf * give_ibuf_threaded(int rectx, int recty, int cfra, 
+				  int chanshown);
+
+
 void free_imbuf_seq_except(int cfra);
 void free_imbuf_seq_with_ipo(struct Ipo * ipo);
 void free_imbuf_seq(void);
Index: include/BIF_spacetypes.h
===================================================================
--- include/BIF_spacetypes.h	(revision 11922)
+++ include/BIF_spacetypes.h	(working copy)
@@ -35,6 +35,7 @@
 
 typedef struct _SpaceType	SpaceType;
 
+typedef	void	(*SpacePrefetchDrawFP)	(struct ScrArea *sa, void *spacedata);
 typedef	void	(*SpaceDrawFP)		(struct ScrArea *sa, void *spacedata);
 typedef	void	(*SpaceChangeFP)	(struct ScrArea *sa, void *spacedata);
 typedef	void	(*SpaceHandleFP)	(struct ScrArea *sa, void *spacedata, struct BWinEvent *evt);
@@ -43,7 +44,7 @@
 
 SpaceType*	spacetype_new			(char *name);
 
-void		spacetype_set_winfuncs	(SpaceType *st, SpaceDrawFP draw, SpaceChangeFP change, SpaceHandleFP handle);
+void		spacetype_set_winfuncs	(SpaceType *st, SpacePrefetchDrawFP prefetch, SpaceDrawFP draw, SpaceChangeFP change, SpaceHandleFP handle);
 
 	/***/
 
Index: include/BIF_space.h
===================================================================
--- include/BIF_space.h	(revision 11922)
+++ include/BIF_space.h	(working copy)
@@ -92,6 +92,7 @@
 #define B_RECALCLIGHT 	3310
 
 
+void	scrarea_do_winprefetchdraw	(struct ScrArea *sa);
 void	scrarea_do_windraw		(struct ScrArea *sa);
 void	scrarea_do_winchange	(struct ScrArea *sa);
 void	scrarea_do_winhandle	(struct ScrArea *sa, struct BWinEvent *evt);
Index: makesdna/DNA_userdef_types.h
===================================================================
--- makesdna/DNA_userdef_types.h	(revision 11922)
+++ makesdna/DNA_userdef_types.h	(working copy)
@@ -171,6 +171,7 @@
 	short tw_hotspot, tw_flag, tw_handlesize, tw_size;
 	int textimeout, texcollectrate;
 	int memcachelimit;
+	int prefetchframes;
 	short frameserverport;
 	short pad_rot_angle;	/*control the rotation step of the view when PAD2,PAD4,PAD6&PAD8 is use*/
 	short obcenter_dia;
@@ -181,7 +182,6 @@
 	short recent_files;		/* maximum number of recently used files to remember  */
 	short smooth_viewtx;	/* miliseconds to spend spinning the view */
 	short glreslimit;
-	char pad[4];
 } UserDef;
 
 extern UserDef U; /* from usiblender.c !!!! */
Index: src/sequence.c
===================================================================
--- src/sequence.c	(revision 11922)
+++ src/sequence.c	(working copy)
@@ -70,6 +70,7 @@
 #include "RE_pipeline.h"		// talks to entire render API
 
 #include "blendef.h"
+#include <pthread.h>
 
 int seqrectx, seqrecty;
 
@@ -1179,6 +1180,217 @@
 
 }
 
+/* threading api */
+
+static ListBase running_threads;
+static ListBase prefetch_wait;
+static ListBase prefetch_done;
+
+static pthread_mutex_t queue_lock  = PTHREAD_MUTEX_INITIALIZER;
+static pthread_mutex_t wakeup_lock = PTHREAD_MUTEX_INITIALIZER;
+static pthread_cond_t  wakeup_cond = PTHREAD_COND_INITIALIZER;
+
+static pthread_mutex_t prefetch_ready_lock = PTHREAD_MUTEX_INITIALIZER;
+static pthread_cond_t  prefetch_ready_cond = PTHREAD_COND_INITIALIZER;
+
+static volatile int seq_thread_shutdown = FALSE;
+static volatile int seq_last_given_cfra = 0;
+
+typedef struct PrefetchThread {
+	struct PrefetchThread *next, *prev;
+	pthread_t pthread;
+	int running;
+} PrefetchThread;
+
+typedef struct PrefetchQueueElem {
+	struct PrefetchQueueElem *next, *prev;
+	
+	int rectx;
+	int recty;
+	int cfra;
+	int chanshown;
+
+	struct ImBuf * ibuf;
+} PrefetchQueueElem;
+
+
+static void * seq_prefetch_thread(void * This_)
+{
+	PrefetchThread * This = This_;
+
+	while (!seq_thread_shutdown) {
+		PrefetchQueueElem * e;
+		int s_last;
+
+		pthread_mutex_lock(&queue_lock);
+		e = prefetch_wait.first;
+		if (e) {
+			BLI_remlink(&prefetch_wait, e);
+		}
+		s_last = seq_last_given_cfra;
+
+		pthread_mutex_unlock(&queue_lock);
+
+		if (!e) {
+			pthread_mutex_lock(&prefetch_ready_lock);
+
+			This->running = FALSE;
+
+			pthread_cond_signal(&prefetch_ready_cond);
+			pthread_mutex_unlock(&prefetch_ready_lock);
+
+			pthread_mutex_lock(&wakeup_lock);
+			pthread_cond_wait(&wakeup_cond, &wakeup_lock);
+			pthread_mutex_unlock(&wakeup_lock);
+			continue;
+		}
+
+		This->running = TRUE;
+
+		if (e->cfra >= s_last) { 
+			e->ibuf = give_ibuf_seq(e->rectx, e->recty, e->cfra, 
+						e->chanshown);
+		}
+
+		if (e->ibuf) {
+			IMB_cache_limiter_ref(e->ibuf);
+		}
+
+		pthread_mutex_lock(&queue_lock);
+
+		BLI_addtail(&prefetch_done, e);
+
+		for (e = prefetch_wait.first; e; e = e->next) {
+			if (s_last > e->cfra) {
+				BLI_remlink(&prefetch_done, e);
+				MEM_freeN(e);
+			}
+		}
+
+		for (e = prefetch_done.first; e; e = e->next) {
+			if (s_last > e->cfra) {
+				if (e->ibuf) {
+					IMB_cache_limiter_unref(e->ibuf);
+				}
+				BLI_remlink(&prefetch_done, e);
+				MEM_freeN(e);
+			}
+		}
+
+		pthread_mutex_unlock(&queue_lock);
+
+	}
+	return 0;
+}
+
+void seq_start_threads()
+{
+	int i;
+
+	running_threads.first = running_threads.last = NULL;
+	prefetch_wait.first = prefetch_wait.last = NULL;
+	prefetch_done.first = prefetch_done.last = NULL;
+
+	seq_thread_shutdown = FALSE;
+	seq_last_given_cfra = MAXFRAME;
+
+	/* since global structures are modified during the processing
+	   of one frame, only one render thread is currently possible... 
+
+	   (but we code, in the hope, that we can remove this restriction
+	   soon...)
+	*/
+
+	for (i = 0; i < 1; i++) {
+		PrefetchThread *t = MEM_callocN(sizeof(PrefetchThread), 
+						"prefetch_thread");
+		BLI_addtail(&running_threads, t);
+
+		pthread_create(&t->pthread, NULL, seq_prefetch_thread, t);
+	}
+}
+
+void seq_stop_threads()
+{
+	PrefetchThread *tslot;
+
+	seq_thread_shutdown = TRUE;
+	
+	pthread_mutex_lock(&wakeup_lock);
+        pthread_cond_broadcast(&wakeup_cond);
+        pthread_mutex_unlock(&wakeup_lock);
+
+	for(tslot = running_threads.first; tslot; tslot= tslot->next) {
+		pthread_join(tslot->pthread, NULL);
+	}
+
+	BLI_freelistN(&running_threads);
+}
+
+void give_ibuf_prefetch_request(int rectx, int recty, int cfra, int chanshown)
+{
+	PrefetchQueueElem * e = MEM_callocN(sizeof(PrefetchQueueElem),
+					    "prefetch_queue_elem");
+	e->rectx = rectx;
+	e->recty = recty;
+	e->cfra = cfra;
+	e->chanshown = chanshown;
+
+	pthread_mutex_lock(&queue_lock);
+	BLI_addtail(&prefetch_wait, e);
+	pthread_mutex_unlock(&queue_lock);
+
+	pthread_mutex_lock(&wakeup_lock);
+        pthread_cond_signal(&wakeup_cond);
+        pthread_mutex_unlock(&wakeup_lock);
+}
+
+void seq_wait_for_prefetch_ready()
+{
+	PrefetchThread *tslot;
+
+	pthread_mutex_lock(&prefetch_ready_lock);
+
+	for(;;) {
+		for(tslot = running_threads.first; tslot; tslot= tslot->next) {
+			if (tslot->running) {
+				break;
+			}
+		}
+		if (!tslot) {
+			break;
+		}
+		pthread_cond_wait(&prefetch_ready_cond, &prefetch_ready_lock);
+	}
+
+	pthread_mutex_unlock(&prefetch_ready_lock);
+}
+
+ImBuf * give_ibuf_threaded(int rectx, int recty, int cfra, int chanshown)
+{
+	PrefetchQueueElem * e = 0;
+
+	pthread_mutex_lock(&queue_lock);
+
+	for (e = prefetch_done.first; e; e = e->next) {
+		if (cfra == e->cfra &&
+		    chanshown == e->chanshown &&
+		    rectx == e->rectx && 
+		    recty == e->recty) {
+			break;
+		}
+	}
+
+	/* e->ibuf is unrefed by render thread on next round. */
+	seq_last_given_cfra = cfra;
+
+	pthread_mutex_unlock(&queue_lock);
+	
+	return e ? e->ibuf : 0;
+}
+
+
+
 /* Functions to free imbuf and anim data on changes */
 
 static void free_imbuf_strip_elem(StripElem *se)
@@ -1371,11 +1583,12 @@
 		*/
 		{
 			extern int mem_in_use;
+			extern int mmap_in_use;
 
 			int max = MEM_CacheLimiter_get_maximum();
-			if (max != 0 && mem_in_use > max) {
+			if (max != 0 && mem_in_use + mmap_in_use > max) {
 				fprintf(stderr, "mem_in_use = %d, max = %d\n",
-					mem_in_use, max);
+					mem_in_use + mmap_in_use, max);
 				fprintf(stderr, "Cleaning up, please wait...\n"
 					"If this happens very often,\n"
 					"consider "
Index: src/drawview.c
===================================================================
--- src/drawview.c	(revision 11922)
+++ src/drawview.c	(working copy)
@@ -3168,6 +3168,9 @@
 
 
 double tottime = 0.0;
+static ScrArea *oldsa;
+static double swaptime;
+static int curmode;
 
 int update_time(void)
 {
@@ -3183,12 +3186,67 @@
 	return (tottime < 0.0);
 }
 
+static void inner_play_prefetch_frame(int mode, int cfra)
+{
+	ScrArea *sa;
+	int oldcfra = CFRA;
+
+	if (!U.prefetchframes) {
+		return;
+	}
+
+	CFRA = cfra;
+
+	sa= G.curscreen->areabase.first;
+	while(sa) {
+		if(sa==oldsa) {
+			scrarea_do_winprefetchdraw(sa);
+		}
+		else if(curmode & 1) { /* all view3d and seq spaces */
+			if ELEM(sa->spacetype, SPACE_VIEW3D, SPACE_SEQ) {
+				scrarea_do_winprefetchdraw(sa);
+			}
+		}
+		else if(curmode & 4) { /* all seq spaces */
+			if (sa->spacetype == SPACE_SEQ) {
+				scrarea_do_winprefetchdraw(sa);
+			}
+		}		
+		
+		sa= sa->next;	
+	}
+
+	CFRA = oldcfra;
+}
+
+static void inner_play_prefetch_startup(int mode)
+{
+	int i;
+
+	if (!U.prefetchframes) {
+		return;
+	}
+
+	seq_start_threads();
+
+	for (i = 0; i <= U.prefetchframes; i++) {
+		inner_play_prefetch_frame(mode, CFRA + i);
+	}
+
+	seq_wait_for_prefetch_ready();
+}
+
+static void inner_play_prefetch_shutdown(int mode)
+{
+	if (!U.prefetchframes) {
+		return;
+	}
+	seq_stop_threads();
+}
+
 void inner_play_anim_loop(int init, int mode)
 {
 	ScrArea *sa;
-	static ScrArea *oldsa;
-	static double swaptime;
-	static int curmode;
 
 	/* init */
 	if(init) {
@@ -3223,6 +3281,8 @@
 		sa= sa->next;	
 	}
 	
+	inner_play_prefetch_frame(mode, CFRA + U.prefetchframes);
+
 	/* make sure that swaptime passed by */
 	tottime -= swaptime;
 	while (update_time()) PIL_sleep_ms(1);
@@ -3265,6 +3325,8 @@
 	cfraont= CFRA;
 	oldsa= curarea;
 
+	inner_play_prefetch_startup(mode);
+
 	audiostream_start( CFRA );
 	
 	if (curarea && curarea->spacetype == SPACE_SEQ) {
@@ -3313,6 +3375,7 @@
 	if(event==SPACEKEY);
 	else CFRA= cfraont;
 	
+	inner_play_prefetch_shutdown(mode);
 	audiostream_stop();
 
 	if(oldsa!=curarea) areawinset(oldsa->win);
Index: src/spacetypes.c
===================================================================
--- src/spacetypes.c	(revision 11922)
+++ src/spacetypes.c	(working copy)
@@ -52,6 +52,7 @@
 struct _SpaceType {
 	char			name[32];
 	
+	SpacePrefetchDrawFP winprefetchdraw;
 	SpaceDrawFP		windraw;
 	SpaceChangeFP	winchange;
 	SpaceHandleFP	winhandle;
@@ -70,8 +71,9 @@
 	return st;
 }
 
-void spacetype_set_winfuncs(SpaceType *st, SpaceDrawFP draw, SpaceChangeFP change, SpaceHandleFP handle) 
+void spacetype_set_winfuncs(SpaceType *st, SpacePrefetchDrawFP prefetchdraw, SpaceDrawFP draw, SpaceChangeFP change, SpaceHandleFP handle) 
 {
+	st->winprefetchdraw = prefetchdraw;
 	st->windraw= draw;
 	st->winchange= change;
 	st->winhandle= handle;
@@ -105,6 +107,17 @@
 	}
 }
 
+void scrarea_do_winprefetchdraw(ScrArea *area)
+{
+	SpaceType *st= spacetype_from_area(area);
+	
+	areawinset(area->win);
+
+	if(area->win && st->winprefetchdraw) {
+		st->winprefetchdraw(area, area->spacedata.first);
+	}
+}
+
 void scrarea_do_windraw(ScrArea *area)
 {
 	SpaceType *st= spacetype_from_area(area);
Index: src/space.c
===================================================================
--- src/space.c	(revision 11922)
+++ src/space.c	(working copy)
@@ -3126,8 +3126,8 @@
 	uiBlock *block;
 	static short cur_light=0;
 	float fac, col[3];
-	short xpos, ypos, ypostab,  buth, rspace, dx, y1, y2, y3, y4, y5, y6;
-	short y2label, y3label, y4label, y5label, y6label;
+	short xpos, ypos, ypostab,  buth, rspace, dx, y1, y2, y3, y4, y5, y6, y7;
+	short y2label, y3label, y4label, y5label, y6label, y7label;
 	short spref, mpref, lpref, smfileselbut;
 	short edgsp, midsp;
 	char naam[32];
@@ -3178,6 +3178,7 @@
 	y4 = ypos+3*(buth+rspace);
 	y5 = ypos+4*(buth+rspace);
 	y6 = ypos+5*(buth+rspace);
+	y7 = ypos+6*(buth+rspace);
 
 
 	y2label = y2-2;		/* adjustments to offset the labels down to align better */
@@ -3185,6 +3186,7 @@
 	y4label = y4-2;
 	y5label = y5-2;
 	y6label = y6-2;
+	y7label = y7-2;
 
 
 	/* set the color to blue and draw the main 'tab' controls */
@@ -3768,8 +3770,13 @@
 
 
 		uiDefBut(block, LABEL,0,"System:",
-			(xpos+edgsp+(4*midsp)+(4*mpref)),y6label,mpref,buth,
+			(xpos+edgsp+(4*midsp)+(4*mpref)),y7label,mpref,buth,
 			0, 0, 0, 0, 0, "");
+		uiDefButI(block, NUM, B_REDR, "Prefetch frames ",
+			  (xpos+edgsp+(4*mpref)+(4*midsp)), y6, mpref, buth, 
+			  &U.prefetchframes, 0.0, 50.0, 20, 2, 
+			  "Number of frames to render ahead during playback.");
+
 		uiDefButI(block, NUM, B_MEMCACHELIMIT, "MEM Cache Limit ",
 			  (xpos+edgsp+(4*mpref)+(4*midsp)), y5, mpref, buth, 
 			  &U.memcachelimit, 0.0, 1024.0, 30, 2, 
@@ -6171,7 +6178,7 @@
 	
 	if (!st) {
 		st= spacetype_new("Action");
-		spacetype_set_winfuncs(st, drawactionspace, changeactionspace, winqreadactionspace);
+		spacetype_set_winfuncs(st, NULL, drawactionspace, changeactionspace, winqreadactionspace);
 	}
 
 	return st;
@@ -6182,7 +6189,7 @@
 	
 	if (!st) {
 		st= spacetype_new("Buts");
-		spacetype_set_winfuncs(st, drawbutspace, changebutspace, winqreadbutspace);
+		spacetype_set_winfuncs(st, NULL, drawbutspace, changebutspace, winqreadbutspace);
 	}
 
 	return st;
@@ -6193,7 +6200,7 @@
 	
 	if (!st) {
 		st= spacetype_new("File");
-		spacetype_set_winfuncs(st, drawfilespace, NULL, winqreadfilespace);
+		spacetype_set_winfuncs(st, NULL, drawfilespace, NULL, winqreadfilespace);
 	}
 
 	return st;
@@ -6204,7 +6211,7 @@
 	
 	if (!st) {
 		st= spacetype_new("Image");
-		spacetype_set_winfuncs(st, drawimagespace, changeimagepace, winqreadimagespace);
+		spacetype_set_winfuncs(st, NULL, drawimagespace, changeimagepace, winqreadimagespace);
 	}
 
 	return st;
@@ -6215,7 +6222,7 @@
 	
 	if (!st) {
 		st= spacetype_new("Imasel");
-		spacetype_set_winfuncs(st, drawimaselspace, changeimaselspace, winqreadimaselspace);
+		spacetype_set_winfuncs(st, NULL, drawimaselspace, changeimaselspace, winqreadimaselspace);
 	}
 
 	return st;
@@ -6226,7 +6233,7 @@
 	
 	if (!st) {
 		st= spacetype_new("Info");
-		spacetype_set_winfuncs(st, drawinfospace, NULL, winqreadinfospace);
+		spacetype_set_winfuncs(st, NULL, drawinfospace, NULL, winqreadinfospace);
 	}
 
 	return st;
@@ -6237,7 +6244,7 @@
 	
 	if (!st) {
 		st= spacetype_new("Ipo");
-		spacetype_set_winfuncs(st, drawipospace, changeview2dspace, winqreadipospace);
+		spacetype_set_winfuncs(st, NULL, drawipospace, changeview2dspace, winqreadipospace);
 	}
 
 	return st;
@@ -6248,7 +6255,7 @@
 	
 	if (!st) {
 		st= spacetype_new("Nla");
-		spacetype_set_winfuncs(st, drawnlaspace, changeview2dspace, winqreadnlaspace);
+		spacetype_set_winfuncs(st, NULL, drawnlaspace, changeview2dspace, winqreadnlaspace);
 	}
 
 	return st;
@@ -6259,7 +6266,7 @@
 	
 	if (!st) {
 		st= spacetype_new("Oops");
-		spacetype_set_winfuncs(st, drawoopsspace, changeview2dspace, winqreadoopsspace);
+		spacetype_set_winfuncs(st, NULL, drawoopsspace, changeview2dspace, winqreadoopsspace);
 	}
 
 	return st;
@@ -6270,7 +6277,7 @@
 	
 	if (!st) {
 		st= spacetype_new("Sequence");
-		spacetype_set_winfuncs(st, drawseqspace, changeview2dspace, winqreadseqspace);
+		spacetype_set_winfuncs(st, drawprefetchseqspace, drawseqspace, changeview2dspace, winqreadseqspace);
 	}
 
 	return st;
@@ -6281,7 +6288,7 @@
 	
 	if (!st) {
 		st= spacetype_new("Sound");
-		spacetype_set_winfuncs(st, drawsoundspace, changeview2dspace, winqreadsoundspace);
+		spacetype_set_winfuncs(st, NULL, drawsoundspace, changeview2dspace, winqreadsoundspace);
 	}
 
 	return st;
@@ -6292,7 +6299,7 @@
 	
 	if (!st) {
 		st= spacetype_new("Text");
-		spacetype_set_winfuncs(st, drawtextspace, NULL, winqreadtextspace);
+		spacetype_set_winfuncs(st, NULL, drawtextspace, NULL, winqreadtextspace);
 	}
 
 	return st;
@@ -6316,7 +6323,7 @@
 
 	if (!st) {
 		st = spacetype_new("Script");
-		spacetype_set_winfuncs(st, drawscriptspace, spacescript_change, winqreadscriptspace);
+		spacetype_set_winfuncs(st, NULL, drawscriptspace, spacescript_change, winqreadscriptspace);
 	}
 
 	return st;
@@ -6327,7 +6334,7 @@
 	
 	if (!st) {
 		st= spacetype_new("View3D");
-		spacetype_set_winfuncs(st, drawview3dspace, changeview3dspace, winqreadview3dspace);
+		spacetype_set_winfuncs(st, NULL, drawview3dspace, changeview3dspace, winqreadview3dspace);
 	}
 
 	return st;
@@ -6338,7 +6345,7 @@
 	
 	if (!st) {
 		st= spacetype_new("Time");
-		spacetype_set_winfuncs(st, drawtimespace, NULL, winqreadtimespace);
+		spacetype_set_winfuncs(st, NULL, drawtimespace, NULL, winqreadtimespace);
 	}
 	
 	return st;
@@ -6350,7 +6357,7 @@
 	
 	if (!st) {
 		st= spacetype_new("Node");
-		spacetype_set_winfuncs(st, drawnodespace, changeview2dspace, winqreadnodespace);
+		spacetype_set_winfuncs(st, NULL, drawnodespace, changeview2dspace, winqreadnodespace);
 	}
 	
 	return st;
Index: src/drawseq.c
===================================================================
--- src/drawseq.c	(revision 11922)
+++ src/drawseq.c	(working copy)
@@ -51,6 +51,7 @@
 #include "DNA_screen_types.h"
 #include "DNA_space_types.h"
 #include "DNA_view2d_types.h"
+#include "DNA_userdef_types.h"
 
 #include "BKE_global.h"
 #include "BKE_plugin_types.h"
@@ -788,7 +789,11 @@
 		return;
 	else {
 		recursive= 1;
-		ibuf= (ImBuf *)give_ibuf_seq(rectx, recty, (G.scene->r.cfra), sseq->chanshown);
+		if (!U.prefetchframes || (G.f & G_PLAYANIM) == 0) {
+			ibuf= (ImBuf *)give_ibuf_seq(rectx, recty, (G.scene->r.cfra), sseq->chanshown);
+		} else {
+			ibuf= (ImBuf *)give_ibuf_threaded(rectx, recty, (G.scene->r.cfra), sseq->chanshown);
+		}
 		recursive= 0;
 		
 		/* HURMF! the give_ibuf_seq can call image display in this window */
@@ -1276,6 +1281,20 @@
 
 }
 
+void drawprefetchseqspace(ScrArea *sa, void *spacedata)
+{
+	SpaceSeq *sseq= sa->spacedata.first;
+	int rectx, recty;
+
+	rectx= (G.scene->r.size*G.scene->r.xsch)/100;
+	recty= (G.scene->r.size*G.scene->r.ysch)/100;
+
+	if(sseq->mainb) {
+		give_ibuf_prefetch_request(
+			rectx, recty, (G.scene->r.cfra), sseq->chanshown);
+	}
+}
+
 void drawseqspace(ScrArea *sa, void *spacedata)
 {
 	SpaceSeq *sseq= sa->spacedata.first;