Yet another set of jitter buffer changes (this time some scheduling improvements) (bug #4319)

git-svn-id: https://origsvn.digium.com/svn/asterisk/trunk@5722 65c4cc65-6c06-0410-ace0-fbb531ad65f3

channels/chan_iax2.c

@@ -2222,6 +2222,7 @@ static int schedule_delivery(struct iax_frame *fr, int reallydeliver, int update
 {
 #ifdef NEWJB
 	int type, len;
+	int ret;
 #else
 	int x;
 	int ms;
@@ -2387,10 +2388,11 @@ static int schedule_delivery(struct iax_frame *fr, int reallydeliver, int update
 
 	/* insert into jitterbuffer */
 	/* TODO: Perhaps we could act immediately if it's not droppable and late */
-	if(jb_put(iaxs[fr->callno]->jb, fr, type, len, fr->ts,
-	     calc_rxstamp(iaxs[fr->callno],fr->ts)) == JB_DROP) {
+	ret = jb_put(iaxs[fr->callno]->jb, fr, type, len, fr->ts,
+			calc_rxstamp(iaxs[fr->callno],fr->ts));
+	if (ret == JB_DROP) {
 		iax2_frame_free(fr);
-	} else {
+	} else if (ret == JB_SCHED) {
 		update_jbsched(iaxs[fr->callno]);
 	}
 #else

jitterbuf.c

@@ -300,10 +300,12 @@ static void history_get(jitterbuf *jb)
 	jb->info.jitter = jitter;
 }
 
-static void queue_put(jitterbuf *jb, void *data, int type, long ms, long ts) 
+/* returns 1 if frame was inserted into head of queue, 0 otherwise */
+static int queue_put(jitterbuf *jb, void *data, int type, long ms, long ts) 
 {
 	jb_frame *frame;
 	jb_frame *p;
+	int head = 0;
 	long resync_ts = ts - jb->info.resync_offset;
 
 	frame = jb->free;
@@ -315,7 +317,7 @@ static void queue_put(jitterbuf *jb, void *data, int type, long ms, long ts)
 
 	if (!frame) {
 		jb_err("cannot allocate frame\n");
-		return;
+		return 0;
 	}
 
 	jb->info.frames_cur++;
@@ -334,6 +336,7 @@ static void queue_put(jitterbuf *jb, void *data, int type, long ms, long ts)
 		jb->frames = frame;
 		frame->next = frame;
 		frame->prev = frame;
+		head = 1;
 	} else if (resync_ts < jb->frames->ts) {
 		frame->next = jb->frames;
 		frame->prev = jb->frames->prev;
@@ -345,6 +348,7 @@ static void queue_put(jitterbuf *jb, void *data, int type, long ms, long ts)
 		jb->info.frames_ooo++;
 
 		jb->frames = frame;
+		head = 1;
 	} else { 
 		p = jb->frames;
 
@@ -360,6 +364,7 @@ static void queue_put(jitterbuf *jb, void *data, int type, long ms, long ts)
 		frame->next->prev = frame;
 		frame->prev->next = frame;
 	}
+	return head;
 }
 
 static long queue_next(jitterbuf *jb) 
@@ -502,8 +507,10 @@ int jb_put(jitterbuf *jb, void *data, int type, long ms, long ts, long now)
 			return JB_DROP;
 	}
 
-	queue_put(jb,data,type,ms,ts);
-
+	/* if put into head of queue, caller needs to reschedule */
+	if (queue_put(jb,data,type,ms,ts)) {
+		return JB_SCHED;
+	}
 	return JB_OK;
 }
 

jitterbuf.h

@@ -42,6 +42,7 @@ extern "C" {
 #define JB_NOFRAME	2
 #define JB_INTERP	3
 #define JB_DROP		4
+#define JB_SCHED	5
 
 /* frame types */
 #define JB_TYPE_CONTROL	0
@@ -112,7 +113,11 @@ void			jb_destroy(jitterbuf *jb);
 void			jb_reset(jitterbuf *jb);
 
 /* queue a frame data=frame data, timings (in ms): ms=length of frame (for voice), ts=ts (sender's time) 
- * now=now (in receiver's time)*/
+ * now=now (in receiver's time) return value is one of 
+ * JB_OK: Frame added. Last call to jb_next() still valid
+ * JB_DROP: Drop this frame immediately
+ * JB_SCHED: Frame added. Call jb_next() to get a new time for the next frame
+ */
 int 			jb_put(jitterbuf *jb, void *data, int type, long ms, long ts, long now);
 
 /* get a frame for time now (receiver's time)  return value is one of