control maximum number of interpolation frames generated during silence by jitterbuffer (bug #4295)

git-svn-id: https://origsvn.digium.com/svn/asterisk/trunk@5951 65c4cc65-6c06-0410-ace0-fbb531ad65f3

channels/chan_iax2.c

@@ -136,6 +136,7 @@ static int maxnontrunkcall = 1;
 static int maxjitterbuffer=1000;
 #ifdef NEWJB
 static int resyncthreshold=1000;
+static int maxjitterinterps=10;
 #endif
 static int jittershrinkrate=2;
 static int trunkfreq = 20;
@@ -870,6 +871,7 @@ static struct chan_iax2_pvt *new_iax(struct sockaddr_in *sin, int lockpeer, cons
 			tmp->jbid = -1;
 			jbconf.max_jitterbuf = maxjitterbuffer;
 			jbconf.resync_threshold = resyncthreshold;
+			jbconf.max_contig_interp = maxjitterinterps;
 			jb_setconf(tmp->jb,&jbconf);
 		}
 #endif
@@ -8343,6 +8345,8 @@ static int set_config(char *config_file, int reload)
 #ifdef NEWJB
 		else if (!strcasecmp(v->name, "resyncthreshold")) 
 			resyncthreshold = atoi(v->value);
+		else if (!strcasecmp(v->name, "maxjitterinterps")) 
+			maxjitterinterps = atoi(v->value);
 #endif
 		else if (!strcasecmp(v->name, "jittershrinkrate")) 
 			jittershrinkrate = atoi(v->value);

configs/iax.conf.sample

@@ -110,6 +110,12 @@ disallow=lpc10			; Icky sound quality...  Mr. Roboto.
 ; Resycning can be disabled by setting this parameter to -1.
 ; [This option presently applies only to the new jitterbuffer implementation]
 ;
+; maxjitterinterps: the maximum number of interpolation frames the jitterbuffer should
+; return in a row. Since some clients do not send CNG/DTX frames to indicate
+; silence, the jitterbuffer will assume silence has begun after returning this
+; many interpolations. This prevents interpolating throughout a long silence.
+; [This option presently applies only to the new jitterbuffer implementation]
+;
 ; maxexcessbuffer: If conditions improve after a period of high jitter,
 ; the jitter buffer can end up bigger than necessary.  If it ends up
 ; more than "maxexcessbuffer" bigger than needed, Asterisk will start
@@ -132,6 +138,7 @@ jitterbuffer=no
 forcejitterbuffer=no
 ;dropcount=2
 ;maxjitterbuffer=1000
+;maxjitterinterps=10
 ;resyncthreshold=1000
 ;maxexcessbuffer=80
 ;minexcessbuffer=10

jitterbuf.c

@@ -564,6 +564,10 @@ static int _jb_get(jitterbuf *jb, jb_frame *frameout, long now, long interpl)
 			jb->info.next_voice_ts += interpl;
 			jb->info.last_voice_ms = interpl;
 			jb->info.last_adjustment = now;
+			jb->info.cnt_contig_interp++;
+			if (jb->info.conf.max_contig_interp && jb->info.cnt_contig_interp >= jb->info.conf.max_contig_interp) {
+				jb->info.silence_begin_ts = jb->info.next_voice_ts - jb->info.current;
+			}
 			jb_dbg("G");
 			return JB_INTERP;
 		}
@@ -572,8 +576,10 @@ static int _jb_get(jitterbuf *jb, jb_frame *frameout, long now, long interpl)
 
 		/* not a voice frame; just return it. */
 		if (frame && frame->type != JB_TYPE_VOICE) {
-			if (frame->type == JB_TYPE_SILENCE) 
+			if (frame->type == JB_TYPE_SILENCE) {
 				jb->info.silence_begin_ts = frame->ts;
+				jb->info.cnt_contig_interp = 0;
+			}
 
 			*frameout = *frame;
 			jb->info.frames_out++;
@@ -592,6 +598,7 @@ static int _jb_get(jitterbuf *jb, jb_frame *frameout, long now, long interpl)
 				jb->info.next_voice_ts = frame->ts + jb->info.current + frame->ms;
 				jb->info.frames_out++;
 				decrement_losspct(jb);
+				jb->info.cnt_contig_interp = 0;
 				jb_dbg("v");
 				return JB_OK;
 			} else {
@@ -622,6 +629,7 @@ static int _jb_get(jitterbuf *jb, jb_frame *frameout, long now, long interpl)
 			(jb->info.last_adjustment + 500 < now))) {
 
 			jb->info.last_adjustment = now;
+			jb->info.cnt_contig_interp = 0;
 
 			if (frame) {
 				*frameout = *frame;
@@ -669,6 +677,10 @@ static int _jb_get(jitterbuf *jb, jb_frame *frameout, long now, long interpl)
 			increment_losspct(jb);
 			jb->info.next_voice_ts += interpl;
 			jb->info.last_voice_ms = interpl;
+			jb->info.cnt_contig_interp++;
+			if (jb->info.conf.max_contig_interp && jb->info.cnt_contig_interp >= jb->info.conf.max_contig_interp) {
+				jb->info.silence_begin_ts = jb->info.next_voice_ts - jb->info.current;
+			}
 			jb_dbg("L");
 			return JB_INTERP;
 		}
@@ -677,6 +689,7 @@ static int _jb_get(jitterbuf *jb, jb_frame *frameout, long now, long interpl)
 		*frameout = *frame;
 		jb->info.next_voice_ts += frame->ms;
 		jb->info.frames_out++;
+		jb->info.cnt_contig_interp = 0;
 		decrement_losspct(jb);
 		jb_dbg("v");
 		return JB_OK;
@@ -795,6 +808,7 @@ int jb_setconf(jitterbuf *jb, jb_conf *conf)
 
 	jb->info.conf.max_jitterbuf = conf->max_jitterbuf;
  	jb->info.conf.resync_threshold = conf->resync_threshold;
+	jb->info.conf.max_contig_interp = conf->max_contig_interp;
 
 	return JB_OK;
 }

jitterbuf.h

@@ -55,6 +55,7 @@ typedef struct jb_conf {
 	/* settings */
 	long max_jitterbuf;	/* defines a hard clamp to use in setting the jitter buffer delay */
  	long resync_threshold;  /* the jb will resync when delay increases to (2 * jitter) + this param */
+	long max_contig_interp; /* the max interp frames to return in a row */
 } jb_conf;
 
 typedef struct jb_info {
@@ -80,6 +81,7 @@ typedef struct jb_info {
  	long last_delay;        /* the last now added to history */
  	long cnt_delay_discont;	/* the count of discontinuous delays */
  	long resync_offset;     /* the amount to offset ts to support resyncs */
+	long cnt_contig_interp; /* the number of contiguous interp frames returned */
 } jb_info;
 
 typedef struct jb_frame {