enum jb_return_code jb_get(jitterbuf *jb, jb_frame *frameout, long now, long interpl)
{
enum jb_return_code ret = _jb_get(jb, frameout, now, interpl);
#if 0
static int lastts=0;
int thists = ((ret == JB_OK) || (ret == JB_DROP)) ? frameout->ts : 0;
jb_warn("jb_get(%x,%x,%ld) = %d (%d)\n", jb, frameout, now, ret, thists);
if (thists && thists < lastts) jb_warn("XXXX timestamp roll-back!!!\n");
lastts = thists;
#endif
return ret;
}
int jb_get(jitterbuf *jb, jb_frame *frameout, long now, long interpl)
{
int ret = _jb_get(jb,frameout,now,interpl);
#if 0
static int lastts=0;
int thists = ((ret == JB_OK) || (ret == JB_DROP)) ? frameout->ts : 0;
jb_warn("jb_get(%x,%x,%ld) = %d (%d)\n", jb, frameout, now, ret, thists);
if (thists && thists < lastts) jb_warn("XXXX timestamp roll-back!!!\n");
lastts = thists;
#endif
if(ret == JB_INTERP)
frameout->ms = jb->info.last_voice_ms;
return ret;
}
static void resync(jitterbuf *jb, long ts, long now)
{
long delay = now - (ts - jb->info.resync_offset);
long threshold = 2 * jb->info.jitter + jb->conf.resync_threshold;
/* resync the jitterbuffer */
jb->info.cnt_delay_discont = 0;
jb->hist_ptr = 0;
jb->hist_maxbuf_valid = 0;
jb->force_resync = 0;
jb_warn("Resyncing the jb. last_delay %ld, this delay %ld, threshold %ld, new offset %ld\n", jb->info.last_delay, delay, threshold, ts - now);
jb->info.resync_offset = ts - now;
jb->info.last_delay = 0; /* after resync, frame is right on time */
}
static int check_resync(jitterbuf *jb, long ts, long now, long ms, const enum jb_frame_type type, long *delay)
{
long numts = 0;
long threshold = 2 * jb->info.jitter + jb->info.conf.resync_threshold;
/* Check for overfill of the buffer */
if (jb->frames) {
numts = jb->frames->prev->ts - jb->frames->ts;
}
if (numts >= (jb->info.conf.max_jitterbuf)) {
if (!jb->dropem) {
ast_debug(1, "Attempting to exceed Jitterbuf max %ld timeslots\n",
jb->info.conf.max_jitterbuf);
jb->dropem = 1;
}
jb->info.frames_dropped++;
return -1;
} else {
jb->dropem = 0;
}
/* check for drastic change in delay */
if (jb->info.conf.resync_threshold != -1) {
if (abs(*delay - jb->info.last_delay) > threshold) {
jb->info.cnt_delay_discont++;
/* resync the jitterbuffer on 3 consecutive discontinuities,
* or immediately if a control frame */
if ((jb->info.cnt_delay_discont > 3) || (type == JB_TYPE_CONTROL)) {
jb->info.cnt_delay_discont = 0;
jb->hist_ptr = 0;
jb->hist_maxbuf_valid = 0;
jb_warn("Resyncing the jb. last_delay %ld, this delay %ld, threshold %ld, new offset %ld\n", jb->info.last_delay, *delay, threshold, ts - now);
jb->info.resync_offset = ts - now;
jb->info.last_delay = *delay = 0; /* after resync, frame is right on time */
} else {
jb->info.frames_dropped++;
return -1;
}
} else {
jb->info.last_delay = *delay;
jb->info.cnt_delay_discont = 0;
}
}
return 0;
}
/* drop parameter determines whether we will drop outliers to minimize
* delay */
static int history_put(jitterbuf *jb, long ts, long now, long ms)
{
long delay = now - (ts - jb->info.resync_offset);
long threshold = 2 * jb->info.jitter + jb->info.conf.resync_threshold;
long kicked;
/* don't add special/negative times to history */
if (ts <= 0)
return 0;
/* check for drastic change in delay */
if (jb->info.conf.resync_threshold != -1) {
if (abs(delay - jb->info.last_delay) > threshold) {
jb->info.cnt_delay_discont++;
if (jb->info.cnt_delay_discont > 3) {
/* resync the jitterbuffer */
jb->info.cnt_delay_discont = 0;
jb->hist_ptr = 0;
jb->hist_maxbuf_valid = 0;
jb_warn("Resyncing the jb. last_delay %ld, this delay %ld, threshold %ld, new offset %ld\n", jb->info.last_delay, delay, threshold, ts - now);
jb->info.resync_offset = ts - now;
jb->info.last_delay = delay = 0; /* after resync, frame is right on time */
} else {
return -1;
}
} else {
jb->info.last_delay = delay;
jb->info.cnt_delay_discont = 0;
}
}
kicked = jb->history[jb->hist_ptr % JB_HISTORY_SZ];
jb->history[(jb->hist_ptr++) % JB_HISTORY_SZ] = delay;
/* optimization; the max/min buffers don't need to be recalculated, if this packet's
* entry doesn't change them. This happens if this packet is not involved, _and_ any packet
* that got kicked out of the history is also not involved
* We do a number of comparisons, but it's probably still worthwhile, because it will usually
* succeed, and should be a lot faster than going through all 500 packets in history */
if (!jb->hist_maxbuf_valid)
return 0;
/* don't do this until we've filled history
* (reduces some edge cases below) */
if (jb->hist_ptr < JB_HISTORY_SZ)
goto invalidate;
/* if the new delay would go into min */
if (delay < jb->hist_minbuf[JB_HISTORY_MAXBUF_SZ-1])
goto invalidate;
/* or max.. */
if (delay > jb->hist_maxbuf[JB_HISTORY_MAXBUF_SZ-1])
goto invalidate;
/* or the kicked delay would be in min */
if (kicked <= jb->hist_minbuf[JB_HISTORY_MAXBUF_SZ-1])
goto invalidate;
if (kicked >= jb->hist_maxbuf[JB_HISTORY_MAXBUF_SZ-1])
goto invalidate;
/* if we got here, we don't need to invalidate, 'cause this delay didn't
* affect things */
return 0;
/* end optimization */
invalidate:
jb->hist_maxbuf_valid = 0;
return 0;
}
