Changeset 1887 for pjproject

Timestamp:

Mar 21, 2008 1:47:23 PM (17 years ago)

Author:

bennylp

Message:

Ticket #505: optimizing the jitter buffer delay

Location:

pjproject/trunk/pjmedia/src/pjmedia

Files:

• jbuf.c (modified) (10 diffs)
• stream.c (modified) (1 diff)

pjproject/trunk/pjmedia/src/pjmedia/jbuf.c

@@ -30 +30 @@
 #define THIS_FILE   "jbuf.c"
 
+#define SAFE_SHRINKING_DIFF     2
+#define USE_PREFETCH_BUFFERING  0
 
 typedef struct jb_framelist_t
@@ -55 +57 @@
     int             jb_level;             // delay between source & destination
                                           // (calculated according of the number of get/put operations)
-    int             jb_last_level;        // last delay 
-    int             jb_last_jitter;       // last jitter calculated
-    int             jb_max_hist_jitter;   // max jitter during the last jitter calculations
+    int             jb_max_hist_level;    // max level during the last level calculations
     int             jb_stable_hist;       // num of times the delay has been lower then the prefetch num
-    unsigned        jb_op_count;          // of of operations.
     int             jb_last_op;           // last operation executed on the framelist->flist_buffer (put/get)
     int             jb_last_seq_no;       // seq no. of the last frame inserted to the framelist->flist_buffer
@@ -84 +83 @@
  * second.
  */
-#if 0
+#if 1
 #  define TRACE__(args)     PJ_LOG(4,args)
 #else
@@ -305 +304 @@
     jb->jb_last_seq_no   = -1;
     jb->jb_level         = 0;
-    jb->jb_last_level    = 0;
-    jb->jb_last_jitter   = 0;
     jb->jb_last_op       = JB_OP_INIT;
     jb->jb_prefetch      = PJ_MIN(PJMEDIA_JB_DEFAULT_INIT_DELAY,max_count*4/5);
@@ -314 +311 @@
     jb->jb_stable_hist   = 0;
     jb->jb_status        = JB_STATUS_INITIALIZING;
-    jb->jb_max_hist_jitter = 0;
+    jb->jb_max_hist_level = 0;
     jb->jb_max_count     = max_count;
 
@@ -367 +364 @@
     jb->jb_last_seq_no   = -1;
     jb->jb_level         = 0;
-    jb->jb_last_level    = 0;
-    jb->jb_last_jitter   = 0;
     jb->jb_last_op       = JB_OP_INIT;
     jb->jb_prefetch_cnt  = 0;
     jb->jb_stable_hist   = 0;
     jb->jb_status        = JB_STATUS_INITIALIZING;
-    jb->jb_max_hist_jitter = 0;
+    jb->jb_max_hist_level = 0;
 
     jb_framelist_remove_head(&jb->jb_framelist, 
@@ -389 +384 @@
 static void jbuf_calculate_jitter(pjmedia_jbuf *jb)
 {
-    unsigned stable_history_limit;
-
-    stable_history_limit = 1000 / jb->jb_frame_ptime;
-
-    jb->jb_last_jitter = PJ_ABS(jb->jb_level-jb->jb_last_level);
-    jb->jb_last_level = jb->jb_level;
-    jb->jb_max_hist_jitter = PJ_MAX(jb->jb_max_hist_jitter,jb->jb_last_jitter);
-    jb->jb_op_count++;
-
-    if (jb->jb_last_jitter < jb->jb_prefetch) {
-        jb->jb_stable_hist += jb->jb_last_jitter;
-        if (jb->jb_stable_hist > (int)stable_history_limit) {
-            int seq_diff = (jb->jb_prefetch - jb->jb_max_hist_jitter)/3;
-            if (seq_diff<1) seq_diff = 1;
-
-            jb->jb_prefetch -= seq_diff;
-            if (jb->jb_prefetch < jb->jb_min_prefetch) 
-                jb->jb_prefetch = jb->jb_min_prefetch;
-
+    int diff;
+
+    /* Only apply burst-level calculation on PUT operation since if VAD is 
+     * active the burst-level may not be accurate.
+     */
+    if (jb->jb_last_op == JB_OP_PUT) {
+
+        jb->jb_max_hist_level = PJ_MAX(jb->jb_max_hist_level,jb->jb_level);
+
+        /* Level is decreasing */
+        if (jb->jb_level < jb->jb_prefetch) {
+
+            static const int stable_history_limit = 100;
+            
+            jb->jb_stable_hist++;
+            
+            /* Only update the prefetch if 'stable' condition is reached 
+             * (not just short time impulse)
+             */
+            if (jb->jb_stable_hist > (int)stable_history_limit) {
+                diff = (jb->jb_prefetch - jb->jb_max_hist_level) / 3;
+
+                if (diff < 1)
+                    diff = 1;
+
+                jb->jb_prefetch -= diff;
+                if (jb->jb_prefetch < jb->jb_min_prefetch) 
+                    jb->jb_prefetch = jb->jb_min_prefetch;
+
+                TRACE__((jb->name.ptr,"jb updated(1), prefetch=%d, size=%d", 
+                         jb->jb_prefetch, jb_framelist_size(&jb->jb_framelist)));
+
+                jb->jb_stable_hist = 0;
+                jb->jb_max_hist_level = 0;
+            }
+        }
+
+        /* Level is increasing */
+        else if (jb->jb_level > jb->jb_prefetch) {
+
+            /* Instaneous set prefetch */
+            jb->jb_prefetch = PJ_MIN(jb->jb_max_hist_level,
+                                     (int)(jb->jb_max_count*4/5));
+            if (jb->jb_prefetch > jb->jb_max_prefetch)
+                jb->jb_prefetch = jb->jb_max_prefetch;
             jb->jb_stable_hist = 0;
-            jb->jb_max_hist_jitter = 0;
-
-            TRACE__((THIS_FILE,"jb updated(1), prefetch=%d, size=%d", 
+            jb->jb_max_hist_level = 0;
+
+            TRACE__((jb->name.ptr,"jb updated(2), prefetch=%d, size=%d", 
                      jb->jb_prefetch, jb_framelist_size(&jb->jb_framelist)));
-
-            /* These code is used to shorten the delay in the jitter buffer.
-
-            if (jb->jb_op_count >= stable_history_limit*2 &&
-                (int)jb_framelist_size(&jb->jb_framelist) > jb->jb_prefetch+2)
-            {
-                jb_framelist_remove_head(&jb->jb_framelist,1);
-
-                PJ_LOG(5,(jb->name.ptr, 
-                          "jbuf optimizing, prefetch: %d, size=%d", 
-                          jb->jb_prefetch,
-                          jb_framelist_size(&jb->jb_framelist)));
-                jb->jb_op_count = 0;
-            }
-            */
-
-        }
-    } else {
-        jb->jb_prefetch = PJ_MIN(jb->jb_last_jitter,
-                                 (int)(jb->jb_max_count*4/5));
-        if (jb->jb_prefetch > jb->jb_max_prefetch)
-            jb->jb_prefetch = jb->jb_max_prefetch;
-        jb->jb_stable_hist = 0;
-        jb->jb_max_hist_jitter = 0;
-
-        TRACE__((THIS_FILE,"jb updated(2), prefetch=%d, size=%d", 
-                 jb->jb_prefetch, jb_framelist_size(&jb->jb_framelist)));
-
-        /* These code is used to shorten the delay in the jitter buffer
-           when the current size is larger than the prefetch. But it does
-           not really work when the stream supports multiple frames, since
-           the size may grow only temporarily.
-
-        if (jb->jb_op_count >= stable_history_limit * 2) {
-            if ((int)jb_framelist_size(&jb->jb_framelist) > jb->jb_prefetch+2) 
-            {
-                jb_framelist_remove_head(&jb->jb_framelist,1);
-
-                PJ_LOG(5,(jb->name.ptr, 
-                          "jbuf optimizing prefetch: %d, size=%d",
-                          jb->jb_prefetch,
-                          jb_framelist_size(&jb->jb_framelist)));
-            }
-
-            jb->jb_op_count = 0;
-        }
-        */
-    }
-}
-
-static void jbuf_update(pjmedia_jbuf *jb, int oper)
+        }
+
+        /* Level is unchanged */
+        else {
+            jb->jb_stable_hist = 0;
+        }
+    }
+
+    /* These code is used for shortening the delay in the jitter buffer. */
+    diff = jb_framelist_size(&jb->jb_framelist) - jb->jb_prefetch;
+    if (diff > SAFE_SHRINKING_DIFF) {
+        
+        /* Drop some frames so jitter buffer size should be == jb_prefetch */
+        jb_framelist_remove_head(&jb->jb_framelist, diff);
+
+        TRACE__((jb->name.ptr, 
+                 "JB shrinking %d frames, size=%d", diff,
+                 jb_framelist_size(&jb->jb_framelist)));
+    }
+
+    jb->jb_level = 0;
+}
+
+PJ_INLINE(void) jbuf_update(pjmedia_jbuf *jb, int oper)
 {
     if(jb->jb_last_op != oper) {
@@ -490 +484 @@
         jb->jb_status = JB_STATUS_PROCESSING;
         jb->jb_level = 0;
-        jb->jb_last_level = 0;
-        jb->jb_last_jitter = 0;
     } else {
         jbuf_update(jb, JB_OP_PUT);
@@ -538 +530 @@
     pjmedia_jb_frame_type ftype;
 
-    jb->jb_level--;
+    jb->jb_level++;
 
     jbuf_update(jb, JB_OP_GET);
+
+#if USE_PREFETCH_BUFFERING
 
     if (jb_framelist_size(&jb->jb_framelist) == 0) {
@@ -561 +555 @@
     }
 
+#endif
+
     /* Retrieve a frame from frame list */
     if (jb_framelist_get(&jb->jb_framelist,frame,size,&ftype) == PJ_FALSE) {

pjproject/trunk/pjmedia/src/pjmedia/stream.c

@@ -1459 +1459 @@
         jb_min_pre = info->jb_min_pre;
     else
-        jb_min_pre = 60 / stream->codec_param.info.frm_ptime;
+        //jb_min_pre = 60 / stream->codec_param.info.frm_ptime;
+        jb_min_pre = 1;
 
     if (info->jb_max_pre > 0)
         jb_max_pre = info->jb_max_pre;
     else
-        jb_max_pre = 240 / stream->codec_param.info.frm_ptime;
+        //jb_max_pre = 240 / stream->codec_param.info.frm_ptime;
+        jb_max_pre = jb_max * 4 / 5;
 
     if (info->jb_init >= 0)
         jb_init = info->jb_init;
     else
-        jb_init = (jb_min_pre + jb_max_pre) / 2;
+        //jb_init = (jb_min_pre + jb_max_pre) / 2;
+        jb_init = jb_min_pre;