Changeset 1072 for pjproject/trunk

Timestamp:

Mar 15, 2007 10:05:39 PM (18 years ago)

Author:

bennylp

Message:

Fixed ticket #183: Add flag in SDP negotiator to specify codec order preference (thanks Esbjorn Dominique)

Location:

pjproject/trunk/pjmedia

Files:

• include/pjmedia/config.h (modified) (1 diff)
• include/pjmedia/sdp_neg.h (modified) (1 diff)
• src/pjmedia/sdp_neg.c (modified) (13 diffs)

pjproject/trunk/pjmedia/include/pjmedia/config.h

@@ -281 +281 @@
 
 /**
+ * This specifies the behavior of the SDP negotiator when responding to an
+ * offer, whether it should rather use the codec preference as set by
+ * remote, or should it rather use the codec preference as specified by
+ * local endpoint.
+ *
+ * For example, suppose incoming call has codec order "8 0 3", while 
+ * local codec order is "3 0 8". If remote codec order is preferable,
+ * the selected codec will be 8, while if local codec order is preferable,
+ * the selected codec will be 3.
+ *
+ * If set to non-zero, the negotiator will use the codec order as specified
+ * by remote in the offer.
+ *
+ * Note that this behavior can be changed during run-time by calling
+ * pjmedia_sdp_neg_set_prefer_remote_codec_order().
+ *
+ * Default is 1 (to maintain backward compatibility)
+ */
+#ifndef PJMEDIA_SDP_NEG_PREFER_REMOTE_CODEC_ORDER
+#   define PJMEDIA_SDP_NEG_PREFER_REMOTE_CODEC_ORDER    1
+#endif
+
+
+/**
  * Support for sending and decoding RTCP port in SDP (RFC 3605).
  * Default is yes.

pjproject/trunk/pjmedia/include/pjmedia/sdp_neg.h

@@ -355 +355 @@
 
 /**
+ * This specifies the behavior of the SDP negotiator when responding to an
+ * offer, whether it should rather use the codec preference as set by
+ * remote, or should it rather use the codec preference as specified by
+ * local endpoint.
+ *
+ * For example, suppose incoming call has codec order "8 0 3", while 
+ * local codec order is "3 0 8". If remote codec order is preferable,
+ * the selected codec will be 8, while if local codec order is preferable,
+ * the selected codec will be 3.
+ *
+ * By default, the value in PJMEDIA_SDP_NEG_PREFER_REMOTE_CODEC_ORDER will
+ * be used.
+ *
+ * @param neg           The SDP negotiator instance.
+ * @param prefer_remote If non-zero, the negotiator will use the codec
+ *                      order as specified in remote offer. If zero, it
+ *                      will prefer to use the local codec order.
+ */
+PJ_DECL(pj_status_t)
+pjmedia_sdp_neg_set_prefer_remote_codec_order(pjmedia_sdp_neg *neg,
+                                              pj_bool_t prefer_remote);
+
+
+/**
  * Get SDP negotiator state.
  *

pjproject/trunk/pjmedia/src/pjmedia/sdp_neg.c

@@ -32 +32 @@
 {
     pjmedia_sdp_neg_state state;            /**< Negotiator state.           */
+    pj_bool_t             prefer_remote_codec_order;
     pj_bool_t             has_remote_answer;
     pj_bool_t             answer_was_remote;
@@ -87 +88 @@
 
     neg->state = PJMEDIA_SDP_NEG_STATE_LOCAL_OFFER;
+    neg->prefer_remote_codec_order = PJMEDIA_SDP_NEG_PREFER_REMOTE_CODEC_ORDER;
     neg->initial_sdp = pjmedia_sdp_session_clone(pool, local);
     neg->neg_local_sdp = pjmedia_sdp_session_clone(pool, local);
@@ -120 +122 @@
     PJ_ASSERT_RETURN(neg != NULL, PJ_ENOMEM);
 
+    neg->prefer_remote_codec_order = PJMEDIA_SDP_NEG_PREFER_REMOTE_CODEC_ORDER;
     neg->neg_remote_sdp = pjmedia_sdp_session_clone(pool, remote);
 
@@ -140 +143 @@
     return PJ_SUCCESS;
 }
+
+
+/*
+ * Set codec order preference.
+ */
+PJ_DEF(pj_status_t)
+pjmedia_sdp_neg_set_prefer_remote_codec_order(pjmedia_sdp_neg *neg,
+                                              pj_bool_t prefer_remote)
+{
+    PJ_ASSERT_RETURN(neg, PJ_EINVAL);
+    neg->prefer_remote_codec_order = prefer_remote;
+    return PJ_SUCCESS;
+}
+
 
 /*
@@ -668 +685 @@
 static pj_status_t match_offer(pj_pool_t *pool,
                                const pjmedia_sdp_media *offer,
-                               const pjmedia_sdp_media *local,
+                               const pjmedia_sdp_media *preanswer,
+                               const pjmedia_sdp_media *orig_local,
                                pjmedia_sdp_media **p_answer)
 {
@@ -711 +729 @@
 
                 /* Find matching codec in local descriptor. */
-                for (j=0; j<local->desc.fmt_count; ++j) {
+                for (j=0; j<preanswer->desc.fmt_count; ++j) {
                     unsigned p;
-                    p = pj_strtoul(&local->desc.fmt[j]);
-                    if (p == pt && pj_isdigit(*local->desc.fmt[j].ptr)) {
+                    p = pj_strtoul(&preanswer->desc.fmt[j]);
+                    if (p == pt && pj_isdigit(*preanswer->desc.fmt[j].ptr)) {
                         found_matching_codec = 1;
-                        pt_answer[pt_answer_count++] = local->desc.fmt[j];
+                        pt_answer[pt_answer_count++] = preanswer->desc.fmt[j];
                         break;
                     }
@@ -754 +772 @@
                  * encoding name and clock rate.
                  */
-                for (j=0; j<local->desc.fmt_count; ++j) {
-                    a = pjmedia_sdp_media_find_attr2(local, "rtpmap", 
-                                                     &local->desc.fmt[j]);
+                for (j=0; j<preanswer->desc.fmt_count; ++j) {
+                    a = pjmedia_sdp_media_find_attr2(preanswer, "rtpmap", 
+                                                     &preanswer->desc.fmt[j]);
                     if (a) {
                         pjmedia_sdp_rtpmap lr;
@@ -774 +792 @@
                             else
                                 found_matching_telephone_event = 1;
-                            pt_answer[pt_answer_count++] = local->desc.fmt[j];
+                            pt_answer[pt_answer_count++] = preanswer->desc.fmt[j];
                             break;
                         }
@@ -792 +810 @@
                 continue;
 
-            for (j=0; j<local->desc.fmt_count; ++j) {
-                if (!pj_strcmp(&offer->desc.fmt[i], &local->desc.fmt[j])) {
+            for (j=0; j<preanswer->desc.fmt_count; ++j) {
+                if (!pj_strcmp(&offer->desc.fmt[i], &preanswer->desc.fmt[j])) {
                     /* Match */
                     found_matching_other = 1;
-                    pt_answer[pt_answer_count++] = local->desc.fmt[j];
+                    pt_answer[pt_answer_count++] = preanswer->desc.fmt[j];
                     break;
                 }
@@ -824 +842 @@
      * to suit the offer.
      */
-    answer = pjmedia_sdp_media_clone(pool, local);
+    answer = pjmedia_sdp_media_clone(pool, orig_local);
     for (i=0; i<pt_answer_count; ++i) {
         unsigned j;
@@ -868 +886 @@
 /* Create complete answer for remote's offer. */
 static pj_status_t create_answer( pj_pool_t *pool,
+                                  pj_bool_t prefer_remote_codec_order,
                                   const pjmedia_sdp_session *initial,
                                   const pjmedia_sdp_session *offer,
@@ -915 +934 @@
             {
                 /* See if it has matching codec. */
-                status = match_offer(pool, om, im, &am);
+                if (prefer_remote_codec_order) {
+                    status = match_offer(pool, om, im, im, &am);
+                } else {
+                    status = match_offer(pool, im, om, im, &am);
+                }
+
                 if (status == PJ_SUCCESS) {
                     /* Mark media as used. */
@@ -992 +1016 @@
         pjmedia_sdp_session *answer = NULL;
 
-        status = create_answer(pool, neg->neg_local_sdp, neg->neg_remote_sdp,
+        status = create_answer(pool, neg->prefer_remote_codec_order, 
+                               neg->neg_local_sdp, neg->neg_remote_sdp,
                                &answer);
         if (status == PJ_SUCCESS) {