Changeset 6103 for pjproject/trunk/pjmedia/src/pjmedia/sdp_neg.c

Timestamp:

Nov 8, 2019 10:17:16 AM (5 years ago)

Author:

nanang

Message:

Close #2088: Generate and negotiate telephone-event with multiple clock-rates in SDP offer/answer.

File:

• pjproject/trunk/pjmedia/src/pjmedia/sdp_neg.c (modified) (7 diffs)

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

@@ -1071 +1071 @@
     pjmedia_sdp_media *answer;
     const pjmedia_sdp_media *master, *slave;
+    unsigned nclockrate = 0, clockrate[PJMEDIA_MAX_SDP_FMT];
 
     /* If offer has zero port, just clone the offer */
@@ -1131 +1132 @@
                     p = pj_strtoul(&slave->desc.fmt[j]);
                     if (p == pt && pj_isdigit(*slave->desc.fmt[j].ptr)) {
+                        unsigned k;
+
                         found_matching_codec = 1;
                         pt_offer[pt_answer_count] = slave->desc.fmt[j];
                         pt_answer[pt_answer_count++] = slave->desc.fmt[j];
+
+                        /* Take note of clock rate for tel-event. Note: for
+                         * static PT, we assume the clock rate is 8000.
+                         */
+                        for (k=0; k<nclockrate; ++k)
+                            if (clockrate[k] == 8000)
+                                break;
+                        if (k == nclockrate)
+                            clockrate[nclockrate++] = 8000;
                         break;
                     }
@@ -1145 +1157 @@
                 const pjmedia_sdp_attr *a;
                 pjmedia_sdp_rtpmap or_;
-                pj_bool_t is_codec;
+                pj_bool_t is_codec = 0;
 
                 /* Get the rtpmap for the payload type in the master. */
@@ -1156 +1168 @@
                 pjmedia_sdp_attr_get_rtpmap(a, &or_);
 
-                if (!pj_stricmp2(&or_.enc_name, "telephone-event")) {
-                    if (found_matching_telephone_event)
-                        continue;
-                    is_codec = 0;
-                } else {
+                if (pj_stricmp2(&or_.enc_name, "telephone-event")) {
                     master_has_codec = 1;
                     if (!answer_with_multiple_codecs && found_matching_codec)
@@ -1192 +1200 @@
                                 pjmedia_sdp_media *o_med, *a_med;
                                 unsigned o_fmt_idx, a_fmt_idx;
+                                unsigned k;
 
                                 o_med = (pjmedia_sdp_media*)offer;
@@ -1208 +1217 @@
                                 }
                                 found_matching_codec = 1;
+
+                                /* Take note of clock rate for tel-event */
+                                for (k=0; k<nclockrate; ++k)
+                                    if (clockrate[k] == or_.clock_rate)
+                                        break;
+                                if (k == nclockrate)
+                                    clockrate[nclockrate++] = or_.clock_rate;
                             } else {
                                 found_matching_telephone_event = 1;
@@ -1270 +1286 @@
     }
 
-    /* Seems like everything is in order.
-     * Build the answer by cloning from preanswer, but rearrange the payload
+    /* Seems like everything is in order. */
+
+    /* Remove unwanted telephone-event formats. */
+    if (found_matching_telephone_event) {
+        pj_str_t first_televent_offer = {0};
+        pj_str_t first_televent_answer = {0};
+        unsigned matched_cnt = 0;
+
+        for (i=0; i<pt_answer_count; ) {
+            const pjmedia_sdp_attr *a;
+            pjmedia_sdp_rtpmap r;
+            unsigned j;
+
+            /* Skip static PT, as telephone-event uses dynamic PT */
+            if (!pj_isdigit(*pt_answer[i].ptr) || pj_strtol(&pt_answer[i])<96)
+            {
+                ++i;
+                continue;
+            }
+
+            /* Get the rtpmap for format. */
+            a = pjmedia_sdp_media_find_attr2(preanswer, "rtpmap",
+                                             &pt_answer[i]);
+            pj_assert(a);
+            pjmedia_sdp_attr_get_rtpmap(a, &r);
+
+            /* Only care for telephone-event format */
+            if (pj_stricmp2(&r.enc_name, "telephone-event")) {
+                ++i;
+                continue;
+            }
+
+            if (first_televent_offer.slen == 0) {
+                first_televent_offer = pt_offer[i];
+                first_televent_answer = pt_answer[i];
+            }
+
+            for (j=0; j<nclockrate; ++j) {
+                if (r.clock_rate==clockrate[j])
+                    break;
+            }
+
+            /* This tel-event's clockrate is unwanted, remove the tel-event */
+            if (j==nclockrate) {
+                pj_array_erase(pt_answer, sizeof(pt_answer[0]),
+                               pt_answer_count, i);
+                pj_array_erase(pt_offer, sizeof(pt_offer[0]),
+                               pt_answer_count, i);
+                pt_answer_count--;
+            } else {
+                ++matched_cnt;
+                ++i;
+            }
+        }
+
+        /* Tel-event is wanted, but no matched clock rate (to the selected
+         * audio codec), just put back any first matched tel-event formats.
+         */
+        if (!matched_cnt) {
+            pt_offer[pt_answer_count] = first_televent_offer;
+            pt_answer[pt_answer_count++] = first_televent_answer;
+        }
+    }
+
+    /* Build the answer by cloning from preanswer, and reorder the payload
      * to suit the offer.
      */