fix release freeswitch media properly (#550)

* fix release freeswitch media properly

* if a leg is opus, modify b leg offer opus first

* if a leg is opus, modify b leg offer opus first

* wip

* wip

* fix review comments

* fix review comments

* fix review comments

lib/tasks/dial.js

@@ -17,7 +17,7 @@ const dbUtils = require('../utils/db-utils');
 const debug = require('debug')('jambonz:feature-server');
 const {parseUri} = require('drachtio-srf');
 const {ANCHOR_MEDIA_ALWAYS, JAMBONZ_DISABLE_DIAL_PAI_HEADER} = require('../config');
-const { isOnhold } = require('../utils/sdp-utils');
+const { isOnhold, isOpusFirst } = require('../utils/sdp-utils');
 const { normalizeJambones } = require('@jambonz/verb-specifications');
 
 function parseDtmfOptions(logger, dtmfCapture) {
@@ -488,7 +488,8 @@ class TaskDial extends Task {
       headers: this.headers,
       proxy: `sip:${sbcAddress}`,
       callingNumber: this.callerId || req.callingNumber,
-      ...(this.callerName && {callingName: this.callerName})
+      ...(this.callerName && {callingName: this.callerName}),
+      opusFirst: isOpusFirst(this.cs.ep.remote.sdp)
     };
 
     const t = this.target.find((t) => t.type === 'teams');
@@ -790,9 +791,11 @@ class TaskDial extends Task {
     assert(cs.ep && sd.ep);
 
     try {
+      // Wait until we got new SDP from B leg to ofter to A Leg
       const aLegSdp = cs.ep.remote.sdp;
+      await sd.releaseMediaToSBC(aLegSdp, cs.ep.local.sdp);
       const bLegSdp = sd.dlg.remote.sdp;
-      await Promise.all[sd.releaseMediaToSBC(aLegSdp, cs.ep.local.sdp), cs.releaseMediaToSBC(bLegSdp)];
+      await cs.releaseMediaToSBC(bLegSdp);
       this.epOther = null;
       this.logger.info('Dial:_releaseMedia - successfully released media from freewitch');
     } catch (err) {

lib/utils/place-outdial.js

@@ -15,6 +15,7 @@ const RootSpan = require('./call-tracer');
 const uuidv4 = require('uuid-random');
 const HttpRequestor = require('./http-requestor');
 const WsRequestor = require('./ws-requestor');
+const {makeOpusFirst} = require('./sdp-utils');
 
 class SingleDialer extends Emitter {
   constructor({logger, sbcAddress, target, opts, application, callInfo, accountInfo, rootSpan, startSpan, dialTask}) {
@@ -151,7 +152,7 @@ class SingleDialer extends Emitter {
 
       Object.assign(opts, {
         proxy: `sip:${this.sbcAddress}`,
-        localSdp: this.ep.local.sdp
+        localSdp: opts.opusFirst ? makeOpusFirst(this.ep.local.sdp) : this.ep.local.sdp
       });
       if (this.target.auth) opts.auth = this.target.auth;
       inviteSpan = this.startSpan('invite', {

lib/utils/sdp-utils.js

@@ -12,6 +12,30 @@ const mergeSdpMedia = (sdp1, sdp2) => {
   return sdpTransform.write(parsedSdp1);
 };
 
+const getCodecPlacement = (parsedSdp, codec) => parsedSdp?.media[0]?.rtp?.findIndex((e) => e.codec === codec);
+
+const isOpusFirst = (sdp) => {
+  return getCodecPlacement(sdpTransform.parse(sdp), 'opus') === 0;
+};
+
+const makeOpusFirst = (sdp) => {
+  const parsedSdp = sdpTransform.parse(sdp);
+  // Find the index of the OPUS codec
+  const opusIndex = getCodecPlacement(parsedSdp, 'opus');
+
+  // Move OPUS codec to the beginning
+  if (opusIndex > 0) {
+    const opusEntry = parsedSdp.media[0].rtp.splice(opusIndex, 1)[0];
+    parsedSdp.media[0].rtp.unshift(opusEntry);
+
+    // Also move the corresponding payload type in the "m" line
+    const opusPayloadType = parsedSdp.media[0].payloads.split(' ')[opusIndex];
+    const otherPayloadTypes = parsedSdp.media[0].payloads.split(' ').filter((pt) => pt != opusPayloadType);
+    parsedSdp.media[0].payloads = [opusPayloadType, ...otherPayloadTypes].join(' ');
+  }
+  return sdpTransform.write(parsedSdp);
+};
+
 const extractSdpMedia = (sdp) => {
   const parsedSdp1 = sdpTransform.parse(sdp);
   if (parsedSdp1.media.length > 1) {
@@ -28,5 +52,7 @@ const extractSdpMedia = (sdp) => {
 module.exports = {
   isOnhold,
   mergeSdpMedia,
-  extractSdpMedia
+  extractSdpMedia,
+  isOpusFirst,
+  makeOpusFirst
 };