From c21b32e40dc673dae8895c11a99269d64bae9a66 Mon Sep 17 00:00:00 2001
From: Sangwon Oh <rock@airensoft.com>
Date: Thu, 2 Sep 2021 17:27:42 +0900
Subject: [PATCH] Add function to append additional string to the a=fmtp
 sections of SDP

---
 README.md          |  5 ++++
 package.json       |  2 +-
 src/OvenLiveKit.js | 62 +++++++++++++++++++++++++++++++++++-----------
 3 files changed, 53 insertions(+), 16 deletions(-)

diff --git a/README.md b/README.md
index 38f0c5f..ea2e16a 100644
--- a/README.md
+++ b/README.md
@@ -288,6 +288,11 @@ ovenLivekit.getUserMedia().then(function () {
     - Number: Unit is Kbps.
 - If set limits max bitrates of streaming to OvenMediaEngine.
 
+##### `sdp.appendFmtp`
+- type
+    - String: String you want to append to a=fmtp of SDP.
+- If set video format is appended to the a=fmtp sections of SDP.
+
 ## For more information
 * [WebRTC Input in OvenPlayer Demo](https://demo.ovenplayer.com/demo_input.html)
   * Test Player based on OvenPlayer. 
diff --git a/package.json b/package.json
index 7e0e59e..9043bae 100644
--- a/package.json
+++ b/package.json
@@ -1,6 +1,6 @@
 {
   "name": "ovenlivekit",
-  "version": "1.0.0",
+  "version": "1.0.1",
   "description": "OvenLiveKit for Web is an open source JavaScript SDK suite for live streaming from web browsers to OvenMediaEngine.",
   "main": "dist/OvenLiveKit.min.js",
   "scripts": {
diff --git a/src/OvenLiveKit.js b/src/OvenLiveKit.js
index c55bf65..c0db3e3 100644
--- a/src/OvenLiveKit.js
+++ b/src/OvenLiveKit.js
@@ -331,34 +331,56 @@ function addMethod(instance) {
 
     }
 
-    function removeH264(sdp) {
+    function appendFmtp(sdp) {
 
-        let newLines = [];
-        let lines = sdp.split('\n');
+        const fmtpStr = instance.connectionConfig.sdp.appendFmtp;
+
+        const lines = sdp.split('\n');
+        const payloads = [];
 
         for (let i = 0; i < lines.length; i++) {
 
             if (lines[i].indexOf('m=video') === 0) {
-                newLines.push(lines[i].replace(' 100', ''));
-            } else if (lines[i].indexOf('100') > -1) {
 
-            } else {
-                newLines.push(lines[i]);
+                let tokens = lines[i].split(' ')
 
-                if (lines[i].indexOf('a=rtpmap:101') > -1) {
-                    // newLines.push('a=fmtp:101 useadaptivelayering=true;useadaptivelayering_v2=true');
+                for (let j = 3; j < tokens.length; j++) {
+
+                    payloads.push(tokens[j].replace('\r', ''));
                 }
+
+                break;
             }
         }
 
-        return newLines.join('\n')
-    }
+        for (let i = 0; i < payloads.length; i++) {
 
-    function createPeerConnection(id, peerId, offer, candidates, iceServers) {
+            let fmtpLineFound = false;
+
+            for (let j = 0; j < lines.length; j++) {
+
+                if (lines[j].indexOf('a=fmtp:' + payloads[i]) === 0) {
+                    fmtpLineFound = true;
+                    lines[j] += ';' + fmtpStr;
+                }
+            }
+
+            if (!fmtpLineFound) {
+
+                for (let j = 0; j < lines.length; j++) {
 
-        // console.log(removeH264(offer.sdp));
+                    if (lines[j].indexOf('a=rtpmap:' + payloads[i]) === 0) {
 
-        // offer.sdp = removeH264(offer.sdp);
+                        lines[j] += '\na=fmtp:' + payloads[i] + ' ' + fmtpStr;
+                    }
+                }
+            }
+        }
+
+        return lines.join('\n')
+    }
+
+    function createPeerConnection(id, peerId, offer, candidates, iceServers) {
 
         let peerConnectionConfig = {};
 
@@ -470,12 +492,22 @@ function addMethod(instance) {
             offer.sdp = setBitrateLimit(offer.sdp, 'video', instance.connectionConfig.maxVideoBitrate);
         }
 
+        if (instance.connectionConfig.sdp && instance.connectionConfig.sdp.appendFmtp) {
+
+            offer.sdp = appendFmtp(offer.sdp);
+        }
+
         peerConnection.setRemoteDescription(new RTCSessionDescription(offer))
             .then(function () {
 
                 peerConnection.createAnswer()
                     .then(function (answer) {
 
+                        if (instance.connectionConfig.sdp && instance.connectionConfig.sdp.appendFmtp) {
+
+                            answer.sdp = appendFmtp(answer.sdp);
+                        }
+
                         peerConnection.setLocalDescription(answer)
                             .then(function () {
 
@@ -655,7 +687,7 @@ function addMethod(instance) {
 // static methods
 OvenLiveKit.create = function (options) {
 
-    console.info(logEventHeader, 'Create WebRTC Input');
+    console.info(logEventHeader, 'Create WebRTC Input v1.0.1');
 
     let instance = {};