From ea4415238d9b875acec70a1a7032c53f59b031a8 Mon Sep 17 00:00:00 2001
From: cmoore <cyril.moore@Review.com>
Date: Thu, 14 Sep 2023 17:32:33 -0400
Subject: [PATCH] Add ability to set sequence number for cases where sequence
 number is not generated locally. For example webrtc media servers.

---
 src/net/RTP/MediaStream.cs | 18 ++++++++++++++++--
 src/net/RTP/RTPSession.cs  | 21 +++++++++++++++++++++
 2 files changed, 37 insertions(+), 2 deletions(-)

diff --git a/src/net/RTP/MediaStream.cs b/src/net/RTP/MediaStream.cs
index 3231961ff..e23e3ff49 100644
--- a/src/net/RTP/MediaStream.cs
+++ b/src/net/RTP/MediaStream.cs
@@ -352,7 +352,7 @@ protected Boolean CheckIfCanSendRtpRaw()
             return true;
         }
 
-        protected void SendRtpRaw(byte[] data, uint timestamp, int markerBit, int payloadType, Boolean checkDone)
+        protected void SendRtpRaw(byte[] data, uint timestamp, int markerBit, int payloadType, Boolean checkDone, ushort? seqNum = null)
         {
             if (checkDone || CheckIfCanSendRtpRaw())
             {
@@ -361,7 +361,7 @@ protected void SendRtpRaw(byte[] data, uint timestamp, int markerBit, int payloa
 
                 RTPPacket rtpPacket = new RTPPacket(data.Length + srtpProtectionLength);
                 rtpPacket.Header.SyncSource = LocalTrack.Ssrc;
-                rtpPacket.Header.SequenceNumber = LocalTrack.GetNextSeqNum();
+                rtpPacket.Header.SequenceNumber = seqNum ?? LocalTrack.GetNextSeqNum();
                 rtpPacket.Header.Timestamp = timestamp;
                 rtpPacket.Header.MarkerBit = markerBit;
                 rtpPacket.Header.PayloadType = payloadType;
@@ -393,6 +393,20 @@ protected void SendRtpRaw(byte[] data, uint timestamp, int markerBit, int payloa
             }
         }
 
+        /// <summary>
+        /// Allows additional control for sending raw RTP payloads. No framing or other processing is carried out.
+        /// </summary>
+        /// <param name="mediaType">The media type of the RTP packet being sent. Must be audio or video.</param>
+        /// <param name="payload">The RTP packet payload.</param>
+        /// <param name="timestamp">The timestamp to set on the RTP header.</param>
+        /// <param name="markerBit">The value to set on the RTP header marker bit, should be 0 or 1.</param>
+        /// <param name="payloadTypeID">The payload ID to set in the RTP header.</param>
+        /// <param name="seqNum"> The RTP sequence number </param>
+        public void SendRtpRaw(byte[] data, uint timestamp, int markerBit, int payloadType, ushort seqNum)
+        {
+            SendRtpRaw(data, timestamp, markerBit, payloadType, false, seqNum);
+        }
+
         /// <summary>
         /// Allows additional control for sending raw RTP payloads. No framing or other processing is carried out.
         /// </summary>
diff --git a/src/net/RTP/RTPSession.cs b/src/net/RTP/RTPSession.cs
index 0c3fbd4fb..01aca0dd0 100644
--- a/src/net/RTP/RTPSession.cs
+++ b/src/net/RTP/RTPSession.cs
@@ -2403,6 +2403,27 @@ private MediaStream GetMediaStream(RTCPCompoundPacket rtcpPkt)
             return null;
         }
 
+        /// <summary>
+        /// Allows additional control for sending raw RTP payloads (on the primary one). No framing or other processing is carried out.
+        /// </summary>
+        /// <param name="mediaType">The media type of the RTP packet being sent. Must be audio or video.</param>
+        /// <param name="payload">The RTP packet payload.</param>
+        /// <param name="timestamp">The timestamp to set on the RTP header.</param>
+        /// <param name="markerBit">The value to set on the RTP header marker bit, should be 0 or 1.</param>
+        /// <param name="payloadTypeID">The payload ID to set in the RTP header.</param>
+        /// <param name="seqNum">The sequence number of the packet.</param>
+        public void SendRtpRaw(SDPMediaTypesEnum mediaType, byte[] payload, uint timestamp, int markerBit, int payloadTypeID, ushort seqNum)
+        {
+            if (mediaType == SDPMediaTypesEnum.audio)
+            {
+                AudioStream.SendRtpRaw(payload, timestamp, markerBit, payloadTypeID, seqNum);
+            }
+            else if (mediaType == SDPMediaTypesEnum.video)
+            {
+                VideoStream?.SendRtpRaw(payload, timestamp, markerBit, payloadTypeID, seqNum);
+            }
+        }
+
         /// <summary>
         /// Allows additional control for sending raw RTP payloads (on the primary one). No framing or other processing is carried out.
         /// </summary>