From 4f80a9f5ccea5eaf6a78a841af417c597eb7db73 Mon Sep 17 00:00:00 2001
From: Marvin W <git@larma.de>
Date: Sat, 18 Dec 2021 21:43:12 +0100
Subject: [PATCH] RTP: Correctly handle timestamp after re-enabling a stream

---
 plugins/rtp/src/device.vala |  6 +++++-
 plugins/rtp/src/stream.vala | 11 +++++++++--
 2 files changed, 14 insertions(+), 3 deletions(-)

diff --git a/plugins/rtp/src/device.vala b/plugins/rtp/src/device.vala
index 89d499ed..de46bea4 100644
--- a/plugins/rtp/src/device.vala
+++ b/plugins/rtp/src/device.vala
@@ -96,7 +96,7 @@ public class Dino.Plugins.Rtp.Device : MediaDevice, Object {
         return element;
     }
 
-    public Gst.Element? link_source(PayloadType? payload_type = null, uint ssrc = Random.next_int(), int seqnum_offset = -1) {
+    public Gst.Element? link_source(PayloadType? payload_type = null, uint ssrc = Random.next_int(), int seqnum_offset = -1, uint32 timestamp_offset = 0) {
         if (!is_source) return null;
         if (element == null) create();
         links++;
@@ -122,8 +122,12 @@ public class Dino.Plugins.Rtp.Device : MediaDevice, Object {
                 var payload = (Gst.RTP.BasePayload) ((Gst.Bin) payloaders[payload_type][ssrc]).get_by_name(@"$(id)_$(codec)_$(ssrc)_rtp_pay");
                 payload.ssrc = ssrc;
                 payload.seqnum_offset = seqnum_offset;
+                if (timestamp_offset != 0) {
+                    payload.timestamp_offset = timestamp_offset;
+                }
                 pipe.add(payloaders[payload_type][ssrc]);
                 codec_tees[payload_type].link(payloaders[payload_type][ssrc]);
+                debug("Payload for %s with %s using ssrc %u, seqnum_offset %u, timestamp_offset %u", media, codec, ssrc, seqnum_offset, timestamp_offset);
             }
             if (!payloader_tees.has_key(payload_type)) {
                 payloader_tees[payload_type] = new HashMap<uint, Gst.Element>();
diff --git a/plugins/rtp/src/stream.vala b/plugins/rtp/src/stream.vala
index 85864022..2cc40783 100644
--- a/plugins/rtp/src/stream.vala
+++ b/plugins/rtp/src/stream.vala
@@ -29,7 +29,7 @@ public class Dino.Plugins.Rtp.Stream : Xmpp.Xep.JingleRtp.Stream {
     public Device input_device { get { return _input_device; } set {
         if (!paused) {
             var input = this.input;
-            set_input(value != null ? value.link_source(payload_type, our_ssrc, next_seqnum_offset) : null);
+            set_input(value != null ? value.link_source(payload_type, our_ssrc, next_seqnum_offset, next_timestamp_offset) : null);
             if (this._input_device != null) this._input_device.unlink(input);
         }
         this._input_device = value;
@@ -46,6 +46,13 @@ public class Dino.Plugins.Rtp.Stream : Xmpp.Xep.JingleRtp.Stream {
     private bool push_recv_data = false;
     private uint our_ssrc = Random.next_int();
     private int next_seqnum_offset = -1;
+    private uint32 next_timestamp_offset_base = 0;
+    private int64 next_timestamp_offset_stamp = 0;
+    private uint32 next_timestamp_offset { get {
+        if (next_timestamp_offset_base == 0) return 0;
+        int64 monotonic_diff = get_monotonic_time() - next_timestamp_offset_stamp;
+        return next_timestamp_offset_base + (uint32)((double)monotonic_diff / 1000000.0 * payload_type.clockrate);
+    } }
     private uint32 participant_ssrc = 0;
 
     private Gst.Pad recv_rtcp_sink_pad;
@@ -657,7 +664,7 @@ public class Dino.Plugins.Rtp.Stream : Xmpp.Xep.JingleRtp.Stream {
 
     public void unpause() {
         if (!paused) return;
-        set_input_and_pause(input_device != null ? input_device.link_source(payload_type, our_ssrc, next_seqnum_offset) : null, false);
+        set_input_and_pause(input_device != null ? input_device.link_source(payload_type, our_ssrc, next_seqnum_offset, next_timestamp_offset) : null, false);
     }
 
     public uint get_participant_ssrc(Xmpp.Jid participant) {