rtptwcc: changes to use rtp buffer arrival time and current time.

For TWCC we are more interested to track the arrival time (receive side)
and the current time (sender side) of the buffers rather than the
running time.

Part-of: <https://gitlab.freedesktop.org/gstreamer/gst-plugins-good/-/merge_requests/927>

3 files changed, 14 insertions, 5 deletions

diff --git a/gst/rtpmanager/rtpsession.c b/gst/rtpmanager/rtpsession.c
index 9bd537c93..84fbfee22 100644
--- a/gst/rtpmanager/rtpsession.c
+++ b/gst/rtpmanager/rtpsession.c
@@ -2172,9 +2172,11 @@ update_packet_info (RTPSession * sess, RTPPacketInfo * pinfo,
     res =
         gst_buffer_list_foreach (list, (GstBufferListFunc) update_packet,
         pinfo);
+    pinfo->arrival_time = GST_CLOCK_TIME_NONE;
   } else {
     GstBuffer *buffer = GST_BUFFER_CAST (data);
     res = update_packet (&buffer, 0, pinfo);
+    pinfo->arrival_time = GST_BUFFER_DTS (buffer);
   }
 
   return res;
diff --git a/gst/rtpmanager/rtpstats.h b/gst/rtpmanager/rtpstats.h
index 1804aa6cf..4b08e1629 100644
--- a/gst/rtpmanager/rtpstats.h
+++ b/gst/rtpmanager/rtpstats.h
@@ -70,6 +70,7 @@ typedef struct {
  * @address: address of the sender of the packet
  * @current_time: current time according to the system clock
  * @running_time: time of a packet as buffer running_time
+ * @arrival_time: time of arrival of a packet
  * @ntpnstime: time of a packet NTP time in nanoseconds
  * @header_len: number of overhead bytes per packet
  * @bytes: bytes of the packet including lowlevel overhead
@@ -92,6 +93,7 @@ typedef struct {
   GSocketAddress *address;
   GstClockTime  current_time;
   GstClockTime  running_time;
+  GstClockTime  arrival_time;
   guint64       ntpnstime;
   guint         header_len;
   guint         bytes;
diff --git a/gst/rtpmanager/rtptwcc.c b/gst/rtpmanager/rtptwcc.c
index bcb4fc02c..691428c21 100644
--- a/gst/rtpmanager/rtptwcc.c
+++ b/gst/rtpmanager/rtptwcc.c
@@ -159,7 +159,11 @@ recv_packet_init (RecvPacket * packet, guint16 seqnum, RTPPacketInfo * pinfo)
 {
   memset (packet, 0, sizeof (RecvPacket));
   packet->seqnum = seqnum;
-  packet->ts = pinfo->running_time;
+
+  if (GST_CLOCK_TIME_IS_VALID (pinfo->arrival_time))
+    packet->ts = pinfo->arrival_time;
+  else
+    packet->ts = pinfo->current_time;
 }
 
 static guint8
@@ -784,7 +788,7 @@ rtp_twcc_manager_recv_packet (RTPTWCCManager * twcc, RTPPacketInfo * pinfo)
 
   GST_LOG ("Receive: twcc-seqnum: %u, pt: %u, marker: %d, ts: %"
       GST_TIME_FORMAT, seqnum, pinfo->pt, pinfo->marker,
-      GST_TIME_ARGS (pinfo->running_time));
+      GST_TIME_ARGS (pinfo->arrival_time));
 
   if (!pinfo->marker)
     twcc->packet_count_no_marker++;
@@ -841,7 +845,7 @@ static void
 sent_packet_init (SentPacket * packet, guint16 seqnum, RTPPacketInfo * pinfo)
 {
   packet->seqnum = seqnum;
-  packet->ts = pinfo->running_time;
+  packet->ts = pinfo->current_time;
   packet->size = pinfo->payload_len;
   packet->pt = pinfo->pt;
   packet->remote_ts = GST_CLOCK_TIME_NONE;
@@ -864,8 +868,9 @@ rtp_twcc_manager_send_packet (RTPTWCCManager * twcc, RTPPacketInfo * pinfo)
   g_array_append_val (twcc->sent_packets, packet);
 
 
-  GST_LOG ("Send: twcc-seqnum: %u, pt: %u, marker: %d, ts: %" GST_TIME_FORMAT,
-      seqnum, pinfo->pt, pinfo->marker, GST_TIME_ARGS (pinfo->running_time));
+  GST_LOG ("Send: twcc-seqnum: %u, pt: %u, marker: %d, ts: %"
+      GST_TIME_FORMAT, seqnum, pinfo->pt, pinfo->marker,
+      GST_TIME_ARGS (pinfo->current_time));
 }
 
 static void