Fix: ST40/ST41 first packet timestamp

Packet timestamps were only calculated when
the RTP time differed from the previous frame,
which failed for the initial packet. This caused
the first TX packet to be transmitted with
timestamp 0, resulting in DDoS-like behavior
on the RX side.

Author: DawidWesierski4

lib/src/st2110/st_header.h

@@ -1190,7 +1190,7 @@ struct st_rx_ancillary_session_impl {
 
   struct mt_rtcp_rx* rtcp_rx[MTL_SESSION_PORT_MAX];
 
-  uint32_t tmstamp;
+  int64_t tmstamp;
   /* status */
   rte_atomic32_t stat_frames_received;
   int stat_pkts_dropped;
@@ -1363,7 +1363,8 @@ struct st_rx_fastmetadata_session_impl {
 
   struct mt_rtcp_rx* rtcp_rx[MTL_SESSION_PORT_MAX];
 
-  uint32_t tmstamp;
+  /* the timestamp */
+  int64_t tmstamp;
   /* status */
   rte_atomic32_t stat_frames_received;
   int stat_pkts_redundant;

lib/src/st2110/st_rx_ancillary_session.c

@@ -152,7 +152,7 @@ static int rx_ancillary_session_handle_pkt(struct mtl_main_impl* impl,
       dbg("%s(%d,%d), redundant seq now %u session last %d\n", __func__, s->idx, s_port,
           seq_id, s->session_seq_id);
     } else {
-      dbg("%s(%d,%d), redundant tmstamp now %u session last %u\n", __func__, s->idx,
+      dbg("%s(%d,%d), redundant tmstamp now %u session last %ld\n", __func__, s->idx,
           s_port, tmstamp, s->tmstamp);
     }
 

lib/src/st2110/st_rx_fastmetadata_session.c

@@ -135,7 +135,7 @@ static int rx_fastmetadata_session_handle_pkt(struct mtl_main_impl* impl,
       dbg("%s(%d,%d), redundant seq now %u session last %d\n", __func__, s->idx, s_port,
           seq_id, s->session_seq_id);
     } else {
-      dbg("%s(%d,%d), redundant tmstamp now %u session last %u\n", __func__, s->idx,
+      dbg("%s(%d,%d), redundant tmstamp now %u session last %ld\n", __func__, s->idx,
           s_port, tmstamp, s->tmstamp);
     }
 

lib/src/st2110/st_tx_ancillary_session.c

@@ -189,6 +189,7 @@ static int tx_ancillary_session_init_hdr(struct mtl_main_impl* impl,
   rtp->base.ssrc = htonl(ssrc);
   s->st40_seq_id = 0;
   s->st40_ext_seq_id = 0;
+  s->st40_rtp_time = -1;
 
   info("%s(%d,%d), ip %u.%u.%u.%u port %u:%u\n", __func__, idx, s_port, dip[0], dip[1],
        dip[2], dip[3], s->st40_src_port[s_port], s->st40_dst_port[s_port]);

lib/src/st2110/st_tx_fastmetadata_session.c

@@ -188,6 +188,7 @@ static int tx_fastmetadata_session_init_hdr(struct mtl_main_impl* impl,
   uint32_t ssrc = ops->ssrc ? ops->ssrc : s->idx + 0x323450;
   rtp->base.ssrc = htonl(ssrc);
   s->st41_seq_id = 0;
+  s->st41_rtp_time = -1;
 
   info("%s(%d,%d), ip %u.%u.%u.%u port %u:%u\n", __func__, idx, s_port, dip[0], dip[1],
        dip[2], dip[3], s->st41_src_port[s_port], s->st41_dst_port[s_port]);