[vlc-commits] commit: RTP: fix timestamp wrap - fix #1645 ( Rémi Denis-Courmont )

[git at videolan.org]

vlc | branch: master | Rémi Denis-Courmont <remi at remlab.net> | Sun Mar 28 20:56:14 2010 +0300| [9d223efe5ddfb4064099214cd0c3b7c5757a0cd7] | committer: Rémi Denis-Courmont 

RTP: fix timestamp wrap - fix #1645

> http://git.videolan.org/gitweb.cgi/vlc.git/?a=commit;h=9d223efe5ddfb4064099214cd0c3b7c5757a0cd7
---

 modules/access/rtp/session.c |   16 +++++++++++++---
 1 files changed, 13 insertions(+), 3 deletions(-)

diff --git a/modules/access/rtp/session.c b/modules/access/rtp/session.c
index c86aa08..5bf624c 100644
--- a/modules/access/rtp/session.c
+++ b/modules/access/rtp/session.c
@@ -141,6 +141,9 @@ struct rtp_source_t
     mtime_t  last_rx; /* last received packet local timestamp */
     uint32_t last_ts; /* last received packet RTP timestamp */
 
+    uint32_t ref_rtp; /* sender RTP timestamp reference */
+    mtime_t  ref_ntp; /* sender NTP timestamp reference */
+
     uint16_t bad_seq; /* tentatively next expected sequence for resync */
     uint16_t max_seq; /* next expected sequence */
 
@@ -164,6 +167,9 @@ rtp_source_create (demux_t *demux, const rtp_session_t *session,
 
     source->ssrc = ssrc;
     source->jitter = 0;
+    source->ref_rtp = 0;
+    /* TODO: use 0, but VLC does not like negative PTS at the moment */
+    source->ref_ntp = UINT64_C (1) << 62;
     source->max_seq = source->bad_seq = init_seq;
     source->last_seq = init_seq - 1;
     source->blocks = NULL;
@@ -408,10 +414,14 @@ rtp_decode (demux_t *demux, const rtp_session_t *session, rtp_source_t *src)
      * DTS is unknown. Also, while the clock frequency depends on the payload
      * format, a single source MUST only use payloads of a chosen frequency.
      * Otherwise it would be impossible to compute consistent timestamps. */
-    /* FIXME: handle timestamp wrap properly */
-    /* TODO: inter-medias/sessions sync (using RTCP-SR) */
     const uint32_t timestamp = rtp_timestamp (block);
-    block->i_pts = CLOCK_FREQ * timestamp / pt->frequency;
+    block->i_pts = src->ref_ntp
+       + CLOCK_FREQ * (int32_t)(timestamp - src->ref_rtp) / pt->frequency;
+    msg_Info (demux, "PTS = %lld, NTP = %lld, RTPd = %d",
+              block->i_pts, src->ref_ntp, timestamp - src->ref_rtp);
+    /* TODO: proper inter-medias/sessions sync (using RTCP-SR) */
+    src->ref_ntp = block->i_pts;
+    src->ref_rtp = timestamp;
 
     /* CSRC count */
     size_t skip = 12u + (block->p_buffer[0] & 0x0F) * 4;