avformat/rtpdec: attach producer reference time if available

This produces true wallclock time at rtp source instead of the
local wallclock time at rtp client.

Signed-off-by: James Almer <jamrial@gmail.com>

1 files changed, 19 insertions, 0 deletions

diff --git a/libavformat/rtpdec.c b/libavformat/rtpdec.c
index fd4601e654..1edb64b9bf 100644
--- a/libavformat/rtpdec.c
+++ b/libavformat/rtpdec.c
@@ -622,6 +622,19 @@ void ff_rtp_parse_set_crypto(RTPDemuxContext *s, const char *suite,
         s->srtp_enabled = 1;
 }
 
+static int rtp_set_prft(RTPDemuxContext *s, AVPacket *pkt, uint32_t timestamp) {
+    AVProducerReferenceTime *prft =
+        (AVProducerReferenceTime *) av_packet_new_side_data(
+            pkt, AV_PKT_DATA_PRFT, sizeof(AVProducerReferenceTime));
+    if (!prft)
+        return AVERROR(ENOMEM);
+
+    prft->wallclock = ff_parse_ntp_time(s->last_rtcp_ntp_time) - NTP_OFFSET_US +
+                      timestamp - s->last_rtcp_timestamp;
+    prft->flags = 24;
+    return 0;
+}
+
 /**
  * This was the second switch in rtp_parse packet.
  * Normalizes time, if required, sets stream_index, etc.
@@ -633,6 +646,12 @@ static void finalize_packet(RTPDemuxContext *s, AVPacket *pkt, uint32_t timestam
     if (timestamp == RTP_NOTS_VALUE)
         return;
 
+    if (s->last_rtcp_ntp_time != AV_NOPTS_VALUE) {
+        if (rtp_set_prft(s, pkt, timestamp) < 0) {
+            av_log(s->ic, AV_LOG_WARNING, "rtpdec: failed to set prft");
+        }
+    }
+
     if (s->last_rtcp_ntp_time != AV_NOPTS_VALUE && s->ic->nb_streams > 1) {
         int64_t addend;
         int delta_timestamp;