[FFmpeg-devel] [PATCH] avformat/demux: use producer timestamp as wallclock when available

Clément Péron peron.clem at gmail.com
Wed Oct 25 14:42:45 EEST 2023


When use_wallclock_as_timestamps option is enabled the demux rely on
the time of the system even when a producer wallclock is available.

If a Producer Reference Timestamp is available use it instead of the
system timestamp.

Signed-off-by: Clément Péron <peron.clem at gmail.com>
---
 libavformat/demux.c | 13 +++++++++++--
 1 file changed, 11 insertions(+), 2 deletions(-)

diff --git a/libavformat/demux.c b/libavformat/demux.c
index 6decb08698..94a622e0cc 100644
--- a/libavformat/demux.c
+++ b/libavformat/demux.c
@@ -635,8 +635,17 @@ FF_ENABLE_DEPRECATION_WARNINGS
         force_codec_ids(s, st);
 
         /* TODO: audio: time filter; video: frame reordering (pts != dts) */
-        if (s->use_wallclock_as_timestamps)
-            pkt->dts = pkt->pts = av_rescale_q(av_gettime(), AV_TIME_BASE_Q, st->time_base);
+        if (s->use_wallclock_as_timestamps) {
+            AVProducerReferenceTime *prft;
+            size_t side_data_size;
+
+            // User Producer Reference time as wallclock when available
+            prft = (AVProducerReferenceTime *)av_packet_get_side_data(pkt, AV_PKT_DATA_PRFT, &side_data_size);
+            if (prft && side_data_size == sizeof(AVProducerReferenceTime) && prft->flags == 24)
+                pkt->dts = pkt->pts = av_rescale_q(prft->wallclock, AV_TIME_BASE_Q, st->time_base);
+            else
+                pkt->dts = pkt->pts = av_rescale_q(av_gettime(), AV_TIME_BASE_Q, st->time_base);
+        }
 
         if (!pktl && sti->request_probe <= 0)
             return 0;
-- 
2.42.0



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