mirrors/gstreamer
mirrors/gstreamer
1
1
Fork 0
mirror of https://gitlab.freedesktop.org/gstreamer/gstreamer.git synced 2024-11-25 03:01:03 +00:00
Code Issues 1 Projects Releases Wiki Activity

mpegtsdemux: Handle PTS/DTS wraparound with ignore-pcr=true

Browse source 
The wraparound handling code assumes that the PCR gets updated regularly for
being able to detect wraparounds. With ignore-pcr=true that was not the case and
it stayed initialized at 1h forever.

To avoid this problem, update the fake PCR whenever the PTS advanced by more
than 5s, and also detect wraparounds in these fake PCRs.

Problem can be reproduced with

  $ gst-launch-1.0 videotestsrc pattern=black ! video/x-raw,framerate=1/5 ! \
    x264enc speed-preset=ultrafast tune=zerolatency ! mpegtsmux ! \
    tsdemux ignore-pcr=true ! fakesink

which restarts timestamps at 0 after around 26h30m.

Part-of: <https://gitlab.freedesktop.org/gstreamer/gstreamer/-/merge_requests/7588>
This commit is contained in:
Sebastian Dröge 2024-09-30 15:51:04 +03:00 committed by GStreamer Marge Bot
parent 0f7be28eb1
commit 493f8e440a
1 changed files with 18 additions and 4 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

22
subprojects/gst-plugins-bad/gst/mpegtsdemux/mpegtspacketizer.c
View file

@ -2261,10 +2261,24 @@ mpegts_packetizer_pts_to_ts_internal (MpegTSPacketizer2 * packetizer,
PACKETIZER_GROUP_LOCK (packetizer);
pcrtable = get_pcr_table (packetizer, pcr_pid);
if (!GST_CLOCK_TIME_IS_VALID (pcrtable->base_time) && pcr_pid == 0x1fff &&
GST_CLOCK_TIME_IS_VALID (packetizer->last_in_time)) {
pcrtable->base_time = packetizer->last_in_time;
pcrtable->base_pcrtime = pts;
if (pcr_pid == 0x1fff && GST_CLOCK_TIME_IS_VALID (packetizer->last_in_time)) {
if (!GST_CLOCK_TIME_IS_VALID (pcrtable->base_time)) {
pcrtable->base_time = packetizer->last_in_time;
pcrtable->base_pcrtime = pts;
} else if (check_diff) {
/* Handle discont and wraparound */
guint64 tmp_pts = pts + pcrtable->pcroffset + packetizer->extra_shift;
if (pcrtable->base_pcrtime < tmp_pts
&& tmp_pts - pcrtable->base_pcrtime >= 5 * GST_SECOND) {
guint64 diff = tmp_pts - pcrtable->base_pcrtime - 2 * GST_SECOND;
pcrtable->base_time += diff;
pcrtable->base_pcrtime += diff;
} else if (pcrtable->base_pcrtime > tmp_pts
&& pcrtable->base_pcrtime > PCR_GST_MAX_VALUE / 2) {
pcrtable->pcroffset += PCR_GST_MAX_VALUE;
}
}
}
/* Use clock skew if present */