mirrors/gstreamer
mirrors/gstreamer
1
1
Fork 0
mirror of https://gitlab.freedesktop.org/gstreamer/gstreamer.git synced 2024-11-26 19:51:11 +00:00
Code Issues 1 Projects Releases Wiki Activity

rtpjitterbuffer: Fix calculation of RFC7273 RTP time period start

Browse source 
This has to be based directly on the current estimated clock time and
has to allow for negative period starts.

Part-of: <https://gitlab.freedesktop.org/gstreamer/gstreamer/-/merge_requests/2655>
This commit is contained in:
Sebastian Dröge 2022-06-24 13:32:34 +03:00 committed by GStreamer Marge Bot
parent 5386a426f3
commit eb0746ba97
1 changed files with 50 additions and 21 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

71
subprojects/gst-plugins-good/gst/rtpmanager/rtpjitterbuffer.c
View file

@ -877,6 +877,7 @@ rtp_jitter_buffer_calculate_pts (RTPJitterBuffer * jbuf, GstClockTime dts,
GstClockTime internal, external; GstClockTime internal, external;
GstClockTime rate_num, rate_denom; GstClockTime rate_num, rate_denom;
GstClockTime ntprtptime_period_start; GstClockTime ntprtptime_period_start;
gboolean negative_ntprtptime_period_start;
/* Don't do any of the dts related adjustments further down */ /* Don't do any of the dts related adjustments further down */
dts = -1; dts = -1;
@ -890,23 +891,31 @@ rtp_jitter_buffer_calculate_pts (RTPJitterBuffer * jbuf, GstClockTime dts,
/* Current NTP clock estimation */ /* Current NTP clock estimation */
ntptime = gst_clock_get_internal_time (media_clock); ntptime = gst_clock_get_internal_time (media_clock);
/* Current RTP time based on the estimated NTP clock */ /* Current RTP time based on the estimated NTP clock and the corresponding
ntprtptime = gst_util_uint64_scale (ntptime, jbuf->clock_rate, GST_SECOND); * RTP time period start */
ntprtptime = ntprtptime_period_start =
gst_util_uint64_scale (ntptime, jbuf->clock_rate, GST_SECOND);
ntprtptime += media_clock_offset; ntprtptime += media_clock_offset;
ntprtptime &= 0xffffffff;
/* If we're in the first period then the start of the period might be
* before the clock epoch */
if (ntprtptime_period_start >= ntprtptime) {
ntprtptime_period_start = ntprtptime_period_start - ntprtptime;
negative_ntprtptime_period_start = FALSE;
} else {
ntprtptime_period_start = ntprtptime - ntprtptime_period_start;
negative_ntprtptime_period_start = TRUE;
}
GST_TRACE ("Current NTP time %" GST_TIME_FORMAT " (RTP: %" G_GUINT64_FORMAT GST_TRACE ("Current NTP time %" GST_TIME_FORMAT " (RTP: %" G_GUINT64_FORMAT
")", GST_TIME_ARGS (ntptime), ntprtptime); ")", GST_TIME_ARGS (ntptime), ntprtptime);
GST_TRACE ("Current NTP RTP time period start %c%" GST_TIME_FORMAT
/* Start RTP time of the current RTP time period we are in */ " (RTP: %c%" G_GUINT64_FORMAT ")",
ntprtptime_period_start = ntprtptime & 0xffffffff00000000; negative_ntprtptime_period_start ? '-' : '+',
/* Current RTP timestamp in this RTP time period */
ntprtptime &= 0xffffffff;
GST_TRACE ("Current NTP RTP time period start %" GST_TIME_FORMAT " (RTP: %"
G_GUINT64_FORMAT ")",
GST_TIME_ARGS (gst_util_uint64_scale (ntprtptime_period_start, GST_TIME_ARGS (gst_util_uint64_scale (ntprtptime_period_start,
GST_SECOND, jbuf->clock_rate)), ntprtptime_period_start); GST_SECOND, jbuf->clock_rate)),
negative_ntprtptime_period_start ? '-' : '+', ntprtptime_period_start);
GST_TRACE ("Current NTP RTP time related to period start %" GST_TIME_FORMAT GST_TRACE ("Current NTP RTP time related to period start %" GST_TIME_FORMAT
" (RTP: %" G_GUINT64_FORMAT ")", " (RTP: %" G_GUINT64_FORMAT ")",
GST_TIME_ARGS (gst_util_uint64_scale (ntprtptime, GST_SECOND, GST_TIME_ARGS (gst_util_uint64_scale (ntprtptime, GST_SECOND,
@ -928,24 +937,44 @@ rtp_jitter_buffer_calculate_pts (RTPJitterBuffer * jbuf, GstClockTime dts,
* *
*/ */
if (ntprtptime > rtptime && ntprtptime - rtptime >= 0x80000000) { if (ntprtptime > rtptime && ntprtptime - rtptime >= 0x80000000) {
ntprtptime_period_start += 0x100000000; if (negative_ntprtptime_period_start) {
negative_ntprtptime_period_start = FALSE;
g_assert (ntprtptime_period_start <= 0x100000000);
ntprtptime_period_start = 0x100000000 - ntprtptime_period_start;
} else {
ntprtptime_period_start += 0x100000000;
}
} else if (rtptime > ntprtptime && rtptime - ntprtptime >= 0x80000000) { } else if (rtptime > ntprtptime && rtptime - ntprtptime >= 0x80000000) {
/* If there was not a full RTP time period yet then assume we're if (negative_ntprtptime_period_start) {
* actually that far away. This can only really happen if the epoch of ntprtptime_period_start += 0x100000000;
* the clock is very close to now. */ } else if (ntprtptime_period_start < 0x100000000) {
if (ntprtptime_period_start >= 0x100000000) negative_ntprtptime_period_start = TRUE;
ntprtptime_period_start = 0x100000000 - ntprtptime_period_start;
} else {
ntprtptime_period_start -= 0x100000000; ntprtptime_period_start -= 0x100000000;
}
} }
GST_TRACE ("Wraparound adjusted NTP RTP time period start %" GST_TIME_FORMAT GST_TRACE ("Wraparound adjusted NTP RTP time period start %c%"
" (RTP: %" G_GUINT64_FORMAT ")", GST_TIME_FORMAT " (RTP: %c%" G_GUINT64_FORMAT ")",
negative_ntprtptime_period_start ? '-' : '+',
GST_TIME_ARGS (gst_util_uint64_scale (ntprtptime_period_start, GST_TIME_ARGS (gst_util_uint64_scale (ntprtptime_period_start,
GST_SECOND, jbuf->clock_rate)), ntprtptime_period_start); GST_SECOND, jbuf->clock_rate)),
negative_ntprtptime_period_start ? '-' : '+', ntprtptime_period_start);
/* Packet timestamp according to the NTP clock in RTP time units. /* Packet timestamp according to the NTP clock in RTP time units.
* Note that this does not include any inaccuracy caused by the estimation * Note that this does not include any inaccuracy caused by the estimation
* of the NTP clock unless it is more than 2**31 RTP time units off. */ * of the NTP clock unless it is more than 2**31 RTP time units off. */
ntprtptime = ntprtptime_period_start + rtptime; if (negative_ntprtptime_period_start) {
if (rtptime >= ntprtptime_period_start) {
ntprtptime = rtptime - ntprtptime_period_start;
} else {
/* Packet is timestamped before the NTP clock epoch! */
ntprtptime = 0;
}
} else {
ntprtptime = ntprtptime_period_start + rtptime;
}
/* Packet timestamp in nanoseconds according to the NTP clock. */ /* Packet timestamp in nanoseconds according to the NTP clock. */
ntptime = gst_util_uint64_scale (ntprtptime, GST_SECOND, jbuf->clock_rate); ntptime = gst_util_uint64_scale (ntprtptime, GST_SECOND, jbuf->clock_rate);