rtpsession: Update 64-bit NTP header extensions with the actual NTP time in senders

Part-of: <https://gitlab.freedesktop.org/gstreamer/gstreamer/-/merge_requests/2132>
This commit is contained in:
Sebastian Dröge 2022-04-06 15:39:14 +03:00 committed by GStreamer Marge Bot
parent 8980c35efe
commit 7ffc830959
4 changed files with 278 additions and 4 deletions

View file

@ -2402,6 +2402,8 @@ gst_rtp_session_chain_send_rtp_common (GstRtpSession * rtpsession,
GstFlowReturn ret;
GstClockTime timestamp, running_time;
GstClockTime current_time;
guint64 ntpnstime;
GstClock *clock;
priv = rtpsession->priv;
@ -2435,8 +2437,83 @@ gst_rtp_session_chain_send_rtp_common (GstRtpSession * rtpsession,
}
current_time = gst_clock_get_time (priv->sysclock);
/* Calculate the NTP time of this packet based on the session configuration
* and the running time from above */
GST_OBJECT_LOCK (rtpsession);
if (running_time != -1 && (clock = GST_ELEMENT_CLOCK (rtpsession))) {
GstClockTime base_time;
base_time = GST_ELEMENT_CAST (rtpsession)->base_time;
gst_object_ref (clock);
GST_OBJECT_UNLOCK (rtpsession);
if (rtpsession->priv->use_pipeline_clock) {
ntpnstime = running_time;
/* add constant to convert from 1970 based time to 1900 based time */
ntpnstime += (2208988800LL * GST_SECOND);
} else {
switch (rtpsession->priv->ntp_time_source) {
case GST_RTP_NTP_TIME_SOURCE_NTP:
case GST_RTP_NTP_TIME_SOURCE_UNIX:{
GstClockTime wallclock_now, pipeline_now;
/* pipeline clock time for this packet */
ntpnstime = running_time + base_time;
/* get current wallclock and pipeline clock time */
wallclock_now = g_get_real_time () * GST_USECOND;
pipeline_now = gst_clock_get_time (clock);
/* adjust pipeline clock time by the current diff.
* Note that this will include some jitter for each packet */
if (wallclock_now > pipeline_now) {
GstClockTime diff = wallclock_now - pipeline_now;
ntpnstime += diff;
} else {
GstClockTime diff = pipeline_now - wallclock_now;
if (diff > ntpnstime) {
/* This can't really happen unless the clock configuration is
* broken */
ntpnstime = GST_CLOCK_TIME_NONE;
} else {
ntpnstime -= diff;
}
}
/* add constant to convert from 1970 based time to 1900 based time */
if (ntpnstime != GST_CLOCK_TIME_NONE
&& rtpsession->priv->ntp_time_source ==
GST_RTP_NTP_TIME_SOURCE_NTP)
ntpnstime += (2208988800LL * GST_SECOND);
break;
}
case GST_RTP_NTP_TIME_SOURCE_RUNNING_TIME:
ntpnstime = running_time;
break;
case GST_RTP_NTP_TIME_SOURCE_CLOCK_TIME:
ntpnstime = running_time + base_time;
break;
default:
ntpnstime = -1;
g_assert_not_reached ();
break;
}
}
gst_object_unref (clock);
} else {
if (!GST_ELEMENT_CLOCK (rtpsession)) {
GST_WARNING_OBJECT (rtpsession,
"Don't have a clock yet and can't determine NTP time for this packet");
}
GST_OBJECT_UNLOCK (rtpsession);
ntpnstime = GST_CLOCK_TIME_NONE;
}
ret = rtp_session_send_rtp (priv->session, data, is_list, current_time,
running_time);
running_time, ntpnstime);
if (ret != GST_FLOW_OK)
goto push_error;

View file

@ -2118,6 +2118,25 @@ update_packet (GstBuffer ** buffer, guint idx, RTPPacketInfo * pinfo)
pinfo->header_ext = gst_rtp_buffer_get_extension_bytes (&rtp,
&pinfo->header_ext_bit_pattern);
}
if (pinfo->ntp64_ext_id != 0 && pinfo->send && !pinfo->have_ntp64_ext) {
guint8 *data;
guint size;
/* Remember here that there is a 64-bit NTP header extension on this buffer
* or any of the other buffers in the buffer list.
* Later we update this after making the buffer(list) writable.
*/
if ((gst_rtp_buffer_get_extension_onebyte_header (&rtp,
pinfo->ntp64_ext_id, 0, (gpointer *) & data, &size)
&& size == 8)
|| (gst_rtp_buffer_get_extension_twobytes_header (&rtp, NULL,
pinfo->ntp64_ext_id, 0, (gpointer *) & data, &size)
&& size == 8)) {
pinfo->have_ntp64_ext = TRUE;
}
}
gst_rtp_buffer_unmap (&rtp);
}
@ -2166,6 +2185,8 @@ update_packet_info (RTPSession * sess, RTPPacketInfo * pinfo,
pinfo->payload_len = 0;
pinfo->packets = 0;
pinfo->marker = FALSE;
pinfo->ntp64_ext_id = send ? sess->send_ntp64_ext_id : 0;
pinfo->have_ntp64_ext = FALSE;
if (is_list) {
GstBufferList *list = GST_BUFFER_LIST_CAST (data);
@ -3125,6 +3146,29 @@ invalid_packet:
}
}
static guint8
_get_extmap_id_for_attribute (const GstStructure * s, const gchar * ext_name)
{
guint i;
guint8 extmap_id = 0;
guint n_fields = gst_structure_n_fields (s);
for (i = 0; i < n_fields; i++) {
const gchar *field_name = gst_structure_nth_field_name (s, i);
if (g_str_has_prefix (field_name, "extmap-")) {
const gchar *str = gst_structure_get_string (s, field_name);
if (str && g_strcmp0 (str, ext_name) == 0) {
gint64 id = g_ascii_strtoll (field_name + 7, NULL, 10);
if (id > 0 && id < 15) {
extmap_id = id;
break;
}
}
}
}
return extmap_id;
}
/**
* rtp_session_update_send_caps:
* @sess: an #RTPSession
@ -3180,9 +3224,151 @@ rtp_session_update_send_caps (RTPSession * sess, GstCaps * caps)
sess->internal_ssrc_from_caps_or_property = FALSE;
}
sess->send_ntp64_ext_id =
_get_extmap_id_for_attribute (s,
GST_RTP_HDREXT_BASE GST_RTP_HDREXT_NTP_64);
rtp_twcc_manager_parse_send_ext_id (sess->twcc, s);
}
static void
update_ntp64_header_ext_data (RTPPacketInfo * pinfo, GstBuffer * buffer)
{
GstRTPBuffer rtp = GST_RTP_BUFFER_INIT;
if (gst_rtp_buffer_map (buffer, GST_MAP_READWRITE, &rtp)) {
guint16 bits;
guint8 *data;
guint wordlen;
if (gst_rtp_buffer_get_extension_data (&rtp, &bits, (gpointer *) & data,
&wordlen)) {
gsize len = wordlen * 4;
/* One-byte header */
if (bits == 0xBEDE) {
/* One-byte header extension */
while (TRUE) {
guint8 ext_id, ext_len;
if (len < 1)
break;
ext_id = GST_READ_UINT8 (data) >> 4;
ext_len = (GST_READ_UINT8 (data) & 0xF) + 1;
data += 1;
len -= 1;
if (ext_id == 0) {
/* Skip padding */
continue;
} else if (ext_id == 15) {
/* Stop parsing */
break;
}
/* extension doesn't fit into the header */
if (ext_len > len)
break;
if (ext_id == pinfo->ntp64_ext_id && ext_len == 8) {
if (pinfo->ntpnstime != GST_CLOCK_TIME_NONE) {
guint64 ntptime = gst_util_uint64_scale (pinfo->ntpnstime,
G_GUINT64_CONSTANT (1) << 32,
GST_SECOND);
GST_WRITE_UINT64_BE (data, ntptime);
} else {
/* Replace extension with padding */
memset (data - 1, 0, 1 + ext_len);
}
}
/* skip to the next extension */
data += ext_len;
len -= ext_len;
}
} else if ((bits >> 4) == 0x100) {
/* Two-byte header extension */
while (TRUE) {
guint8 ext_id, ext_len;
if (len < 1)
break;
ext_id = GST_READ_UINT8 (data);
data += 1;
len -= 1;
if (ext_id == 0) {
/* Skip padding */
continue;
}
ext_len = GST_READ_UINT8 (data);
data += 1;
len -= 1;
/* extension doesn't fit into the header */
if (ext_len > len)
break;
if (ext_id == pinfo->ntp64_ext_id && ext_len == 8) {
if (pinfo->ntpnstime != GST_CLOCK_TIME_NONE) {
guint64 ntptime = gst_util_uint64_scale (pinfo->ntpnstime,
G_GUINT64_CONSTANT (1) << 32,
GST_SECOND);
GST_WRITE_UINT64_BE (data, ntptime);
} else {
/* Replace extension with padding */
memset (data - 2, 0, 2 + ext_len);
}
}
/* skip to the next extension */
data += ext_len;
len -= ext_len;
}
}
}
gst_rtp_buffer_unmap (&rtp);
}
}
static void
update_ntp64_header_ext (RTPPacketInfo * pinfo)
{
/* Early return if we don't know the header extension id or the packets
* don't contain the header extension */
if (pinfo->ntp64_ext_id == 0 || !pinfo->have_ntp64_ext)
return;
/* If no NTP time is known then the header extension will be replaced with
* padding, otherwise it will be updated */
GST_TRACE
("Updating NTP-64 header extension for SSRC %08x packet with RTP time %u and running time %"
GST_TIME_FORMAT " to %" GST_TIME_FORMAT, pinfo->ssrc, pinfo->rtptime,
GST_TIME_ARGS (pinfo->running_time), GST_TIME_ARGS (pinfo->ntpnstime));
if (GST_IS_BUFFER_LIST (pinfo->data)) {
GstBufferList *list;
guint i = 0;
pinfo->data = gst_buffer_list_make_writable (pinfo->data);
list = GST_BUFFER_LIST (pinfo->data);
for (i = 0; i < gst_buffer_list_length (list); i++) {
GstBuffer *buffer = gst_buffer_list_get_writable (list, i);
update_ntp64_header_ext_data (pinfo, buffer);
}
} else {
pinfo->data = gst_buffer_make_writable (pinfo->data);
update_ntp64_header_ext_data (pinfo, pinfo->data);
}
}
/**
* rtp_session_send_rtp:
* @sess: an #RTPSession
@ -3198,7 +3384,7 @@ rtp_session_update_send_caps (RTPSession * sess, GstCaps * caps)
*/
GstFlowReturn
rtp_session_send_rtp (RTPSession * sess, gpointer data, gboolean is_list,
GstClockTime current_time, GstClockTime running_time)
GstClockTime current_time, GstClockTime running_time, guint64 ntpnstime)
{
GstFlowReturn result;
RTPSource *source;
@ -3214,9 +3400,11 @@ rtp_session_send_rtp (RTPSession * sess, gpointer data, gboolean is_list,
RTP_SESSION_LOCK (sess);
if (!update_packet_info (sess, &pinfo, TRUE, TRUE, is_list, data,
current_time, running_time, -1))
current_time, running_time, ntpnstime))
goto invalid_packet;
/* Update any 64-bit NTP header extensions with the actual NTP time here */
update_ntp64_header_ext (&pinfo);
rtp_twcc_manager_send_packet (sess->twcc, &pinfo);
source = obtain_internal_source (sess, pinfo.ssrc, &created, current_time);

View file

@ -309,6 +309,9 @@ struct _RTPSession {
gboolean timestamp_sender_reports;
/* RFC6051 64-bit NTP header extension */
guint8 send_ntp64_ext_id;
/* Transport-wide cc-extension */
RTPTWCCManager *twcc;
RTPTWCCStats *twcc_stats;
@ -410,7 +413,8 @@ GstFlowReturn rtp_session_process_rtcp (RTPSession *sess, GstBuffer
/* processing packets for sending */
void rtp_session_update_send_caps (RTPSession *sess, GstCaps *caps);
GstFlowReturn rtp_session_send_rtp (RTPSession *sess, gpointer data, gboolean is_list,
GstClockTime current_time, GstClockTime running_time);
GstClockTime current_time, GstClockTime running_time,
guint64 ntpnstime);
/* scheduling bye */
void rtp_session_mark_all_bye (RTPSession *sess, const gchar *reason);

View file

@ -83,6 +83,9 @@ typedef struct {
* @csrcs: CSRCs
* @header_ext: Header extension data
* @header_ext_bit_pattern: Header extension bit pattern
* @ntp64_ext_id: Extension header ID for RFC6051 64-bit NTP timestamp.
* @have_ntp64_ext: If there is at least one 64-bit NTP timestamp header
* extension.
*
* Structure holding information about the packet.
*/
@ -109,6 +112,8 @@ typedef struct {
guint32 csrcs[16];
GBytes *header_ext;
guint16 header_ext_bit_pattern;
guint8 ntp64_ext_id;
gboolean have_ntp64_ext;
} RTPPacketInfo;
/**