gstreamer/gst/rtpmanager/rtpstats.c
2010-12-14 17:15:23 +01:00

288 lines
8.6 KiB
C

/* GStreamer
* Copyright (C) <2007> Wim Taymans <wim.taymans@gmail.com>
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Library General Public
* License as published by the Free Software Foundation; either
* version 2 of the License, or (at your option) any later version.
*
* This library is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Library General Public License for more details.
*
* You should have received a copy of the GNU Library General Public
* License along with this library; if not, write to the
* Free Software Foundation, Inc., 59 Temple Place - Suite 330,
* Boston, MA 02111-1307, USA.
*/
#include "rtpstats.h"
/**
* rtp_stats_init_defaults:
* @stats: an #RTPSessionStats struct
*
* Initialize @stats with its default values.
*/
void
rtp_stats_init_defaults (RTPSessionStats * stats)
{
rtp_stats_set_bandwidths (stats, -1, -1, -1, -1);
stats->min_interval = RTP_STATS_MIN_INTERVAL;
stats->bye_timeout = RTP_STATS_BYE_TIMEOUT;
}
/**
* rtp_stats_set_bandwidths:
* @stats: an #RTPSessionStats struct
* @rtp_bw: RTP bandwidth
* @rtcp_bw: RTCP bandwidth
* @rs: sender RTCP bandwidth
* @rr: receiver RTCP bandwidth
*
* Configure the bandwidth parameters in the stats. When an input variable is
* set to -1, it will be calculated from the other input variables and from the
* defaults.
*/
void
rtp_stats_set_bandwidths (RTPSessionStats * stats, guint rtp_bw,
gdouble rtcp_bw, guint rs, guint rr)
{
GST_DEBUG ("recalc bandwidths: RTP %u, RTCP %f, RS %u, RR %u", rtp_bw,
rtcp_bw, rs, rr);
/* when given, sender and receive bandwidth add up to the total
* rtcp bandwidth */
if (rs != -1 && rr != -1)
rtcp_bw = rs + rr;
/* If rtcp_bw is between 0 and 1, it is a fraction of rtp_bw */
if (rtcp_bw > 0.0 && rtcp_bw < 1.0) {
if (rtp_bw > 0.0)
rtcp_bw = rtp_bw * rtcp_bw;
else
rtcp_bw = -1.0;
}
/* RTCP is 5% of the RTP bandwidth */
if (rtp_bw == -1 && rtcp_bw > 1.0)
rtp_bw = rtcp_bw * 20;
else if (rtp_bw != -1 && rtcp_bw < 0.0)
rtcp_bw = rtp_bw / 20;
else if (rtp_bw == -1 && rtcp_bw < 0.0) {
/* nothing given, take defaults */
rtp_bw = RTP_STATS_BANDWIDTH;
rtcp_bw = rtp_bw * RTP_STATS_RTCP_FRACTION;
}
stats->bandwidth = rtp_bw;
stats->rtcp_bandwidth = rtcp_bw;
/* now figure out the fractions */
if (rs == -1) {
/* rs unknown */
if (rr == -1) {
/* both not given, use defaults */
rs = stats->rtcp_bandwidth * RTP_STATS_SENDER_FRACTION;
rr = stats->rtcp_bandwidth * RTP_STATS_RECEIVER_FRACTION;
} else {
/* rr known, calculate rs */
if (stats->rtcp_bandwidth > rr)
rs = stats->rtcp_bandwidth - rr;
else
rs = 0;
}
} else if (rr == -1) {
/* rs known, calculate rr */
if (stats->rtcp_bandwidth > rs)
rr = stats->rtcp_bandwidth - rs;
else
rr = 0;
}
if (stats->rtcp_bandwidth > 0) {
stats->sender_fraction = ((gdouble) rs) / ((gdouble) stats->rtcp_bandwidth);
stats->receiver_fraction = 1.0 - stats->sender_fraction;
} else {
/* no RTCP bandwidth, set dummy values */
stats->sender_fraction = 0.0;
stats->receiver_fraction = 0.0;
}
GST_DEBUG ("bandwidths: RTP %u, RTCP %u, RS %f, RR %f", stats->bandwidth,
stats->rtcp_bandwidth, stats->sender_fraction, stats->receiver_fraction);
}
/**
* rtp_stats_calculate_rtcp_interval:
* @stats: an #RTPSessionStats struct
* @sender: if we are a sender
* @first: if this is the first time
*
* Calculate the RTCP interval. The result of this function is the amount of
* time to wait (in nanoseconds) before sending a new RTCP message.
*
* Returns: the RTCP interval.
*/
GstClockTime
rtp_stats_calculate_rtcp_interval (RTPSessionStats * stats, gboolean we_send,
gboolean first)
{
gdouble members, senders, n;
gdouble avg_rtcp_size, rtcp_bw;
gdouble interval;
gdouble rtcp_min_time;
/* Very first call at application start-up uses half the min
* delay for quicker notification while still allowing some time
* before reporting for randomization and to learn about other
* sources so the report interval will converge to the correct
* interval more quickly.
*/
rtcp_min_time = stats->min_interval;
if (first)
rtcp_min_time /= 2.0;
/* Dedicate a fraction of the RTCP bandwidth to senders unless
* the number of senders is large enough that their share is
* more than that fraction.
*/
n = members = stats->active_sources;
senders = (gdouble) stats->sender_sources;
rtcp_bw = stats->rtcp_bandwidth;
if (senders <= members * stats->sender_fraction) {
if (we_send) {
rtcp_bw *= stats->sender_fraction;
n = senders;
} else {
rtcp_bw *= stats->receiver_fraction;
n -= senders;
}
}
/* no bandwidth for RTCP, return NONE to signal that we don't want to send
* RTCP packets */
if (rtcp_bw <= 0.00001)
return GST_CLOCK_TIME_NONE;
avg_rtcp_size = stats->avg_rtcp_packet_size;
/*
* The effective number of sites times the average packet size is
* the total number of octets sent when each site sends a report.
* Dividing this by the effective bandwidth gives the time
* interval over which those packets must be sent in order to
* meet the bandwidth target, with a minimum enforced. In that
* time interval we send one report so this time is also our
* average time between reports.
*/
GST_DEBUG ("avg size %f, n %f, rtcp_bw %f", avg_rtcp_size, n, rtcp_bw);
interval = avg_rtcp_size * n / rtcp_bw;
if (interval < rtcp_min_time)
interval = rtcp_min_time;
return interval * GST_SECOND;
}
/**
* rtp_stats_add_rtcp_jitter:
* @stats: an #RTPSessionStats struct
* @interval: an RTCP interval
*
* Apply a random jitter to the @interval. @interval is typically obtained with
* rtp_stats_calculate_rtcp_interval().
*
* Returns: the new RTCP interval.
*/
GstClockTime
rtp_stats_add_rtcp_jitter (RTPSessionStats * stats, GstClockTime interval)
{
gdouble temp;
/* see RFC 3550 p 30
* To compensate for "unconditional reconsideration" converging to a
* value below the intended average.
*/
#define COMPENSATION (2.71828 - 1.5);
temp = (interval * g_random_double_range (0.5, 1.5)) / COMPENSATION;
return (GstClockTime) temp;
}
/**
* rtp_stats_calculate_bye_interval:
* @stats: an #RTPSessionStats struct
*
* Calculate the BYE interval. The result of this function is the amount of
* time to wait (in nanoseconds) before sending a BYE message.
*
* Returns: the BYE interval.
*/
GstClockTime
rtp_stats_calculate_bye_interval (RTPSessionStats * stats)
{
gdouble members;
gdouble avg_rtcp_size, rtcp_bw;
gdouble interval;
gdouble rtcp_min_time;
/* no interval when we have less than 50 members */
if (stats->active_sources < 50)
return 0;
rtcp_min_time = (stats->min_interval) / 2.0;
/* Dedicate a fraction of the RTCP bandwidth to senders unless
* the number of senders is large enough that their share is
* more than that fraction.
*/
members = stats->bye_members;
rtcp_bw = stats->rtcp_bandwidth * stats->receiver_fraction;
/* no bandwidth for RTCP, return NONE to signal that we don't want to send
* RTCP packets */
if (rtcp_bw <= 0.0001)
return GST_CLOCK_TIME_NONE;
avg_rtcp_size = stats->avg_rtcp_packet_size;
/*
* The effective number of sites times the average packet size is
* the total number of octets sent when each site sends a report.
* Dividing this by the effective bandwidth gives the time
* interval over which those packets must be sent in order to
* meet the bandwidth target, with a minimum enforced. In that
* time interval we send one report so this time is also our
* average time between reports.
*/
interval = avg_rtcp_size * members / rtcp_bw;
if (interval < rtcp_min_time)
interval = rtcp_min_time;
return interval * GST_SECOND;
}
/**
* rtp_stats_get_packets_lost:
* @stats: an #RTPSourceStats struct
*
* Calculate the total number of RTP packets lost since beginning of
* reception. Packets that arrive late are not considered lost, and
* duplicates are not taken into account. Hence, the loss may be negative
* if there are duplicates.
*
* Returns: total RTP packets lost.
*/
gint64
rtp_stats_get_packets_lost (const RTPSourceStats * stats)
{
gint64 lost;
guint64 extended_max, expected;
extended_max = stats->cycles + stats->max_seq;
expected = extended_max - stats->base_seq + 1;
lost = expected - stats->packets_received;
return lost;
}