1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
|
/* 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)
{
stats->bandwidth = RTP_STATS_BANDWIDTH;
stats->sender_fraction = RTP_STATS_SENDER_FRACTION;
stats->receiver_fraction = RTP_STATS_RECEIVER_FRACTION;
stats->rtcp_bandwidth = RTP_STATS_RTCP_BANDWIDTH;
stats->min_interval = RTP_STATS_MIN_INTERVAL;
stats->bye_timeout = RTP_STATS_BYE_TIMEOUT;
}
/**
* 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 * RTP_STATS_SENDER_FRACTION) {
if (we_send) {
rtcp_bw *= RTP_STATS_SENDER_FRACTION;
n = senders;
} else {
rtcp_bw *= RTP_STATS_RECEIVER_FRACTION;
n -= senders;
}
}
avg_rtcp_size = stats->avg_rtcp_packet_size / 16.0;
/*
* 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 * 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;
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 * RTP_STATS_RECEIVER_FRACTION;
avg_rtcp_size = stats->avg_rtcp_packet_size / 16.0;
/*
* 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;
}
|
