1 /*****************************************************************************
2 * rtcp.c: RTCP stream output support
3 *****************************************************************************
4 * Copyright © 2007 Rémi Denis-Courmont
6 * This library is free software; you can redistribute it and/or
7 * modify it under the terms of the GNU Lesser General Public
8 * License as published by the Free Software Foundation; either
9 * version 2.1 of the License, or (at your option) any later version.
11 * This library is distributed in the hope that it will be useful,
12 * but WITHOUT ANY WARRANTY; without even the implied warranty of
13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
14 * Lesser General Public License for more details.
16 * You should have received a copy of the GNU Lesser General Public
17 * License along with this library; if not, write to the Free Software
18 * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
19 *****************************************************************************/
21 /*****************************************************************************
23 *****************************************************************************/
29 #include <vlc_common.h>
30 #include <vlc_block.h>
32 #include <vlc_network.h>
40 # define SOL_IP IPPROTO_IP
44 * NOTE on RTCP implementation:
45 * - there is a single sender (us), no conferencing here! => n = sender = 1,
46 * - as such we need not bother to include Receiver Reports,
47 * - in unicast case, there is a single receiver => members = 1 + 1 = 2,
48 * and obviously n > 25% of members,
49 * - in multicast case, we do not want to maintain the number of receivers
50 * and we assume it is big (i.e. than 3) because that's what broadcasting is
52 * - it is assumed we_sent = true (could be wrong), since we are THE sender,
53 * - we always send SR + SDES, while running,
54 * - FIXME: we do not implement separate rate limiting for SDES,
55 * - we do not implement any profile-specific extensions for the time being.
59 size_t length
; /* RTCP packet length */
60 uint8_t payload
[28 + 8 + (2 * 257) + 8];
61 int handle
; /* RTCP socket handler */
63 uint32_t packets
; /* RTP packets sent */
64 uint32_t bytes
; /* RTP bytes sent */
65 unsigned counter
; /* RTP packets sent since last RTCP packet */
69 rtcp_sender_t
*OpenRTCP (vlc_object_t
*obj
, int rtp_fd
, int proto
,
75 char src
[NI_MAXNUMERICHOST
];
78 if (net_GetSockAddress (rtp_fd
, src
, &sport
))
83 /* RTP/RTCP mux: duplicate the socket */
85 fd
= vlc_dup (rtp_fd
);
87 WSAPROTOCOL_INFO info
;
88 WSADuplicateSocket (rtp_fd
, GetCurrentProcessId (), &info
);
89 fd
= WSASocket (info
.iAddressFamily
, info
.iSocketType
, info
.iProtocol
,
95 /* RTCP on a separate port */
96 char dst
[NI_MAXNUMERICHOST
];
99 if (net_GetPeerAddress (rtp_fd
, dst
, &dport
))
105 fd
= net_OpenDgram (obj
, src
, sport
, dst
, dport
, proto
);
108 /* Copy the multicast IPv4 TTL value (useless for IPv6) */
110 socklen_t len
= sizeof (ttl
);
112 if (!getsockopt (rtp_fd
, SOL_IP
, IP_MULTICAST_TTL
, &ttl
, &len
))
113 setsockopt (fd
, SOL_IP
, IP_MULTICAST_TTL
, &ttl
, len
);
115 /* Ignore all incoming RTCP-RR packets */
116 setsockopt (fd
, SOL_SOCKET
, SO_RCVBUF
, &(int){ 0 }, sizeof (int));
123 rtcp
= malloc (sizeof (*rtcp
));
131 rtcp
->bytes
= rtcp
->packets
= rtcp
->counter
= 0;
133 ptr
= (uint8_t *)strchr (src
, '%');
135 *ptr
= '\0'; /* remove scope ID frop IPv6 addresses */
140 ptr
[0] = 2 << 6; /* V = 2, P = RC = 0 */
141 ptr
[1] = 200; /* payload type: Sender Report */
142 SetWBE (ptr
+ 2, 6); /* length = 6 (7 double words) */
143 memset (ptr
+ 4, 0, 4); /* SSRC unknown yet */
144 SetQWBE (ptr
+ 8, NTPtime64 ());
145 memset (ptr
+ 16, 0, 12); /* timestamp and counters */
148 /* Source description */
150 ptr
[0] = (2 << 6) | 1; /* V = 2, P = 0, SC = 1 */
151 ptr
[1] = 202; /* payload type: Source Description */
152 uint8_t *lenptr
= ptr
+ 2;
153 memset (ptr
+ 4, 0, 4); /* SSRC unknown yet */
156 ptr
[0] = 1; /* CNAME - mandatory */
157 assert (NI_MAXNUMERICHOST
<= 256);
158 ptr
[1] = strlen (src
);
159 memcpy (ptr
+ 2, src
, ptr
[1]);
162 static const char tool
[] = PACKAGE_STRING
;
163 ptr
[0] = 6; /* TOOL */
164 ptr
[1] = (sizeof (tool
) > 256) ? 255 : (sizeof (tool
) - 1);
165 memcpy (ptr
+ 2, tool
, ptr
[1]);
168 while ((ptr
- sdes
) & 3) /* 32-bits padding */
170 SetWBE (lenptr
, (ptr
- sdes
- 1) >> 2);
172 rtcp
->length
= ptr
- rtcp
->payload
;
177 void CloseRTCP (rtcp_sender_t
*rtcp
)
182 uint8_t *ptr
= rtcp
->payload
;
183 uint64_t now64
= NTPtime64 ();
184 SetQWBE (ptr
+ 8, now64
); /* Update the Sender Report timestamp */
188 ptr
[0] = (2 << 6) | 1; /* V = 2, P = 0, SC = 1 */
189 ptr
[1] = 203; /* payload type: Bye */
191 memcpy (ptr
+ 4, rtcp
->payload
+ 4, 4); /* Copy SSRC from Sender Report */
194 /* We are THE sender, so we are more important than anybody else, so
195 * we can afford not to check bandwidth constraints here. */
196 send (rtcp
->handle
, rtcp
->payload
, rtcp
->length
, 0);
197 net_Close (rtcp
->handle
);
202 void SendRTCP (rtcp_sender_t
*restrict rtcp
, const block_t
*rtp
)
204 if ((rtcp
== NULL
) /* RTCP sender off */
205 || (rtp
->i_buffer
< 12)) /* too short RTP packet */
208 /* Updates statistics */
210 rtcp
->bytes
+= rtp
->i_buffer
;
211 rtcp
->counter
+= rtp
->i_buffer
;
213 /* 1.25% rate limit */
214 if ((rtcp
->counter
/ 80) < rtcp
->length
)
217 uint8_t *ptr
= rtcp
->payload
;
218 uint32_t last
= GetDWBE (ptr
+ 8); // last RTCP SR send time
219 uint64_t now64
= NTPtime64 ();
220 if ((now64
>> 32) < (last
+ 5))
221 return; // no more than one SR every 5 seconds
223 memcpy (ptr
+ 4, rtp
->p_buffer
+ 8, 4); /* SR SSRC */
224 SetQWBE (ptr
+ 8, now64
);
225 memcpy (ptr
+ 16, rtp
->p_buffer
+ 4, 4); /* RTP timestamp */
226 SetDWBE (ptr
+ 20, rtcp
->packets
);
227 SetDWBE (ptr
+ 24, rtcp
->bytes
);
228 memcpy (ptr
+ 28 + 4, rtp
->p_buffer
+ 8, 4); /* SDES SSRC */
230 if (send (rtcp
->handle
, ptr
, rtcp
->length
, 0) == (ssize_t
)rtcp
->length
)