1 /*****************************************************************************
2 * rtcp.c: RTCP stream output support
3 *****************************************************************************
4 * Copyright © 2007 Rémi Denis-Courmont
7 * This library is free software; you can redistribute it and/or
8 * modify it under the terms of the GNU Lesser General Public
9 * License as published by the Free Software Foundation; either
10 * version 2.1 of the License, or (at your option) any later version.
12 * This library is distributed in the hope that it will be useful,
13 * but WITHOUT ANY WARRANTY; without even the implied warranty of
14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
15 * Lesser General Public License for more details.
17 * You should have received a copy of the GNU Lesser General Public
18 * License along with this library; if not, write to the Free Software
19 * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
20 *****************************************************************************/
22 /*****************************************************************************
24 *****************************************************************************/
30 #include <vlc_common.h>
31 #include <vlc_block.h>
33 #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 */
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, AF_UNSPEC, proto);
107 /* Copy the multicast IPv4 TTL value (useless for IPv6) */
111 socklen_t len = sizeof (ttl);
113 if (!getsockopt (rtp_fd, SOL_IP, IP_MULTICAST_TTL, &ttl, &len))
114 setsockopt (fd, SOL_IP, IP_MULTICAST_TTL, &ttl, len);
121 rtcp = malloc (sizeof (*rtcp));
129 rtcp->bytes = rtcp->packets = rtcp->counter = 0;
131 ptr = (uint8_t *)strchr (src, '%');
133 *ptr = '\0'; /* remove scope ID frop IPv6 addresses */
138 ptr[0] = 2 << 6; /* V = 2, P = RC = 0 */
139 ptr[1] = 200; /* payload type: Sender Report */
140 SetWBE (ptr + 2, 6); /* length = 6 (7 double words) */
141 memset (ptr + 4, 0, 4); /* SSRC unknown yet */
142 SetQWBE (ptr + 8, NTPtime64 ());
143 memset (ptr + 16, 0, 12); /* timestamp and counters */
146 /* Source description */
148 ptr[0] = (2 << 6) | 1; /* V = 2, P = 0, SC = 1 */
149 ptr[1] = 202; /* payload type: Source Description */
150 uint8_t *lenptr = ptr + 2;
151 memset (ptr + 4, 0, 4); /* SSRC unknown yet */
154 ptr[0] = 1; /* CNAME - mandatory */
155 assert (NI_MAXNUMERICHOST <= 256);
156 ptr[1] = strlen (src);
157 memcpy (ptr + 2, src, ptr[1]);
160 static const char tool[] = PACKAGE_STRING;
161 ptr[0] = 6; /* TOOL */
162 ptr[1] = (sizeof (tool) > 256) ? 255 : (sizeof (tool) - 1);
163 memcpy (ptr + 2, tool, ptr[1]);
166 while ((ptr - sdes) & 3) /* 32-bits padding */
168 SetWBE (lenptr, (ptr - sdes - 1) >> 2);
170 rtcp->length = ptr - rtcp->payload;
175 void CloseRTCP (rtcp_sender_t *rtcp)
180 uint8_t *ptr = rtcp->payload;
181 uint64_t now64 = NTPtime64 ();
182 SetQWBE (ptr + 8, now64); /* Update the Sender Report timestamp */
186 ptr[0] = (2 << 6) | 1; /* V = 2, P = 0, SC = 1 */
187 ptr[1] = 203; /* payload type: Bye */
189 memcpy (ptr + 4, rtcp->payload + 4, 4); /* Copy SSRC from Sender Report */
192 /* We are THE sender, so we are more important than anybody else, so
193 * we can afford not to check bandwidth constraints here. */
194 send (rtcp->handle, rtcp->payload, rtcp->length, 0);
195 net_Close (rtcp->handle);
200 void SendRTCP (rtcp_sender_t *restrict rtcp, const block_t *rtp)
202 if ((rtcp == NULL) /* RTCP sender off */
203 || (rtp->i_buffer < 12)) /* too short RTP packet */
206 /* Updates statistics */
208 rtcp->bytes += rtp->i_buffer;
209 rtcp->counter += rtp->i_buffer;
211 /* 1.25% rate limit */
212 if ((rtcp->counter / 80) < rtcp->length)
215 uint8_t *ptr = rtcp->payload;
216 uint32_t last = GetDWBE (ptr + 8); // last RTCP SR send time
217 uint64_t now64 = NTPtime64 ();
218 if ((now64 >> 32) < (last + 5))
219 return; // no more than one SR every 5 seconds
221 memcpy (ptr + 4, rtp->p_buffer + 8, 4); /* SR SSRC */
222 SetQWBE (ptr + 8, now64);
223 memcpy (ptr + 16, rtp->p_buffer + 4, 4); /* RTP timestamp */
224 SetDWBE (ptr + 20, rtcp->packets);
225 SetDWBE (ptr + 24, rtcp->bytes);
226 memcpy (ptr + 28 + 4, rtp->p_buffer + 8, 4); /* SDES SSRC */
228 if (send (rtcp->handle, ptr, rtcp->length, 0) == (ssize_t)rtcp->length)