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 * NOTE on RTCP implementation:
41 * - there is a single sender (us), no conferencing here! => n = sender = 1,
42 * - as such we need not bother to include Receiver Reports,
43 * - in unicast case, there is a single receiver => members = 1 + 1 = 2,
44 * and obviously n > 25% of members,
45 * - in multicast case, we do not want to maintain the number of receivers
46 * and we assume it is big (i.e. than 3) because that's what broadcasting is
48 * - it is assumed we_sent = true (could be wrong), since we are THE sender,
49 * - we always send SR + SDES, while running,
50 * - FIXME: we do not implement separate rate limiting for SDES,
51 * - we do not implement any profile-specific extensions for the time being.
55 size_t length; /* RTCP packet length */
56 uint8_t payload[28 + 8 + (2 * 257) + 8];
57 int handle; /* RTCP socket handler */
59 uint32_t packets; /* RTP packets sent */
60 uint32_t bytes; /* RTP bytes sent */
61 unsigned counter; /* RTP packets sent since last RTCP packet */
65 rtcp_sender_t *OpenRTCP (vlc_object_t *obj, int rtp_fd, int proto,
71 char src[NI_MAXNUMERICHOST];
74 if (net_GetSockAddress (rtp_fd, src, &sport))
79 /* RTP/RTCP mux: duplicate the socket */
83 WSAPROTOCOL_INFO info;
84 WSADuplicateSocket (rtp_fd, GetCurrentProcessId (), &info);
85 fd = WSASocket (info.iAddressFamily, info.iSocketType, info.iProtocol,
91 /* RTCP on a separate port */
92 char dst[NI_MAXNUMERICHOST];
95 if (net_GetPeerAddress (rtp_fd, dst, &dport))
101 fd = net_OpenDgram (obj, src, sport, dst, dport, AF_UNSPEC, proto);
107 rtcp = malloc (sizeof (*rtcp));
115 rtcp->bytes = rtcp->packets = rtcp->counter = 0;
117 ptr = (uint8_t *)strchr (src, '%');
119 *ptr = '\0'; /* remove scope ID frop IPv6 addresses */
124 ptr[0] = 2 << 6; /* V = 2, P = RC = 0 */
125 ptr[1] = 200; /* payload type: Sender Report */
126 SetWBE (ptr + 2, 6); /* length = 6 (7 double words) */
127 memset (ptr + 4, 0, 4); /* SSRC unknown yet */
128 SetQWBE (ptr + 8, NTPtime64 ());
129 memset (ptr + 16, 0, 12); /* timestamp and counters */
132 /* Source description */
134 ptr[0] = (2 << 6) | 1; /* V = 2, P = 0, SC = 1 */
135 ptr[1] = 202; /* payload type: Source Description */
136 uint8_t *lenptr = ptr + 2;
137 memset (ptr + 4, 0, 4); /* SSRC unknown yet */
140 ptr[0] = 1; /* CNAME - mandatory */
141 assert (NI_MAXNUMERICHOST <= 256);
142 ptr[1] = strlen (src);
143 memcpy (ptr + 2, src, ptr[1]);
146 static const char tool[] = PACKAGE_STRING;
147 ptr[0] = 6; /* TOOL */
148 ptr[1] = (sizeof (tool) > 256) ? 255 : (sizeof (tool) - 1);
149 memcpy (ptr + 2, tool, ptr[1]);
152 while ((ptr - sdes) & 3) /* 32-bits padding */
154 SetWBE (lenptr, (ptr - sdes - 1) >> 2);
156 rtcp->length = ptr - rtcp->payload;
161 void CloseRTCP (rtcp_sender_t *rtcp)
166 uint8_t *ptr = rtcp->payload;
167 uint64_t now64 = NTPtime64 ();
168 SetQWBE (ptr + 8, now64); /* Update the Sender Report timestamp */
172 ptr[0] = (2 << 6) | 1; /* V = 2, P = 0, SC = 1 */
173 ptr[1] = 203; /* payload type: Bye */
175 memcpy (ptr + 4, rtcp->payload + 4, 4); /* Copy SSRC from Sender Report */
178 /* We are THE sender, so we are more important than anybody else, so
179 * we can afford not to check bandwidth constraints here. */
180 send (rtcp->handle, rtcp->payload, rtcp->length, 0);
181 net_Close (rtcp->handle);
186 void SendRTCP (rtcp_sender_t *restrict rtcp, const block_t *rtp)
188 if ((rtcp == NULL) /* RTCP sender off */
189 || (rtp->i_buffer < 12)) /* too short RTP packet */
192 /* Updates statistics */
194 rtcp->bytes += rtp->i_buffer;
195 rtcp->counter += rtp->i_buffer;
197 /* 1.25% rate limit */
198 if ((rtcp->counter / 80) < rtcp->length)
201 uint8_t *ptr = rtcp->payload;
202 uint32_t last = GetDWBE (ptr + 8); // last RTCP SR send time
203 uint64_t now64 = NTPtime64 ();
204 if ((now64 >> 32) < (last + 5))
205 return; // no more than one SR every 5 seconds
207 memcpy (ptr + 4, rtp->p_buffer + 8, 4); /* SR SSRC */
208 SetQWBE (ptr + 8, now64);
209 memcpy (ptr + 16, rtp->p_buffer + 4, 4); /* RTP timestamp */
210 SetDWBE (ptr + 20, rtcp->packets);
211 SetDWBE (ptr + 24, rtcp->bytes);
212 memcpy (ptr + 28 + 4, rtp->p_buffer + 8, 4); /* SDES SSRC */
214 if (send (rtcp->handle, ptr, rtcp->length, 0) == (ssize_t)rtcp->length)