libavformat/rtpproto.c

   1 /*
   2  * RTP network protocol
   3  * Copyright (c) 2002 Fabrice Bellard.
   4  *
   5  * This library is free software; you can redistribute it and/or
   6  * modify it under the terms of the GNU Lesser General Public
   7  * License as published by the Free Software Foundation; either
   8  * version 2 of the License, or (at your option) any later version.
   9  *
  10  * This library is distributed in the hope that it will be useful,
  11  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  13  * Lesser General Public License for more details.
  14  *
  15  * You should have received a copy of the GNU Lesser General Public
  16  * License along with this library; if not, write to the Free Software
  17  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
  18  */
  19 #include "avformat.h"
  20
  21 #include <unistd.h>
  22 #include <stdarg.h>
  23 #include <sys/types.h>
  24 #include <sys/socket.h>
  25 #include <netinet/in.h>
  26 #ifndef __BEOS__
  27 # include <arpa/inet.h>
  28 #else
  29 # include "barpainet.h"
  30 #endif
  31 #include <netdb.h>
  32 #include <fcntl.h>
  33
  34 #define RTP_TX_BUF_SIZE  (64 * 1024)
  35 #define RTP_RX_BUF_SIZE  (128 * 1024)
  36
  37 typedef struct RTPContext {
  38     URLContext *rtp_hd, *rtcp_hd;
  39     int rtp_fd, rtcp_fd;
  40 } RTPContext;
  41
  42 /**
  43  * If no filename is given to av_open_input_file because you want to
  44  * get the local port first, then you must call this function to set
  45  * the remote server address.
  46  *
  47  * @param s1 media file context
  48  * @param uri of the remote server
  49  * @return zero if no error.
  50  */
  51 int rtp_set_remote_url(URLContext *h, const char *uri)
  52 {
  53     RTPContext *s = h->priv_data;
  54     char hostname[256];
  55     int port;
  56
  57     char buf[1024];
  58     char path[1024];
  59
  60     url_split(NULL, 0, hostname, sizeof(hostname), &port,
  61               path, sizeof(path), uri);
  62
  63     snprintf(buf, sizeof(buf), "udp://%s:%d%s", hostname, port, path);
  64     udp_set_remote_url(s->rtp_hd, buf);
  65
  66     snprintf(buf, sizeof(buf), "udp://%s:%d%s", hostname, port + 1, path);
  67     udp_set_remote_url(s->rtcp_hd, buf);
  68     return 0;
  69 }
  70
  71
  72 /* add option to url of the form:
  73    "http://host:port/path?option1=val1&option2=val2... */
  74 static void url_add_option(char *buf, int buf_size, const char *fmt, ...)
  75 {
  76     char buf1[1024];
  77     va_list ap;
  78
  79     va_start(ap, fmt);
  80     if (strchr(buf, '?'))
  81         pstrcat(buf, buf_size, "&");
  82     else
  83         pstrcat(buf, buf_size, "?");
  84     vsnprintf(buf1, sizeof(buf1), fmt, ap);
  85     pstrcat(buf, buf_size, buf1);
  86     va_end(ap);
  87 }
  88
  89 static void build_udp_url(char *buf, int buf_size,
  90                           const char *hostname, int port,
  91                           int local_port, int multicast, int ttl)
  92 {
  93     snprintf(buf, buf_size, "udp://%s:%d", hostname, port);
  94     if (local_port >= 0)
  95         url_add_option(buf, buf_size, "localport=%d", local_port);
  96     if (multicast)
  97         url_add_option(buf, buf_size, "multicast=1", multicast);
  98     if (ttl >= 0)
  99         url_add_option(buf, buf_size, "ttl=%d", ttl);
 100 }
 101
 102 /*
 103  * url syntax: rtp://host:port[?option=val...]
 104  * option: 'multicast=1' : enable multicast
 105  *         'ttl=n'       : set the ttl value (for multicast only)
 106  *         'localport=n' : set the local port to n
 107  *
 108  */
 109 static int rtp_open(URLContext *h, const char *uri, int flags)
 110 {
 111     RTPContext *s;
 112     int port, is_output, is_multicast, ttl, local_port;
 113     char hostname[256];
 114     char buf[1024];
 115     char path[1024];
 116     const char *p;
 117
 118     is_output = (flags & URL_WRONLY);
 119
 120     s = av_mallocz(sizeof(RTPContext));
 121     if (!s)
 122         return -ENOMEM;
 123     h->priv_data = s;
 124
 125     url_split(NULL, 0, hostname, sizeof(hostname), &port,
 126               path, sizeof(path), uri);
 127     /* extract parameters */
 128     is_multicast = 0;
 129     ttl = -1;
 130     local_port = -1;
 131     p = strchr(uri, '?');
 132     if (p) {
 133         is_multicast = find_info_tag(buf, sizeof(buf), "multicast", p);
 134         if (find_info_tag(buf, sizeof(buf), "ttl", p)) {
 135             ttl = strtol(buf, NULL, 10);
 136         }
 137         if (find_info_tag(buf, sizeof(buf), "localport", p)) {
 138             local_port = strtol(buf, NULL, 10);
 139         }
 140     }
 141
 142     build_udp_url(buf, sizeof(buf),
 143                   hostname, port, local_port, is_multicast, ttl);
 144     if (url_open(&s->rtp_hd, buf, flags) < 0)
 145         goto fail;
 146     local_port = udp_get_local_port(s->rtp_hd);
 147     /* XXX: need to open another connexion if the port is not even */
 148
 149     /* well, should suppress localport in path */
 150
 151     build_udp_url(buf, sizeof(buf),
 152                   hostname, port + 1, local_port + 1, is_multicast, ttl);
 153     if (url_open(&s->rtcp_hd, buf, flags) < 0)
 154         goto fail;
 155
 156     /* just to ease handle access. XXX: need to suppress direct handle
 157        access */
 158     s->rtp_fd = udp_get_file_handle(s->rtp_hd);
 159     s->rtcp_fd = udp_get_file_handle(s->rtcp_hd);
 160
 161     h->max_packet_size = url_get_max_packet_size(s->rtp_hd);
 162     h->is_streamed = 1;
 163     return 0;
 164
 165  fail:
 166     if (s->rtp_hd)
 167         url_close(s->rtp_hd);
 168     if (s->rtcp_hd)
 169         url_close(s->rtcp_hd);
 170     av_free(s);
 171     return -EIO;
 172 }
 173
 174 static int rtp_read(URLContext *h, UINT8 *buf, int size)
 175 {
 176     RTPContext *s = h->priv_data;
 177     struct sockaddr_in from;
 178     int from_len, len, fd_max, n;
 179     fd_set rfds;
 180 #if 0
 181     for(;;) {
 182         from_len = sizeof(from);
 183         len = recvfrom (s->rtp_fd, buf, size, 0,
 184                         (struct sockaddr *)&from, &from_len);
 185         if (len < 0) {
 186             if (errno == EAGAIN || errno == EINTR)
 187                 continue;
 188             return -EIO;
 189         }
 190         break;
 191     }
 192 #else
 193     for(;;) {
 194         /* build fdset to listen to RTP and RTCP packets */
 195         FD_ZERO(&rfds);
 196         fd_max = s->rtp_fd;
 197         FD_SET(s->rtp_fd, &rfds);
 198         if (s->rtcp_fd > fd_max)
 199             fd_max = s->rtcp_fd;
 200         FD_SET(s->rtcp_fd, &rfds);
 201         n = select(fd_max + 1, &rfds, NULL, NULL, NULL);
 202         if (n > 0) {
 203             /* first try RTCP */
 204             if (FD_ISSET(s->rtcp_fd, &rfds)) {
 205                 from_len = sizeof(from);
 206                 len = recvfrom (s->rtcp_fd, buf, size, 0,
 207                                 (struct sockaddr *)&from, &from_len);
 208                 if (len < 0) {
 209                     if (errno == EAGAIN || errno == EINTR)
 210                         continue;
 211                     return -EIO;
 212                 }
 213                 break;
 214             }
 215             /* then RTP */
 216             if (FD_ISSET(s->rtp_fd, &rfds)) {
 217                 from_len = sizeof(from);
 218                 len = recvfrom (s->rtp_fd, buf, size, 0,
 219                                 (struct sockaddr *)&from, &from_len);
 220                 if (len < 0) {
 221                     if (errno == EAGAIN || errno == EINTR)
 222                         continue;
 223                     return -EIO;
 224                 }
 225                 break;
 226             }
 227         }
 228     }
 229 #endif
 230     return len;
 231 }
 232
 233 static int rtp_write(URLContext *h, UINT8 *buf, int size)
 234 {
 235     RTPContext *s = h->priv_data;
 236     int ret;
 237     URLContext *hd;
 238
 239     if (buf[1] >= 200 && buf[1] <= 204) {
 240         /* RTCP payload type */
 241         hd = s->rtcp_hd;
 242     } else {
 243         /* RTP payload type */
 244         hd = s->rtp_hd;
 245     }
 246
 247     ret = url_write(hd, buf, size);
 248 #if 0
 249     {
 250         struct timespec ts;
 251         ts.tv_sec = 0;
 252         ts.tv_nsec = 10 * 1000000;
 253         nanosleep(&ts, NULL);
 254     }
 255 #endif
 256     return ret;
 257 }
 258
 259 static int rtp_close(URLContext *h)
 260 {
 261     RTPContext *s = h->priv_data;
 262
 263     url_close(s->rtp_hd);
 264     url_close(s->rtcp_hd);
 265     av_free(s);
 266     return 0;
 267 }
 268
 269 /**
 270  * Return the local port used by the RTP connexion
 271  * @param s1 media file context
 272  * @return the local port number
 273  */
 274 int rtp_get_local_port(URLContext *h)
 275 {
 276     RTPContext *s = h->priv_data;
 277     return udp_get_local_port(s->rtp_hd);
 278 }
 279
 280 /**
 281  * Return the rtp and rtcp file handles for select() usage to wait for several RTP
 282  * streams at the same time.
 283  * @param h media file context
 284  */
 285 void rtp_get_file_handles(URLContext *h, int *prtp_fd, int *prtcp_fd)
 286 {
 287     RTPContext *s = h->priv_data;
 288
 289     *prtp_fd = s->rtp_fd;
 290     *prtcp_fd = s->rtcp_fd;
 291 }
 292
 293 URLProtocol rtp_protocol = {
 294     "rtp",
 295     rtp_open,
 296     rtp_read,
 297     rtp_write,
 298     NULL, /* seek */
 299     rtp_close,
 300 };