libav/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 #include <arpa/inet.h>
  27 #include <netdb.h>
  28 #include <fcntl.h>
  29
  30 #define RTP_TX_BUF_SIZE  (64 * 1024)
  31 #define RTP_RX_BUF_SIZE  (128 * 1024)
  32
  33 typedef struct RTPContext {
  34     URLContext *rtp_hd, *rtcp_hd;
  35     int rtp_fd, rtcp_fd;
  36 } RTPContext;
  37
  38 /**
  39  * If no filename is given to av_open_input_file because you want to
  40  * get the local port first, then you must call this function to set
  41  * the remote server address.
  42  *
  43  * @param s1 media file context
  44  * @param uri of the remote server
  45  * @return zero if no error.
  46  */
  47 int rtp_set_remote_url(URLContext *h, const char *uri)
  48 {
  49     RTPContext *s = h->priv_data;
  50     char hostname[256];
  51     int port;
  52
  53     char buf[1024];
  54     char path[1024];
  55
  56     url_split(NULL, 0, hostname, sizeof(hostname), &port,
  57               path, sizeof(path), uri);
  58
  59     snprintf(buf, sizeof(buf), "udp://%s:%d%s", hostname, port, path);
  60     udp_set_remote_url(s->rtp_hd, buf);
  61
  62     snprintf(buf, sizeof(buf), "udp://%s:%d%s", hostname, port + 1, path);
  63     udp_set_remote_url(s->rtcp_hd, buf);
  64     return 0;
  65 }
  66
  67
  68 /* add option to url of the form:
  69    "http://host:port/path?option1=val1&option2=val2... */
  70 void url_add_option(char *buf, int buf_size, const char *fmt, ...)
  71 {
  72     char buf1[1024];
  73     va_list ap;
  74
  75     va_start(ap, fmt);
  76     if (strchr(buf, '?'))
  77         pstrcat(buf, buf_size, "&");
  78     else
  79         pstrcat(buf, buf_size, "?");
  80     vsnprintf(buf1, sizeof(buf1), fmt, ap);
  81     pstrcat(buf, buf_size, buf1);
  82     va_end(ap);
  83 }
  84
  85 void build_udp_url(char *buf, int buf_size,
  86                    const char *hostname, int port,
  87                    int local_port, int multicast, int ttl)
  88 {
  89     snprintf(buf, buf_size, "udp://%s:%d", hostname, port);
  90     if (local_port >= 0)
  91         url_add_option(buf, buf_size, "localport=%d", local_port);
  92     if (multicast)
  93         url_add_option(buf, buf_size, "multicast=1", multicast);
  94     if (ttl >= 0)
  95         url_add_option(buf, buf_size, "ttl=%d", ttl);
  96 }
  97
  98 /*
  99  * url syntax: rtp://host:port[?option=val...]
 100  * option: 'multicast=1' : enable multicast
 101  *         'ttl=n'       : set the ttl value (for multicast only)
 102  *         'localport=n' : set the local port to n
 103  *
 104  */
 105 static int rtp_open(URLContext *h, const char *uri, int flags)
 106 {
 107     RTPContext *s;
 108     int port, is_output, is_multicast, ttl, local_port;
 109     char hostname[256];
 110     char buf[1024];
 111     char path[1024];
 112     const char *p;
 113
 114     is_output = (flags & URL_WRONLY);
 115
 116     s = av_mallocz(sizeof(RTPContext));
 117     if (!s)
 118         return -ENOMEM;
 119     h->priv_data = s;
 120
 121     url_split(NULL, 0, hostname, sizeof(hostname), &port,
 122               path, sizeof(path), uri);
 123     /* extract parameters */
 124     is_multicast = 0;
 125     ttl = -1;
 126     local_port = -1;
 127     p = strchr(uri, '?');
 128     if (p) {
 129         is_multicast = find_info_tag(buf, sizeof(buf), "multicast", p);
 130         if (find_info_tag(buf, sizeof(buf), "ttl", p)) {
 131             ttl = strtol(buf, NULL, 10);
 132         }
 133         if (find_info_tag(buf, sizeof(buf), "localport", p)) {
 134             local_port = strtol(buf, NULL, 10);
 135         }
 136     }
 137
 138     build_udp_url(buf, sizeof(buf),
 139                   hostname, port, local_port, is_multicast, ttl);
 140     if (url_open(&s->rtp_hd, buf, flags) < 0)
 141         goto fail;
 142     local_port = udp_get_local_port(s->rtp_hd);
 143     /* XXX: need to open another connexion if the port is not even */
 144
 145     /* well, should suppress localport in path */
 146
 147     build_udp_url(buf, sizeof(buf),
 148                   hostname, port + 1, local_port + 1, is_multicast, ttl);
 149     if (url_open(&s->rtcp_hd, buf, flags) < 0)
 150         goto fail;
 151
 152     /* just to ease handle access. XXX: need to suppress direct handle
 153        access */
 154     s->rtp_fd = udp_get_file_handle(s->rtp_hd);
 155     s->rtcp_fd = udp_get_file_handle(s->rtcp_hd);
 156
 157     h->max_packet_size = url_get_max_packet_size(s->rtp_hd);
 158     h->is_streamed = 1;
 159     return 0;
 160
 161  fail:
 162     if (s->rtp_hd)
 163         url_close(s->rtp_hd);
 164     if (s->rtcp_hd)
 165         url_close(s->rtcp_hd);
 166     av_free(s);
 167     return -EIO;
 168 }
 169
 170 static int rtp_read(URLContext *h, UINT8 *buf, int size)
 171 {
 172     RTPContext *s = h->priv_data;
 173     struct sockaddr_in from;
 174     int from_len, len, fd_max, n;
 175     fd_set rfds;
 176 #if 0
 177     for(;;) {
 178         from_len = sizeof(from);
 179         len = recvfrom (s->rtp_fd, buf, size, 0,
 180                         (struct sockaddr *)&from, &from_len);
 181         if (len < 0) {
 182             if (errno == EAGAIN || errno == EINTR)
 183                 continue;
 184             return -EIO;
 185         }
 186         break;
 187     }
 188 #else
 189     for(;;) {
 190         /* build fdset to listen to RTP and RTCP packets */
 191         FD_ZERO(&rfds);
 192         fd_max = s->rtp_fd;
 193         FD_SET(s->rtp_fd, &rfds);
 194         if (s->rtcp_fd > fd_max)
 195             fd_max = s->rtcp_fd;
 196         FD_SET(s->rtcp_fd, &rfds);
 197         n = select(fd_max + 1, &rfds, NULL, NULL, NULL);
 198         if (n > 0) {
 199             /* first try RTCP */
 200             if (FD_ISSET(s->rtcp_fd, &rfds)) {
 201                 from_len = sizeof(from);
 202                 len = recvfrom (s->rtcp_fd, buf, size, 0,
 203                                 (struct sockaddr *)&from, &from_len);
 204                 if (len < 0) {
 205                     if (errno == EAGAIN || errno == EINTR)
 206                         continue;
 207                     return -EIO;
 208                 }
 209                 break;
 210             }
 211             /* then RTP */
 212             if (FD_ISSET(s->rtp_fd, &rfds)) {
 213                 from_len = sizeof(from);
 214                 len = recvfrom (s->rtp_fd, buf, size, 0,
 215                                 (struct sockaddr *)&from, &from_len);
 216                 if (len < 0) {
 217                     if (errno == EAGAIN || errno == EINTR)
 218                         continue;
 219                     return -EIO;
 220                 }
 221                 break;
 222             }
 223         }
 224     }
 225 #endif
 226     return len;
 227 }
 228
 229 static int rtp_write(URLContext *h, UINT8 *buf, int size)
 230 {
 231     RTPContext *s = h->priv_data;
 232     int ret;
 233     URLContext *hd;
 234
 235     if (buf[1] >= 200 && buf[1] <= 204) {
 236         /* RTCP payload type */
 237         hd = s->rtcp_hd;
 238     } else {
 239         /* RTP payload type */
 240         hd = s->rtp_hd;
 241     }
 242
 243     ret = url_write(hd, buf, size);
 244 #if 0
 245     {
 246         struct timespec ts;
 247         ts.tv_sec = 0;
 248         ts.tv_nsec = 10 * 1000000;
 249         nanosleep(&ts, NULL);
 250     }
 251 #endif
 252     return ret;
 253 }
 254
 255 static int rtp_close(URLContext *h)
 256 {
 257     RTPContext *s = h->priv_data;
 258
 259     url_close(s->rtp_hd);
 260     url_close(s->rtcp_hd);
 261     av_free(s);
 262     return 0;
 263 }
 264
 265 /**
 266  * Return the local port used by the RTP connexion
 267  * @param s1 media file context
 268  * @return the local port number
 269  */
 270 int rtp_get_local_port(URLContext *h)
 271 {
 272     RTPContext *s = h->priv_data;
 273     return udp_get_local_port(s->rtp_hd);
 274 }
 275
 276 /**
 277  * Return the rtp and rtcp file handles for select() usage to wait for several RTP
 278  * streams at the same time.
 279  * @param h media file context
 280  */
 281 void rtp_get_file_handles(URLContext *h, int *prtp_fd, int *prtcp_fd)
 282 {
 283     RTPContext *s = h->priv_data;
 284
 285     *prtp_fd = s->rtp_fd;
 286     *prtcp_fd = s->rtcp_fd;
 287 }
 288
 289 URLProtocol rtp_protocol = {
 290     "rtp",
 291     rtp_open,
 292     rtp_read,
 293     rtp_write,
 294     NULL, /* seek */
 295     rtp_close,
 296 };