libavformat/rtpproto.c

   1 /*
   2  * RTP network protocol
   3  * Copyright (c) 2002 Fabrice Bellard.
   4  *
   5  * This file is part of FFmpeg.
   6  *
   7  * FFmpeg 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.
  11  *
  12  * FFmpeg 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.
  16  *
  17  * You should have received a copy of the GNU Lesser General Public
  18  * License along with FFmpeg; if not, write to the Free Software
  19  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
  20  */
  21
  22 /**
  23  * @file rtpproto.c
  24  * RTP protocol
  25  */
  26
  27 #include "libavutil/avstring.h"
  28 #include "avformat.h"
  29
  30 #include <unistd.h>
  31 #include <stdarg.h>
  32 #include "network.h"
  33 #include "os_support.h"
  34 #include <fcntl.h>
  35
  36 #define RTP_TX_BUF_SIZE  (64 * 1024)
  37 #define RTP_RX_BUF_SIZE  (128 * 1024)
  38
  39 typedef struct RTPContext {
  40     URLContext *rtp_hd, *rtcp_hd;
  41     int rtp_fd, rtcp_fd;
  42 } RTPContext;
  43
  44 /**
  45  * If no filename is given to av_open_input_file because you want to
  46  * get the local port first, then you must call this function to set
  47  * the remote server address.
  48  *
  49  * @param s1 media file context
  50  * @param uri of the remote server
  51  * @return zero if no error.
  52  */
  53
  54 int rtp_set_remote_url(URLContext *h, const char *uri)
  55 {
  56     RTPContext *s = h->priv_data;
  57     char hostname[256];
  58     int port;
  59
  60     char buf[1024];
  61     char path[1024];
  62
  63     url_split(NULL, 0, NULL, 0, hostname, sizeof(hostname), &port,
  64               path, sizeof(path), uri);
  65
  66     snprintf(buf, sizeof(buf), "udp://%s:%d%s", hostname, port, path);
  67     udp_set_remote_url(s->rtp_hd, buf);
  68
  69     snprintf(buf, sizeof(buf), "udp://%s:%d%s", hostname, port + 1, path);
  70     udp_set_remote_url(s->rtcp_hd, buf);
  71     return 0;
  72 }
  73
  74
  75 /**
  76  * add option to url of the form:
  77  * "http://host:port/path?option1=val1&option2=val2...
  78  */
  79
  80 static void url_add_option(char *buf, int buf_size, const char *fmt, ...)
  81 {
  82     char buf1[1024];
  83     va_list ap;
  84
  85     va_start(ap, fmt);
  86     if (strchr(buf, '?'))
  87         av_strlcat(buf, "&", buf_size);
  88     else
  89         av_strlcat(buf, "?", buf_size);
  90     vsnprintf(buf1, sizeof(buf1), fmt, ap);
  91     av_strlcat(buf, buf1, buf_size);
  92     va_end(ap);
  93 }
  94
  95 static void build_udp_url(char *buf, int buf_size,
  96                           const char *hostname, int port,
  97                           int local_port, int ttl,
  98                           int max_packet_size)
  99 {
 100     snprintf(buf, buf_size, "udp://%s:%d", hostname, port);
 101     if (local_port >= 0)
 102         url_add_option(buf, buf_size, "localport=%d", local_port);
 103     if (ttl >= 0)
 104         url_add_option(buf, buf_size, "ttl=%d", ttl);
 105     if (max_packet_size >=0)
 106         url_add_option(buf, buf_size, "pkt_size=%d", max_packet_size);
 107 }
 108
 109 /**
 110  * url syntax: rtp://host:port[?option=val...]
 111  * option: 'ttl=n'       : set the ttl value (for multicast only)
 112  *         'localport=n' : set the local port to n
 113  *         'pkt_size=n'  : set max packet size
 114  *
 115  */
 116
 117 static int rtp_open(URLContext *h, const char *uri, int flags)
 118 {
 119     RTPContext *s;
 120     int port, is_output, ttl, local_port, max_packet_size;
 121     char hostname[256];
 122     char buf[1024];
 123     char path[1024];
 124     const char *p;
 125
 126     is_output = (flags & URL_WRONLY);
 127
 128     s = av_mallocz(sizeof(RTPContext));
 129     if (!s)
 130         return AVERROR(ENOMEM);
 131     h->priv_data = s;
 132
 133     url_split(NULL, 0, NULL, 0, hostname, sizeof(hostname), &port,
 134               path, sizeof(path), uri);
 135     /* extract parameters */
 136     ttl = -1;
 137     local_port = -1;
 138     max_packet_size = -1;
 139
 140     p = strchr(uri, '?');
 141     if (p) {
 142         if (find_info_tag(buf, sizeof(buf), "ttl", p)) {
 143             ttl = strtol(buf, NULL, 10);
 144         }
 145         if (find_info_tag(buf, sizeof(buf), "localport", p)) {
 146             local_port = strtol(buf, NULL, 10);
 147         }
 148         if (find_info_tag(buf, sizeof(buf), "pkt_size", p)) {
 149             max_packet_size = strtol(buf, NULL, 10);
 150         }
 151     }
 152
 153     build_udp_url(buf, sizeof(buf),
 154                   hostname, port, local_port, ttl, max_packet_size);
 155     if (url_open(&s->rtp_hd, buf, flags) < 0)
 156         goto fail;
 157     local_port = udp_get_local_port(s->rtp_hd);
 158     /* XXX: need to open another connection if the port is not even */
 159
 160     /* well, should suppress localport in path */
 161
 162     build_udp_url(buf, sizeof(buf),
 163                   hostname, port + 1, local_port + 1, ttl, max_packet_size);
 164     if (url_open(&s->rtcp_hd, buf, flags) < 0)
 165         goto fail;
 166
 167     /* just to ease handle access. XXX: need to suppress direct handle
 168        access */
 169     s->rtp_fd = udp_get_file_handle(s->rtp_hd);
 170     s->rtcp_fd = udp_get_file_handle(s->rtcp_hd);
 171
 172     h->max_packet_size = url_get_max_packet_size(s->rtp_hd);
 173     h->is_streamed = 1;
 174     return 0;
 175
 176  fail:
 177     if (s->rtp_hd)
 178         url_close(s->rtp_hd);
 179     if (s->rtcp_hd)
 180         url_close(s->rtcp_hd);
 181     av_free(s);
 182     return AVERROR(EIO);
 183 }
 184
 185 static int rtp_read(URLContext *h, uint8_t *buf, int size)
 186 {
 187     RTPContext *s = h->priv_data;
 188     struct sockaddr_in from;
 189     socklen_t from_len;
 190     int len, fd_max, n;
 191     fd_set rfds;
 192 #if 0
 193     for(;;) {
 194         from_len = sizeof(from);
 195         len = recvfrom (s->rtp_fd, buf, size, 0,
 196                         (struct sockaddr *)&from, &from_len);
 197         if (len < 0) {
 198             if (ff_neterrno() == FF_NETERROR(EAGAIN) ||
 199                 ff_neterrno() == FF_NETERROR(EINTR))
 200                 continue;
 201             return AVERROR(EIO);
 202         }
 203         break;
 204     }
 205 #else
 206     for(;;) {
 207         /* build fdset to listen to RTP and RTCP packets */
 208         FD_ZERO(&rfds);
 209         fd_max = s->rtp_fd;
 210         FD_SET(s->rtp_fd, &rfds);
 211         if (s->rtcp_fd > fd_max)
 212             fd_max = s->rtcp_fd;
 213         FD_SET(s->rtcp_fd, &rfds);
 214         n = select(fd_max + 1, &rfds, NULL, NULL, NULL);
 215         if (n > 0) {
 216             /* first try RTCP */
 217             if (FD_ISSET(s->rtcp_fd, &rfds)) {
 218                 from_len = sizeof(from);
 219                 len = recvfrom (s->rtcp_fd, buf, size, 0,
 220                                 (struct sockaddr *)&from, &from_len);
 221                 if (len < 0) {
 222                     if (ff_neterrno() == FF_NETERROR(EAGAIN) ||
 223                         ff_neterrno() == FF_NETERROR(EINTR))
 224                         continue;
 225                     return AVERROR(EIO);
 226                 }
 227                 break;
 228             }
 229             /* then RTP */
 230             if (FD_ISSET(s->rtp_fd, &rfds)) {
 231                 from_len = sizeof(from);
 232                 len = recvfrom (s->rtp_fd, buf, size, 0,
 233                                 (struct sockaddr *)&from, &from_len);
 234                 if (len < 0) {
 235                     if (ff_neterrno() == FF_NETERROR(EAGAIN) ||
 236                         ff_neterrno() == FF_NETERROR(EINTR))
 237                         continue;
 238                     return AVERROR(EIO);
 239                 }
 240                 break;
 241             }
 242         }
 243     }
 244 #endif
 245     return len;
 246 }
 247
 248 static int rtp_write(URLContext *h, uint8_t *buf, int size)
 249 {
 250     RTPContext *s = h->priv_data;
 251     int ret;
 252     URLContext *hd;
 253
 254     if (buf[1] >= 200 && buf[1] <= 204) {
 255         /* RTCP payload type */
 256         hd = s->rtcp_hd;
 257     } else {
 258         /* RTP payload type */
 259         hd = s->rtp_hd;
 260     }
 261
 262     ret = url_write(hd, buf, size);
 263 #if 0
 264     {
 265         struct timespec ts;
 266         ts.tv_sec = 0;
 267         ts.tv_nsec = 10 * 1000000;
 268         nanosleep(&ts, NULL);
 269     }
 270 #endif
 271     return ret;
 272 }
 273
 274 static int rtp_close(URLContext *h)
 275 {
 276     RTPContext *s = h->priv_data;
 277
 278     url_close(s->rtp_hd);
 279     url_close(s->rtcp_hd);
 280     av_free(s);
 281     return 0;
 282 }
 283
 284 /**
 285  * Return the local port used by the RTP connection
 286  * @param s1 media file context
 287  * @return the local port number
 288  */
 289
 290 int rtp_get_local_port(URLContext *h)
 291 {
 292     RTPContext *s = h->priv_data;
 293     return udp_get_local_port(s->rtp_hd);
 294 }
 295
 296 /**
 297  * Return the rtp and rtcp file handles for select() usage to wait for
 298  * several RTP streams at the same time.
 299  * @param h media file context
 300  */
 301
 302 void rtp_get_file_handles(URLContext *h, int *prtp_fd, int *prtcp_fd)
 303 {
 304     RTPContext *s = h->priv_data;
 305
 306     *prtp_fd = s->rtp_fd;
 307     *prtcp_fd = s->rtcp_fd;
 308 }
 309
 310 URLProtocol rtp_protocol = {
 311     "rtp",
 312     rtp_open,
 313     rtp_read,
 314     rtp_write,
 315     NULL, /* seek */
 316     rtp_close,
 317 };