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