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 #include "avstring.h"
  23
  24 #include <unistd.h>
  25 #include <stdarg.h>
  26 #include "network.h"
  27 #include "os_support.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, 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 static 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         av_strlcat(buf, "&", buf_size);
  78     else
  79         av_strlcat(buf, "?", buf_size);
  80     vsnprintf(buf1, sizeof(buf1), fmt, ap);
  81     av_strlcat(buf, buf1, buf_size);
  82     va_end(ap);
  83 }
  84
  85 static void build_udp_url(char *buf, int buf_size,
  86                           const char *hostname, int port,
  87                           int local_port, 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 (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: 'ttl=n'       : set the ttl value (for multicast only)
  99  *         'localport=n' : set the local port to n
 100  *
 101  */
 102 static int rtp_open(URLContext *h, const char *uri, int flags)
 103 {
 104     RTPContext *s;
 105     int port, is_output, ttl, local_port;
 106     char hostname[256];
 107     char buf[1024];
 108     char path[1024];
 109     const char *p;
 110
 111     is_output = (flags & URL_WRONLY);
 112
 113     s = av_mallocz(sizeof(RTPContext));
 114     if (!s)
 115         return AVERROR(ENOMEM);
 116     h->priv_data = s;
 117
 118     url_split(NULL, 0, NULL, 0, hostname, sizeof(hostname), &port,
 119               path, sizeof(path), uri);
 120     /* extract parameters */
 121     ttl = -1;
 122     local_port = -1;
 123     p = strchr(uri, '?');
 124     if (p) {
 125         if (find_info_tag(buf, sizeof(buf), "ttl", p)) {
 126             ttl = strtol(buf, NULL, 10);
 127         }
 128         if (find_info_tag(buf, sizeof(buf), "localport", p)) {
 129             local_port = strtol(buf, NULL, 10);
 130         }
 131     }
 132
 133     build_udp_url(buf, sizeof(buf),
 134                   hostname, port, local_port, ttl);
 135     if (url_open(&s->rtp_hd, buf, flags) < 0)
 136         goto fail;
 137     local_port = udp_get_local_port(s->rtp_hd);
 138     /* XXX: need to open another connection if the port is not even */
 139
 140     /* well, should suppress localport in path */
 141
 142     build_udp_url(buf, sizeof(buf),
 143                   hostname, port + 1, local_port + 1, ttl);
 144     if (url_open(&s->rtcp_hd, buf, flags) < 0)
 145         goto fail;
 146
 147     /* just to ease handle access. XXX: need to suppress direct handle
 148        access */
 149     s->rtp_fd = udp_get_file_handle(s->rtp_hd);
 150     s->rtcp_fd = udp_get_file_handle(s->rtcp_hd);
 151
 152     h->max_packet_size = url_get_max_packet_size(s->rtp_hd);
 153     h->is_streamed = 1;
 154     return 0;
 155
 156  fail:
 157     if (s->rtp_hd)
 158         url_close(s->rtp_hd);
 159     if (s->rtcp_hd)
 160         url_close(s->rtcp_hd);
 161     av_free(s);
 162     return AVERROR(EIO);
 163 }
 164
 165 static int rtp_read(URLContext *h, uint8_t *buf, int size)
 166 {
 167     RTPContext *s = h->priv_data;
 168     struct sockaddr_in from;
 169     socklen_t from_len;
 170     int len, fd_max, n;
 171     fd_set rfds;
 172 #if 0
 173     for(;;) {
 174         from_len = sizeof(from);
 175         len = recvfrom (s->rtp_fd, buf, size, 0,
 176                         (struct sockaddr *)&from, &from_len);
 177         if (len < 0) {
 178             if (ff_neterrno() == FF_NETERROR(EAGAIN) ||
 179                 ff_neterrno() == FF_NETERROR(EINTR))
 180                 continue;
 181             return AVERROR(EIO);
 182         }
 183         break;
 184     }
 185 #else
 186     for(;;) {
 187         /* build fdset to listen to RTP and RTCP packets */
 188         FD_ZERO(&rfds);
 189         fd_max = s->rtp_fd;
 190         FD_SET(s->rtp_fd, &rfds);
 191         if (s->rtcp_fd > fd_max)
 192             fd_max = s->rtcp_fd;
 193         FD_SET(s->rtcp_fd, &rfds);
 194         n = select(fd_max + 1, &rfds, NULL, NULL, NULL);
 195         if (n > 0) {
 196             /* first try RTCP */
 197             if (FD_ISSET(s->rtcp_fd, &rfds)) {
 198                 from_len = sizeof(from);
 199                 len = recvfrom (s->rtcp_fd, buf, size, 0,
 200                                 (struct sockaddr *)&from, &from_len);
 201                 if (len < 0) {
 202                     if (ff_neterrno() == FF_NETERROR(EAGAIN) ||
 203                         ff_neterrno() == FF_NETERROR(EINTR))
 204                         continue;
 205                     return AVERROR(EIO);
 206                 }
 207                 break;
 208             }
 209             /* then RTP */
 210             if (FD_ISSET(s->rtp_fd, &rfds)) {
 211                 from_len = sizeof(from);
 212                 len = recvfrom (s->rtp_fd, buf, size, 0,
 213                                 (struct sockaddr *)&from, &from_len);
 214                 if (len < 0) {
 215                     if (ff_neterrno() == FF_NETERROR(EAGAIN) ||
 216                         ff_neterrno() == FF_NETERROR(EINTR))
 217                         continue;
 218                     return AVERROR(EIO);
 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 connection
 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 };