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sapenc.c
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1 /*
2  * Session Announcement Protocol (RFC 2974) muxer
3  * Copyright (c) 2010 Martin Storsjo
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 #include "avformat.h"
23 #include "libavutil/parseutils.h"
24 #include "libavutil/random_seed.h"
25 #include "libavutil/avstring.h"
26 #include "libavutil/dict.h"
27 #include "libavutil/intreadwrite.h"
28 #include "libavutil/time.h"
29 #include "internal.h"
30 #include "network.h"
31 #include "os_support.h"
32 #include "rtpenc_chain.h"
33 #include "url.h"
34 
35 struct SAPState {
37  int ann_size;
39  int64_t last_time;
40 };
41 
43 {
44  struct SAPState *sap = s->priv_data;
45  int i;
46 
47  for (i = 0; i < s->nb_streams; i++) {
48  AVFormatContext *rtpctx = s->streams[i]->priv_data;
49  if (!rtpctx)
50  continue;
51  av_write_trailer(rtpctx);
52  avio_close(rtpctx->pb);
53  avformat_free_context(rtpctx);
54  s->streams[i]->priv_data = NULL;
55  }
56 
57  if (sap->last_time && sap->ann && sap->ann_fd) {
58  sap->ann[0] |= 4; /* Session deletion*/
59  ffurl_write(sap->ann_fd, sap->ann, sap->ann_size);
60  }
61 
62  av_freep(&sap->ann);
63  if (sap->ann_fd)
64  ffurl_close(sap->ann_fd);
66  return 0;
67 }
68 
70 {
71  struct SAPState *sap = s->priv_data;
72  char host[1024], path[1024], url[1024], announce_addr[50] = "";
73  char *option_list;
74  int port = 9875, base_port = 5004, i, pos = 0, same_port = 0, ttl = 255;
75  AVFormatContext **contexts = NULL;
76  int ret = 0;
77  struct sockaddr_storage localaddr;
78  socklen_t addrlen = sizeof(localaddr);
79  int udp_fd;
80  AVDictionaryEntry* title = av_dict_get(s->metadata, "title", NULL, 0);
81 
82  if (!ff_network_init())
83  return AVERROR(EIO);
84 
85  /* extract hostname and port */
86  av_url_split(NULL, 0, NULL, 0, host, sizeof(host), &base_port,
87  path, sizeof(path), s->filename);
88  if (base_port < 0)
89  base_port = 5004;
90 
91  /* search for options */
92  option_list = strrchr(path, '?');
93  if (option_list) {
94  char buf[50];
95  if (av_find_info_tag(buf, sizeof(buf), "announce_port", option_list)) {
96  port = strtol(buf, NULL, 10);
97  }
98  if (av_find_info_tag(buf, sizeof(buf), "same_port", option_list)) {
99  same_port = strtol(buf, NULL, 10);
100  }
101  if (av_find_info_tag(buf, sizeof(buf), "ttl", option_list)) {
102  ttl = strtol(buf, NULL, 10);
103  }
104  if (av_find_info_tag(buf, sizeof(buf), "announce_addr", option_list)) {
105  av_strlcpy(announce_addr, buf, sizeof(announce_addr));
106  }
107  }
108 
109  if (!announce_addr[0]) {
110  struct addrinfo hints = { 0 }, *ai = NULL;
111  hints.ai_family = AF_UNSPEC;
112  if (getaddrinfo(host, NULL, &hints, &ai)) {
113  av_log(s, AV_LOG_ERROR, "Unable to resolve %s\n", host);
114  ret = AVERROR(EIO);
115  goto fail;
116  }
117  if (ai->ai_family == AF_INET) {
118  /* Also known as sap.mcast.net */
119  av_strlcpy(announce_addr, "224.2.127.254", sizeof(announce_addr));
120 #if HAVE_STRUCT_SOCKADDR_IN6
121  } else if (ai->ai_family == AF_INET6) {
122  /* With IPv6, you can use the same destination in many different
123  * multicast subnets, to choose how far you want it routed.
124  * This one is intended to be routed globally. */
125  av_strlcpy(announce_addr, "ff0e::2:7ffe", sizeof(announce_addr));
126 #endif
127  } else {
128  freeaddrinfo(ai);
129  av_log(s, AV_LOG_ERROR, "Host %s resolved to unsupported "
130  "address family\n", host);
131  ret = AVERROR(EIO);
132  goto fail;
133  }
134  freeaddrinfo(ai);
135  }
136 
137  contexts = av_mallocz(sizeof(AVFormatContext*) * s->nb_streams);
138  if (!contexts) {
139  ret = AVERROR(ENOMEM);
140  goto fail;
141  }
142 
145  for (i = 0; i < s->nb_streams; i++) {
146  URLContext *fd;
147 
148  ff_url_join(url, sizeof(url), "rtp", NULL, host, base_port,
149  "?ttl=%d", ttl);
150  if (!same_port)
151  base_port += 2;
152  ret = ffurl_open(&fd, url, AVIO_FLAG_WRITE, &s->interrupt_callback, NULL);
153  if (ret) {
154  ret = AVERROR(EIO);
155  goto fail;
156  }
157  ret = ff_rtp_chain_mux_open(&contexts[i], s, s->streams[i], fd, 0, i);
158  if (ret < 0)
159  goto fail;
160  s->streams[i]->priv_data = contexts[i];
161  s->streams[i]->time_base = contexts[i]->streams[0]->time_base;
162  av_strlcpy(contexts[i]->filename, url, sizeof(contexts[i]->filename));
163  }
164 
165  if (s->nb_streams > 0 && title)
166  av_dict_set(&contexts[0]->metadata, "title", title->value, 0);
167 
168  ff_url_join(url, sizeof(url), "udp", NULL, announce_addr, port,
169  "?ttl=%d&connect=1", ttl);
170  ret = ffurl_open(&sap->ann_fd, url, AVIO_FLAG_WRITE,
171  &s->interrupt_callback, NULL);
172  if (ret) {
173  ret = AVERROR(EIO);
174  goto fail;
175  }
176 
177  udp_fd = ffurl_get_file_handle(sap->ann_fd);
178  if (getsockname(udp_fd, (struct sockaddr*) &localaddr, &addrlen)) {
179  ret = AVERROR(EIO);
180  goto fail;
181  }
182  if (localaddr.ss_family != AF_INET
183 #if HAVE_STRUCT_SOCKADDR_IN6
184  && localaddr.ss_family != AF_INET6
185 #endif
186  ) {
187  av_log(s, AV_LOG_ERROR, "Unsupported protocol family\n");
188  ret = AVERROR(EIO);
189  goto fail;
190  }
191  sap->ann_size = 8192;
192  sap->ann = av_mallocz(sap->ann_size);
193  if (!sap->ann) {
194  ret = AVERROR(EIO);
195  goto fail;
196  }
197  sap->ann[pos] = (1 << 5);
198 #if HAVE_STRUCT_SOCKADDR_IN6
199  if (localaddr.ss_family == AF_INET6)
200  sap->ann[pos] |= 0x10;
201 #endif
202  pos++;
203  sap->ann[pos++] = 0; /* Authentication length */
204  AV_WB16(&sap->ann[pos], av_get_random_seed());
205  pos += 2;
206  if (localaddr.ss_family == AF_INET) {
207  memcpy(&sap->ann[pos], &((struct sockaddr_in*)&localaddr)->sin_addr,
208  sizeof(struct in_addr));
209  pos += sizeof(struct in_addr);
210 #if HAVE_STRUCT_SOCKADDR_IN6
211  } else {
212  memcpy(&sap->ann[pos], &((struct sockaddr_in6*)&localaddr)->sin6_addr,
213  sizeof(struct in6_addr));
214  pos += sizeof(struct in6_addr);
215 #endif
216  }
217 
218  av_strlcpy(&sap->ann[pos], "application/sdp", sap->ann_size - pos);
219  pos += strlen(&sap->ann[pos]) + 1;
220 
221  if (av_sdp_create(contexts, s->nb_streams, &sap->ann[pos],
222  sap->ann_size - pos)) {
223  ret = AVERROR_INVALIDDATA;
224  goto fail;
225  }
226  av_freep(&contexts);
227  av_log(s, AV_LOG_VERBOSE, "SDP:\n%s\n", &sap->ann[pos]);
228  pos += strlen(&sap->ann[pos]);
229  sap->ann_size = pos;
230 
231  if (sap->ann_size > sap->ann_fd->max_packet_size) {
232  av_log(s, AV_LOG_ERROR, "Announcement too large to send in one "
233  "packet\n");
234  goto fail;
235  }
236 
237  return 0;
238 
239 fail:
240  av_free(contexts);
241  sap_write_close(s);
242  return ret;
243 }
244 
246 {
247  AVFormatContext *rtpctx;
248  struct SAPState *sap = s->priv_data;
249  int64_t now = av_gettime_relative();
250 
251  if (!sap->last_time || now - sap->last_time > 5000000) {
252  int ret = ffurl_write(sap->ann_fd, sap->ann, sap->ann_size);
253  /* Don't abort even if we get "Destination unreachable" */
254  if (ret < 0 && ret != AVERROR(ECONNREFUSED))
255  return ret;
256  sap->last_time = now;
257  }
258  rtpctx = s->streams[pkt->stream_index]->priv_data;
259  return ff_write_chained(rtpctx, 0, pkt, s);
260 }
261 
263  .name = "sap",
264  .long_name = NULL_IF_CONFIG_SMALL("SAP output"),
265  .priv_data_size = sizeof(struct SAPState),
266  .audio_codec = AV_CODEC_ID_AAC,
267  .video_codec = AV_CODEC_ID_MPEG4,
268  .write_header = sap_write_header,
269  .write_packet = sap_write_packet,
270  .write_trailer = sap_write_close,
271  .flags = AVFMT_NOFILE | AVFMT_GLOBALHEADER,
272 };