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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 "libavutil/dict.h"
30 #include "internal.h"
31 #include "network.h"
32 #include "os_support.h"
33 #include "rtpenc_chain.h"
34 #include "url.h"
35 
36 struct SAPState {
38  int ann_size;
40  int64_t last_time;
41 };
42 
44 {
45  struct SAPState *sap = s->priv_data;
46  int i;
47 
48  for (i = 0; i < s->nb_streams; i++) {
49  AVFormatContext *rtpctx = s->streams[i]->priv_data;
50  if (!rtpctx)
51  continue;
52  av_write_trailer(rtpctx);
53  avio_close(rtpctx->pb);
54  avformat_free_context(rtpctx);
55  s->streams[i]->priv_data = NULL;
56  }
57 
58  if (sap->last_time && sap->ann && sap->ann_fd) {
59  sap->ann[0] |= 4; /* Session deletion*/
60  ffurl_write(sap->ann_fd, sap->ann, sap->ann_size);
61  }
62 
63  av_freep(&sap->ann);
64  if (sap->ann_fd)
65  ffurl_close(sap->ann_fd);
67  return 0;
68 }
69 
71 {
72  struct SAPState *sap = s->priv_data;
73  char host[1024], path[1024], url[1024], announce_addr[50] = "";
74  char *option_list;
75  int port = 9875, base_port = 5004, i, pos = 0, same_port = 0, ttl = 255;
76  AVFormatContext **contexts = NULL;
77  int ret = 0;
78  struct sockaddr_storage localaddr;
79  socklen_t addrlen = sizeof(localaddr);
80  int udp_fd;
81  AVDictionaryEntry* title = av_dict_get(s->metadata, "title", NULL, 0);
82 
83  if (!ff_network_init())
84  return AVERROR(EIO);
85 
86  /* extract hostname and port */
87  av_url_split(NULL, 0, NULL, 0, host, sizeof(host), &base_port,
88  path, sizeof(path), s->filename);
89  if (base_port < 0)
90  base_port = 5004;
91 
92  /* search for options */
93  option_list = strrchr(path, '?');
94  if (option_list) {
95  char buf[50];
96  if (av_find_info_tag(buf, sizeof(buf), "announce_port", option_list)) {
97  port = strtol(buf, NULL, 10);
98  }
99  if (av_find_info_tag(buf, sizeof(buf), "same_port", option_list)) {
100  same_port = strtol(buf, NULL, 10);
101  }
102  if (av_find_info_tag(buf, sizeof(buf), "ttl", option_list)) {
103  ttl = strtol(buf, NULL, 10);
104  }
105  if (av_find_info_tag(buf, sizeof(buf), "announce_addr", option_list)) {
106  av_strlcpy(announce_addr, buf, sizeof(announce_addr));
107  }
108  }
109 
110  if (!announce_addr[0]) {
111  struct addrinfo hints = { 0 }, *ai = NULL;
112  hints.ai_family = AF_UNSPEC;
113  if (getaddrinfo(host, NULL, &hints, &ai)) {
114  av_log(s, AV_LOG_ERROR, "Unable to resolve %s\n", host);
115  ret = AVERROR(EIO);
116  goto fail;
117  }
118  if (ai->ai_family == AF_INET) {
119  /* Also known as sap.mcast.net */
120  av_strlcpy(announce_addr, "224.2.127.254", sizeof(announce_addr));
121 #if HAVE_STRUCT_SOCKADDR_IN6
122  } else if (ai->ai_family == AF_INET6) {
123  /* With IPv6, you can use the same destination in many different
124  * multicast subnets, to choose how far you want it routed.
125  * This one is intended to be routed globally. */
126  av_strlcpy(announce_addr, "ff0e::2:7ffe", sizeof(announce_addr));
127 #endif
128  } else {
129  freeaddrinfo(ai);
130  av_log(s, AV_LOG_ERROR, "Host %s resolved to unsupported "
131  "address family\n", host);
132  ret = AVERROR(EIO);
133  goto fail;
134  }
135  freeaddrinfo(ai);
136  }
137 
138  contexts = av_mallocz(sizeof(AVFormatContext*) * s->nb_streams);
139  if (!contexts) {
140  ret = AVERROR(ENOMEM);
141  goto fail;
142  }
143 
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  av_strlcpy(contexts[i]->filename, url, sizeof(contexts[i]->filename));
162  }
163 
164  if (s->nb_streams > 0 && title)
165  av_dict_set(&contexts[0]->metadata, "title", title->value, 0);
166 
167  ff_url_join(url, sizeof(url), "udp", NULL, announce_addr, port,
168  "?ttl=%d&connect=1", ttl);
169  ret = ffurl_open(&sap->ann_fd, url, AVIO_FLAG_WRITE,
170  &s->interrupt_callback, NULL);
171  if (ret) {
172  ret = AVERROR(EIO);
173  goto fail;
174  }
175 
176  udp_fd = ffurl_get_file_handle(sap->ann_fd);
177  if (getsockname(udp_fd, (struct sockaddr*) &localaddr, &addrlen)) {
178  ret = AVERROR(EIO);
179  goto fail;
180  }
181  if (localaddr.ss_family != AF_INET
182 #if HAVE_STRUCT_SOCKADDR_IN6
183  && localaddr.ss_family != AF_INET6
184 #endif
185  ) {
186  av_log(s, AV_LOG_ERROR, "Unsupported protocol family\n");
187  ret = AVERROR(EIO);
188  goto fail;
189  }
190  sap->ann_size = 8192;
191  sap->ann = av_mallocz(sap->ann_size);
192  if (!sap->ann) {
193  ret = AVERROR(EIO);
194  goto fail;
195  }
196  sap->ann[pos] = (1 << 5);
197 #if HAVE_STRUCT_SOCKADDR_IN6
198  if (localaddr.ss_family == AF_INET6)
199  sap->ann[pos] |= 0x10;
200 #endif
201  pos++;
202  sap->ann[pos++] = 0; /* Authentication length */
203  AV_WB16(&sap->ann[pos], av_get_random_seed());
204  pos += 2;
205  if (localaddr.ss_family == AF_INET) {
206  memcpy(&sap->ann[pos], &((struct sockaddr_in*)&localaddr)->sin_addr,
207  sizeof(struct in_addr));
208  pos += sizeof(struct in_addr);
209 #if HAVE_STRUCT_SOCKADDR_IN6
210  } else {
211  memcpy(&sap->ann[pos], &((struct sockaddr_in6*)&localaddr)->sin6_addr,
212  sizeof(struct in6_addr));
213  pos += sizeof(struct in6_addr);
214 #endif
215  }
216 
217  av_strlcpy(&sap->ann[pos], "application/sdp", sap->ann_size - pos);
218  pos += strlen(&sap->ann[pos]) + 1;
219 
220  if (av_sdp_create(contexts, s->nb_streams, &sap->ann[pos],
221  sap->ann_size - pos)) {
222  ret = AVERROR_INVALIDDATA;
223  goto fail;
224  }
225  av_freep(&contexts);
226  av_log(s, AV_LOG_VERBOSE, "SDP:\n%s\n", &sap->ann[pos]);
227  pos += strlen(&sap->ann[pos]);
228  sap->ann_size = pos;
229 
230  if (sap->ann_size > sap->ann_fd->max_packet_size) {
231  av_log(s, AV_LOG_ERROR, "Announcement too large to send in one "
232  "packet\n");
233  goto fail;
234  }
235 
236  return 0;
237 
238 fail:
239  av_free(contexts);
240  sap_write_close(s);
241  return ret;
242 }
243 
245 {
246  AVFormatContext *rtpctx;
247  struct SAPState *sap = s->priv_data;
248  int64_t now = av_gettime();
249 
250  if (!sap->last_time || now - sap->last_time > 5000000) {
251  int ret = ffurl_write(sap->ann_fd, sap->ann, sap->ann_size);
252  /* Don't abort even if we get "Destination unreachable" */
253  if (ret < 0 && ret != AVERROR(ECONNREFUSED))
254  return ret;
255  sap->last_time = now;
256  }
257  rtpctx = s->streams[pkt->stream_index]->priv_data;
258  return ff_write_chained(rtpctx, 0, pkt, s);
259 }
260 
262  .name = "sap",
263  .long_name = NULL_IF_CONFIG_SMALL("SAP output"),
264  .priv_data_size = sizeof(struct SAPState),
265  .audio_codec = AV_CODEC_ID_AAC,
266  .video_codec = AV_CODEC_ID_MPEG4,
267  .write_header = sap_write_header,
268  .write_packet = sap_write_packet,
269  .write_trailer = sap_write_close,
270  .flags = AVFMT_NOFILE | AVFMT_GLOBALHEADER,
271 };