libavformat/sdp.c

   1 /*
   2  * copyright (c) 2007 Luca Abeni
   3  *
   4  * This file is part of FFmpeg.
   5  *
   6  * FFmpeg is free software; you can redistribute it and/or
   7  * modify it under the terms of the GNU Lesser General Public
   8  * License as published by the Free Software Foundation; either
   9  * version 2.1 of the License, or (at your option) any later version.
  10  *
  11  * FFmpeg is distributed in the hope that it will be useful,
  12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  14  * Lesser General Public License for more details.
  15  *
  16  * You should have received a copy of the GNU Lesser General Public
  17  * License along with FFmpeg; if not, write to the Free Software
  18  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
  19  */
  20
  21 #include "libavutil/avstring.h"
  22 #include "libavutil/base64.h"
  23 #include "avformat.h"
  24 #include "internal.h"
  25 #include "avc.h"
  26 #include "rtp.h"
  27
  28 #if CONFIG_RTP_MUXER
  29 #define MAX_EXTRADATA_SIZE ((INT_MAX - 10) / 2)
  30
  31 struct sdp_session_level {
  32     int sdp_version;      /**< protocol version (currently 0) */
  33     int id;               /**< session ID */
  34     int version;          /**< session version */
  35     int start_time;       /**< session start time (NTP time, in seconds),
  36                                or 0 in case of permanent session */
  37     int end_time;         /**< session end time (NTP time, in seconds),
  38                                or 0 if the session is not bounded */
  39     int ttl;              /**< TTL, in case of multicast stream */
  40     const char *user;     /**< username of the session's creator */
  41     const char *src_addr; /**< IP address of the machine from which the session was created */
  42     const char *dst_addr; /**< destination IP address (can be multicast) */
  43     const char *name;     /**< session name (can be an empty string) */
  44 };
  45
  46 static void sdp_write_address(char *buff, int size, const char *dest_addr, int ttl)
  47 {
  48     if (dest_addr) {
  49         if (ttl > 0) {
  50             av_strlcatf(buff, size, "c=IN IP4 %s/%d\r\n", dest_addr, ttl);
  51         } else {
  52             av_strlcatf(buff, size, "c=IN IP4 %s\r\n", dest_addr);
  53         }
  54     }
  55 }
  56
  57 static void sdp_write_header(char *buff, int size, struct sdp_session_level *s)
  58 {
  59     av_strlcatf(buff, size, "v=%d\r\n"
  60                             "o=- %d %d IN IP4 %s\r\n"
  61                             "t=%d %d\r\n"
  62                             "s=%s\r\n"
  63                             "a=tool:libavformat " AV_STRINGIFY(LIBAVFORMAT_VERSION) "\r\n",
  64                             s->sdp_version,
  65                             s->id, s->version, s->src_addr,
  66                             s->start_time, s->end_time,
  67                             s->name);
  68     sdp_write_address(buff, size, s->dst_addr, s->ttl);
  69 }
  70
  71 static int sdp_get_address(char *dest_addr, int size, int *ttl, const char *url)
  72 {
  73     int port;
  74     const char *p;
  75
  76     url_split(NULL, 0, NULL, 0, dest_addr, size, &port, NULL, 0, url);
  77
  78     *ttl = 0;
  79     p = strchr(url, '?');
  80     if (p) {
  81         char buff[64];
  82         int is_multicast = find_info_tag(buff, sizeof(buff), "multicast", p);
  83
  84         if (is_multicast) {
  85             if (find_info_tag(buff, sizeof(buff), "ttl", p)) {
  86                 *ttl = strtol(buff, NULL, 10);
  87             } else {
  88                 *ttl = 5;
  89             }
  90         }
  91     }
  92
  93     return port;
  94 }
  95
  96 #define MAX_PSET_SIZE 1024
  97 static char *extradata2psets(AVCodecContext *c)
  98 {
  99     char *psets, *p;
 100     const uint8_t *r;
 101     const char *pset_string = "; sprop-parameter-sets=";
 102
 103     if (c->extradata_size > MAX_EXTRADATA_SIZE) {
 104         av_log(c, AV_LOG_ERROR, "Too much extradata!\n");
 105
 106         return NULL;
 107     }
 108
 109     psets = av_mallocz(MAX_PSET_SIZE);
 110     if (psets == NULL) {
 111         av_log(c, AV_LOG_ERROR, "Cannot allocate memory for the parameter sets.\n");
 112         return NULL;
 113     }
 114     memcpy(psets, pset_string, strlen(pset_string));
 115     p = psets + strlen(pset_string);
 116     r = ff_avc_find_startcode(c->extradata, c->extradata + c->extradata_size);
 117     while (r < c->extradata + c->extradata_size) {
 118         const uint8_t *r1;
 119         uint8_t nal_type;
 120
 121         while (!*(r++));
 122         nal_type = *r & 0x1f;
 123         r1 = ff_avc_find_startcode(r, c->extradata + c->extradata_size);
 124         if (nal_type != 7 && nal_type != 8) { /* Only output SPS and PPS */
 125             r = r1;
 126             continue;
 127         }
 128         if (p != (psets + strlen(pset_string))) {
 129             *p = ',';
 130             p++;
 131         }
 132         if (av_base64_encode(p, MAX_PSET_SIZE - (p - psets), r, r1 - r) == NULL) {
 133             av_log(c, AV_LOG_ERROR, "Cannot Base64-encode %td %td!\n", MAX_PSET_SIZE - (p - psets), r1 - r);
 134             av_free(psets);
 135
 136             return NULL;
 137         }
 138         p += strlen(p);
 139         r = r1;
 140     }
 141
 142     return psets;
 143 }
 144
 145 static char *extradata2config(AVCodecContext *c)
 146 {
 147     char *config;
 148
 149     if (c->extradata_size > MAX_EXTRADATA_SIZE) {
 150         av_log(c, AV_LOG_ERROR, "Too much extradata!\n");
 151
 152         return NULL;
 153     }
 154     config = av_malloc(10 + c->extradata_size * 2);
 155     if (config == NULL) {
 156         av_log(c, AV_LOG_ERROR, "Cannot allocate memory for the config info.\n");
 157         return NULL;
 158     }
 159     memcpy(config, "; config=", 9);
 160     ff_data_to_hex(config + 9, c->extradata, c->extradata_size);
 161     config[9 + c->extradata_size * 2] = 0;
 162
 163     return config;
 164 }
 165
 166 static char *sdp_write_media_attributes(char *buff, int size, AVCodecContext *c, int payload_type)
 167 {
 168     char *config = NULL;
 169
 170     switch (c->codec_id) {
 171         case CODEC_ID_H264:
 172             if (c->extradata_size) {
 173                 config = extradata2psets(c);
 174             }
 175             av_strlcatf(buff, size, "a=rtpmap:%d H264/90000\r\n"
 176                                     "a=fmtp:%d packetization-mode=1%s\r\n",
 177                                      payload_type,
 178                                      payload_type, config ? config : "");
 179             break;
 180         case CODEC_ID_H263:
 181         case CODEC_ID_H263P:
 182             av_strlcatf(buff, size, "a=rtpmap:%d H263-2000/90000\r\n", payload_type);
 183             break;
 184         case CODEC_ID_MPEG4:
 185             if (c->extradata_size) {
 186                 config = extradata2config(c);
 187             }
 188             av_strlcatf(buff, size, "a=rtpmap:%d MP4V-ES/90000\r\n"
 189                                     "a=fmtp:%d profile-level-id=1%s\r\n",
 190                                      payload_type,
 191                                      payload_type, config ? config : "");
 192             break;
 193         case CODEC_ID_AAC:
 194             if (c->extradata_size) {
 195                 config = extradata2config(c);
 196             } else {
 197                 /* FIXME: maybe we can forge config information based on the
 198                  *        codec parameters...
 199                  */
 200                 av_log(c, AV_LOG_ERROR, "AAC with no global headers is currently not supported.\n");
 201                 return NULL;
 202             }
 203             if (config == NULL) {
 204                 return NULL;
 205             }
 206             av_strlcatf(buff, size, "a=rtpmap:%d MPEG4-GENERIC/%d/%d\r\n"
 207                                     "a=fmtp:%d profile-level-id=1;"
 208                                     "mode=AAC-hbr;sizelength=13;indexlength=3;"
 209                                     "indexdeltalength=3%s\r\n",
 210                                      payload_type, c->sample_rate, c->channels,
 211                                      payload_type, config);
 212             break;
 213         case CODEC_ID_PCM_S16BE:
 214             if (payload_type >= 96)
 215                 av_strlcatf(buff, size, "a=rtpmap:%d L16/%d/%d\r\n",
 216                                          payload_type,
 217                                          c->sample_rate, c->channels);
 218             break;
 219         case CODEC_ID_PCM_MULAW:
 220             if (payload_type >= 96)
 221                 av_strlcatf(buff, size, "a=rtpmap:%d PCMU/%d/%d\r\n",
 222                                          payload_type,
 223                                          c->sample_rate, c->channels);
 224             break;
 225         case CODEC_ID_PCM_ALAW:
 226             if (payload_type >= 96)
 227                 av_strlcatf(buff, size, "a=rtpmap:%d PCMA/%d/%d\r\n",
 228                                          payload_type,
 229                                          c->sample_rate, c->channels);
 230             break;
 231         case CODEC_ID_AMR_NB:
 232             av_strlcatf(buff, size, "a=rtpmap:%d AMR/%d/%d\r\n"
 233                                     "a=fmtp:%d octet-align=1\r\n",
 234                                      payload_type, c->sample_rate, c->channels,
 235                                      payload_type);
 236             break;
 237         case CODEC_ID_AMR_WB:
 238             av_strlcatf(buff, size, "a=rtpmap:%d AMR-WB/%d/%d\r\n"
 239                                     "a=fmtp:%d octet-align=1\r\n",
 240                                      payload_type, c->sample_rate, c->channels,
 241                                      payload_type);
 242             break;
 243         default:
 244             /* Nothing special to do here... */
 245             break;
 246     }
 247
 248     av_free(config);
 249
 250     return buff;
 251 }
 252
 253 static void sdp_write_media(char *buff, int size, AVCodecContext *c, const char *dest_addr, int port, int ttl)
 254 {
 255     const char *type;
 256     int payload_type;
 257
 258     payload_type = ff_rtp_get_payload_type(c);
 259     if (payload_type < 0) {
 260         payload_type = 96;  /* FIXME: how to assign a private pt? rtp.c is broken too */
 261     }
 262
 263     switch (c->codec_type) {
 264         case CODEC_TYPE_VIDEO   : type = "video"      ; break;
 265         case CODEC_TYPE_AUDIO   : type = "audio"      ; break;
 266         case CODEC_TYPE_SUBTITLE: type = "text"       ; break;
 267         default                 : type = "application"; break;
 268     }
 269
 270     av_strlcatf(buff, size, "m=%s %d RTP/AVP %d\r\n", type, port, payload_type);
 271     sdp_write_address(buff, size, dest_addr, ttl);
 272     if (c->bit_rate) {
 273         av_strlcatf(buff, size, "b=AS:%d\r\n", c->bit_rate / 1000);
 274     }
 275
 276     sdp_write_media_attributes(buff, size, c, payload_type);
 277 }
 278
 279 int avf_sdp_create(AVFormatContext *ac[], int n_files, char *buff, int size)
 280 {
 281     AVMetadataTag *title = av_metadata_get(ac[0]->metadata, "title", NULL, 0);
 282     struct sdp_session_level s;
 283     int i, j, port, ttl;
 284     char dst[32];
 285
 286     memset(buff, 0, size);
 287     memset(&s, 0, sizeof(struct sdp_session_level));
 288     s.user = "-";
 289     s.src_addr = "127.0.0.1";    /* FIXME: Properly set this */
 290     s.name = title ? title->value : "No Name";
 291
 292     port = 0;
 293     ttl = 0;
 294     if (n_files == 1) {
 295         port = sdp_get_address(dst, sizeof(dst), &ttl, ac[0]->filename);
 296         if (port > 0) {
 297             s.dst_addr = dst;
 298             s.ttl = ttl;
 299         }
 300     }
 301     sdp_write_header(buff, size, &s);
 302
 303     dst[0] = 0;
 304     for (i = 0; i < n_files; i++) {
 305         if (n_files != 1) {
 306             port = sdp_get_address(dst, sizeof(dst), &ttl, ac[i]->filename);
 307         }
 308         for (j = 0; j < ac[i]->nb_streams; j++) {
 309             sdp_write_media(buff, size,
 310                                   ac[i]->streams[j]->codec, dst[0] ? dst : NULL,
 311                                   (port > 0) ? port + j * 2 : 0, ttl);
 312             if (port <= 0) {
 313                 av_strlcatf(buff, size,
 314                                    "a=control:streamid=%d\r\n", i + j);
 315             }
 316         }
 317     }
 318
 319     return 0;
 320 }
 321 #else
 322 int avf_sdp_create(AVFormatContext *ac[], int n_files, char *buff, int size)
 323 {
 324     return AVERROR(ENOSYS);
 325 }
 326 #endif