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
 120         while (!*(r++));
 121         r1 = ff_avc_find_startcode(r, c->extradata + c->extradata_size);
 122         if (p != (psets + strlen(pset_string))) {
 123             *p = ',';
 124             p++;
 125         }
 126         if (av_base64_encode(p, MAX_PSET_SIZE - (p - psets), r, r1 - r) == NULL) {
 127             av_log(c, AV_LOG_ERROR, "Cannot Base64-encode %td %td!\n", MAX_PSET_SIZE - (p - psets), r1 - r);
 128             av_free(psets);
 129
 130             return NULL;
 131         }
 132         p += strlen(p);
 133         r = r1;
 134     }
 135
 136     return psets;
 137 }
 138
 139 static char *extradata2config(AVCodecContext *c)
 140 {
 141     char *config;
 142
 143     if (c->extradata_size > MAX_EXTRADATA_SIZE) {
 144         av_log(c, AV_LOG_ERROR, "Too much extradata!\n");
 145
 146         return NULL;
 147     }
 148     config = av_malloc(10 + c->extradata_size * 2);
 149     if (config == NULL) {
 150         av_log(c, AV_LOG_ERROR, "Cannot allocate memory for the config info.\n");
 151         return NULL;
 152     }
 153     memcpy(config, "; config=", 9);
 154     ff_data_to_hex(config + 9, c->extradata, c->extradata_size);
 155     config[9 + c->extradata_size * 2] = 0;
 156
 157     return config;
 158 }
 159
 160 static char *sdp_write_media_attributes(char *buff, int size, AVCodecContext *c, int payload_type)
 161 {
 162     char *config = NULL;
 163
 164     switch (c->codec_id) {
 165         case CODEC_ID_H264:
 166             if (c->extradata_size) {
 167                 config = extradata2psets(c);
 168             }
 169             av_strlcatf(buff, size, "a=rtpmap:%d H264/90000\r\n"
 170                                     "a=fmtp:%d packetization-mode=1%s\r\n",
 171                                      payload_type,
 172                                      payload_type, config ? config : "");
 173             break;
 174         case CODEC_ID_MPEG4:
 175             if (c->extradata_size) {
 176                 config = extradata2config(c);
 177             }
 178             av_strlcatf(buff, size, "a=rtpmap:%d MP4V-ES/90000\r\n"
 179                                     "a=fmtp:%d profile-level-id=1%s\r\n",
 180                                      payload_type,
 181                                      payload_type, config ? config : "");
 182             break;
 183         case CODEC_ID_AAC:
 184             if (c->extradata_size) {
 185                 config = extradata2config(c);
 186             } else {
 187                 /* FIXME: maybe we can forge config information based on the
 188                  *        codec parameters...
 189                  */
 190                 av_log(c, AV_LOG_ERROR, "AAC with no global headers is currently not supported.\n");
 191                 return NULL;
 192             }
 193             if (config == NULL) {
 194                 return NULL;
 195             }
 196             av_strlcatf(buff, size, "a=rtpmap:%d MPEG4-GENERIC/%d/%d\r\n"
 197                                     "a=fmtp:%d profile-level-id=1;"
 198                                     "mode=AAC-hbr;sizelength=13;indexlength=3;"
 199                                     "indexdeltalength=3%s\r\n",
 200                                      payload_type, c->sample_rate, c->channels,
 201                                      payload_type, config);
 202             break;
 203         case CODEC_ID_PCM_S16BE:
 204             if (payload_type >= 96)
 205                 av_strlcatf(buff, size, "a=rtpmap:%d L16/%d/%d\r\n",
 206                                          payload_type,
 207                                          c->sample_rate, c->channels);
 208             break;
 209         case CODEC_ID_PCM_MULAW:
 210             if (payload_type >= 96)
 211                 av_strlcatf(buff, size, "a=rtpmap:%d PCMU/%d/%d\r\n",
 212                                          payload_type,
 213                                          c->sample_rate, c->channels);
 214             break;
 215         case CODEC_ID_PCM_ALAW:
 216             if (payload_type >= 96)
 217                 av_strlcatf(buff, size, "a=rtpmap:%d PCMA/%d/%d\r\n",
 218                                          payload_type,
 219                                          c->sample_rate, c->channels);
 220             break;
 221         default:
 222             /* Nothing special to do here... */
 223             break;
 224     }
 225
 226     av_free(config);
 227
 228     return buff;
 229 }
 230
 231 static void sdp_write_media(char *buff, int size, AVCodecContext *c, const char *dest_addr, int port, int ttl)
 232 {
 233     const char *type;
 234     int payload_type;
 235
 236     payload_type = ff_rtp_get_payload_type(c);
 237     if (payload_type < 0) {
 238         payload_type = 96;  /* FIXME: how to assign a private pt? rtp.c is broken too */
 239     }
 240
 241     switch (c->codec_type) {
 242         case CODEC_TYPE_VIDEO   : type = "video"      ; break;
 243         case CODEC_TYPE_AUDIO   : type = "audio"      ; break;
 244         case CODEC_TYPE_SUBTITLE: type = "text"       ; break;
 245         default                 : type = "application"; break;
 246     }
 247
 248     av_strlcatf(buff, size, "m=%s %d RTP/AVP %d\r\n", type, port, payload_type);
 249     sdp_write_address(buff, size, dest_addr, ttl);
 250     if (c->bit_rate) {
 251         av_strlcatf(buff, size, "b=AS:%d\r\n", c->bit_rate / 1000);
 252     }
 253
 254     sdp_write_media_attributes(buff, size, c, payload_type);
 255 }
 256
 257 int avf_sdp_create(AVFormatContext *ac[], int n_files, char *buff, int size)
 258 {
 259     AVMetadataTag *title = av_metadata_get(ac[0]->metadata, "title", NULL, 0);
 260     struct sdp_session_level s;
 261     int i, j, port, ttl;
 262     char dst[32];
 263
 264     memset(buff, 0, size);
 265     memset(&s, 0, sizeof(struct sdp_session_level));
 266     s.user = "-";
 267     s.src_addr = "127.0.0.1";    /* FIXME: Properly set this */
 268     s.name = title ? title->value : "No Name";
 269
 270     port = 0;
 271     ttl = 0;
 272     if (n_files == 1) {
 273         port = sdp_get_address(dst, sizeof(dst), &ttl, ac[0]->filename);
 274         if (port > 0) {
 275             s.dst_addr = dst;
 276             s.ttl = ttl;
 277         }
 278     }
 279     sdp_write_header(buff, size, &s);
 280
 281     dst[0] = 0;
 282     for (i = 0; i < n_files; i++) {
 283         if (n_files != 1) {
 284             port = sdp_get_address(dst, sizeof(dst), &ttl, ac[i]->filename);
 285         }
 286         for (j = 0; j < ac[i]->nb_streams; j++) {
 287             sdp_write_media(buff, size,
 288                                   ac[i]->streams[j]->codec, dst[0] ? dst : NULL,
 289                                   (port > 0) ? port + j * 2 : 0, ttl);
 290             if (port <= 0) {
 291                 av_strlcatf(buff, size,
 292                                    "a=control:streamid=%d\r\n", i + j);
 293             }
 294         }
 295     }
 296
 297     return 0;
 298 }
 299 #else
 300 int avf_sdp_create(AVFormatContext *ac[], int n_files, char *buff, int size)
 301 {
 302     return AVERROR(ENOSYS);
 303 }
 304 #endif