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 "avc.h"
  25 #include "rtp.h"
  26
  27 #ifdef CONFIG_RTP_MUXER
  28 #define MAX_EXTRADATA_SIZE ((INT_MAX - 10) / 2)
  29
  30 struct sdp_session_level {
  31     int sdp_version;      /**< protocol version (currently 0) */
  32     int id;               /**< session id */
  33     int version;          /**< session version */
  34     int start_time;       /**< session start time (NTP time, in seconds),
  35                              or 0 in case of permanent session */
  36     int end_time;         /**< session end time (NTP time, in seconds),
  37                                or 0 if the session is not bounded */
  38     int ttl;              /**< TTL, in case of multicast stream */
  39     const char *user;     /**< username of the session's creator */
  40     const char *src_addr; /**< IP address of the machine from which the session was created */
  41     const char *dst_addr; /**< destination IP address (can be multicast) */
  42     const char *name;     /**< session name (can be an empty string) */
  43 };
  44
  45 static void dest_write(char *buff, int size, const char *dest_addr, int ttl)
  46 {
  47     if (dest_addr) {
  48         if (ttl > 0) {
  49             av_strlcatf(buff, size, "c=IN IP4 %s/%d\r\n", dest_addr, ttl);
  50         } else {
  51             av_strlcatf(buff, size, "c=IN IP4 %s\r\n", dest_addr);
  52         }
  53     }
  54 }
  55
  56 static void sdp_write_header(char *buff, int size, struct sdp_session_level *s)
  57 {
  58     av_strlcatf(buff, size, "v=%d\r\n"
  59                             "o=- %d %d IN IPV4 %s\r\n"
  60                             "t=%d %d\r\n"
  61                             "s=%s\r\n"
  62                             "a=tool:libavformat\r\n",
  63                             s->sdp_version,
  64                             s->id, s->version, s->src_addr,
  65                             s->start_time, s->end_time,
  66                             s->name[0] ? s->name : "No Name");
  67     dest_write(buff, size, s->dst_addr, s->ttl);
  68 }
  69
  70 static int get_address(char *dest_addr, int size, int *ttl, const char *url)
  71 {
  72     int port;
  73     const char *p;
  74
  75     url_split(NULL, 0, NULL, 0, dest_addr, size, &port, NULL, 0, url);
  76
  77     *ttl = 0;
  78     p = strchr(url, '?');
  79     if (p) {
  80         char buff[64];
  81         int is_multicast = find_info_tag(buff, sizeof(buff), "multicast", p);
  82
  83         if (is_multicast) {
  84             if (find_info_tag(buff, sizeof(buff), "ttl", p)) {
  85                 *ttl = strtol(buff, NULL, 10);
  86             } else {
  87                 *ttl = 5;
  88             }
  89         }
  90     }
  91
  92     return port;
  93 }
  94
  95 #define MAX_PSET_SIZE 1024
  96 static char *extradata2psets(AVCodecContext *c)
  97 {
  98     char *psets, *p;
  99     const uint8_t *r;
 100     const char *pset_string = "; sprop-parameter-sets=";
 101
 102     if (c->extradata_size > MAX_EXTRADATA_SIZE) {
 103         av_log(c, AV_LOG_ERROR, "Too many extra data!\n");
 104
 105         return NULL;
 106     }
 107
 108     psets = av_mallocz(MAX_PSET_SIZE);
 109     if (psets == NULL) {
 110         av_log(c, AV_LOG_ERROR, "Cannot allocate memory for the parameter sets\n");
 111         return NULL;
 112     }
 113     memcpy(psets, pset_string, strlen(pset_string));
 114     p = psets + strlen(pset_string);
 115     r = ff_avc_find_startcode(c->extradata, c->extradata + c->extradata_size);
 116     while (r < c->extradata + c->extradata_size) {
 117         const uint8_t *r1;
 118
 119         while (!*(r++));
 120         r1 = ff_avc_find_startcode(r, c->extradata + c->extradata_size);
 121         if (p != (psets + strlen(pset_string))) {
 122             *p = ',';
 123             p++;
 124         }
 125         if (av_base64_encode(p, MAX_PSET_SIZE - (p - psets), r, r1 - r) == NULL) {
 126             av_log(c, AV_LOG_ERROR, "Cannot BASE64 encode %td %td!\n", MAX_PSET_SIZE - (p - psets), r1 - r);
 127             av_free(psets);
 128
 129             return NULL;
 130         }
 131         p += strlen(p);
 132         r = r1;
 133     }
 134
 135     return psets;
 136 }
 137
 138 static void digit_to_char(char *dst, uint8_t src)
 139 {
 140     if (src < 10) {
 141         *dst = '0' + src;
 142     } else {
 143         *dst = 'A' + src - 10;
 144     }
 145 }
 146
 147 static char *data_to_hex(char *buff, const uint8_t *src, int s)
 148 {
 149     int i;
 150
 151     for(i = 0; i < s; i++) {
 152         digit_to_char(buff + 2 * i, src[i] >> 4);
 153         digit_to_char(buff + 2 * i + 1, src[i] & 0xF);
 154     }
 155
 156     return buff;
 157 }
 158
 159 static char *extradata2config(AVCodecContext *c)
 160 {
 161     char *config;
 162
 163     if (c->extradata_size > MAX_EXTRADATA_SIZE) {
 164         av_log(c, AV_LOG_ERROR, "Too many extra data!\n");
 165
 166         return NULL;
 167     }
 168     config = av_malloc(10 + c->extradata_size * 2);
 169     if (config == NULL) {
 170         av_log(c, AV_LOG_ERROR, "Cannot allocate memory for the config info\n");
 171         return NULL;
 172     }
 173     memcpy(config, "; config=", 9);
 174     data_to_hex(config + 9, c->extradata, c->extradata_size);
 175     config[9 + c->extradata_size * 2] = 0;
 176
 177     return config;
 178 }
 179
 180 static char *sdp_media_attributes(char *buff, int size, AVCodecContext *c, int payload_type)
 181 {
 182     char *config = NULL;
 183
 184     switch (c->codec_id) {
 185         case CODEC_ID_H264:
 186             if (c->extradata_size) {
 187                 config = extradata2psets(c);
 188             }
 189             av_strlcatf(buff, size, "a=rtpmap:%d H264/90000\r\n"
 190                                     "a=fmtp:%d packetization-mode=1%s\r\n",
 191                                      payload_type,
 192                                      payload_type, config ? config : "");
 193             break;
 194         case CODEC_ID_MPEG4:
 195             if (c->extradata_size) {
 196                 config = extradata2config(c);
 197             }
 198             av_strlcatf(buff, size, "a=rtpmap:%d MP4V-ES/90000\r\n"
 199                                     "a=fmtp:%d profile-level-id=1%s\r\n",
 200                                      payload_type,
 201                                      payload_type, config ? config : "");
 202             break;
 203         case CODEC_ID_AAC:
 204             if (c->extradata_size) {
 205                 config = extradata2config(c);
 206             } else {
 207                 /* FIXME: maybe we can forge config information based on the
 208                  *        codec parameters...
 209                  */
 210                 av_log(c, AV_LOG_ERROR, "AAC with no global headers is currently not supported\n");
 211                 return NULL;
 212             }
 213             if (config == NULL) {
 214                 return NULL;
 215             }
 216             av_strlcatf(buff, size, "a=rtpmap:%d MPEG4-GENERIC/%d/%d\r\n"
 217                                     "a=fmtp:%d profile-level-id=1;"
 218                                     "mode=AAC-hbr;sizelength=13;indexlength=3;"
 219                                     "indexdeltalength=3%s\r\n",
 220                                      payload_type, c->sample_rate, c->channels,
 221                                      payload_type, config);
 222             break;
 223         case CODEC_ID_PCM_S16BE:
 224             if (payload_type >= 96)
 225                 av_strlcatf(buff, size, "a=rtpmap:%d L16/%d/%d\r\n",
 226                                          payload_type,
 227                                          c->sample_rate, c->channels);
 228             break;
 229         case CODEC_ID_PCM_MULAW:
 230             if (payload_type >= 96)
 231                 av_strlcatf(buff, size, "a=rtpmap:%d PCMU/%d/%d\r\n",
 232                                          payload_type,
 233                                          c->sample_rate, c->channels);
 234             break;
 235         case CODEC_ID_PCM_ALAW:
 236             if (payload_type >= 96)
 237                 av_strlcatf(buff, size, "a=rtpmap:%d PCMA/%d/%d\r\n",
 238                                          payload_type,
 239                                          c->sample_rate, c->channels);
 240             break;
 241         default:
 242             /* Nothing special to do, here... */
 243             break;
 244     }
 245
 246     av_free(config);
 247
 248     return buff;
 249 }
 250
 251 static void sdp_write_media(char *buff, int size, AVCodecContext *c, const char *dest_addr, int port, int ttl)
 252 {
 253     const char *type;
 254     int payload_type;
 255
 256     payload_type = rtp_get_payload_type(c);
 257     if (payload_type < 0) {
 258         payload_type = 96;  /* FIXME: how to assign a private pt? rtp.c is broken too */
 259     }
 260
 261     switch (c->codec_type) {
 262         case CODEC_TYPE_VIDEO   : type = "video"      ; break;
 263         case CODEC_TYPE_AUDIO   : type = "audio"      ; break;
 264         case CODEC_TYPE_SUBTITLE: type = "text"       ; break;
 265         default                 : type = "application"; break;
 266     }
 267
 268     av_strlcatf(buff, size, "m=%s %d RTP/AVP %d\r\n", type, port, payload_type);
 269     dest_write(buff, size, dest_addr, ttl);
 270     if (c->bit_rate) {
 271         av_strlcatf(buff, size, "b=AS:%d\r\n", c->bit_rate / 1000);
 272     }
 273
 274     sdp_media_attributes(buff, size, c, payload_type);
 275 }
 276
 277 int avf_sdp_create(AVFormatContext *ac[], int n_files, char *buff, int size)
 278 {
 279     struct sdp_session_level s;
 280     int i, j, port, ttl;
 281     char dst[32];
 282
 283     memset(buff, 0, size);
 284     memset(&s, 0, sizeof(struct sdp_session_level));
 285     s.user = "-";
 286     s.src_addr = "127.0.0.1";    /* FIXME: Properly set this */
 287     s.name = ac[0]->title;
 288
 289     port = 0;
 290     ttl = 0;
 291     if (n_files == 1) {
 292         port = get_address(dst, sizeof(dst), &ttl, ac[0]->filename);
 293         if (port > 0) {
 294             s.dst_addr = dst;
 295             s.ttl = ttl;
 296         }
 297     }
 298     sdp_write_header(buff, size, &s);
 299
 300     dst[0] = 0;
 301     for (i = 0; i < n_files; i++) {
 302         if (n_files != 1) {
 303             port = get_address(dst, sizeof(dst), &ttl, ac[i]->filename);
 304         }
 305         for (j = 0; j < ac[i]->nb_streams; j++) {
 306             sdp_write_media(buff, size,
 307                                   ac[i]->streams[j]->codec, dst[0] ? dst : NULL,
 308                                   (port > 0) ? port + j * 2 : 0, ttl);
 309             if (port <= 0) {
 310                 av_strlcatf(buff, size,
 311                                    "a=control:streamid=%d\r\n", i + j);
 312             }
 313         }
 314     }
 315
 316     return 0;
 317 }
 318 #else
 319 int avf_sdp_create(AVFormatContext *ac[], int n_files, char *buff, int size)
 320 {
 321     return AVERROR(ENOSYS);
 322 }
 323 #endif