/*
  * copyright (c) 2007 Luca Abeni
  *
  * This file is part of FFmpeg.
  *
  * FFmpeg is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Lesser General Public
  * License as published by the Free Software Foundation; either
  * version 2.1 of the License, or (at your option) any later version.
  *
  * FFmpeg is distributed in the hope that it will be useful,
  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  * Lesser General Public License for more details.
  *
  * You should have received a copy of the GNU Lesser General Public
  * License along with FFmpeg; if not, write to the Free Software
  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
  */
 

 #include "libavutil/avstring.h"
 #include "libavutil/base64.h"

 #include "avformat.h"

 #include "internal.h"

 #include "avc.h"

 #include "rtp.h"

 #if CONFIG_RTP_MUXER

 #define MAX_EXTRADATA_SIZE ((INT_MAX - 10) / 2)
 
 struct sdp_session_level {
     int sdp_version;      /**< protocol version (currently 0) */

     int id;               /**< session ID */

     int version;          /**< session version */
     int start_time;       /**< session start time (NTP time, in seconds),

                                or 0 in case of permanent session */

     int end_time;         /**< session end time (NTP time, in seconds),
                                or 0 if the session is not bounded */
     int ttl;              /**< TTL, in case of multicast stream */
     const char *user;     /**< username of the session's creator */
     const char *src_addr; /**< IP address of the machine from which the session was created */
     const char *dst_addr; /**< destination IP address (can be multicast) */
     const char *name;     /**< session name (can be an empty string) */
 };
 

 static void sdp_write_address(char *buff, int size, const char *dest_addr, int ttl)

 {
     if (dest_addr) {
         if (ttl > 0) {
             av_strlcatf(buff, size, "c=IN IP4 %s/%d\r\n", dest_addr, ttl);
         } else {
             av_strlcatf(buff, size, "c=IN IP4 %s\r\n", dest_addr);
         }
     }
 }
 
 static void sdp_write_header(char *buff, int size, struct sdp_session_level *s)
 {
     av_strlcatf(buff, size, "v=%d\r\n"

                             "o=- %d %d IN IP4 %s\r\n"

                             "t=%d %d\r\n"
                             "s=%s\r\n"

                             "a=tool:libavformat " AV_STRINGIFY(LIBAVFORMAT_VERSION) "\r\n",

                             s->sdp_version,
                             s->id, s->version, s->src_addr,
                             s->start_time, s->end_time,

                             s->name);

     sdp_write_address(buff, size, s->dst_addr, s->ttl);

 }
 

 static int sdp_get_address(char *dest_addr, int size, int *ttl, const char *url)

 {
     int port;
     const char *p;
 
     url_split(NULL, 0, NULL, 0, dest_addr, size, &port, NULL, 0, url);
 
     *ttl = 0;
     p = strchr(url, '?');
     if (p) {
         char buff[64];
         int is_multicast = find_info_tag(buff, sizeof(buff), "multicast", p);
 
         if (is_multicast) {
             if (find_info_tag(buff, sizeof(buff), "ttl", p)) {
                 *ttl = strtol(buff, NULL, 10);
             } else {
                 *ttl = 5;
             }
         }
     }
 
     return port;
 }
 

 #define MAX_PSET_SIZE 1024
 static char *extradata2psets(AVCodecContext *c)
 {
     char *psets, *p;

     const uint8_t *r;

     const char *pset_string = "; sprop-parameter-sets=";
 
     if (c->extradata_size > MAX_EXTRADATA_SIZE) {

         av_log(c, AV_LOG_ERROR, "Too much extradata!\n");

 
         return NULL;
     }
 
     psets = av_mallocz(MAX_PSET_SIZE);
     if (psets == NULL) {

         av_log(c, AV_LOG_ERROR, "Cannot allocate memory for the parameter sets.\n");

         return NULL;
     }
     memcpy(psets, pset_string, strlen(pset_string));
     p = psets + strlen(pset_string);
     r = ff_avc_find_startcode(c->extradata, c->extradata + c->extradata_size);
     while (r < c->extradata + c->extradata_size) {

         const uint8_t *r1;

 
         while (!*(r++));
         r1 = ff_avc_find_startcode(r, c->extradata + c->extradata_size);
         if (p != (psets + strlen(pset_string))) {
             *p = ',';
             p++;
         }
         if (av_base64_encode(p, MAX_PSET_SIZE - (p - psets), r, r1 - r) == NULL) {

             av_log(c, AV_LOG_ERROR, "Cannot Base64-encode %td %td!\n", MAX_PSET_SIZE - (p - psets), r1 - r);

             av_free(psets);
 
             return NULL;
         }
         p += strlen(p);
         r = r1;
     }
 
     return psets;
 }
 

 static char *extradata2config(AVCodecContext *c)

 {
     char *config;
 

     if (c->extradata_size > MAX_EXTRADATA_SIZE) {

         av_log(c, AV_LOG_ERROR, "Too much extradata!\n");

 
         return NULL;
     }

     config = av_malloc(10 + c->extradata_size * 2);

     if (config == NULL) {

         av_log(c, AV_LOG_ERROR, "Cannot allocate memory for the config info.\n");

         return NULL;
     }
     memcpy(config, "; config=", 9);

     ff_data_to_hex(config + 9, c->extradata, c->extradata_size);

     config[9 + c->extradata_size * 2] = 0;

 
     return config;
 }
 

 static char *sdp_write_media_attributes(char *buff, int size, AVCodecContext *c, int payload_type)

 {
     char *config = NULL;
 
     switch (c->codec_id) {

         case CODEC_ID_H264:

             if (c->extradata_size) {
                 config = extradata2psets(c);
             }

             av_strlcatf(buff, size, "a=rtpmap:%d H264/90000\r\n"
                                     "a=fmtp:%d packetization-mode=1%s\r\n",
                                      payload_type,
                                      payload_type, config ? config : "");
             break;

         case CODEC_ID_MPEG4:

             if (c->extradata_size) {

                 config = extradata2config(c);

             }
             av_strlcatf(buff, size, "a=rtpmap:%d MP4V-ES/90000\r\n"
                                     "a=fmtp:%d profile-level-id=1%s\r\n",
                                      payload_type,
                                      payload_type, config ? config : "");
             break;

         case CODEC_ID_AAC:

             if (c->extradata_size) {

                 config = extradata2config(c);

             } else {
                 /* FIXME: maybe we can forge config information based on the
                  *        codec parameters...
                  */

                 av_log(c, AV_LOG_ERROR, "AAC with no global headers is currently not supported.\n");

                 return NULL;
             }
             if (config == NULL) {
                 return NULL;
             }
             av_strlcatf(buff, size, "a=rtpmap:%d MPEG4-GENERIC/%d/%d\r\n"
                                     "a=fmtp:%d profile-level-id=1;"
                                     "mode=AAC-hbr;sizelength=13;indexlength=3;"
                                     "indexdeltalength=3%s\r\n",
                                      payload_type, c->sample_rate, c->channels,
                                      payload_type, config);
             break;

         case CODEC_ID_PCM_S16BE:
             if (payload_type >= 96)
                 av_strlcatf(buff, size, "a=rtpmap:%d L16/%d/%d\r\n",
                                          payload_type,
                                          c->sample_rate, c->channels);
             break;
         case CODEC_ID_PCM_MULAW:
             if (payload_type >= 96)
                 av_strlcatf(buff, size, "a=rtpmap:%d PCMU/%d/%d\r\n",
                                          payload_type,
                                          c->sample_rate, c->channels);
             break;
         case CODEC_ID_PCM_ALAW:
             if (payload_type >= 96)
                 av_strlcatf(buff, size, "a=rtpmap:%d PCMA/%d/%d\r\n",
                                          payload_type,
                                          c->sample_rate, c->channels);
             break;

         default:

             /* Nothing special to do here... */

             break;
     }
 
     av_free(config);
 
     return buff;
 }
 
 static void sdp_write_media(char *buff, int size, AVCodecContext *c, const char *dest_addr, int port, int ttl)
 {
     const char *type;
     int payload_type;
 

     payload_type = ff_rtp_get_payload_type(c);

     if (payload_type < 0) {
         payload_type = 96;  /* FIXME: how to assign a private pt? rtp.c is broken too */
     }
 
     switch (c->codec_type) {
         case CODEC_TYPE_VIDEO   : type = "video"      ; break;
         case CODEC_TYPE_AUDIO   : type = "audio"      ; break;
         case CODEC_TYPE_SUBTITLE: type = "text"       ; break;
         default                 : type = "application"; break;
     }
 
     av_strlcatf(buff, size, "m=%s %d RTP/AVP %d\r\n", type, port, payload_type);

     sdp_write_address(buff, size, dest_addr, ttl);

     if (c->bit_rate) {
         av_strlcatf(buff, size, "b=AS:%d\r\n", c->bit_rate / 1000);
     }

     sdp_write_media_attributes(buff, size, c, payload_type);

 }
 

 int avf_sdp_create(AVFormatContext *ac[], int n_files, char *buff, int size)

 {

     AVMetadataTag *title = av_metadata_get(ac[0]->metadata, "title", NULL, 0);

     struct sdp_session_level s;
     int i, j, port, ttl;
     char dst[32];
 

     memset(buff, 0, size);

     memset(&s, 0, sizeof(struct sdp_session_level));
     s.user = "-";
     s.src_addr = "127.0.0.1";    /* FIXME: Properly set this */

     s.name = title ? title->value : "No Name";

 
     port = 0;
     ttl = 0;
     if (n_files == 1) {

         port = sdp_get_address(dst, sizeof(dst), &ttl, ac[0]->filename);

         if (port > 0) {
             s.dst_addr = dst;
             s.ttl = ttl;
         }
     }

     sdp_write_header(buff, size, &s);

 
     dst[0] = 0;
     for (i = 0; i < n_files; i++) {
         if (n_files != 1) {

             port = sdp_get_address(dst, sizeof(dst), &ttl, ac[i]->filename);

         }
         for (j = 0; j < ac[i]->nb_streams; j++) {

             sdp_write_media(buff, size,

                                   ac[i]->streams[j]->codec, dst[0] ? dst : NULL,
                                   (port > 0) ? port + j * 2 : 0, ttl);
             if (port <= 0) {

                 av_strlcatf(buff, size,

                                    "a=control:streamid=%d\r\n", i + j);
             }
         }
     }
 

     return 0;

 }

 #else

 int avf_sdp_create(AVFormatContext *ac[], int n_files, char *buff, int size)

 {

     return AVERROR(ENOSYS);

 }
 #endif