rtsp.c

mplayer播放器的源码

  if (what) {
    buf=strdup(what);
  } else
  {
    buf=malloc(strlen(s->host)+16);
    sprintf(buf,"rtsp://%s:%i", s->host, s->port);
  }
  rtsp_send_request(s,RTSP_METHOD_OPTIONS,buf);
  free(buf);

  return rtsp_get_answers(s);
}

int rtsp_request_describe(rtsp_t *s, const char *what) {

  char *buf;

  if (what) {
    buf=strdup(what);
  } else
  {
    buf=malloc(strlen(s->host)+strlen(s->path)+16);
    sprintf(buf,"rtsp://%s:%i/%s", s->host, s->port, s->path);
  }
  rtsp_send_request(s,RTSP_METHOD_DESCRIBE,buf);
  free(buf);
  
  return rtsp_get_answers(s);
}

int rtsp_request_setup(rtsp_t *s, const char *what, char *control) {

  char *buf = NULL;

  if (what)
    buf = strdup (what);
  else
  {
    int len = strlen (s->host) + strlen (s->path) + 16;
    if (control)
      len += strlen (control) + 1;
    
    buf = malloc (len);
    sprintf (buf, "rtsp://%s:%i/%s%s%s", s->host, s->port, s->path,
             control ? "/" : "", control ? control : "");
  }
  
  rtsp_send_request (s, RTSP_METHOD_SETUP, buf);
  free (buf);
  return rtsp_get_answers (s);
}

int rtsp_request_setparameter(rtsp_t *s, const char *what) {

  char *buf;

  if (what) {
    buf=strdup(what);
  } else
  {
    buf=malloc(strlen(s->host)+strlen(s->path)+16);
    sprintf(buf,"rtsp://%s:%i/%s", s->host, s->port, s->path);
  }
  rtsp_send_request(s,RTSP_METHOD_SET_PARAMETER,buf);
  free(buf);
  
  return rtsp_get_answers(s);
}

int rtsp_request_play(rtsp_t *s, const char *what) {

  char *buf;
  int ret;
  
  if (what) {
    buf=strdup(what);
  } else
  {
    buf=malloc(strlen(s->host)+strlen(s->path)+16);
    sprintf(buf,"rtsp://%s:%i/%s", s->host, s->port, s->path);
  }
  rtsp_send_request(s,RTSP_METHOD_PLAY,buf);
  free(buf);
  
  ret = rtsp_get_answers (s);
  if (ret == RTSP_STATUS_OK)
    s->server_state = RTSP_PLAYING;

  return ret;
}

int rtsp_request_teardown(rtsp_t *s, const char *what) {

  char *buf;
  
  if (what)
    buf = strdup (what);
  else
  {
    buf =
      malloc (strlen (s->host) + strlen (s->path) + 16);
    sprintf (buf, "rtsp://%s:%i/%s", s->host, s->port, s->path);
  }
  rtsp_send_request (s, RTSP_METHOD_TEARDOWN, buf);
  free (buf);

  /* after teardown we're done with RTSP streaming, no need to get answer as
     reading more will only result to garbage and buffer overflow */
  return RTSP_STATUS_OK;
}

/*
 * read opaque data from stream
 */

int rtsp_read_data(rtsp_t *s, char *buffer, unsigned int size) {

  int i,seq;

  if (size>=4) {
    i=read_stream(s->s, buffer, 4);
    if (i<4) return i;
    if (((buffer[0]=='S')&&(buffer[1]=='E')&&(buffer[2]=='T')&&(buffer[3]=='_')) ||
        ((buffer[0]=='O')&&(buffer[1]=='P')&&(buffer[2]=='T')&&(buffer[3]=='I'))) // OPTIONS
    {
      char *rest=rtsp_get(s);
      if (!rest)
        return -1;      

      seq=-1;
      do {
        free(rest);
        rest=rtsp_get(s);
        if (!rest)
          return -1;
        if (!strncasecmp(rest,"CSeq:",5))
          sscanf(rest,"%*s %u",&seq);
      } while (strlen(rest)!=0);
      free(rest);
      if (seq<0) {
#ifdef LOG
        mp_msg(MSGT_OPEN, MSGL_WARN, "rtsp: warning: CSeq not recognized!\n");
#endif
        seq=1;
      }
      /* let's make the server happy */
      rtsp_put(s, "RTSP/1.0 451 Parameter Not Understood");
      rest=malloc(17);
      sprintf(rest,"CSeq: %u", seq);
      rtsp_put(s, rest);
      free(rest);
      rtsp_put(s, "");
      i=read_stream(s->s, buffer, size);
    } else
    {
      i=read_stream(s->s, buffer+4, size-4);
      i+=4;
    }
  } else
    i=read_stream(s->s, buffer, size);
#ifdef LOG
  mp_msg(MSGT_OPEN, MSGL_INFO, "librtsp: << %d of %d bytes\n", i, size);
#endif

  return i;
}

/*
 * connect to a rtsp server
 */

//rtsp_t *rtsp_connect(const char *mrl, const char *user_agent) {
rtsp_t *rtsp_connect(int fd, char* mrl, char *path, char *host, int port, char *user_agent) {

  rtsp_t *s=malloc(sizeof(rtsp_t));
  int i;
  
  for (i=0; i<MAX_FIELDS; i++) {
    s->answers[i]=NULL;
    s->scheduled[i]=NULL;
  }

  s->server=NULL;
  s->server_state=0;
  s->server_caps=0;
  
  s->cseq=0;
  s->session=NULL;
  
  if (user_agent)
    s->user_agent=strdup(user_agent);
  else
    s->user_agent=strdup("User-Agent: RealMedia Player Version 6.0.9.1235 (linux-2.0-libc6-i386-gcc2.95)");

  s->mrl = strdup(mrl);
  s->host = strdup(host);
  s->port = port;
  s->path = strdup(path);
  while (*path == '/')
    path++;
  if ((s->param = strchr(s->path, '?')) != NULL)
    s->param++;
  //mp_msg(MSGT_OPEN, MSGL_INFO, "path=%s\n", s->path);
  //mp_msg(MSGT_OPEN, MSGL_INFO, "param=%s\n", s->param ? s->param : "NULL");
  s->s = fd;

  if (s->s < 0) {
    mp_msg(MSGT_OPEN, MSGL_ERR, "rtsp: failed to connect to '%s'\n", s->host);
    rtsp_close(s);
    return NULL;
  }

  s->server_state=RTSP_CONNECTED;

  /* now let's send an options request. */
  rtsp_schedule_field(s, "CSeq: 1");
  rtsp_schedule_field(s, s->user_agent);
  rtsp_schedule_field(s, "ClientChallenge: 9e26d33f2984236010ef6253fb1887f7");
  rtsp_schedule_field(s, "PlayerStarttime: [28/03/2003:22:50:23 00:00]");
  rtsp_schedule_field(s, "CompanyID: KnKV4M4I/B2FjJ1TToLycw==");
  rtsp_schedule_field(s, "GUID: 00000000-0000-0000-0000-000000000000");
  rtsp_schedule_field(s, "RegionData: 0");
  rtsp_schedule_field(s, "ClientID: Linux_2.4_6.0.9.1235_play32_RN01_EN_586");
  /*rtsp_schedule_field(s, "Pragma: initiate-session");*/
  rtsp_request_options(s, NULL);

  return s;
}


/*
 * closes an rtsp connection 
 */

void rtsp_close(rtsp_t *s) {

  if (s->server_state)
  {
    if (s->server_state == RTSP_PLAYING)
      rtsp_request_teardown (s, NULL);
    closesocket (s->s);
  }

  if (s->path) free(s->path);
  if (s->host) free(s->host);
  if (s->mrl) free(s->mrl);
  if (s->session) free(s->session);
  if (s->user_agent) free(s->user_agent);
  rtsp_free_answers(s);
  rtsp_unschedule_all(s);
  free(s);  
}

/*
 * search in answers for tags. returns a pointer to the content
 * after the first matched tag. returns NULL if no match found.
 */

char *rtsp_search_answers(rtsp_t *s, const char *tag) {

  char **answer;
  char *ptr;
  
  if (!s->answers) return NULL;
  answer=s->answers;

  while (*answer) {
    if (!strncasecmp(*answer,tag,strlen(tag))) {
      ptr=strchr(*answer,':');
      if (!ptr) return NULL;
      ptr++;
      while(*ptr==' ') ptr++;
      return ptr;
    }
    answer++;
  }

  return NULL;
}

/*
 * session id management
 */

void rtsp_set_session(rtsp_t *s, const char *id) {

  if (s->session) free(s->session);

  s->session=strdup(id);

}

char *rtsp_get_session(rtsp_t *s) {

  return s->session;

}

char *rtsp_get_mrl(rtsp_t *s) {

  return s->mrl;

}

char *rtsp_get_param(rtsp_t *s, const char *p) {
  int len;
  char *param;
  if (!s->param)
    return NULL;
  if (!p)
    return strdup(s->param);
  len = strlen(p);
  param = s->param;
  while (param && *param) {
    char *nparam = strchr(param, '&');
    if (strncmp(param, p, len) == 0 && param[len] == '=') {
      param += len + 1;
      len = nparam ? nparam - param : strlen(param);
      nparam = malloc(len + 1);
      memcpy(nparam, param, len);
      nparam[len] = 0;
      return nparam;
    }
    param = nparam ? nparam + 1 : NULL;
  }
  return NULL;
}
  
/*
 * schedules a field for transmission
 */

void rtsp_schedule_field(rtsp_t *s, const char *string) {

  int i=0;
  
  if (!string) return;

  while(s->scheduled[i]) {
    i++;
  }
  s->scheduled[i]=strdup(string);
}

/*
 * removes the first scheduled field which prefix matches string. 
 */

void rtsp_unschedule_field(rtsp_t *s, const char *string) {

  char **ptr=s->scheduled;
  
  if (!string) return;

  while(*ptr) {
    if (!strncmp(*ptr, string, strlen(string)))
      break;
    else
      ptr++;
  }
  if (*ptr) free(*ptr);
  ptr++;
  do {
    *(ptr-1)=*ptr;
  } while(*ptr);
}

/*
 * unschedule all fields
 */

void rtsp_unschedule_all(rtsp_t *s) {

  char **ptr;
  
  if (!s->scheduled) return;
  ptr=s->scheduled;

  while (*ptr) {
    free(*ptr);
    *ptr=NULL;
    ptr++;
  }
}
/*
 * free answers
 */

void rtsp_free_answers(rtsp_t *s) {

  char **answer;
  
  if (!s->answers) return;
  answer=s->answers;

  while (*answer) {
    free(*answer);
    *answer=NULL;
    answer++;
  }
}