real.c

mplayer播放器的源码

    mp_msg(MSGT_STREAM, MSGL_WARN, "realrtsp: rdt chunk not recognized: got 0x%02x\n",
      header[0]);
    return 0;
  }
  /* header[1] is channel, normally 0, ignored */
  size=(header[2]<<8)+header[3];
  flags1=header[4];
  if ((flags1!=0x40)&&(flags1!=0x42)&&(flags1!=0x41))
  {
#ifdef LOG
    printf("got flags1: 0x%02x\n",flags1);
#endif
    if(header[6] == 0x06) { // eof packet
      rtsp_read_data(rtsp_session, header, 7); // Skip the rest of the eof packet
      /* Some files have short auxiliary streams, we must ignore eof packets
       * for these streams to avoid premature eof.
       * Now the code declares eof only if the stream with id == 0 gets eof
       * (old code was: eof on the first eof packet received).
       */
      if(flags1 & 0x7c) // ignore eof for streams with id != 0
        return 0;
      mp_msg(MSGT_STREAM, MSGL_INFO, "realrtsp: Stream EOF detected\n");
      return -1;
    }
    header[0]=header[5];
    header[1]=header[6];
    header[2]=header[7];
    n=rtsp_read_data(rtsp_session, header+3, 5);
    if (n<5) return 0;
#ifdef LOG
    printf("ignoring bytes:\n");
    hexdump(header, 8);
#endif
    n=rtsp_read_data(rtsp_session, header+4, 4);
    if (n<4) return 0;
    flags1=header[4];
    size-=9;
  }
  flags2=header[7];
  // header[5..6] == frame number in stream
  unknown1=(header[5]<<16)+(header[6]<<8)+(header[7]);
  n=rtsp_read_data(rtsp_session, header, 6);
  if (n<6) return 0;
  ts=AV_RB32(header);
  
#ifdef LOG
  printf("ts: %u, size: %u, flags: 0x%02x, unknown values: 0x%06x 0x%02x 0x%02x\n", 
          ts, size, flags1, unknown1, header[4], header[5]);
#endif
  size+=2;
  
  ph.object_version=0;
  ph.length=size;
  ph.stream_number=(flags1>>1)&0x1f;
  ph.timestamp=ts;
  ph.reserved=0;
  if ((flags2&1) == 0 && (prev_ts != ts || prev_stream_number != ph.stream_number))
  {
    prev_ts = ts;
    prev_stream_number = ph.stream_number;
    ph.flags=2;
  }
  else
    ph.flags=0;
  *buffer = xbuffer_ensure_size(*buffer, 12+size);
  if(rdt_rawdata) {
    n=rtsp_read_data(rtsp_session, *buffer, size-12);
    return (n <= 0) ? 0 : n;
  }
  rmff_dump_pheader(&ph, *buffer);
  size-=12;
  n=rtsp_read_data(rtsp_session, (*buffer)+12, size);
  
  return (n <= 0) ? 0 : n+12;
}

static int convert_timestamp(char *str, int *sec, int *msec) {
  int hh, mm, ss, ms = 0;

  // Timestamp may be optionally quoted with ", skip it
  // Since the url is escaped when we get here, we skip the string "%22"
  if (!strncmp(str, "%22", 3))
    str += 3;
  if (sscanf(str, "%d:%d:%d.%d", &hh, &mm, &ss, &ms) < 3) {
    hh = 0;
    if (sscanf(str, "%d:%d.%d", &mm, &ss, &ms) < 2) {
      mm = 0;
      if (sscanf(str, "%d.%d", &ss, &ms) < 1) {
	ss = 0;
	ms = 0;
      }
    }
  }
  if (sec)
    *sec = hh * 3600 + mm * 60 + ss;
  if (msec)
    *msec = ms;
  return 1;
}

//! maximum size of the rtsp description, must be < INT_MAX
#define MAX_DESC_BUF (20 * 1024 * 1024)
rmff_header_t *real_setup_and_get_header(rtsp_t *rtsp_session, uint32_t bandwidth,
  char *username, char *password) {

  char *description=NULL;
  char *session_id=NULL;
  rmff_header_t *h;
  char *challenge1;
  char challenge2[64];
  char checksum[34];
  char *subscribe;
  char *buf = xbuffer_init(256);
  char *mrl=rtsp_get_mrl(rtsp_session);
  unsigned int size;
  int status;
  uint32_t maxbandwidth = bandwidth;
  char* authfield = NULL;
  int i;
  
  /* get challenge */
  challenge1=strdup(rtsp_search_answers(rtsp_session,"RealChallenge1"));
#ifdef LOG
  printf("real: Challenge1: %s\n", challenge1);
#endif

  /* set a reasonable default to get the best stream, unless bandwidth given */
  if (!bandwidth)
      bandwidth = 10485800;
  
  /* request stream description */
rtsp_send_describe:
  rtsp_schedule_field(rtsp_session, "Accept: application/sdp");
  sprintf(buf, "Bandwidth: %u", bandwidth);
  rtsp_schedule_field(rtsp_session, buf);
  rtsp_schedule_field(rtsp_session, "GUID: 00000000-0000-0000-0000-000000000000");
  rtsp_schedule_field(rtsp_session, "RegionData: 0");
  rtsp_schedule_field(rtsp_session, "ClientID: Linux_2.4_6.0.9.1235_play32_RN01_EN_586");
  rtsp_schedule_field(rtsp_session, "SupportsMaximumASMBandwidth: 1");
  rtsp_schedule_field(rtsp_session, "Language: en-US");
  rtsp_schedule_field(rtsp_session, "Require: com.real.retain-entity-for-setup");
  if(authfield)
    rtsp_schedule_field(rtsp_session, authfield);
  status=rtsp_request_describe(rtsp_session,NULL);

  if (status == 401) {
    int authlen, b64_authlen;
    char *authreq;
    char* authstr = NULL;

    if (authfield) {
      mp_msg(MSGT_STREAM, MSGL_ERR, "realrtsp: authorization failed, check your credentials\n");
      goto autherr;
    }
    if (!(authreq = rtsp_search_answers(rtsp_session,"WWW-Authenticate"))) {
      mp_msg(MSGT_STREAM, MSGL_ERR, "realrtsp: 401 but no auth request, aborting\n");
      goto autherr;
    }
    if (!username) {
      mp_msg(MSGT_STREAM, MSGL_ERR, "realrtsp: auth required but no username supplied\n");
      goto autherr;
    }
    if (!strstr(authreq, "Basic")) {
      mp_msg(MSGT_STREAM, MSGL_ERR, "realrtsp: authenticator not supported (%s)\n", authreq);
      goto autherr;
    }
    authlen = strlen(username) + (password ? strlen(password) : 0) + 2;
    authstr = malloc(authlen);
    sprintf(authstr, "%s:%s", username, password ? password : "");
    authfield = malloc(authlen*2+22);
    strcpy(authfield, "Authorization: Basic ");
    b64_authlen = base64_encode(authstr, authlen, authfield+21, authlen*2);
    free(authstr);
    if (b64_authlen < 0) {
      mp_msg(MSGT_STREAM, MSGL_ERR, "realrtsp: base64 output overflow, this should never happen\n");
      goto autherr;
    }
    authfield[b64_authlen+21] = 0;
    goto rtsp_send_describe;
  }
autherr:

  if (authfield)
     free(authfield);

  if ( status<200 || status>299 )
  {
    char *alert=rtsp_search_answers(rtsp_session,"Alert");
    if (alert) {
      mp_msg(MSGT_STREAM, MSGL_WARN, "realrtsp: got message from server:\n%s\n",
        alert);
    }
    rtsp_send_ok(rtsp_session);
    buf = xbuffer_free(buf);
    return NULL;
  }

  /* receive description */
  size=0;
  if (!rtsp_search_answers(rtsp_session,"Content-length"))
    mp_msg(MSGT_STREAM, MSGL_WARN, "real: got no Content-length!\n");
  else
    size=atoi(rtsp_search_answers(rtsp_session,"Content-length"));

  // as size is unsigned this also catches the case (size < 0)
  if (size > MAX_DESC_BUF) {
    mp_msg(MSGT_STREAM, MSGL_ERR, "realrtsp: Content-length for description too big (> %uMB)!\n",
            MAX_DESC_BUF/(1024*1024) );
    xbuffer_free(buf);
    return NULL;
  }

  if (!rtsp_search_answers(rtsp_session,"ETag"))
    mp_msg(MSGT_STREAM, MSGL_WARN, "realrtsp: got no ETag!\n");
  else
    session_id=strdup(rtsp_search_answers(rtsp_session,"ETag"));
    
#ifdef LOG
  printf("real: Stream description size: %u\n", size);
#endif

  description=malloc(size+1);

  if( rtsp_read_data(rtsp_session, description, size) <= 0) {
    buf = xbuffer_free(buf);
    return NULL;
  }
  description[size]=0;

  /* parse sdp (sdpplin) and create a header and a subscribe string */
  subscribe = xbuffer_init(256);
  strcpy(subscribe, "Subscribe: ");
  h=real_parse_sdp(description, &subscribe, bandwidth);
  if (!h) {
    subscribe = xbuffer_free(subscribe);
    buf = xbuffer_free(buf);
    return NULL;
  }
  rmff_fix_header(h);

#ifdef LOG
  printf("Title: %s\nCopyright: %s\nAuthor: %s\nStreams: %i\n",
    h->cont->title, h->cont->copyright, h->cont->author, h->prop->num_streams);
#endif
  
  /* setup our streams */
  real_calc_response_and_checksum (challenge2, checksum, challenge1);
  buf = xbuffer_ensure_size(buf, strlen(challenge2) + strlen(checksum) + 32);
  sprintf(buf, "RealChallenge2: %s, sd=%s", challenge2, checksum);
  rtsp_schedule_field(rtsp_session, buf);
  buf = xbuffer_ensure_size(buf, strlen(session_id) + 32);
  sprintf(buf, "If-Match: %s", session_id);
  rtsp_schedule_field(rtsp_session, buf);
  rtsp_schedule_field(rtsp_session, "Transport: x-pn-tng/tcp;mode=play,rtp/avp/tcp;unicast;mode=play");
  buf = xbuffer_ensure_size(buf, strlen(mrl) + 32);
  sprintf(buf, "%s/streamid=0", mrl);
  rtsp_request_setup(rtsp_session,buf,NULL);

  /* Do setup for all the other streams we subscribed to */
  for (i = 1; i < h->prop->num_streams; i++) {
    rtsp_schedule_field(rtsp_session, "Transport: x-pn-tng/tcp;mode=play,rtp/avp/tcp;unicast;mode=play");
    buf = xbuffer_ensure_size(buf, strlen(session_id) + 32);
    sprintf(buf, "If-Match: %s", session_id);
    rtsp_schedule_field(rtsp_session, buf);

    buf = xbuffer_ensure_size(buf, strlen(mrl) + 32);
    sprintf(buf, "%s/streamid=%d", mrl, i);
    rtsp_request_setup(rtsp_session,buf,NULL);
  }
  /* set stream parameter (bandwidth) with our subscribe string */
  rtsp_schedule_field(rtsp_session, subscribe);
  rtsp_request_setparameter(rtsp_session,NULL);

  /* set delivery bandwidth */
  if (maxbandwidth) {
      sprintf(buf, "SetDeliveryBandwidth: Bandwidth=%u;BackOff=0", maxbandwidth);
      rtsp_schedule_field(rtsp_session, buf);
      rtsp_request_setparameter(rtsp_session,NULL);
  }

  {
    int s_ss = 0, s_ms = 0, e_ss = 0, e_ms = 0;
    char *str;
    if ((str = rtsp_get_param(rtsp_session, "start"))) {
      convert_timestamp(str, &s_ss, &s_ms);
      free(str);
    }
    if ((str = rtsp_get_param(rtsp_session, "end"))) {
      convert_timestamp(str, &e_ss, &e_ms);
      free(str);
    }
    str = buf + sprintf(buf, s_ms ? "%s%d.%d-" : "%s%d-", "Range: npt=", s_ss, s_ms);
    if (e_ss || e_ms)
      sprintf(str, e_ms ? "%d.%d" : "%d", e_ss, e_ms);
  }
  rtsp_schedule_field(rtsp_session, buf);
  /* and finally send a play request */
  rtsp_request_play(rtsp_session,NULL);

  subscribe = xbuffer_free(subscribe);
  buf = xbuffer_free(buf);
  return h;
}

struct real_rtsp_session_t *
init_real_rtsp_session (void)
{
  struct real_rtsp_session_t *real_rtsp_session = NULL;

  real_rtsp_session = malloc (sizeof (struct real_rtsp_session_t));
  real_rtsp_session->recv = xbuffer_init (BUF_SIZE);
  real_rtsp_session->rdteof = 0;
  real_rtsp_session->rdt_rawdata = 0;

  return real_rtsp_session;
}

void
free_real_rtsp_session (struct real_rtsp_session_t* real_session)
{
  if (!real_session)
    return;
  
  xbuffer_free (real_session->recv);
  free (real_session);
}