/*
  * RTSP demuxer
  * Copyright (c) 2002 Fabrice Bellard
  *
  * 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/intreadwrite.h"

 #include "libavutil/mathematics.h"

 #include "libavutil/random_seed.h"

 #include "libavutil/time.h"

 #include "avformat.h"
 
 #include "internal.h"
 #include "network.h"
 #include "os_support.h"

 #include "rtpproto.h"

 #include "rtsp.h"
 #include "rdt.h"

 #include "url.h"

 static const struct RTSPStatusMessage {
     enum RTSPStatusCode code;
     const char *message;
 } status_messages[] = {
     { RTSP_STATUS_OK,             "OK"                               },
     { RTSP_STATUS_METHOD,         "Method Not Allowed"               },
     { RTSP_STATUS_BANDWIDTH,      "Not Enough Bandwidth"             },
     { RTSP_STATUS_SESSION,        "Session Not Found"                },
     { RTSP_STATUS_STATE,          "Method Not Valid in This State"   },
     { RTSP_STATUS_AGGREGATE,      "Aggregate operation not allowed"  },
     { RTSP_STATUS_ONLY_AGGREGATE, "Only aggregate operation allowed" },
     { RTSP_STATUS_TRANSPORT,      "Unsupported transport"            },
     { RTSP_STATUS_INTERNAL,       "Internal Server Error"            },
     { RTSP_STATUS_SERVICE,        "Service Unavailable"              },
     { RTSP_STATUS_VERSION,        "RTSP Version not supported"       },
     { 0,                          "NULL"                             }
 };
 

 static int rtsp_read_close(AVFormatContext *s)
 {
     RTSPState *rt = s->priv_data;
 

     if (!(rt->rtsp_flags & RTSP_FLAG_LISTEN))
         ff_rtsp_send_cmd_async(s, "TEARDOWN", rt->control_uri, NULL);

 
     ff_rtsp_close_streams(s);
     ff_rtsp_close_connections(s);
     ff_network_close();
     rt->real_setup = NULL;
     av_freep(&rt->real_setup_cache);
     return 0;
 }
 

 static inline int read_line(AVFormatContext *s, char *rbuf, const int rbufsize,
                             int *rbuflen)
 {
     RTSPState *rt = s->priv_data;
     int idx       = 0;
     int ret       = 0;
     *rbuflen      = 0;
 
     do {
         ret = ffurl_read_complete(rt->rtsp_hd, rbuf + idx, 1);

         if (ret <= 0)
             return ret ? ret : AVERROR_EOF;

         if (rbuf[idx] == '\r') {
             /* Ignore */
         } else if (rbuf[idx] == '\n') {
             rbuf[idx] = '\0';
             *rbuflen  = idx;
             return 0;
         } else
             idx++;
     } while (idx < rbufsize);
     av_log(s, AV_LOG_ERROR, "Message too long\n");
     return AVERROR(EIO);
 }
 
 static int rtsp_send_reply(AVFormatContext *s, enum RTSPStatusCode code,
                            const char *extracontent, uint16_t seq)
 {
     RTSPState *rt = s->priv_data;
     char message[4096];
     int index = 0;
     while (status_messages[index].code) {
         if (status_messages[index].code == code) {
             snprintf(message, sizeof(message), "RTSP/1.0 %d %s\r\n",
                      code, status_messages[index].message);
             break;
         }
         index++;
     }
     if (!status_messages[index].code)
         return AVERROR(EINVAL);
     av_strlcatf(message, sizeof(message), "CSeq: %d\r\n", seq);
     av_strlcatf(message, sizeof(message), "Server: %s\r\n", LIBAVFORMAT_IDENT);
     if (extracontent)
         av_strlcat(message, extracontent, sizeof(message));
     av_strlcat(message, "\r\n", sizeof(message));
     av_dlog(s, "Sending response:\n%s", message);
     ffurl_write(rt->rtsp_hd, message, strlen(message));
 
     return 0;
 }
 
 static inline int check_sessionid(AVFormatContext *s,
                                   RTSPMessageHeader *request)
 {
     RTSPState *rt = s->priv_data;
     unsigned char *session_id = rt->session_id;
     if (!session_id[0]) {
         av_log(s, AV_LOG_WARNING, "There is no session-id at the moment\n");
         return 0;
     }
     if (strcmp(session_id, request->session_id)) {
         av_log(s, AV_LOG_ERROR, "Unexpected session-id %s\n",
                request->session_id);
         rtsp_send_reply(s, RTSP_STATUS_SESSION, NULL, request->seq);
         return AVERROR_STREAM_NOT_FOUND;
     }
     return 0;
 }
 
 static inline int rtsp_read_request(AVFormatContext *s,
                                     RTSPMessageHeader *request,
                                     const char *method)
 {
     RTSPState *rt = s->priv_data;
     char rbuf[1024];
     int rbuflen, ret;
     do {
         ret = read_line(s, rbuf, sizeof(rbuf), &rbuflen);
         if (ret)
             return ret;
         if (rbuflen > 1) {
             av_dlog(s, "Parsing[%d]: %s\n", rbuflen, rbuf);
             ff_rtsp_parse_line(request, rbuf, rt, method);
         }
     } while (rbuflen > 0);
     if (request->seq != rt->seq + 1) {
         av_log(s, AV_LOG_ERROR, "Unexpected Sequence number %d\n",
                request->seq);
         return AVERROR(EINVAL);
     }
     if (rt->session_id[0] && strcmp(method, "OPTIONS")) {
         ret = check_sessionid(s, request);
         if (ret)
             return ret;
     }
 
     return 0;
 }
 
 static int rtsp_read_announce(AVFormatContext *s)
 {
     RTSPState *rt             = s->priv_data;
     RTSPMessageHeader request = { 0 };
     char sdp[4096];
     int  ret;
 
     ret = rtsp_read_request(s, &request, "ANNOUNCE");
     if (ret)
         return ret;
     rt->seq++;
     if (strcmp(request.content_type, "application/sdp")) {
         av_log(s, AV_LOG_ERROR, "Unexpected content type %s\n",
                request.content_type);
         rtsp_send_reply(s, RTSP_STATUS_SERVICE, NULL, request.seq);
         return AVERROR_OPTION_NOT_FOUND;
     }
     if (request.content_length && request.content_length < sizeof(sdp) - 1) {
         /* Read SDP */
         if (ffurl_read_complete(rt->rtsp_hd, sdp, request.content_length)
             < request.content_length) {
             av_log(s, AV_LOG_ERROR,
                    "Unable to get complete SDP Description in ANNOUNCE\n");
             rtsp_send_reply(s, RTSP_STATUS_INTERNAL, NULL, request.seq);
             return AVERROR(EIO);
         }
         sdp[request.content_length] = '\0';
         av_log(s, AV_LOG_VERBOSE, "SDP: %s\n", sdp);
         ret = ff_sdp_parse(s, sdp);
         if (ret)
             return ret;
         rtsp_send_reply(s, RTSP_STATUS_OK, NULL, request.seq);
         return 0;
     }
     av_log(s, AV_LOG_ERROR,
            "Content-Length header value exceeds sdp allocated buffer (4KB)\n");
     rtsp_send_reply(s, RTSP_STATUS_INTERNAL,
                     "Content-Length exceeds buffer size", request.seq);
     return AVERROR(EIO);
 }
 
 static int rtsp_read_options(AVFormatContext *s)
 {
     RTSPState *rt             = s->priv_data;
     RTSPMessageHeader request = { 0 };
     int ret                   = 0;
 
     /* Parsing headers */
     ret = rtsp_read_request(s, &request, "OPTIONS");
     if (ret)
         return ret;
     rt->seq++;
     /* Send Reply */
     rtsp_send_reply(s, RTSP_STATUS_OK,
                     "Public: ANNOUNCE, PAUSE, SETUP, TEARDOWN, RECORD\r\n",
                     request.seq);
     return 0;
 }
 
 static int rtsp_read_setup(AVFormatContext *s, char* host, char *controlurl)
 {
     RTSPState *rt             = s->priv_data;
     RTSPMessageHeader request = { 0 };
     int ret                   = 0;
     char url[1024];
     RTSPStream *rtsp_st;
     char responseheaders[1024];
     int localport    = -1;
     int transportidx = 0;
     int streamid     = 0;
 
     ret = rtsp_read_request(s, &request, "SETUP");
     if (ret)
         return ret;
     rt->seq++;
     if (!request.nb_transports) {
         av_log(s, AV_LOG_ERROR, "No transport defined in SETUP\n");
         return AVERROR_INVALIDDATA;
     }
     for (transportidx = 0; transportidx < request.nb_transports;
          transportidx++) {
         if (!request.transports[transportidx].mode_record ||
             (request.transports[transportidx].lower_transport !=
              RTSP_LOWER_TRANSPORT_UDP &&
              request.transports[transportidx].lower_transport !=
              RTSP_LOWER_TRANSPORT_TCP)) {
             av_log(s, AV_LOG_ERROR, "mode=record/receive not set or transport"
                    " protocol not supported (yet)\n");
             return AVERROR_INVALIDDATA;
         }
     }
     if (request.nb_transports > 1)
         av_log(s, AV_LOG_WARNING, "More than one transport not supported, "
                "using first of all\n");
     for (streamid = 0; streamid < rt->nb_rtsp_streams; streamid++) {
         if (!strcmp(rt->rtsp_streams[streamid]->control_url,
                     controlurl))
             break;
     }
     if (streamid == rt->nb_rtsp_streams) {
         av_log(s, AV_LOG_ERROR, "Unable to find requested track\n");
         return AVERROR_STREAM_NOT_FOUND;
     }
     rtsp_st   = rt->rtsp_streams[streamid];
     localport = rt->rtp_port_min;
 
     if (request.transports[0].lower_transport == RTSP_LOWER_TRANSPORT_TCP) {
         rt->lower_transport = RTSP_LOWER_TRANSPORT_TCP;
         if ((ret = ff_rtsp_open_transport_ctx(s, rtsp_st))) {
             rtsp_send_reply(s, RTSP_STATUS_TRANSPORT, NULL, request.seq);
             return ret;
         }
         rtsp_st->interleaved_min = request.transports[0].interleaved_min;
         rtsp_st->interleaved_max = request.transports[0].interleaved_max;
         snprintf(responseheaders, sizeof(responseheaders), "Transport: "
                  "RTP/AVP/TCP;unicast;mode=receive;interleaved=%d-%d"
                  "\r\n", request.transports[0].interleaved_min,
                  request.transports[0].interleaved_max);
     } else {
         do {
             ff_url_join(url, sizeof(url), "rtp", NULL, host, localport, NULL);
             av_dlog(s, "Opening: %s", url);
             ret = ffurl_open(&rtsp_st->rtp_handle, url, AVIO_FLAG_READ_WRITE,
                              &s->interrupt_callback, NULL);
             if (ret)
                 localport += 2;
         } while (ret || localport > rt->rtp_port_max);
         if (localport > rt->rtp_port_max) {
             rtsp_send_reply(s, RTSP_STATUS_TRANSPORT, NULL, request.seq);
             return ret;
         }
 
         av_dlog(s, "Listening on: %d",
                 ff_rtp_get_local_rtp_port(rtsp_st->rtp_handle));
         if ((ret = ff_rtsp_open_transport_ctx(s, rtsp_st))) {
             rtsp_send_reply(s, RTSP_STATUS_TRANSPORT, NULL, request.seq);
             return ret;
         }
 
         localport = ff_rtp_get_local_rtp_port(rtsp_st->rtp_handle);
         snprintf(responseheaders, sizeof(responseheaders), "Transport: "
                  "RTP/AVP/UDP;unicast;mode=receive;source=%s;"
                  "client_port=%d-%d;server_port=%d-%d\r\n",
                  host, request.transports[0].client_port_min,
                  request.transports[0].client_port_max, localport,
                  localport + 1);
     }
 
     /* Establish sessionid if not previously set */
     /* Put this in a function? */
     /* RFC 2326: session id must be at least 8 digits */
     while (strlen(rt->session_id) < 8)
         av_strlcatf(rt->session_id, 512, "%u", av_get_random_seed());
 
     av_strlcatf(responseheaders, sizeof(responseheaders), "Session: %s\r\n",
                 rt->session_id);
     /* Send Reply */
     rtsp_send_reply(s, RTSP_STATUS_OK, responseheaders, request.seq);
 
     rt->state = RTSP_STATE_PAUSED;
     return 0;
 }
 
 static int rtsp_read_record(AVFormatContext *s)
 {
     RTSPState *rt             = s->priv_data;
     RTSPMessageHeader request = { 0 };
     int ret                   = 0;
     char responseheaders[1024];
 
     ret = rtsp_read_request(s, &request, "RECORD");
     if (ret)
         return ret;
     ret = check_sessionid(s, &request);
     if (ret)
         return ret;
     rt->seq++;
     snprintf(responseheaders, sizeof(responseheaders), "Session: %s\r\n",
              rt->session_id);
     rtsp_send_reply(s, RTSP_STATUS_OK, responseheaders, request.seq);
 
     rt->state = RTSP_STATE_STREAMING;
     return 0;
 }
 
 static inline int parse_command_line(AVFormatContext *s, const char *line,
                                      int linelen, char *uri, int urisize,
                                      char *method, int methodsize,
                                      enum RTSPMethod *methodcode)
 {
     RTSPState *rt = s->priv_data;
     const char *linept, *searchlinept;
     linept = strchr(line, ' ');
     if (linept - line > methodsize - 1) {
         av_log(s, AV_LOG_ERROR, "Method string too long\n");
         return AVERROR(EIO);
     }
     memcpy(method, line, linept - line);
     method[linept - line] = '\0';
     linept++;
     if (!strcmp(method, "ANNOUNCE"))
         *methodcode = ANNOUNCE;
     else if (!strcmp(method, "OPTIONS"))
         *methodcode = OPTIONS;
     else if (!strcmp(method, "RECORD"))
         *methodcode = RECORD;
     else if (!strcmp(method, "SETUP"))
         *methodcode = SETUP;
     else if (!strcmp(method, "PAUSE"))
         *methodcode = PAUSE;
     else if (!strcmp(method, "TEARDOWN"))
         *methodcode = TEARDOWN;
     else
         *methodcode = UNKNOWN;
     /* Check method with the state  */
     if (rt->state == RTSP_STATE_IDLE) {
         if ((*methodcode != ANNOUNCE) && (*methodcode != OPTIONS)) {
             av_log(s, AV_LOG_ERROR, "Unexpected command in Idle State %s\n",
                    line);
             return AVERROR_PROTOCOL_NOT_FOUND;
         }
     } else if (rt->state == RTSP_STATE_PAUSED) {
         if ((*methodcode != OPTIONS) && (*methodcode != RECORD)
             && (*methodcode != SETUP)) {
             av_log(s, AV_LOG_ERROR, "Unexpected command in Paused State %s\n",
                    line);
             return AVERROR_PROTOCOL_NOT_FOUND;
         }
     } else if (rt->state == RTSP_STATE_STREAMING) {
         if ((*methodcode != PAUSE) && (*methodcode != OPTIONS)
             && (*methodcode != TEARDOWN)) {
             av_log(s, AV_LOG_ERROR, "Unexpected command in Streaming State"
                    " %s\n", line);
             return AVERROR_PROTOCOL_NOT_FOUND;
         }
     } else {
         av_log(s, AV_LOG_ERROR, "Unexpected State [%d]\n", rt->state);
         return AVERROR_BUG;
     }
 
     searchlinept = strchr(linept, ' ');
     if (searchlinept == NULL) {
         av_log(s, AV_LOG_ERROR, "Error parsing message URI\n");
         return AVERROR_INVALIDDATA;
     }
     if (searchlinept - linept > urisize - 1) {
         av_log(s, AV_LOG_ERROR, "uri string length exceeded buffer size\n");
         return AVERROR(EIO);
     }
     memcpy(uri, linept, searchlinept - linept);
     uri[searchlinept - linept] = '\0';
     if (strcmp(rt->control_uri, uri)) {
         char host[128], path[512], auth[128];
         int port;
         char ctl_host[128], ctl_path[512], ctl_auth[128];
         int ctl_port;
         av_url_split(NULL, 0, auth, sizeof(auth), host, sizeof(host), &port,
                      path, sizeof(path), uri);
         av_url_split(NULL, 0, ctl_auth, sizeof(ctl_auth), ctl_host,
                      sizeof(ctl_host), &ctl_port, ctl_path, sizeof(ctl_path),
                      rt->control_uri);
         if (strcmp(host, ctl_host))
             av_log(s, AV_LOG_INFO, "Host %s differs from expected %s\n",
                    host, ctl_host);
         if (strcmp(path, ctl_path) && *methodcode != SETUP)
             av_log(s, AV_LOG_WARNING, "WARNING: Path %s differs from expected"
                    " %s\n", path, ctl_path);
         if (*methodcode == ANNOUNCE) {
             av_log(s, AV_LOG_INFO,
                    "Updating control URI to %s\n", uri);

             av_strlcpy(rt->control_uri, uri, sizeof(rt->control_uri));

         }
     }
 
     linept = searchlinept + 1;
     if (!av_strstart(linept, "RTSP/1.0", NULL)) {
         av_log(s, AV_LOG_ERROR, "Error parsing protocol or version\n");
         return AVERROR_PROTOCOL_NOT_FOUND;
     }
     return 0;
 }
 
 int ff_rtsp_parse_streaming_commands(AVFormatContext *s)
 {
     RTSPState *rt = s->priv_data;
     unsigned char rbuf[4096];
     unsigned char method[10];
     char uri[500];
     int ret;
     int rbuflen               = 0;
     RTSPMessageHeader request = { 0 };
     enum RTSPMethod methodcode;
 
     ret = read_line(s, rbuf, sizeof(rbuf), &rbuflen);
     if (ret < 0)
         return ret;
     ret = parse_command_line(s, rbuf, rbuflen, uri, sizeof(uri), method,
                              sizeof(method), &methodcode);
     if (ret) {
         av_log(s, AV_LOG_ERROR, "RTSP: Unexpected Command\n");
         return ret;
     }
 
     ret = rtsp_read_request(s, &request, method);
     if (ret)
         return ret;
     rt->seq++;
     if (methodcode == PAUSE) {
         rt->state = RTSP_STATE_PAUSED;
         ret       = rtsp_send_reply(s, RTSP_STATUS_OK, NULL , request.seq);
         // TODO: Missing date header in response
     } else if (methodcode == OPTIONS) {
         ret = rtsp_send_reply(s, RTSP_STATUS_OK,
                               "Public: ANNOUNCE, PAUSE, SETUP, TEARDOWN, "
                               "RECORD\r\n", request.seq);
     } else if (methodcode == TEARDOWN) {
         rt->state = RTSP_STATE_IDLE;
         ret       = rtsp_send_reply(s, RTSP_STATUS_OK, NULL , request.seq);
         return 0;
     }
     return ret;
 }
 

 static int rtsp_read_play(AVFormatContext *s)
 {
     RTSPState *rt = s->priv_data;
     RTSPMessageHeader reply1, *reply = &reply1;
     int i;
     char cmd[1024];
 
     av_log(s, AV_LOG_DEBUG, "hello state=%d\n", rt->state);
     rt->nb_byes = 0;
 
     if (!(rt->server_type == RTSP_SERVER_REAL && rt->need_subscription)) {

         if (rt->transport == RTSP_TRANSPORT_RTP) {
             for (i = 0; i < rt->nb_rtsp_streams; i++) {
                 RTSPStream *rtsp_st = rt->rtsp_streams[i];
                 RTPDemuxContext *rtpctx = rtsp_st->transport_priv;
                 if (!rtpctx)
                     continue;
                 ff_rtp_reset_packet_queue(rtpctx);
                 rtpctx->last_rtcp_ntp_time  = AV_NOPTS_VALUE;
                 rtpctx->first_rtcp_ntp_time = AV_NOPTS_VALUE;
                 rtpctx->base_timestamp      = 0;

                 rtpctx->timestamp           = 0;
                 rtpctx->unwrapped_timestamp = 0;

                 rtpctx->rtcp_ts_offset      = 0;
             }
         }

         if (rt->state == RTSP_STATE_PAUSED) {
             cmd[0] = 0;
         } else {
             snprintf(cmd, sizeof(cmd),

                      "Range: npt=%"PRId64".%03"PRId64"-\r\n",
                      rt->seek_timestamp / AV_TIME_BASE,
                      rt->seek_timestamp / (AV_TIME_BASE / 1000) % 1000);

         }
         ff_rtsp_send_cmd(s, "PLAY", rt->control_uri, cmd, reply, NULL);
         if (reply->status_code != RTSP_STATUS_OK) {
             return -1;
         }

         if (rt->transport == RTSP_TRANSPORT_RTP &&
             reply->range_start != AV_NOPTS_VALUE) {

             for (i = 0; i < rt->nb_rtsp_streams; i++) {
                 RTSPStream *rtsp_st = rt->rtsp_streams[i];
                 RTPDemuxContext *rtpctx = rtsp_st->transport_priv;
                 AVStream *st = NULL;

                 if (!rtpctx || rtsp_st->stream_index < 0)

                     continue;

                 st = s->streams[rtsp_st->stream_index];

                 rtpctx->range_start_offset =
                     av_rescale_q(reply->range_start, AV_TIME_BASE_Q,
                                  st->time_base);

             }
         }
     }
     rt->state = RTSP_STATE_STREAMING;
     return 0;
 }
 

 /* pause the stream */
 static int rtsp_read_pause(AVFormatContext *s)
 {
     RTSPState *rt = s->priv_data;
     RTSPMessageHeader reply1, *reply = &reply1;
 
     if (rt->state != RTSP_STATE_STREAMING)
         return 0;
     else if (!(rt->server_type == RTSP_SERVER_REAL && rt->need_subscription)) {
         ff_rtsp_send_cmd(s, "PAUSE", rt->control_uri, NULL, reply, NULL);
         if (reply->status_code != RTSP_STATUS_OK) {
             return -1;
         }
     }
     rt->state = RTSP_STATE_PAUSED;
     return 0;
 }
 

 int ff_rtsp_setup_input_streams(AVFormatContext *s, RTSPMessageHeader *reply)
 {
     RTSPState *rt = s->priv_data;
     char cmd[1024];
     unsigned char *content = NULL;
     int ret;
 
     /* describe the stream */
     snprintf(cmd, sizeof(cmd),
              "Accept: application/sdp\r\n");
     if (rt->server_type == RTSP_SERVER_REAL) {
         /**
          * The Require: attribute is needed for proper streaming from
          * Realmedia servers.
          */
         av_strlcat(cmd,
                    "Require: com.real.retain-entity-for-setup\r\n",
                    sizeof(cmd));
     }
     ff_rtsp_send_cmd(s, "DESCRIBE", rt->control_uri, cmd, reply, &content);
     if (!content)
         return AVERROR_INVALIDDATA;
     if (reply->status_code != RTSP_STATUS_OK) {
         av_freep(&content);
         return AVERROR_INVALIDDATA;
     }
 
     av_log(s, AV_LOG_VERBOSE, "SDP:\n%s\n", content);
     /* now we got the SDP description, we parse it */
     ret = ff_sdp_parse(s, (const char *)content);
     av_freep(&content);
     if (ret < 0)

         return ret;

 
     return 0;
 }
 

 static int rtsp_listen(AVFormatContext *s)
 {
     RTSPState *rt = s->priv_data;
     char host[128], path[512], auth[128];
     char uri[500];
     int port;
     char tcpname[500];
     unsigned char rbuf[4096];
     unsigned char method[10];
     int rbuflen = 0;
     int ret;
     enum RTSPMethod methodcode;
 
     /* extract hostname and port */
     av_url_split(NULL, 0, auth, sizeof(auth), host, sizeof(host), &port,
                  path, sizeof(path), s->filename);
 
     /* ff_url_join. No authorization by now (NULL) */
     ff_url_join(rt->control_uri, sizeof(rt->control_uri), "rtsp", NULL, host,
                 port, "%s", path);

 
     if (port < 0)
         port = RTSP_DEFAULT_PORT;
 

     /* Create TCP connection */
     ff_url_join(tcpname, sizeof(tcpname), "tcp", NULL, host, port,
                 "?listen&listen_timeout=%d", rt->initial_timeout * 1000);
 
     if (ret = ffurl_open(&rt->rtsp_hd, tcpname, AVIO_FLAG_READ_WRITE,
                          &s->interrupt_callback, NULL)) {
         av_log(s, AV_LOG_ERROR, "Unable to open RTSP for listening\n");
         return ret;
     }
     rt->state       = RTSP_STATE_IDLE;
     rt->rtsp_hd_out = rt->rtsp_hd;
     for (;;) { /* Wait for incoming RTSP messages */
         ret = read_line(s, rbuf, sizeof(rbuf), &rbuflen);
         if (ret < 0)
             return ret;
         ret = parse_command_line(s, rbuf, rbuflen, uri, sizeof(uri), method,
                                  sizeof(method), &methodcode);
         if (ret) {
             av_log(s, AV_LOG_ERROR, "RTSP: Unexpected Command\n");
             return ret;
         }
 
         if (methodcode == ANNOUNCE) {
             ret       = rtsp_read_announce(s);
             rt->state = RTSP_STATE_PAUSED;
         } else if (methodcode == OPTIONS) {
             ret = rtsp_read_options(s);
         } else if (methodcode == RECORD) {
             ret = rtsp_read_record(s);
             if (!ret)
                 return 0; // We are ready for streaming
         } else if (methodcode == SETUP)
             ret = rtsp_read_setup(s, host, uri);
         if (ret) {
             ffurl_close(rt->rtsp_hd);
             return AVERROR_INVALIDDATA;
         }
     }
     return 0;
 }
 

 static int rtsp_probe(AVProbeData *p)
 {
     if (av_strstart(p->filename, "rtsp:", NULL))
         return AVPROBE_SCORE_MAX;
     return 0;
 }
 

 static int rtsp_read_header(AVFormatContext *s)

 {
     RTSPState *rt = s->priv_data;
     int ret;
 

     if (rt->initial_timeout > 0)
         rt->rtsp_flags |= RTSP_FLAG_LISTEN;

     if (rt->rtsp_flags & RTSP_FLAG_LISTEN) {
         ret = rtsp_listen(s);
         if (ret)
             return ret;

     } else {

         ret = ff_rtsp_connect(s);
         if (ret)
             return ret;
 
         rt->real_setup_cache = !s->nb_streams ? NULL :
             av_mallocz(2 * s->nb_streams * sizeof(*rt->real_setup_cache));
         if (!rt->real_setup_cache && s->nb_streams)
             return AVERROR(ENOMEM);
         rt->real_setup = rt->real_setup_cache + s->nb_streams;
 
         if (rt->initial_pause) {
             /* do not start immediately */
         } else {
             if (rtsp_read_play(s) < 0) {
                 ff_rtsp_close_streams(s);
                 ff_rtsp_close_connections(s);
                 return AVERROR_INVALIDDATA;
             }

         }
     }
 
     return 0;
 }
 
 int ff_rtsp_tcp_read_packet(AVFormatContext *s, RTSPStream **prtsp_st,
                             uint8_t *buf, int buf_size)
 {
     RTSPState *rt = s->priv_data;
     int id, len, i, ret;
     RTSPStream *rtsp_st;
 

     av_dlog(s, "tcp_read_packet:\n");

 redo:
     for (;;) {
         RTSPMessageHeader reply;
 

         ret = ff_rtsp_read_reply(s, &reply, NULL, 1, NULL);

         if (ret < 0)
             return ret;
         if (ret == 1) /* received '$' */
             break;
         /* XXX: parse message */
         if (rt->state != RTSP_STATE_STREAMING)
             return 0;
     }

     ret = ffurl_read_complete(rt->rtsp_hd, buf, 3);

     if (ret != 3)
         return -1;
     id  = buf[0];
     len = AV_RB16(buf + 1);

     av_dlog(s, "id=%d len=%d\n", id, len);

     if (len > buf_size || len < 8)

         goto redo;
     /* get the data */

     ret = ffurl_read_complete(rt->rtsp_hd, buf, len);

     if (ret != len)
         return -1;
     if (rt->transport == RTSP_TRANSPORT_RDT &&
         ff_rdt_parse_header(buf, len, &id, NULL, NULL, NULL, NULL) < 0)
         return -1;
 
     /* find the matching stream */
     for (i = 0; i < rt->nb_rtsp_streams; i++) {
         rtsp_st = rt->rtsp_streams[i];
         if (id >= rtsp_st->interleaved_min &&
             id <= rtsp_st->interleaved_max)
             goto found;
     }
     goto redo;
 found:
     *prtsp_st = rtsp_st;
     return len;
 }

 
 static int resetup_tcp(AVFormatContext *s)
 {
     RTSPState *rt = s->priv_data;
     char host[1024];
     int port;
 
     av_url_split(NULL, 0, NULL, 0, host, sizeof(host), &port, NULL, 0,
                  s->filename);

     ff_rtsp_undo_setup(s, 0);

     return ff_rtsp_make_setup_request(s, host, port, RTSP_LOWER_TRANSPORT_TCP,
                                       rt->real_challenge);
 }
 

 static int rtsp_read_packet(AVFormatContext *s, AVPacket *pkt)
 {
     RTSPState *rt = s->priv_data;
     int ret;
     RTSPMessageHeader reply1, *reply = &reply1;
     char cmd[1024];
 

 retry:

     if (rt->server_type == RTSP_SERVER_REAL) {
         int i;
 
         for (i = 0; i < s->nb_streams; i++)
             rt->real_setup[i] = s->streams[i]->discard;
 
         if (!rt->need_subscription) {
             if (memcmp (rt->real_setup, rt->real_setup_cache,
                         sizeof(enum AVDiscard) * s->nb_streams)) {
                 snprintf(cmd, sizeof(cmd),
                          "Unsubscribe: %s\r\n",
                          rt->last_subscription);
                 ff_rtsp_send_cmd(s, "SET_PARAMETER", rt->control_uri,
                                  cmd, reply, NULL);
                 if (reply->status_code != RTSP_STATUS_OK)
                     return AVERROR_INVALIDDATA;
                 rt->need_subscription = 1;
             }
         }
 
         if (rt->need_subscription) {
             int r, rule_nr, first = 1;
 
             memcpy(rt->real_setup_cache, rt->real_setup,
                    sizeof(enum AVDiscard) * s->nb_streams);
             rt->last_subscription[0] = 0;
 
             snprintf(cmd, sizeof(cmd),
                      "Subscribe: ");
             for (i = 0; i < rt->nb_rtsp_streams; i++) {
                 rule_nr = 0;
                 for (r = 0; r < s->nb_streams; r++) {

                     if (s->streams[r]->id == i) {

                         if (s->streams[r]->discard != AVDISCARD_ALL) {
                             if (!first)
                                 av_strlcat(rt->last_subscription, ",",
                                            sizeof(rt->last_subscription));
                             ff_rdt_subscribe_rule(
                                 rt->last_subscription,
                                 sizeof(rt->last_subscription), i, rule_nr);
                             first = 0;
                         }
                         rule_nr++;
                     }
                 }
             }
             av_strlcatf(cmd, sizeof(cmd), "%s\r\n", rt->last_subscription);
             ff_rtsp_send_cmd(s, "SET_PARAMETER", rt->control_uri,
                              cmd, reply, NULL);
             if (reply->status_code != RTSP_STATUS_OK)
                 return AVERROR_INVALIDDATA;
             rt->need_subscription = 0;
 
             if (rt->state == RTSP_STATE_STREAMING)
                 rtsp_read_play (s);
         }
     }
 
     ret = ff_rtsp_fetch_packet(s, pkt);

     if (ret < 0) {

         if (ret == AVERROR(ETIMEDOUT) && !rt->packets) {

             if (rt->lower_transport == RTSP_LOWER_TRANSPORT_UDP &&
                 rt->lower_transport_mask & (1 << RTSP_LOWER_TRANSPORT_TCP)) {
                 RTSPMessageHeader reply1, *reply = &reply1;
                 av_log(s, AV_LOG_WARNING, "UDP timeout, retrying with TCP\n");
                 if (rtsp_read_pause(s) != 0)
                     return -1;
                 // TEARDOWN is required on Real-RTSP, but might make
                 // other servers close the connection.
                 if (rt->server_type == RTSP_SERVER_REAL)
                     ff_rtsp_send_cmd(s, "TEARDOWN", rt->control_uri, NULL,
                                      reply, NULL);
                 rt->session_id[0] = '\0';
                 if (resetup_tcp(s) == 0) {
                     rt->state = RTSP_STATE_IDLE;
                     rt->need_subscription = 1;
                     if (rtsp_read_play(s) != 0)
                         return -1;
                     goto retry;
                 }
             }
         }

         return ret;

     }
     rt->packets++;

     if (!(rt->rtsp_flags & RTSP_FLAG_LISTEN)) {
         /* send dummy request to keep TCP connection alive */
         if ((av_gettime() - rt->last_cmd_time) / 1000000 >= rt->timeout / 2 ||
             rt->auth_state.stale) {
             if (rt->server_type == RTSP_SERVER_WMS ||
                 (rt->server_type != RTSP_SERVER_REAL &&
                  rt->get_parameter_supported)) {
                 ff_rtsp_send_cmd_async(s, "GET_PARAMETER", rt->control_uri, NULL);
             } else {

                 ff_rtsp_send_cmd_async(s, "OPTIONS", rt->control_uri, NULL);

             }
             /* The stale flag should be reset when creating the auth response in
              * ff_rtsp_send_cmd_async, but reset it here just in case we never
              * called the auth code (if we didn't have any credentials set). */
             rt->auth_state.stale = 0;

         }
     }
 
     return 0;
 }
 
 static int rtsp_read_seek(AVFormatContext *s, int stream_index,
                           int64_t timestamp, int flags)
 {
     RTSPState *rt = s->priv_data;
 
     rt->seek_timestamp = av_rescale_q(timestamp,
                                       s->streams[stream_index]->time_base,
                                       AV_TIME_BASE_Q);
     switch(rt->state) {
     default:
     case RTSP_STATE_IDLE:
         break;
     case RTSP_STATE_STREAMING:
         if (rtsp_read_pause(s) != 0)
             return -1;
         rt->state = RTSP_STATE_SEEKING;
         if (rtsp_read_play(s) != 0)
             return -1;
         break;
     case RTSP_STATE_PAUSED:
         rt->state = RTSP_STATE_IDLE;
         break;
     }
     return 0;
 }
 

 static const AVClass rtsp_demuxer_class = {

     .class_name     = "RTSP demuxer",
     .item_name      = av_default_item_name,

     .option         = ff_rtsp_options,

     .version        = LIBAVUTIL_VERSION_INT,
 };
 

 AVInputFormat ff_rtsp_demuxer = {

     .name           = "rtsp",

     .long_name      = NULL_IF_CONFIG_SMALL("RTSP input"),

     .priv_data_size = sizeof(RTSPState),
     .read_probe     = rtsp_probe,
     .read_header    = rtsp_read_header,
     .read_packet    = rtsp_read_packet,
     .read_close     = rtsp_read_close,
     .read_seek      = rtsp_read_seek,

     .flags          = AVFMT_NOFILE,
     .read_play      = rtsp_read_play,
     .read_pause     = rtsp_read_pause,
     .priv_class     = &rtsp_demuxer_class,

 };