aboutsummaryrefslogtreecommitdiffstats
path: root/libavformat/rtspdec.c
blob: a14ec579d96f1c60bb7e1d67cd9be477caff2ac0 (plain) (blame)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
871
872
873
874
875
876
877
878
879
880
881
882
883
884
885
886
887
888
889
890
891
892
893
894
895
896
897
898
899
900
901
902
903
904
905
906
907
908
909
910
911
912
913
914
915
916
917
918
919
920
921
922
923
924
925
926
927
928
929
930
931
932
933
934
935
936
937
938
/*
 * RTSP demuxer
 * Copyright (c) 2002 Fabrice Bellard
 *
 * This file is part of Libav.
 *
 * Libav 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.
 *
 * Libav 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 Libav; 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) {
        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 < 12)
        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,
};