aboutsummaryrefslogtreecommitdiffstats
path: root/mediaplugin/src/lib/ffmpeg/avio.pas
blob: adb59a447c5606feae7e315d9cde6f7615ba54a5 (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
(*
 * unbuffered io for ffmpeg system
 * copyright (c) 2001 Fabrice Bellard
 *
 * 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
 *
 * This is a part of Pascal porting of ffmpeg.
 * - Originally by Victor Zinetz for Delphi and Free Pascal on Windows.
 * - For Mac OS X, some modifications were made by The Creative CAT, denoted as CAT
 *   in the source codes.
 * - Changes and updates by the UltraStar Deluxe Team
 *
 * Conversion of libavformat/avio.h
 * unbuffered I/O operations
 * @warning This file has to be considered an internal but installed
 * header, so it should not be directly included in your projects.
 *
 * update to
 * Max. avformat version: 52.78.3, revision 24841, Thu Aug 26 02:00:00 2010 CET
 *)

unit avio;

{$IFDEF FPC}
  {$MODE DELPHI }
  {$PACKENUM 4}    (* use 4-byte enums *)
  {$PACKRECORDS C} (* C/C++-compatible record packing *)
{$ELSE}
  {$MINENUMSIZE 4} (* use 4-byte enums *)
{$ENDIF}

{$I switches.inc}

interface

uses
  ctypes,
  avutil,
  avcodec,
  SysUtils,
  UConfig;

(* unbuffered I/O *)

const
  URL_RDONLY = 0;
  URL_WRONLY = 1;
  URL_RDWR   = 2;

 (**
  * Passing this as the "whence" parameter to a seek function causes it to
  * return the filesize without seeking anywhere. Supporting this is optional.
  * If it is not supported then the seek function will return <0.
  *)
  AVSEEK_SIZE = $10000;

{$IF LIBAVFORMAT_VERSION >= 52056000} // 52.56.0
 (**
  * Oring this flag as into the "whence" parameter to a seek function causes it to
  * seek by any means (like reopening and linear reading) or other normally unreasonble
  * means that can be extreemly slow.
  * This may be ignored by the seek code.
  *)
  AVSEEK_FORCE = $20000;
{$IFEND}

type
  TURLInterruptCB = function (): cint; cdecl;

type
  PURLProtocol = ^TURLProtocol;

 (**
  * URL Context.
  * New fields can be added to the end with minor version bumps.
  * Removal, reordering and changes to existing fields require a major
  * version bump.
  * sizeof(URLContext) must not be used outside libav*.
  *)
  PURLContext = ^TURLContext;
  TURLContext = record
    {$IF LIBAVFORMAT_VERSION < 52078003} // < 52.78.3
    av_class: {const} PAVClass; ///< information for av_log(). Set by url_open().
    {$ELSE}
      {$IFDEF FF_API_URL_CLASS}
    av_class: {const} PAVClass; ///< information for av_log(). Set by url_open().
      {$ENDIF}
    {$IFEND}
    prot: PURLProtocol;
    flags: cint;
    is_streamed: cint;  (**< true if streamed (no seek possible), default = false *)
    max_packet_size: cint;  (**< if non zero, the stream is packetized with this max packet size *)
    priv_data: pointer;
    filename: PAnsiChar; (**< specified URL *)
{$IF LIBAVFORMAT_VERSION >= 52070000} // 52.70.0
     is_connected: cint;
{$IFEND}
  end;
  PPURLContext = ^PURLContext;

  PURLPollEntry = ^TURLPollEntry;
  TURLPollEntry = record
    handle: PURLContext;
    events: cint;
    revents: cint;
  end;

  TURLProtocol = record
    name: PAnsiChar;
{$IF LIBAVFORMAT_VERSION < 52047000} // 52.47.0
    url_open: function (h: PURLContext; filename: {const} PAnsiChar; flags: cint): cint; cdecl;
{$ELSE}
    url_open: function (h: PURLContext; url: {const} PAnsiChar; flags: cint): cint; cdecl;
{$IFEND}

(**
 * Read up to size bytes from the resource accessed by h, and store
 * the read bytes in buf.
 *
 * @return The number of bytes actually read, or a negative value
 * corresponding to an AVERROR code in case of error. A value of zero
 * indicates that it is not possible to read more from the accessed
 * resource (except if the value of the size argument is also zero).
 *)
    url_read: function (h: PURLContext; buf: PByteArray; size: cint): cint; cdecl;

(**
 * Read as many bytes as possible (up to size), calling the
 * read function multiple times if necessary.
 * Will also retry if the read function returns AVERROR(EAGAIN).
 * This makes special short-read handling in applications
 * unnecessary, if the return value is < size then it is
 * certain there was either an error or the end of file was reached.
 *)
    url_write: function (h: PURLContext; {const} buf: PByteArray; size: cint): cint; cdecl;

(**
 * Change the position that will be used by the next read/write
 * operation on the resource accessed by h.
 *
 * @param pos specifies the new position to set
 * @param whence specifies how pos should be interpreted, it must be
 * one of SEEK_SET (seek from the beginning), SEEK_CUR (seek from the
 * current position), SEEK_END (seek from the end), or AVSEEK_SIZE
 * (return the filesize of the requested resource, pos is ignored).
 * @return a negative value corresponding to an AVERROR code in case
 * of failure, or the resulting file position, measured in bytes from
 * the beginning of the file. You can use this feature together with
 * SEEK_CUR to read the current file position.
 *)
    url_seek: function (h: PURLContext; pos: cint64; whence: cint): cint64; cdecl;

    url_close: function (h: PURLContext): cint; cdecl;
    next: PURLProtocol;
    {$IF (LIBAVFORMAT_VERSION >= 52001000) and (LIBAVFORMAT_VERSION < 52004000)} // 52.1.0 .. 52.4.0
    url_read_play: function (h: PURLContext): cint; cdecl;
    url_read_pause: function (h: PURLContext): cint; cdecl;
    {$IFEND}
    {$IF LIBAVFORMAT_VERSION >= 52004000} // 52.4.0
    url_read_pause: function (h: PURLContext; pause: cint): cint; cdecl;
    {$IFEND}
    {$IF LIBAVFORMAT_VERSION >= 52001000} // 52.1.0
    url_read_seek: function (h: PURLContext; stream_index: cint;
                             timestamp: cint64; flags: cint): cint64; cdecl;
    {$IFEND}
    {$IF LIBAVFORMAT_VERSION >= 52031000} // 52.31.0
    url_get_file_handle: function (h: PURLContext): cint; cdecl;
    {$IFEND}
    
    {$IF LIBAVFORMAT_VERSION >= 52071000} // 52.71.0
    priv_data_size: cint;
    {const} priv_data_class: PAVClass;
    {$IFEND}
  end;

 (**
  * Bytestream IO Context.
  * New fields can be added to the end with minor version bumps.
  * Removal, reordering and changes to existing fields require a major
  * version bump.
  * sizeof(ByteIOContext) must not be used outside libav*.
  *)
  PByteIOContext = ^TByteIOContext;
  TByteIOContext = record
    buffer: PByteArray;
    buffer_size: cint;
    buf_ptr: PByteArray;
    buf_end: PByteArray;
    opaque: pointer;
    read_packet: function (opaque: pointer; buf: PByteArray; buf_size: cint): cint; cdecl;
    write_packet: function (opaque: pointer; buf: PByteArray; buf_size: cint): cint; cdecl;
    seek: function (opaque: pointer; offset: cint64; whence: cint): cint64; cdecl;
    pos: cint64; (* position in the file of the current buffer *)
    must_flush: cint; (* true if the next seek should flush *)
    eof_reached: cint; (* true if eof reached *)
    write_flag: cint;  (* true if open for writing *)
    is_streamed: cint;
    max_packet_size: cint;
    checksum: culong;
    checksum_ptr: PByteArray;
    update_checksum: function (checksum: culong; buf: {const} PByteArray; size: cuint): culong; cdecl;
    error: cint;         ///< contains the error code or 0 if no error happened
    {$IF (LIBAVFORMAT_VERSION >= 52001000) and (LIBAVFORMAT_VERSION < 52004000)} // 52.1.0 .. 52.4.0
    read_play: function(opaque: Pointer): cint; cdecl;
    read_pause: function(opaque: Pointer): cint; cdecl;
    {$IFEND}
    {$IF LIBAVFORMAT_VERSION >= 52004000} // 52.4.0
    read_pause: function(opaque: Pointer; pause: cint): cint; cdecl;
    {$IFEND}
    {$IF LIBAVFORMAT_VERSION >= 52001000} // 52.1.0
    read_seek: function(opaque: Pointer; stream_index: cint;
                        timestamp: cint64; flags: cint): cint64; cdecl;
    {$IFEND}
  end;

{$IF LIBAVFORMAT_VERSION >= 52070000} // 52.70.0
(**
 * Create a URLContext for accessing to the resource indicated by
 * url, but do not initiate the connection yet.
 *
 * @param puc pointer to the location where, in case of success, the
 * function puts the pointer to the created URLContext
 * @param flags flags which control how the resource indicated by url
 * is to be opened
 * @return 0 in case of success, a negative value corresponding to an
 * AVERROR code in case of failure
 *)
function url_alloc(h: PPURLContext; {const} url: PAnsiChar; flags: cint): cint;
  cdecl; external av__format;

(**
 * Connect an URLContext that has been allocated by url_alloc
 *)
function url_connect(h: PURLContext): cint;
  cdecl; external av__format;
{$IFEND}

{$IF LIBAVFORMAT_VERSION >= 52021000} // 52.21.0
(**
 * Create a URLContext for accessing to the resource indicated by
 * URL, and open it using the URLProtocol up.
 *
 * @param puc pointer to the location where, in case of success, the
 * function puts the pointer to the created URLContext
 * @param flags flags which control how the resource indicated by URL
 * is to be opened
 * @return 0 in case of success, a negative value corresponding to an
 * AVERROR code in case of failure
 *)
function url_open_protocol(puc: PPURLContext; up: PURLProtocol;
{$IF LIBAVFORMAT_VERSION < 52047000} // 52.47.0
                           filename: {const} PAnsiChar; flags: cint): cint;
{$ELSE}
                           url: {const} PAnsiChar; flags: cint): cint;
{$IFEND}
  cdecl; external av__format;
{$IFEND}

(**
 * Create a URLContext for accessing to the resource indicated by
 * url, and open it.
 *
 * @param puc pointer to the location where, in case of success, the
 * function puts the pointer to the created URLContext
 * @param flags flags which control how the resource indicated by url
 * is to be opened
 * @return 0 in case of success, a negative value corresponding to an
 * AVERROR code in case of failure
 *)
{$IF LIBAVFORMAT_VERSION < 52047000} // 52.47.0
function url_open(h: PPointer; filename: {const} PAnsiChar; flags: cint): cint;
{$ELSE}
function url_open(h: PPointer; url: {const} PAnsiChar; flags: cint): cint;
{$IFEND}
  cdecl; external av__format;
function url_read (h: PURLContext; buf: PByteArray; size: cint): cint;
  cdecl; external av__format;
{$IF LIBAVFORMAT_VERSION >= 52034000} // 52.34.0
function url_read_complete (h: PURLContext; buf: PByteArray; size: cint): cint; cdecl;
  cdecl; external av__format;
{$IFEND}
function url_write (h: PURLContext; {const} buf: PByteArray; size: cint): cint;
  cdecl; external av__format;
function url_seek (h: PURLContext; pos: cint64; whence: cint): cint64;
  cdecl; external av__format;

(**
 * Close the resource accessed by the URLContext h, and free the
 * memory used by it.
 *
 * @return a negative value if an error condition occurred, 0
 * otherwise
 *)
function url_close (h: PURLContext): cint;
  cdecl; external av__format;

(**
 * Return a non-zero value if the resource indicated by url
 * exists, 0 otherwise.
 *)
{$IF LIBAVFORMAT_VERSION < 52047000} // 52.47.0
function url_exist(filename: {const} PAnsiChar): cint;
{$ELSE}
function url_exist(url: {const} PAnsiChar): cint;
{$IFEND}
  cdecl; external av__format;

function url_filesize (h: PURLContext): cint64;
  cdecl; external av__format;

(**
 * Return the file descriptor associated with this URL. For RTP, this
 * will return only the RTP file descriptor, not the RTCP file descriptor.
 * To get both, use rtp_get_file_handles().
 *
 * @return the file descriptor associated with this URL, or <0 on error.
 *)
(* not implemented *)
function url_get_file_handle(h: PURLContext): cint;
  cdecl; external av__format;

(**
 * Return the maximum packet size associated to packetized file
 * handle. If the file is not packetized (stream like HTTP or file on
 * disk), then 0 is returned.
 *
 * @param h file handle
 * @return maximum packet size in bytes
 *)
function url_get_max_packet_size(h: PURLContext): cint;
  cdecl; external av__format;
procedure url_get_filename(h: PURLContext; buf: PAnsiChar; buf_size: cint);
  cdecl; external av__format;

(**
 * The callback is called in blocking functions to test regulary if
 * asynchronous interruption is needed. AVERROR(EINTR) is returned
 * in this case by the interrupted function. 'NULL' means no interrupt
 * callback is given.
 *)
procedure url_set_interrupt_cb (interrupt_cb: TURLInterruptCB);
  cdecl; external av__format;

(* not implemented *)
function url_poll(poll_table: PURLPollEntry; n: cint; timeout: cint): cint;
  cdecl; external av__format;

{$IF LIBAVFORMAT_VERSION >= 52004000} // 52.4.0
(**
 * Pause and resume playing - only meaningful if using a network streaming
 * protocol (e.g. MMS).
 * @param pause 1 for pause, 0 for resume
 *)
function av_url_read_pause(h: PURLContext; pause: cint): cint;
  cdecl; external av__format;
{$IFEND}

{$IF LIBAVFORMAT_VERSION >= 52001000} // 52.1.0
(**
 * Seek to a given timestamp relative to some component stream.
 * Only meaningful if using a network streaming protocol (e.g. MMS.).
 * @param stream_index The stream index that the timestamp is relative to.
 *        If stream_index is (-1) the timestamp should be in AV_TIME_BASE
 *        units from the beginning of the presentation.
 *        If a stream_index >= 0 is used and the protocol does not support
 *        seeking based on component streams, the call will fail with ENOTSUP.
 * @param timestamp timestamp in AVStream.time_base units
 *        or if there is no stream specified then in AV_TIME_BASE units.
 * @param flags Optional combination of AVSEEK_FLAG_BACKWARD, AVSEEK_FLAG_BYTE
 *        and AVSEEK_FLAG_ANY. The protocol may silently ignore
 *        AVSEEK_FLAG_BACKWARD and AVSEEK_FLAG_ANY, but AVSEEK_FLAG_BYTE will
 *        fail with ENOTSUP if used and not supported.
 * @return >= 0 on success
 * @see AVInputFormat::read_seek
 *)
function av_url_read_seek(h: PURLContext; stream_index: cint;
                          timestamp: cint64; flags: cint): cint64;
  cdecl; external av__format;
{$IFEND}

(**
var
{$IF LIBAVFORMAT_VERSION < 52078003} // < 52.78.3
  first_protocol: PURLProtocol; external av__format;
{$ELSE}
  {$IFDEF FF_API_REGISTER_PROTOCOL}
  first_protocol: PURLProtocol; external av__format;
  {$IFEND}
{$IFEND}
  url_interrupt_cb: PURLInterruptCB; external av__format;
**)

{$IF LIBAVFORMAT_VERSION >= 52002000} // 52.2.0
(**
 * If protocol is NULL, returns the first registered protocol,
 * if protocol is non-NULL, returns the next registered protocol after protocol,
 * or NULL if protocol is the last one.
 *)
function av_protocol_next(p: PURLProtocol): PURLProtocol;
  cdecl; external av__format;
{$IFEND}

{$IF LIBAVFORMAT_VERSION <= 52028000} // 52.28.0
(**
 * Register the URLProtocol protocol.
 *
 *
 * @deprecated Use av_register_protocol() instead.
 *)
function register_protocol(protocol: PURLProtocol): cint;
  cdecl; external av__format;
(** Alias for register_protocol()
 *
 * @deprecated Use av_register_protocol2() instead.
 *)
function av_register_protocol(protocol: PURLProtocol): cint;
  cdecl; external av__format name 'register_protocol';
{$ELSE}
{$IF LIBAVFORMAT_VERSION < 52078003} // < 52.78.3
function av_register_protocol(protocol: PURLProtocol): cint;
  cdecl; external av__format;
{$ELSE}
  {$IFDEF FF_API_REGISTER_PROTOCOL}
function av_register_protocol(protocol: PURLProtocol): cint;
  cdecl; external av__format;
  {$ENDIF}
{$IFEND}
{$IFEND}
{$IF LIBAVFORMAT_VERSION >= 52069000} // 52.69.0
function av_register_protocol2(protocol: PURLProtocol; size: cint): cint;
  cdecl; external av__format;
{$IFEND}

type
  TReadWriteFunc = function(opaque: Pointer; buf: PByteArray; buf_size: cint): cint; cdecl;
  TSeekFunc = function(opaque: Pointer; offset: cint64; whence: cint): cint64; cdecl;

function init_put_byte(s: PByteIOContext;
                buffer: PByteArray;
                buffer_size: cint; write_flag: cint;
                opaque: pointer;
                read_packet: TReadWriteFunc;
                write_packet: TReadWriteFunc;
                seek: TSeekFunc): cint;
  cdecl; external av__format;
{$IF LIBAVFORMAT_VERSION >= 52004000} // 52.4.0
function av_alloc_put_byte(
                  buffer: PByteArray;
                  buffer_size: cint;
                  write_flag: cint;
                  opaque: Pointer;
                  read_packet: TReadWriteFunc;
                  write_packet: TReadWriteFunc;
                  seek: TSeekFunc): PByteIOContext;
  cdecl; external av__format;
{$IFEND}

procedure put_byte(s: PByteIOContext; b: cint);
  cdecl; external av__format;
procedure put_buffer (s: PByteIOContext; buf: {const} PByteArray; size: cint);
  cdecl; external av__format;
procedure put_le64(s: PByteIOContext; val: cuint64);
  cdecl; external av__format;
procedure put_be64(s: PByteIOContext; val: cuint64);
  cdecl; external av__format;
procedure put_le32(s: PByteIOContext; val: cuint);
  cdecl; external av__format;
procedure put_be32(s: PByteIOContext; val: cuint);
  cdecl; external av__format;
procedure put_le24(s: PByteIOContext; val: cuint);
  cdecl; external av__format;
procedure put_be24(s: PByteIOContext; val: cuint);
  cdecl; external av__format;
procedure put_le16(s: PByteIOContext; val: cuint);
  cdecl; external av__format;
procedure put_be16(s: PByteIOContext; val: cuint);
  cdecl; external av__format;
procedure put_tag(s: PByteIOContext; tag: {const} PAnsiChar);
  cdecl; external av__format;

procedure put_strz(s: PByteIOContext; buf: {const} PAnsiChar);
  cdecl; external av__format;

(**
 * fseek() equivalent for ByteIOContext.
 * @return new position or AVERROR.
 *)
function url_fseek(s: PByteIOContext; offset: cint64; whence: cint): cint64;
  cdecl; external av__format;

(**
 * Skip given number of bytes forward.
 * @param offset number of bytes
 * @return 0 on success, <0 on error
 *)
{$IF LIBAVFORMAT_VERSION < 52074000} // 52.74.0
procedure url_fskip(s: PByteIOContext; offset: cint64);
  cdecl; external av__format;
{$ELSE}
function url_fskip(s: PByteIOContext; offset: cint64): cint;
  cdecl; external av__format;
{$IFEND}

(**
 * ftell() equivalent for ByteIOContext.
 * @return position or AVERROR.
 *)
function url_ftell(s: PByteIOContext): cint64;
  cdecl; external av__format;

(**
 * Get the filesize.
 * @return filesize or AVERROR
 *)
function url_fsize(s: PByteIOContext): cint64;
  cdecl; external av__format;

(**
 * feof() equivalent for ByteIOContext.
 * @return non zero if and only if end of file
 *)
function url_feof(s: PByteIOContext): cint;
  cdecl; external av__format;

function url_ferror(s: PByteIOContext): cint;
  cdecl; external av__format;

{$IF LIBAVFORMAT_VERSION >= 52004000} // 52.4.0
function av_url_read_fpause(h: PByteIOContext; pause: cint): cint;
  cdecl; external av__format;
{$IFEND}

{$IF LIBAVFORMAT_VERSION >= 52001000} // 52.1.0
function av_url_read_fseek(h: PByteIOContext; stream_index: cint;
                           timestamp: cint64; flags: cint): cint64;
  cdecl; external av__format;
{$IFEND}

const
  URL_EOF = -1;
(** @note return URL_EOF (-1) if EOF *)
function url_fgetc(s: PByteIOContext): cint;
  cdecl; external av__format;

(** @warning currently size is limited *)
function url_fprintf(s: PByteIOContext; fmt: {const} PAnsiChar; args: array of const): cint;
  cdecl; external av__format;

(** @note unlike fgets, the EOL character is not returned and a whole
   line is parsed. return NULL if first char read was EOF *)
function url_fgets(s: PByteIOContext; buf: PAnsiChar; buf_size: cint): PAnsiChar;
  cdecl; external av__format;

procedure put_flush_packet (s: PByteIOContext);
  cdecl; external av__format;

(**
 * Read size bytes from ByteIOContext into buf.
 * @return number of bytes read or AVERROR
 *)
function get_buffer(s: PByteIOContext; buf: PByteArray; size: cint): cint;
  cdecl; external av__format;

(**
 * Read size bytes from ByteIOContext into buf.
 * This reads at most 1 packet. If that is not enough fewer bytes will be
 * returned.
 * @return number of bytes read or AVERROR
 *)
function get_partial_buffer(s: PByteIOContext; buf: PByteArray; size: cint): cint;
  cdecl; external av__format;

(** @note return 0 if EOF, so you cannot use it if EOF handling is
   necessary *)
function get_byte(s: PByteIOContext): cint;
  cdecl; external av__format;
function get_le24(s: PByteIOContext): cuint;
  cdecl; external av__format;
function get_le32(s: PByteIOContext): cuint;
  cdecl; external av__format;
function get_le64(s: PByteIOContext): cuint64;
  cdecl; external av__format;
function get_le16(s: PByteIOContext): cuint;
  cdecl; external av__format;

function get_strz(s: PByteIOContext; buf: PAnsiChar; maxlen: cint): PAnsiChar;
  cdecl; external av__format;
function get_be16(s: PByteIOContext): cuint;
  cdecl; external av__format;
function get_be24(s: PByteIOContext): cuint;
  cdecl; external av__format;
function get_be32(s: PByteIOContext): cuint;
  cdecl; external av__format;
function get_be64(s: PByteIOContext): cuint64;
  cdecl; external av__format;

{$IF LIBAVFORMAT_VERSION >= 51017001} // 51.17.1
  {$IF LIBAVFORMAT_VERSION < 52078003} // < 52.78.3
function ff_get_v(bc: PByteIOContext): cuint64;
  cdecl; external av__format;
  {$ELSE}
    {$IFDEF FF_API_URL_RESETBUF}
function ff_get_v(bc: PByteIOContext): cuint64;
  cdecl; external av__format;
    {$ENDIF}
  {$IFEND}
{$IFEND}

function url_is_streamed(s: PByteIOContext): cint; {$IFDEF HasInline}inline;{$ENDIF}

(**
 * Create and initialize a ByteIOContext for accessing the
 * resource referenced by the URLContext h.
 * @note When the URLContext h has been opened in read+write mode, the
 * ByteIOContext can be used only for writing.
 *
 * @param s Used to return the pointer to the created ByteIOContext.
 * In case of failure the pointed to value is set to NULL.
 * @return 0 in case of success, a negative value corresponding to an
 * AVERROR code in case of failure
 *)
{$IF LIBAVFORMAT_VERSION >= 52000000} // 52.0.0
function url_fdopen (var s: PByteIOContext; h: PURLContext): cint;
{$ELSE}
function url_fdopen (s: PByteIOContext; h: PURLContext): cint;
{$IFEND}
  cdecl; external av__format;

(** @warning must be called before any I/O *)
function url_setbufsize (s: PByteIOContext; buf_size: cint): cint;
  cdecl; external av__format;

{$IF LIBAVFORMAT_VERSION_MAJOR < 53}
{$IF LIBAVFORMAT_VERSION >= 51015000} // 51.15.0
(** Reset the buffer for reading or writing.
 * @note Will drop any data currently in the buffer without transmitting it.
 * @param flags URL_RDONLY to set up the buffer for reading, or URL_WRONLY
 *        to set up the buffer for writing. *)
function url_resetbuf(s: PByteIOContext; flags: cint): cint;
  cdecl; external av__format;
{$IFEND}
{$IFEND}

{$IF LIBAVFORMAT_VERSION >= 52061000} // 52.61.0
(**
 * Rewind the ByteIOContext using the specified buffer containing the first buf_size bytes of the file.
 * Used after probing to avoid seeking.
 * Joins buf and s->buffer, taking any overlap into consideration.
 * @note s->buffer must overlap with buf or they can't be joined and the function fails
 * @note This function is NOT part of the public API
 *
 * @param s The read-only ByteIOContext to rewind
 * @param buf The probe buffer containing the first buf_size bytes of the file
 * @param buf_size The size of buf
 * @return 0 in case of success, a negative value corresponding to an
 * AVERROR code in case of failure
 *)
function ff_rewind_with_probe_data(s: PByteIOContext;  buf: PAnsiChar; buf_size: cint): cint;
  cdecl; external av__format;
{$IFEND}

(**
 * Create and initialize a ByteIOContext for accessing the
 * resource indicated by url.
 * @note When the resource indicated by url has been opened in
 * read+write mode, the ByteIOContext can be used only for writing.
 *
 * @param s Used to return the pointer to the created ByteIOContext.
 * In case of failure the pointed to value is set to NULL.
 * @param flags flags which control how the resource indicated by url
 * is to be opened
 * @return 0 in case of success, a negative value corresponding to an
 * AVERROR code in case of failure
 *)
{$IF LIBAVFORMAT_VERSION < 52047000} // 52.47.0
{$IF LIBAVFORMAT_VERSION >= 52000000} // 52.0.0
function url_fopen(var s: PByteIOContext; filename: {const} PAnsiChar; flags: cint): cint;
{$ELSE}
function url_fopen(s: PByteIOContext; filename: {const} PAnsiChar; flags: cint): cint;
{$IFEND}
{$ELSE}
function url_fopen(var s: PByteIOContext; url: {const} PAnsiChar; flags: cint): cint;
{$IFEND}
  cdecl; external av__format;
function url_fclose(s: PByteIOContext): cint;
  cdecl; external av__format;
function url_fileno(s: PByteIOContext): PURLContext;
  cdecl; external av__format;

(**
 * Return the maximum packet size associated to packetized buffered file
 * handle. If the file is not packetized (stream like http or file on
 * disk), then 0 is returned.
 *
 * @param s buffered file handle
 * @return maximum packet size in bytes
 *)
function url_fget_max_packet_size (s: PByteIOContext): cint;
  cdecl; external av__format;

{$IF LIBAVFORMAT_VERSION >= 52000000} // 52.0.0
function url_open_buf(var s: PByteIOContext; buf: PAnsiChar; buf_size: cint; flags: cint): cint;
{$ELSE}
function url_open_buf(s: PByteIOContext; buf: PAnsiChar; buf_size: cint; flags: cint): cint;
{$IFEND}
  cdecl; external av__format;

(** return the written or read size *)
function url_close_buf(s: PByteIOContext): cint;
  cdecl; external av__format;

(**
 * Open a write only memory stream.
 *
 * @param s new IO context
 * @return zero if no error.
 *)
{$IF LIBAVFORMAT_VERSION >= 52000000} // 52.0.0
function url_open_dyn_buf(var s: PByteIOContext): cint;
{$ELSE}
function url_open_dyn_buf(s: PByteIOContext): cint;
{$IFEND}
  cdecl; external av__format;

(**
 * Open a write only packetized memory stream with a maximum packet
 * size of 'max_packet_size'.  The stream is stored in a memory buffer
 * with a big endian 4 byte header giving the packet size in bytes.
 *
 * @param s new IO context
 * @param max_packet_size maximum packet size (must be > 0)
 * @return zero if no error.
 *)
{$IF LIBAVFORMAT_VERSION >= 52000000} // 52.0.0
function url_open_dyn_packet_buf(var s: PByteIOContext; max_packet_size: cint): cint;
{$ELSE}
function url_open_dyn_packet_buf(s: PByteIOContext; max_packet_size: cint): cint;
{$IFEND}
  cdecl; external av__format;

(**
 * Return the written size and a pointer to the buffer. The buffer
 * must be freed with av_free(). If the buffer is opened with
 * url_open_dyn_buf, then padding of FF_INPUT_BUFFER_PADDING_SIZE is
 * added; if opened with url_open_dyn_packet_buf, no padding is added.
 * @param s IO context
 * @param pbuffer pointer to a byte buffer
 * @return the length of the byte buffer
 *)
function url_close_dyn_buf(s: PByteIOContext; pbuffer:PPointer): cint;
  cdecl; external av__format;

{$IF LIBAVFORMAT_VERSION >= 51017001} // 51.17.1
function ff_crc04C11DB7_update(checksum: culong; buf: {const} PByteArray;
                               len: cuint): culong;
  cdecl; external av__format;
{$IFEND}

function get_checksum(s: PByteIOContext): culong;
  cdecl; external av__format;
procedure init_gsum(s: PByteIOContext;
                        update_checksum: pointer;
                        checksum: culong);
  cdecl; external av__format;

(* udp.c *)
function udp_set_remote_url(h: PURLContext; uri: {const} PAnsiChar): cint;
  cdecl; external av__format;
function udp_get_local_port(h: PURLContext): cint;
  cdecl; external av__format;

{$IF LIBAVFORMAT_VERSION_MAJOR <= 52}
function udp_get_file_handle(h: PURLContext): cint;
  cdecl; external av__format;
{$IFEND}
  
implementation

function url_is_streamed(s: PByteIOContext): cint;
begin
  Result := s^.is_streamed;
end;

end.