forked from analogdevicesinc/linux
-
Notifications
You must be signed in to change notification settings - Fork 3
/
video.xml
1971 lines (1926 loc) · 51.6 KB
/
video.xml
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
939
940
941
942
943
944
945
946
947
948
949
950
951
952
953
954
955
956
957
958
959
960
961
962
963
964
965
966
967
968
969
970
971
972
973
974
975
976
977
978
979
980
981
982
983
984
985
986
987
988
989
990
991
992
993
994
995
996
997
998
999
1000
<title>DVB Video Device</title>
<para>The DVB video device controls the MPEG2 video decoder of the DVB hardware. It
can be accessed through <emphasis role="tt">/dev/dvb/adapter0/video0</emphasis>. Data types and and
ioctl definitions can be accessed by including <emphasis role="tt">linux/dvb/video.h</emphasis> in your
application.
</para>
<para>Note that the DVB video device only controls decoding of the MPEG video stream, not
its presentation on the TV or computer screen. On PCs this is typically handled by an
associated video4linux device, e.g. <emphasis role="tt">/dev/video</emphasis>, which allows scaling and defining output
windows.
</para>
<para>Some DVB cards don’t have their own MPEG decoder, which results in the omission of
the audio and video device as well as the video4linux device.
</para>
<para>The ioctls that deal with SPUs (sub picture units) and navigation packets are only
supported on some MPEG decoders made for DVD playback.
</para>
<section id="video_types">
<title>Video Data Types</title>
<section id="video_format_t">
<title>video_format_t</title>
<para>The <emphasis role="tt">video_format_t</emphasis> data type defined by
</para>
<programlisting>
typedef enum {
VIDEO_FORMAT_4_3,
VIDEO_FORMAT_16_9
} video_format_t;
</programlisting>
<para>is used in the VIDEO_SET_FORMAT function (??) to tell the driver which aspect ratio
the output hardware (e.g. TV) has. It is also used in the data structures video_status
(??) returned by VIDEO_GET_STATUS (??) and video_event (??) returned by
VIDEO_GET_EVENT (??) which report about the display format of the current video
stream.
</para>
</section>
<section id="video_display_format_t">
<title>video_display_format_t</title>
<para>In case the display format of the video stream and of the display hardware differ the
application has to specify how to handle the cropping of the picture. This can be done using
the VIDEO_SET_DISPLAY_FORMAT call (??) which accepts
</para>
<programlisting>
typedef enum {
VIDEO_PAN_SCAN,
VIDEO_LETTER_BOX,
VIDEO_CENTER_CUT_OUT
} video_display_format_t;
</programlisting>
<para>as argument.
</para>
</section>
<section id="video_stream_source">
<title>video stream source</title>
<para>The video stream source is set through the VIDEO_SELECT_SOURCE call and can take
the following values, depending on whether we are replaying from an internal (demuxer) or
external (user write) source.
</para>
<programlisting>
typedef enum {
VIDEO_SOURCE_DEMUX,
VIDEO_SOURCE_MEMORY
} video_stream_source_t;
</programlisting>
<para>VIDEO_SOURCE_DEMUX selects the demultiplexer (fed either by the frontend or the
DVR device) as the source of the video stream. If VIDEO_SOURCE_MEMORY
is selected the stream comes from the application through the <emphasis role="tt">write()</emphasis> system
call.
</para>
</section>
<section id="video_play_state">
<title>video play state</title>
<para>The following values can be returned by the VIDEO_GET_STATUS call representing the
state of video playback.
</para>
<programlisting>
typedef enum {
VIDEO_STOPPED,
VIDEO_PLAYING,
VIDEO_FREEZED
} video_play_state_t;
</programlisting>
</section>
<section id="video_event">
<title>struct video_event</title>
<para>The following is the structure of a video event as it is returned by the VIDEO_GET_EVENT
call.
</para>
<programlisting>
struct video_event {
int32_t type;
time_t timestamp;
union {
video_format_t video_format;
} u;
};
</programlisting>
</section>
<section id="video_status">
<title>struct video_status</title>
<para>The VIDEO_GET_STATUS call returns the following structure informing about various
states of the playback operation.
</para>
<programlisting>
struct video_status {
boolean video_blank;
video_play_state_t play_state;
video_stream_source_t stream_source;
video_format_t video_format;
video_displayformat_t display_format;
};
</programlisting>
<para>If video_blank is set video will be blanked out if the channel is changed or if playback is
stopped. Otherwise, the last picture will be displayed. play_state indicates if the video is
currently frozen, stopped, or being played back. The stream_source corresponds to the seleted
source for the video stream. It can come either from the demultiplexer or from memory.
The video_format indicates the aspect ratio (one of 4:3 or 16:9) of the currently
played video stream. Finally, display_format corresponds to the selected cropping
mode in case the source video format is not the same as the format of the output
device.
</para>
</section>
<section id="video_still_picture">
<title>struct video_still_picture</title>
<para>An I-frame displayed via the VIDEO_STILLPICTURE call is passed on within the
following structure.
</para>
<programlisting>
/⋆ pointer to and size of a single iframe in memory ⋆/
struct video_still_picture {
char ⋆iFrame;
int32_t size;
};
</programlisting>
</section>
<section id="video_caps">
<title>video capabilities</title>
<para>A call to VIDEO_GET_CAPABILITIES returns an unsigned integer with the following
bits set according to the hardwares capabilities.
</para>
<programlisting>
/⋆ bit definitions for capabilities: ⋆/
/⋆ can the hardware decode MPEG1 and/or MPEG2? ⋆/
#define VIDEO_CAP_MPEG1 1
#define VIDEO_CAP_MPEG2 2
/⋆ can you send a system and/or program stream to video device?
(you still have to open the video and the audio device but only
send the stream to the video device) ⋆/
#define VIDEO_CAP_SYS 4
#define VIDEO_CAP_PROG 8
/⋆ can the driver also handle SPU, NAVI and CSS encoded data?
(CSS API is not present yet) ⋆/
#define VIDEO_CAP_SPU 16
#define VIDEO_CAP_NAVI 32
#define VIDEO_CAP_CSS 64
</programlisting>
</section>
<section id="video_system">
<title>video system</title>
<para>A call to VIDEO_SET_SYSTEM sets the desired video system for TV output. The
following system types can be set:
</para>
<programlisting>
typedef enum {
VIDEO_SYSTEM_PAL,
VIDEO_SYSTEM_NTSC,
VIDEO_SYSTEM_PALN,
VIDEO_SYSTEM_PALNc,
VIDEO_SYSTEM_PALM,
VIDEO_SYSTEM_NTSC60,
VIDEO_SYSTEM_PAL60,
VIDEO_SYSTEM_PALM60
} video_system_t;
</programlisting>
</section>
<section id="video_highlight">
<title>struct video_highlight</title>
<para>Calling the ioctl VIDEO_SET_HIGHLIGHTS posts the SPU highlight information. The
call expects the following format for that information:
</para>
<programlisting>
typedef
struct video_highlight {
boolean active; /⋆ 1=show highlight, 0=hide highlight ⋆/
uint8_t contrast1; /⋆ 7- 4 Pattern pixel contrast ⋆/
/⋆ 3- 0 Background pixel contrast ⋆/
uint8_t contrast2; /⋆ 7- 4 Emphasis pixel-2 contrast ⋆/
/⋆ 3- 0 Emphasis pixel-1 contrast ⋆/
uint8_t color1; /⋆ 7- 4 Pattern pixel color ⋆/
/⋆ 3- 0 Background pixel color ⋆/
uint8_t color2; /⋆ 7- 4 Emphasis pixel-2 color ⋆/
/⋆ 3- 0 Emphasis pixel-1 color ⋆/
uint32_t ypos; /⋆ 23-22 auto action mode ⋆/
/⋆ 21-12 start y ⋆/
/⋆ 9- 0 end y ⋆/
uint32_t xpos; /⋆ 23-22 button color number ⋆/
/⋆ 21-12 start x ⋆/
/⋆ 9- 0 end x ⋆/
} video_highlight_t;
</programlisting>
</section>
<section id="video_spu">
<title>video SPU</title>
<para>Calling VIDEO_SET_SPU deactivates or activates SPU decoding, according to the
following format:
</para>
<programlisting>
typedef
struct video_spu {
boolean active;
int stream_id;
} video_spu_t;
</programlisting>
</section>
<section id="video_spu_palette">
<title>video SPU palette</title>
<para>The following structure is used to set the SPU palette by calling VIDEO_SPU_PALETTE:
</para>
<programlisting>
typedef
struct video_spu_palette{
int length;
uint8_t ⋆palette;
} video_spu_palette_t;
</programlisting>
</section>
<section id="video_navi_pack">
<title>video NAVI pack</title>
<para>In order to get the navigational data the following structure has to be passed to the ioctl
VIDEO_GET_NAVI:
</para>
<programlisting>
typedef
struct video_navi_pack{
int length; /⋆ 0 ... 1024 ⋆/
uint8_t data[1024];
} video_navi_pack_t;
</programlisting>
</section>
<section id="video_attributes">
<title>video attributes</title>
<para>The following attributes can be set by a call to VIDEO_SET_ATTRIBUTES:
</para>
<programlisting>
typedef uint16_t video_attributes_t;
/⋆ bits: descr. ⋆/
/⋆ 15-14 Video compression mode (0=MPEG-1, 1=MPEG-2) ⋆/
/⋆ 13-12 TV system (0=525/60, 1=625/50) ⋆/
/⋆ 11-10 Aspect ratio (0=4:3, 3=16:9) ⋆/
/⋆ 9- 8 permitted display mode on 4:3 monitor (0=both, 1=only pan-sca ⋆/
/⋆ 7 line 21-1 data present in GOP (1=yes, 0=no) ⋆/
/⋆ 6 line 21-2 data present in GOP (1=yes, 0=no) ⋆/
/⋆ 5- 3 source resolution (0=720x480/576, 1=704x480/576, 2=352x480/57 ⋆/
/⋆ 2 source letterboxed (1=yes, 0=no) ⋆/
/⋆ 0 film/camera mode (0=camera, 1=film (625/50 only)) ⋆/
</programlisting>
</section></section>
<section id="video_function_calls">
<title>Video Function Calls</title>
<section id="video_fopen">
<title>open()</title>
<para>DESCRIPTION
</para>
<informaltable><tgroup cols="1"><tbody><row><entry
align="char">
<para>This system call opens a named video device (e.g. /dev/dvb/adapter0/video0)
for subsequent use.</para>
<para>When an open() call has succeeded, the device will be ready for use.
The significance of blocking or non-blocking mode is described in the
documentation for functions where there is a difference. It does not affect the
semantics of the open() call itself. A device opened in blocking mode can later
be put into non-blocking mode (and vice versa) using the F_SETFL command
of the fcntl system call. This is a standard system call, documented in the Linux
manual page for fcntl. Only one user can open the Video Device in O_RDWR
mode. All other attempts to open the device in this mode will fail, and an
error-code will be returned. If the Video Device is opened in O_RDONLY
mode, the only ioctl call that can be used is VIDEO_GET_STATUS. All other
call will return an error code.</para>
</entry>
</row></tbody></tgroup></informaltable>
<para>SYNOPSIS
</para>
<informaltable><tgroup cols="1"><tbody><row><entry
align="char">
<para>int open(const char ⋆deviceName, int flags);</para>
</entry>
</row></tbody></tgroup></informaltable>
<para>PARAMETERS
</para>
<informaltable><tgroup cols="2"><tbody><row><entry
align="char">
<para>const char
*deviceName</para>
</entry><entry
align="char">
<para>Name of specific video device.</para>
</entry>
</row><row><entry
align="char">
<para>int flags</para>
</entry><entry
align="char">
<para>A bit-wise OR of the following flags:</para>
</entry>
</row><row><entry
align="char">
</entry><entry
align="char">
<para>O_RDONLY read-only access</para>
</entry>
</row><row><entry
align="char">
</entry><entry
align="char">
<para>O_RDWR read/write access</para>
</entry>
</row><row><entry
align="char">
</entry><entry
align="char">
<para>O_NONBLOCK open in non-blocking mode</para>
</entry>
</row><row><entry
align="char">
</entry><entry
align="char">
<para>(blocking mode is the default)</para>
</entry>
</row></tbody></tgroup></informaltable>
<para>ERRORS
</para>
<informaltable><tgroup cols="2"><tbody><row><entry
align="char">
<para>ENODEV</para>
</entry><entry
align="char">
<para>Device driver not loaded/available.</para>
</entry>
</row><row><entry
align="char">
<para>EINTERNAL</para>
</entry><entry
align="char">
<para>Internal error.</para>
</entry>
</row><row><entry
align="char">
<para>EBUSY</para>
</entry><entry
align="char">
<para>Device or resource busy.</para>
</entry>
</row><row><entry
align="char">
<para>EINVAL</para>
</entry><entry
align="char">
<para>Invalid argument.</para>
</entry>
</row></tbody></tgroup></informaltable>
</section>
<section id="video_fclose">
<title>close()</title>
<para>DESCRIPTION
</para>
<informaltable><tgroup cols="1"><tbody><row><entry
align="char">
<para>This system call closes a previously opened video device.</para>
</entry>
</row></tbody></tgroup></informaltable>
<para>SYNOPSIS
</para>
<informaltable><tgroup cols="1"><tbody><row><entry
align="char">
<para>int close(int fd);</para>
</entry>
</row></tbody></tgroup></informaltable>
<para>PARAMETERS
</para>
<informaltable><tgroup cols="2"><tbody><row><entry
align="char">
<para>int fd</para>
</entry><entry
align="char">
<para>File descriptor returned by a previous call to open().</para>
</entry>
</row></tbody></tgroup></informaltable>
<para>ERRORS
</para>
<informaltable><tgroup cols="2"><tbody><row><entry
align="char">
<para>EBADF</para>
</entry><entry
align="char">
<para>fd is not a valid open file descriptor.</para>
</entry>
</row></tbody></tgroup></informaltable>
</section>
<section id="video_fwrite">
<title>write()</title>
<para>DESCRIPTION
</para>
<informaltable><tgroup cols="1"><tbody><row><entry
align="char">
<para>This system call can only be used if VIDEO_SOURCE_MEMORY is selected
in the ioctl call VIDEO_SELECT_SOURCE. The data provided shall be in
PES format, unless the capability allows other formats. If O_NONBLOCK is
not specified the function will block until buffer space is available. The amount
of data to be transferred is implied by count.</para>
</entry>
</row></tbody></tgroup></informaltable>
<para>SYNOPSIS
</para>
<informaltable><tgroup cols="1"><tbody><row><entry
align="char">
<para>size_t write(int fd, const void ⋆buf, size_t count);</para>
</entry>
</row></tbody></tgroup></informaltable>
<para>PARAMETERS
</para>
<informaltable><tgroup cols="2"><tbody><row><entry
align="char">
<para>int fd</para>
</entry><entry
align="char">
<para>File descriptor returned by a previous call to open().</para>
</entry>
</row><row><entry
align="char">
<para>void *buf</para>
</entry><entry
align="char">
<para>Pointer to the buffer containing the PES data.</para>
</entry>
</row><row><entry
align="char">
<para>size_t count</para>
</entry><entry
align="char">
<para>Size of buf.</para>
</entry>
</row></tbody></tgroup></informaltable>
<para>ERRORS
</para>
<informaltable><tgroup cols="2"><tbody><row><entry
align="char">
<para>EPERM</para>
</entry><entry
align="char">
<para>Mode VIDEO_SOURCE_MEMORY not selected.</para>
</entry>
</row><row><entry
align="char">
<para>ENOMEM</para>
</entry><entry
align="char">
<para>Attempted to write more data than the internal buffer can
hold.</para>
</entry>
</row><row><entry
align="char">
<para>EBADF</para>
</entry><entry
align="char">
<para>fd is not a valid open file descriptor.</para>
</entry>
</row></tbody></tgroup></informaltable>
</section><section
role="subsection"><title>VIDEO_STOP</title>
<para>DESCRIPTION
</para>
<informaltable><tgroup cols="1"><tbody><row><entry
align="char">
<para>This ioctl call asks the Video Device to stop playing the current stream.
Depending on the input parameter, the screen can be blanked out or displaying
the last decoded frame.</para>
</entry>
</row></tbody></tgroup></informaltable>
<para>SYNOPSIS
</para>
<informaltable><tgroup cols="1"><tbody><row><entry
align="char">
<para>int ioctl(fd, int request = VIDEO_STOP, boolean
mode);</para>
</entry>
</row></tbody></tgroup></informaltable>
<para>PARAMETERS
</para>
<informaltable><tgroup cols="2"><tbody><row><entry
align="char">
<para>int fd</para>
</entry><entry
align="char">
<para>File descriptor returned by a previous call to open().</para>
</entry>
</row><row><entry
align="char">
<para>int request</para>
</entry><entry
align="char">
<para>Equals VIDEO_STOP for this command.</para>
</entry>
</row><row><entry
align="char">
<para>Boolean mode</para>
</entry><entry
align="char">
<para>Indicates how the screen shall be handled.</para>
</entry>
</row><row><entry
align="char">
</entry><entry
align="char">
<para>TRUE: Blank screen when stop.</para>
</entry>
</row><row><entry
align="char">
</entry><entry
align="char">
<para>FALSE: Show last decoded frame.</para>
</entry>
</row></tbody></tgroup></informaltable>
<para>ERRORS
</para>
<informaltable><tgroup cols="2"><tbody><row><entry
align="char">
<para>EBADF</para>
</entry><entry
align="char">
<para>fd is not a valid open file descriptor</para>
</entry>
</row><row><entry
align="char">
<para>EINTERNAL</para>
</entry><entry
align="char">
<para>Internal error, possibly in the communication with the
DVB subsystem.</para>
</entry>
</row></tbody></tgroup></informaltable>
</section><section
role="subsection"><title>VIDEO_PLAY</title>
<para>DESCRIPTION
</para>
<informaltable><tgroup cols="1"><tbody><row><entry
align="char">
<para>This ioctl call asks the Video Device to start playing a video stream from the
selected source.</para>
</entry>
</row></tbody></tgroup></informaltable>
<para>SYNOPSIS
</para>
<informaltable><tgroup cols="1"><tbody><row><entry
align="char">
<para>int ioctl(fd, int request = VIDEO_PLAY);</para>
</entry>
</row></tbody></tgroup></informaltable>
<para>PARAMETERS
</para>
<informaltable><tgroup cols="2"><tbody><row><entry
align="char">
<para>int fd</para>
</entry><entry
align="char">
<para>File descriptor returned by a previous call to open().</para>
</entry>
</row><row><entry
align="char">
<para>int request</para>
</entry><entry
align="char">
<para>Equals VIDEO_PLAY for this command.</para>
</entry>
</row></tbody></tgroup></informaltable>
<para>ERRORS
</para>
<informaltable><tgroup cols="2"><tbody><row><entry
align="char">
<para>EBADF</para>
</entry><entry
align="char">
<para>fd is not a valid open file descriptor</para>
</entry>
</row><row><entry
align="char">
<para>EINTERNAL</para>
</entry><entry
align="char">
<para>Internal error, possibly in the communication with the
DVB subsystem.</para>
</entry>
</row></tbody></tgroup></informaltable>
</section><section
role="subsection"><title>VIDEO_FREEZE</title>
<para>DESCRIPTION
</para>
<informaltable><tgroup cols="1"><tbody><row><entry
align="char">
<para>This ioctl call suspends the live video stream being played. Decoding
and playing are frozen. It is then possible to restart the decoding
and playing process of the video stream using the VIDEO_CONTINUE
command. If VIDEO_SOURCE_MEMORY is selected in the ioctl call
VIDEO_SELECT_SOURCE, the DVB subsystem will not decode any more
data until the ioctl call VIDEO_CONTINUE or VIDEO_PLAY is performed.</para>
</entry>
</row></tbody></tgroup></informaltable>
<para>SYNOPSIS
</para>
<informaltable><tgroup cols="1"><tbody><row><entry
align="char">
<para>int ioctl(fd, int request = VIDEO_FREEZE);</para>
</entry>
</row></tbody></tgroup></informaltable>
<para>PARAMETERS
</para>
<informaltable><tgroup cols="2"><tbody><row><entry
align="char">
<para>int fd</para>
</entry><entry
align="char">
<para>File descriptor returned by a previous call to open().</para>
</entry>
</row><row><entry
align="char">
<para>int request</para>
</entry><entry
align="char">
<para>Equals VIDEO_FREEZE for this command.</para>
</entry>
</row></tbody></tgroup></informaltable>
<para>ERRORS
</para>
<informaltable><tgroup cols="2"><tbody><row><entry
align="char">
<para>EBADF</para>
</entry><entry
align="char">
<para>fd is not a valid open file descriptor</para>
</entry>
</row><row><entry
align="char">
<para>EINTERNAL</para>
</entry><entry
align="char">
<para>Internal error, possibly in the communication with the
DVB subsystem.</para>
</entry>
</row></tbody></tgroup></informaltable>
</section><section
role="subsection"><title>VIDEO_CONTINUE</title>
<para>DESCRIPTION
</para>
<informaltable><tgroup cols="1"><tbody><row><entry
align="char">
<para>This ioctl call restarts decoding and playing processes of the video stream
which was played before a call to VIDEO_FREEZE was made.</para>
</entry>
</row></tbody></tgroup></informaltable>
<para>SYNOPSIS
</para>
<informaltable><tgroup cols="1"><tbody><row><entry
align="char">
<para>int ioctl(fd, int request = VIDEO_CONTINUE);</para>
</entry>
</row></tbody></tgroup></informaltable>
<para>PARAMETERS
</para>
<informaltable><tgroup cols="2"><tbody><row><entry
align="char">
<para>int fd</para>
</entry><entry
align="char">
<para>File descriptor returned by a previous call to open().</para>
</entry>
</row><row><entry
align="char">
<para>int request</para>
</entry><entry
align="char">
<para>Equals VIDEO_CONTINUE for this command.</para>
</entry>
</row></tbody></tgroup></informaltable>
<para>ERRORS
</para>
<informaltable><tgroup cols="2"><tbody><row><entry
align="char">
<para>EBADF</para>
</entry><entry
align="char">
<para>fd is not a valid open file descriptor</para>
</entry>
</row><row><entry
align="char">
<para>EINTERNAL</para>
</entry><entry
align="char">
<para>Internal error, possibly in the communication with the
DVB subsystem.</para>
</entry>
</row></tbody></tgroup></informaltable>
</section><section
role="subsection"><title>VIDEO_SELECT_SOURCE</title>
<para>DESCRIPTION
</para>
<informaltable><tgroup cols="1"><tbody><row><entry
align="char">
<para>This ioctl call informs the video device which source shall be used for the input
data. The possible sources are demux or memory. If memory is selected, the
data is fed to the video device through the write command.</para>
</entry>
</row></tbody></tgroup></informaltable>
<para>SYNOPSIS
</para>
<informaltable><tgroup cols="1"><tbody><row><entry
align="char">
<para>int ioctl(fd, int request = VIDEO_SELECT_SOURCE,
video_stream_source_t source);</para>
</entry>
</row></tbody></tgroup></informaltable>
<para>PARAMETERS
</para>
<informaltable><tgroup cols="2"><tbody><row><entry
align="char">
<para>int fd</para>
</entry><entry
align="char">
<para>File descriptor returned by a previous call to open().</para>
</entry>
</row><row><entry
align="char">
<para>int request</para>
</entry><entry
align="char">
<para>Equals VIDEO_SELECT_SOURCE for this command.</para>
</entry>
</row><row><entry
align="char">
<para>video_stream_source_t
source</para>
</entry><entry
align="char">
<para>Indicates which source shall be used for the Video stream.</para>
</entry>
</row></tbody></tgroup></informaltable>
<para>ERRORS
</para>
<informaltable><tgroup cols="2"><tbody><row><entry
align="char">
<para>EBADF</para>
</entry><entry
align="char">
<para>fd is not a valid open file descriptor</para>
</entry>
</row><row><entry
align="char">
<para>EINTERNAL</para>
</entry><entry
align="char">
<para>Internal error, possibly in the communication with the
DVB subsystem.</para>
</entry>
</row></tbody></tgroup></informaltable>
</section><section
role="subsection"><title>VIDEO_SET_BLANK</title>
<para>DESCRIPTION
</para>
<informaltable><tgroup cols="1"><tbody><row><entry
align="char">
<para>This ioctl call asks the Video Device to blank out the picture.</para>
</entry>
</row></tbody></tgroup></informaltable>
<para>SYNOPSIS
</para>
<informaltable><tgroup cols="1"><tbody><row><entry
align="char">
<para>int ioctl(fd, int request = VIDEO_SET_BLANK, boolean
mode);</para>
</entry>
</row></tbody></tgroup></informaltable>
<para>PARAMETERS
</para>
<informaltable><tgroup cols="2"><tbody><row><entry
align="char">
<para>int fd</para>
</entry><entry
align="char">
<para>File descriptor returned by a previous call to open().</para>
</entry>
</row><row><entry
align="char">
<para>int request</para>
</entry><entry
align="char">
<para>Equals VIDEO_SET_BLANK for this command.</para>
</entry>
</row><row><entry
align="char">
<para>boolean mode</para>
</entry><entry
align="char">
<para>TRUE: Blank screen when stop.</para>
</entry>
</row><row><entry
align="char">
</entry><entry
align="char">
<para>FALSE: Show last decoded frame.</para>
</entry>
</row></tbody></tgroup></informaltable>
<para>ERRORS
</para>
<informaltable><tgroup cols="2"><tbody><row><entry
align="char">
<para>EBADF</para>
</entry><entry
align="char">
<para>fd is not a valid open file descriptor</para>
</entry>
</row><row><entry
align="char">
<para>EINTERNAL</para>
</entry><entry
align="char">
<para>Internal error, possibly in the communication with the
DVB subsystem.</para>
</entry>
</row><row><entry
align="char">
<para>EINVAL</para>
</entry><entry
align="char">
<para>Illegal input parameter</para>
</entry>
</row></tbody></tgroup></informaltable>
</section><section
role="subsection"><title>VIDEO_GET_STATUS</title>
<para>DESCRIPTION
</para>
<informaltable><tgroup cols="1"><tbody><row><entry
align="char">
<para>This ioctl call asks the Video Device to return the current status of the device.</para>
</entry>
</row></tbody></tgroup></informaltable>
<para>SYNOPSIS
</para>
<informaltable><tgroup cols="1"><tbody><row><entry
align="char">
<para> int ioctl(fd, int request = VIDEO_GET_STATUS, struct
video_status ⋆status);</para>
</entry>
</row></tbody></tgroup></informaltable>
<para>PARAMETERS
</para>
<informaltable><tgroup cols="2"><tbody><row><entry
align="char">
<para>int fd</para>
</entry><entry
align="char">
<para>File descriptor returned by a previous call to open().</para>
</entry>
</row><row><entry
align="char">
<para>int request</para>
</entry><entry
align="char">
<para>Equals VIDEO_GET_STATUS for this command.</para>
</entry>
</row><row><entry
align="char">
<para>struct video_status
*status</para>
</entry><entry
align="char">
<para>Returns the current status of the Video Device.</para>
</entry>
</row></tbody></tgroup></informaltable>
<para>ERRORS
</para>
<informaltable><tgroup cols="2"><tbody><row><entry
align="char">
<para>EBADF</para>
</entry><entry
align="char">
<para>fd is not a valid open file descriptor</para>
</entry>
</row><row><entry
align="char">
<para>EINTERNAL</para>
</entry><entry
align="char">
<para>Internal error, possibly in the communication with the
DVB subsystem.</para>
</entry>
</row><row><entry
align="char">
<para>EFAULT</para>
</entry><entry
align="char">
<para>status points to invalid address</para>
</entry>
</row></tbody></tgroup></informaltable>
</section><section
role="subsection"><title>VIDEO_GET_EVENT</title>
<para>DESCRIPTION
</para>
<informaltable><tgroup cols="1"><tbody><row><entry
align="char">
<para>This ioctl call returns an event of type video_event if available. If an event is
not available, the behavior depends on whether the device is in blocking or
non-blocking mode. In the latter case, the call fails immediately with errno
set to EWOULDBLOCK. In the former case, the call blocks until an event
becomes available. The standard Linux poll() and/or select() system calls can
be used with the device file descriptor to watch for new events. For select(),
the file descriptor should be included in the exceptfds argument, and for
poll(), POLLPRI should be specified as the wake-up condition. Read-only
permissions are sufficient for this ioctl call.</para>
</entry>
</row></tbody></tgroup></informaltable>
<para>SYNOPSIS
</para>
<informaltable><tgroup cols="1"><tbody><row><entry
align="char">
<para> int ioctl(fd, int request = VIDEO_GET_EVENT, struct
video_event ⋆ev);</para>
</entry>
</row></tbody></tgroup></informaltable>
<para>PARAMETERS
</para>
<informaltable><tgroup cols="2"><tbody><row><entry
align="char">
<para>int fd</para>
</entry><entry
align="char">
<para>File descriptor returned by a previous call to open().</para>
</entry>
</row><row><entry
align="char">
<para>int request</para>
</entry><entry
align="char">
<para>Equals VIDEO_GET_EVENT for this command.</para>
</entry>
</row><row><entry
align="char">
<para>struct video_event
*ev</para>
</entry><entry
align="char">
<para>Points to the location where the event, if any, is to be
stored.</para>
</entry>
</row></tbody></tgroup></informaltable>
<para>ERRORS
</para>
<informaltable><tgroup cols="2"><tbody><row><entry
align="char">
<para>EBADF</para>
</entry><entry
align="char">
<para>fd is not a valid open file descriptor</para>
</entry>
</row><row><entry
align="char">
<para>EFAULT</para>
</entry><entry
align="char">
<para>ev points to invalid address</para>
</entry>
</row><row><entry
align="char">