Documentation/linux_tv/media/dvb/audio_function_calls.rst

   1 .. -*- coding: utf-8; mode: rst -*-
   2
   3 .. _audio_function_calls:
   4
   5 ********************
   6 Audio Function Calls
   7 ********************
   8
   9
  10 .. _audio_fopen:
  11
  12 open()
  13 ======
  14
  15 DESCRIPTION
  16
  17 This system call opens a named audio device (e.g.
  18 /dev/dvb/adapter0/audio0) for subsequent use. When an open() call has
  19 succeeded, the device will be ready for use. The significance of
  20 blocking or non-blocking mode is described in the documentation for
  21 functions where there is a difference. It does not affect the semantics
  22 of the open() call itself. A device opened in blocking mode can later be
  23 put into non-blocking mode (and vice versa) using the F_SETFL command
  24 of the fcntl system call. This is a standard system call, documented in
  25 the Linux manual page for fcntl. Only one user can open the Audio Device
  26 in O_RDWR mode. All other attempts to open the device in this mode will
  27 fail, and an error code will be returned. If the Audio Device is opened
  28 in O_RDONLY mode, the only ioctl call that can be used is
  29 AUDIO_GET_STATUS. All other call will return with an error code.
  30
  31 SYNOPSIS
  32
  33 int open(const char *deviceName, int flags);
  34
  35 PARAMETERS
  36
  37
  38
  39 .. flat-table::
  40     :header-rows:  0
  41     :stub-columns: 0
  42
  43
  44     -  .. row 1
  45
  46        -  const char *deviceName
  47
  48        -  Name of specific audio device.
  49
  50     -  .. row 2
  51
  52        -  int flags
  53
  54        -  A bit-wise OR of the following flags:
  55
  56     -  .. row 3
  57
  58        -
  59        -  O_RDONLY read-only access
  60
  61     -  .. row 4
  62
  63        -
  64        -  O_RDWR read/write access
  65
  66     -  .. row 5
  67
  68        -
  69        -  O_NONBLOCK open in non-blocking mode
  70
  71     -  .. row 6
  72
  73        -
  74        -  (blocking mode is the default)
  75
  76
  77 RETURN VALUE
  78
  79
  80
  81 .. flat-table::
  82     :header-rows:  0
  83     :stub-columns: 0
  84
  85
  86     -  .. row 1
  87
  88        -  ENODEV
  89
  90        -  Device driver not loaded/available.
  91
  92     -  .. row 2
  93
  94        -  EBUSY
  95
  96        -  Device or resource busy.
  97
  98     -  .. row 3
  99
 100        -  EINVAL
 101
 102        -  Invalid argument.
 103
 104
 105
 106 .. _audio_fclose:
 107
 108 close()
 109 =======
 110
 111 DESCRIPTION
 112
 113 This system call closes a previously opened audio device.
 114
 115 SYNOPSIS
 116
 117 int close(int fd);
 118
 119 PARAMETERS
 120
 121
 122
 123 .. flat-table::
 124     :header-rows:  0
 125     :stub-columns: 0
 126
 127
 128     -  .. row 1
 129
 130        -  int fd
 131
 132        -  File descriptor returned by a previous call to open().
 133
 134
 135 RETURN VALUE
 136
 137
 138
 139 .. flat-table::
 140     :header-rows:  0
 141     :stub-columns: 0
 142
 143
 144     -  .. row 1
 145
 146        -  EBADF
 147
 148        -  fd is not a valid open file descriptor.
 149
 150
 151
 152 .. _audio_fwrite:
 153
 154 write()
 155 =======
 156
 157 DESCRIPTION
 158
 159 This system call can only be used if AUDIO_SOURCE_MEMORY is selected
 160 in the ioctl call AUDIO_SELECT_SOURCE. The data provided shall be in
 161 PES format. If O_NONBLOCK is not specified the function will block
 162 until buffer space is available. The amount of data to be transferred is
 163 implied by count.
 164
 165 SYNOPSIS
 166
 167 size_t write(int fd, const void *buf, size_t count);
 168
 169 PARAMETERS
 170
 171
 172
 173 .. flat-table::
 174     :header-rows:  0
 175     :stub-columns: 0
 176
 177
 178     -  .. row 1
 179
 180        -  int fd
 181
 182        -  File descriptor returned by a previous call to open().
 183
 184     -  .. row 2
 185
 186        -  void *buf
 187
 188        -  Pointer to the buffer containing the PES data.
 189
 190     -  .. row 3
 191
 192        -  size_t count
 193
 194        -  Size of buf.
 195
 196
 197 RETURN VALUE
 198
 199
 200
 201 .. flat-table::
 202     :header-rows:  0
 203     :stub-columns: 0
 204
 205
 206     -  .. row 1
 207
 208        -  EPERM
 209
 210        -  Mode AUDIO_SOURCE_MEMORY not selected.
 211
 212     -  .. row 2
 213
 214        -  ENOMEM
 215
 216        -  Attempted to write more data than the internal buffer can hold.
 217
 218     -  .. row 3
 219
 220        -  EBADF
 221
 222        -  fd is not a valid open file descriptor.
 223
 224
 225
 226 .. _AUDIO_STOP:
 227
 228 AUDIO_STOP
 229 ==========
 230
 231 DESCRIPTION
 232
 233 This ioctl call asks the Audio Device to stop playing the current
 234 stream.
 235
 236 SYNOPSIS
 237
 238 int ioctl(int fd, int request = AUDIO_STOP);
 239
 240 PARAMETERS
 241
 242
 243
 244 .. flat-table::
 245     :header-rows:  0
 246     :stub-columns: 0
 247
 248
 249     -  .. row 1
 250
 251        -  int fd
 252
 253        -  File descriptor returned by a previous call to open().
 254
 255     -  .. row 2
 256
 257        -  int request
 258
 259        -  Equals AUDIO_STOP for this command.
 260
 261
 262 RETURN VALUE
 263
 264 On success 0 is returned, on error -1 and the ``errno`` variable is set
 265 appropriately. The generic error codes are described at the
 266 :ref:`Generic Error Codes <gen-errors>` chapter.
 267
 268
 269 .. _AUDIO_PLAY:
 270
 271 AUDIO_PLAY
 272 ==========
 273
 274 DESCRIPTION
 275
 276 This ioctl call asks the Audio Device to start playing an audio stream
 277 from the selected source.
 278
 279 SYNOPSIS
 280
 281 int ioctl(int fd, int request = AUDIO_PLAY);
 282
 283 PARAMETERS
 284
 285
 286
 287 .. flat-table::
 288     :header-rows:  0
 289     :stub-columns: 0
 290
 291
 292     -  .. row 1
 293
 294        -  int fd
 295
 296        -  File descriptor returned by a previous call to open().
 297
 298     -  .. row 2
 299
 300        -  int request
 301
 302        -  Equals AUDIO_PLAY for this command.
 303
 304
 305 RETURN VALUE
 306
 307 On success 0 is returned, on error -1 and the ``errno`` variable is set
 308 appropriately. The generic error codes are described at the
 309 :ref:`Generic Error Codes <gen-errors>` chapter.
 310
 311
 312 .. _AUDIO_PAUSE:
 313
 314 AUDIO_PAUSE
 315 ===========
 316
 317 DESCRIPTION
 318
 319 This ioctl call suspends the audio stream being played. Decoding and
 320 playing are paused. It is then possible to restart again decoding and
 321 playing process of the audio stream using AUDIO_CONTINUE command.
 322
 323 SYNOPSIS
 324
 325 int ioctl(int fd, int request = AUDIO_PAUSE);
 326
 327 PARAMETERS
 328
 329
 330
 331 .. flat-table::
 332     :header-rows:  0
 333     :stub-columns: 0
 334
 335
 336     -  .. row 1
 337
 338        -  int fd
 339
 340        -  File descriptor returned by a previous call to open().
 341
 342     -  .. row 2
 343
 344        -  int request
 345
 346        -  Equals AUDIO_PAUSE for this command.
 347
 348
 349 RETURN VALUE
 350
 351 On success 0 is returned, on error -1 and the ``errno`` variable is set
 352 appropriately. The generic error codes are described at the
 353 :ref:`Generic Error Codes <gen-errors>` chapter.
 354
 355
 356 .. _AUDIO_CONTINUE:
 357
 358 AUDIO_CONTINUE
 359 ==============
 360
 361 DESCRIPTION
 362
 363 This ioctl restarts the decoding and playing process previously paused
 364 with AUDIO_PAUSE command.
 365
 366 SYNOPSIS
 367
 368 int ioctl(int fd, int request = AUDIO_CONTINUE);
 369
 370 PARAMETERS
 371
 372
 373
 374 .. flat-table::
 375     :header-rows:  0
 376     :stub-columns: 0
 377
 378
 379     -  .. row 1
 380
 381        -  int fd
 382
 383        -  File descriptor returned by a previous call to open().
 384
 385     -  .. row 2
 386
 387        -  int request
 388
 389        -  Equals AUDIO_CONTINUE for this command.
 390
 391
 392 RETURN VALUE
 393
 394 On success 0 is returned, on error -1 and the ``errno`` variable is set
 395 appropriately. The generic error codes are described at the
 396 :ref:`Generic Error Codes <gen-errors>` chapter.
 397
 398
 399 .. _AUDIO_SELECT_SOURCE:
 400
 401 AUDIO_SELECT_SOURCE
 402 ===================
 403
 404 DESCRIPTION
 405
 406 This ioctl call informs the audio device which source shall be used for
 407 the input data. The possible sources are demux or memory. If
 408 AUDIO_SOURCE_MEMORY is selected, the data is fed to the Audio Device
 409 through the write command.
 410
 411 SYNOPSIS
 412
 413 int ioctl(int fd, int request = AUDIO_SELECT_SOURCE,
 414 audio_stream_source_t source);
 415
 416 PARAMETERS
 417
 418
 419
 420 .. flat-table::
 421     :header-rows:  0
 422     :stub-columns: 0
 423
 424
 425     -  .. row 1
 426
 427        -  int fd
 428
 429        -  File descriptor returned by a previous call to open().
 430
 431     -  .. row 2
 432
 433        -  int request
 434
 435        -  Equals AUDIO_SELECT_SOURCE for this command.
 436
 437     -  .. row 3
 438
 439        -  audio_stream_source_t source
 440
 441        -  Indicates the source that shall be used for the Audio stream.
 442
 443
 444 RETURN VALUE
 445
 446 On success 0 is returned, on error -1 and the ``errno`` variable is set
 447 appropriately. The generic error codes are described at the
 448 :ref:`Generic Error Codes <gen-errors>` chapter.
 449
 450
 451 .. _AUDIO_SET_MUTE:
 452
 453 AUDIO_SET_MUTE
 454 ==============
 455
 456 DESCRIPTION
 457
 458 This ioctl is for DVB devices only. To control a V4L2 decoder use the
 459 V4L2 :ref:`VIDIOC_DECODER_CMD` with the
 460 ``V4L2_DEC_CMD_START_MUTE_AUDIO`` flag instead.
 461
 462 This ioctl call asks the audio device to mute the stream that is
 463 currently being played.
 464
 465 SYNOPSIS
 466
 467 int ioctl(int fd, int request = AUDIO_SET_MUTE, boolean state);
 468
 469 PARAMETERS
 470
 471
 472
 473 .. flat-table::
 474     :header-rows:  0
 475     :stub-columns: 0
 476
 477
 478     -  .. row 1
 479
 480        -  int fd
 481
 482        -  File descriptor returned by a previous call to open().
 483
 484     -  .. row 2
 485
 486        -  int request
 487
 488        -  Equals AUDIO_SET_MUTE for this command.
 489
 490     -  .. row 3
 491
 492        -  boolean state
 493
 494        -  Indicates if audio device shall mute or not.
 495
 496     -  .. row 4
 497
 498        -
 499        -  TRUE Audio Mute
 500
 501     -  .. row 5
 502
 503        -
 504        -  FALSE Audio Un-mute
 505
 506
 507 RETURN VALUE
 508
 509 On success 0 is returned, on error -1 and the ``errno`` variable is set
 510 appropriately. The generic error codes are described at the
 511 :ref:`Generic Error Codes <gen-errors>` chapter.
 512
 513
 514 .. _AUDIO_SET_AV_SYNC:
 515
 516 AUDIO_SET_AV_SYNC
 517 =================
 518
 519 DESCRIPTION
 520
 521 This ioctl call asks the Audio Device to turn ON or OFF A/V
 522 synchronization.
 523
 524 SYNOPSIS
 525
 526 int ioctl(int fd, int request = AUDIO_SET_AV_SYNC, boolean state);
 527
 528 PARAMETERS
 529
 530
 531
 532 .. flat-table::
 533     :header-rows:  0
 534     :stub-columns: 0
 535
 536
 537     -  .. row 1
 538
 539        -  int fd
 540
 541        -  File descriptor returned by a previous call to open().
 542
 543     -  .. row 2
 544
 545        -  int request
 546
 547        -  Equals AUDIO_AV_SYNC for this command.
 548
 549     -  .. row 3
 550
 551        -  boolean state
 552
 553        -  Tells the DVB subsystem if A/V synchronization shall be ON or OFF.
 554
 555     -  .. row 4
 556
 557        -
 558        -  TRUE AV-sync ON
 559
 560     -  .. row 5
 561
 562        -
 563        -  FALSE AV-sync OFF
 564
 565
 566 RETURN VALUE
 567
 568 On success 0 is returned, on error -1 and the ``errno`` variable is set
 569 appropriately. The generic error codes are described at the
 570 :ref:`Generic Error Codes <gen-errors>` chapter.
 571
 572
 573 .. _AUDIO_SET_BYPASS_MODE:
 574
 575 AUDIO_SET_BYPASS_MODE
 576 =====================
 577
 578 DESCRIPTION
 579
 580 This ioctl call asks the Audio Device to bypass the Audio decoder and
 581 forward the stream without decoding. This mode shall be used if streams
 582 that can’t be handled by the DVB system shall be decoded. Dolby
 583 DigitalTM streams are automatically forwarded by the DVB subsystem if
 584 the hardware can handle it.
 585
 586 SYNOPSIS
 587
 588 int ioctl(int fd, int request = AUDIO_SET_BYPASS_MODE, boolean mode);
 589
 590 PARAMETERS
 591
 592
 593
 594 .. flat-table::
 595     :header-rows:  0
 596     :stub-columns: 0
 597
 598
 599     -  .. row 1
 600
 601        -  int fd
 602
 603        -  File descriptor returned by a previous call to open().
 604
 605     -  .. row 2
 606
 607        -  int request
 608
 609        -  Equals AUDIO_SET_BYPASS_MODE for this command.
 610
 611     -  .. row 3
 612
 613        -  boolean mode
 614
 615        -  Enables or disables the decoding of the current Audio stream in
 616           the DVB subsystem.
 617
 618     -  .. row 4
 619
 620        -
 621        -  TRUE Bypass is disabled
 622
 623     -  .. row 5
 624
 625        -
 626        -  FALSE Bypass is enabled
 627
 628
 629 RETURN VALUE
 630
 631 On success 0 is returned, on error -1 and the ``errno`` variable is set
 632 appropriately. The generic error codes are described at the
 633 :ref:`Generic Error Codes <gen-errors>` chapter.
 634
 635
 636 .. _AUDIO_CHANNEL_SELECT:
 637
 638 AUDIO_CHANNEL_SELECT
 639 ====================
 640
 641 DESCRIPTION
 642
 643 This ioctl is for DVB devices only. To control a V4L2 decoder use the
 644 V4L2 ``V4L2_CID_MPEG_AUDIO_DEC_PLAYBACK`` control instead.
 645
 646 This ioctl call asks the Audio Device to select the requested channel if
 647 possible.
 648
 649 SYNOPSIS
 650
 651 int ioctl(int fd, int request = AUDIO_CHANNEL_SELECT,
 652 audio_channel_select_t);
 653
 654 PARAMETERS
 655
 656
 657
 658 .. flat-table::
 659     :header-rows:  0
 660     :stub-columns: 0
 661
 662
 663     -  .. row 1
 664
 665        -  int fd
 666
 667        -  File descriptor returned by a previous call to open().
 668
 669     -  .. row 2
 670
 671        -  int request
 672
 673        -  Equals AUDIO_CHANNEL_SELECT for this command.
 674
 675     -  .. row 3
 676
 677        -  audio_channel_select_t ch
 678
 679        -  Select the output format of the audio (mono left/right, stereo).
 680
 681
 682 RETURN VALUE
 683
 684 On success 0 is returned, on error -1 and the ``errno`` variable is set
 685 appropriately. The generic error codes are described at the
 686 :ref:`Generic Error Codes <gen-errors>` chapter.
 687
 688
 689 .. _AUDIO_BILINGUAL_CHANNEL_SELECT:
 690
 691 AUDIO_BILINGUAL_CHANNEL_SELECT
 692 ==============================
 693
 694 DESCRIPTION
 695
 696 This ioctl is obsolete. Do not use in new drivers. It has been replaced
 697 by the V4L2 ``V4L2_CID_MPEG_AUDIO_DEC_MULTILINGUAL_PLAYBACK`` control
 698 for MPEG decoders controlled through V4L2.
 699
 700 This ioctl call asks the Audio Device to select the requested channel
 701 for bilingual streams if possible.
 702
 703 SYNOPSIS
 704
 705 int ioctl(int fd, int request = AUDIO_BILINGUAL_CHANNEL_SELECT,
 706 audio_channel_select_t);
 707
 708 PARAMETERS
 709
 710
 711
 712 .. flat-table::
 713     :header-rows:  0
 714     :stub-columns: 0
 715
 716
 717     -  .. row 1
 718
 719        -  int fd
 720
 721        -  File descriptor returned by a previous call to open().
 722
 723     -  .. row 2
 724
 725        -  int request
 726
 727        -  Equals AUDIO_BILINGUAL_CHANNEL_SELECT for this command.
 728
 729     -  .. row 3
 730
 731        -  audio_channel_select_t ch
 732
 733        -  Select the output format of the audio (mono left/right, stereo).
 734
 735
 736 RETURN VALUE
 737
 738 On success 0 is returned, on error -1 and the ``errno`` variable is set
 739 appropriately. The generic error codes are described at the
 740 :ref:`Generic Error Codes <gen-errors>` chapter.
 741
 742
 743 .. _AUDIO_GET_PTS:
 744
 745 AUDIO_GET_PTS
 746 =============
 747
 748 DESCRIPTION
 749
 750 This ioctl is obsolete. Do not use in new drivers. If you need this
 751 functionality, then please contact the linux-media mailing list
 752 (`https://linuxtv.org/lists.php <https://linuxtv.org/lists.php>`__).
 753
 754 This ioctl call asks the Audio Device to return the current PTS
 755 timestamp.
 756
 757 SYNOPSIS
 758
 759 int ioctl(int fd, int request = AUDIO_GET_PTS, __u64 *pts);
 760
 761 PARAMETERS
 762
 763
 764
 765 .. flat-table::
 766     :header-rows:  0
 767     :stub-columns: 0
 768
 769
 770     -  .. row 1
 771
 772        -  int fd
 773
 774        -  File descriptor returned by a previous call to open().
 775
 776     -  .. row 2
 777
 778        -  int request
 779
 780        -  Equals AUDIO_GET_PTS for this command.
 781
 782     -  .. row 3
 783
 784        -  __u64 *pts
 785
 786        -  Returns the 33-bit timestamp as defined in ITU T-REC-H.222.0 /
 787           ISO/IEC 13818-1.
 788
 789           The PTS should belong to the currently played frame if possible,
 790           but may also be a value close to it like the PTS of the last
 791           decoded frame or the last PTS extracted by the PES parser.
 792
 793
 794 RETURN VALUE
 795
 796 On success 0 is returned, on error -1 and the ``errno`` variable is set
 797 appropriately. The generic error codes are described at the
 798 :ref:`Generic Error Codes <gen-errors>` chapter.
 799
 800
 801 .. _AUDIO_GET_STATUS:
 802
 803 AUDIO_GET_STATUS
 804 ================
 805
 806 DESCRIPTION
 807
 808 This ioctl call asks the Audio Device to return the current state of the
 809 Audio Device.
 810
 811 SYNOPSIS
 812
 813 int ioctl(int fd, int request = AUDIO_GET_STATUS, struct audio_status
 814 *status);
 815
 816 PARAMETERS
 817
 818
 819
 820 .. flat-table::
 821     :header-rows:  0
 822     :stub-columns: 0
 823
 824
 825     -  .. row 1
 826
 827        -  int fd
 828
 829        -  File descriptor returned by a previous call to open().
 830
 831     -  .. row 2
 832
 833        -  int request
 834
 835        -  Equals AUDIO_GET_STATUS for this command.
 836
 837     -  .. row 3
 838
 839        -  struct audio_status *status
 840
 841        -  Returns the current state of Audio Device.
 842
 843
 844 RETURN VALUE
 845
 846 On success 0 is returned, on error -1 and the ``errno`` variable is set
 847 appropriately. The generic error codes are described at the
 848 :ref:`Generic Error Codes <gen-errors>` chapter.
 849
 850
 851 .. _AUDIO_GET_CAPABILITIES:
 852
 853 AUDIO_GET_CAPABILITIES
 854 ======================
 855
 856 DESCRIPTION
 857
 858 This ioctl call asks the Audio Device to tell us about the decoding
 859 capabilities of the audio hardware.
 860
 861 SYNOPSIS
 862
 863 int ioctl(int fd, int request = AUDIO_GET_CAPABILITIES, unsigned int
 864 *cap);
 865
 866 PARAMETERS
 867
 868
 869
 870 .. flat-table::
 871     :header-rows:  0
 872     :stub-columns: 0
 873
 874
 875     -  .. row 1
 876
 877        -  int fd
 878
 879        -  File descriptor returned by a previous call to open().
 880
 881     -  .. row 2
 882
 883        -  int request
 884
 885        -  Equals AUDIO_GET_CAPABILITIES for this command.
 886
 887     -  .. row 3
 888
 889        -  unsigned int *cap
 890
 891        -  Returns a bit array of supported sound formats.
 892
 893
 894 RETURN VALUE
 895
 896 On success 0 is returned, on error -1 and the ``errno`` variable is set
 897 appropriately. The generic error codes are described at the
 898 :ref:`Generic Error Codes <gen-errors>` chapter.
 899
 900
 901 .. _AUDIO_CLEAR_BUFFER:
 902
 903 AUDIO_CLEAR_BUFFER
 904 ==================
 905
 906 DESCRIPTION
 907
 908 This ioctl call asks the Audio Device to clear all software and hardware
 909 buffers of the audio decoder device.
 910
 911 SYNOPSIS
 912
 913 int ioctl(int fd, int request = AUDIO_CLEAR_BUFFER);
 914
 915 PARAMETERS
 916
 917
 918
 919 .. flat-table::
 920     :header-rows:  0
 921     :stub-columns: 0
 922
 923
 924     -  .. row 1
 925
 926        -  int fd
 927
 928        -  File descriptor returned by a previous call to open().
 929
 930     -  .. row 2
 931
 932        -  int request
 933
 934        -  Equals AUDIO_CLEAR_BUFFER for this command.
 935
 936
 937 RETURN VALUE
 938
 939 On success 0 is returned, on error -1 and the ``errno`` variable is set
 940 appropriately. The generic error codes are described at the
 941 :ref:`Generic Error Codes <gen-errors>` chapter.
 942
 943
 944 .. _AUDIO_SET_ID:
 945
 946 AUDIO_SET_ID
 947 ============
 948
 949 DESCRIPTION
 950
 951 This ioctl selects which sub-stream is to be decoded if a program or
 952 system stream is sent to the video device. If no audio stream type is
 953 set the id has to be in [0xC0,0xDF] for MPEG sound, in [0x80,0x87] for
 954 AC3 and in [0xA0,0xA7] for LPCM. More specifications may follow for
 955 other stream types. If the stream type is set the id just specifies the
 956 substream id of the audio stream and only the first 5 bits are
 957 recognized.
 958
 959 SYNOPSIS
 960
 961 int ioctl(int fd, int request = AUDIO_SET_ID, int id);
 962
 963 PARAMETERS
 964
 965
 966
 967 .. flat-table::
 968     :header-rows:  0
 969     :stub-columns: 0
 970
 971
 972     -  .. row 1
 973
 974        -  int fd
 975
 976        -  File descriptor returned by a previous call to open().
 977
 978     -  .. row 2
 979
 980        -  int request
 981
 982        -  Equals AUDIO_SET_ID for this command.
 983
 984     -  .. row 3
 985
 986        -  int id
 987
 988        -  audio sub-stream id
 989
 990
 991 RETURN VALUE
 992
 993 On success 0 is returned, on error -1 and the ``errno`` variable is set
 994 appropriately. The generic error codes are described at the
 995 :ref:`Generic Error Codes <gen-errors>` chapter.
 996
 997
 998 .. _AUDIO_SET_MIXER:
 999
1000 AUDIO_SET_MIXER
1001 ===============
1002
1003 DESCRIPTION
1004
1005 This ioctl lets you adjust the mixer settings of the audio decoder.
1006
1007 SYNOPSIS
1008
1009 int ioctl(int fd, int request = AUDIO_SET_MIXER, audio_mixer_t
1010 *mix);
1011
1012 PARAMETERS
1013
1014
1015
1016 .. flat-table::
1017     :header-rows:  0
1018     :stub-columns: 0
1019
1020
1021     -  .. row 1
1022
1023        -  int fd
1024
1025        -  File descriptor returned by a previous call to open().
1026
1027     -  .. row 2
1028
1029        -  int request
1030
1031        -  Equals AUDIO_SET_ID for this command.
1032
1033     -  .. row 3
1034
1035        -  audio_mixer_t *mix
1036
1037        -  mixer settings.
1038
1039
1040 RETURN VALUE
1041
1042 On success 0 is returned, on error -1 and the ``errno`` variable is set
1043 appropriately. The generic error codes are described at the
1044 :ref:`Generic Error Codes <gen-errors>` chapter.
1045
1046
1047 .. _AUDIO_SET_STREAMTYPE:
1048
1049 AUDIO_SET_STREAMTYPE
1050 ====================
1051
1052 DESCRIPTION
1053
1054 This ioctl tells the driver which kind of audio stream to expect. This
1055 is useful if the stream offers several audio sub-streams like LPCM and
1056 AC3.
1057
1058 SYNOPSIS
1059
1060 int ioctl(fd, int request = AUDIO_SET_STREAMTYPE, int type);
1061
1062 PARAMETERS
1063
1064
1065
1066 .. flat-table::
1067     :header-rows:  0
1068     :stub-columns: 0
1069
1070
1071     -  .. row 1
1072
1073        -  int fd
1074
1075        -  File descriptor returned by a previous call to open().
1076
1077     -  .. row 2
1078
1079        -  int request
1080
1081        -  Equals AUDIO_SET_STREAMTYPE for this command.
1082
1083     -  .. row 3
1084
1085        -  int type
1086
1087        -  stream type
1088
1089
1090 RETURN VALUE
1091
1092 On success 0 is returned, on error -1 and the ``errno`` variable is set
1093 appropriately. The generic error codes are described at the
1094 :ref:`Generic Error Codes <gen-errors>` chapter.
1095
1096
1097
1098 .. flat-table::
1099     :header-rows:  0
1100     :stub-columns: 0
1101
1102
1103     -  .. row 1
1104
1105        -  EINVAL
1106
1107        -  type is not a valid or supported stream type.
1108
1109
1110
1111 .. _AUDIO_SET_EXT_ID:
1112
1113 AUDIO_SET_EXT_ID
1114 ================
1115
1116 DESCRIPTION
1117
1118 This ioctl can be used to set the extension id for MPEG streams in DVD
1119 playback. Only the first 3 bits are recognized.
1120
1121 SYNOPSIS
1122
1123 int ioctl(fd, int request = AUDIO_SET_EXT_ID, int id);
1124
1125 PARAMETERS
1126
1127
1128
1129 .. flat-table::
1130     :header-rows:  0
1131     :stub-columns: 0
1132
1133
1134     -  .. row 1
1135
1136        -  int fd
1137
1138        -  File descriptor returned by a previous call to open().
1139
1140     -  .. row 2
1141
1142        -  int request
1143
1144        -  Equals AUDIO_SET_EXT_ID for this command.
1145
1146     -  .. row 3
1147
1148        -  int id
1149
1150        -  audio sub_stream_id
1151
1152
1153 RETURN VALUE
1154
1155 On success 0 is returned, on error -1 and the ``errno`` variable is set
1156 appropriately. The generic error codes are described at the
1157 :ref:`Generic Error Codes <gen-errors>` chapter.
1158
1159
1160
1161 .. flat-table::
1162     :header-rows:  0
1163     :stub-columns: 0
1164
1165
1166     -  .. row 1
1167
1168        -  EINVAL
1169
1170        -  id is not a valid id.
1171
1172
1173
1174 .. _AUDIO_SET_ATTRIBUTES:
1175
1176 AUDIO_SET_ATTRIBUTES
1177 ====================
1178
1179 DESCRIPTION
1180
1181 This ioctl is intended for DVD playback and allows you to set certain
1182 information about the audio stream.
1183
1184 SYNOPSIS
1185
1186 int ioctl(fd, int request = AUDIO_SET_ATTRIBUTES, audio_attributes_t
1187 attr );
1188
1189 PARAMETERS
1190
1191
1192
1193 .. flat-table::
1194     :header-rows:  0
1195     :stub-columns: 0
1196
1197
1198     -  .. row 1
1199
1200        -  int fd
1201
1202        -  File descriptor returned by a previous call to open().
1203
1204     -  .. row 2
1205
1206        -  int request
1207
1208        -  Equals AUDIO_SET_ATTRIBUTES for this command.
1209
1210     -  .. row 3
1211
1212        -  audio_attributes_t attr
1213
1214        -  audio attributes according to section ??
1215
1216
1217 RETURN VALUE
1218
1219 On success 0 is returned, on error -1 and the ``errno`` variable is set
1220 appropriately. The generic error codes are described at the
1221 :ref:`Generic Error Codes <gen-errors>` chapter.
1222
1223
1224
1225 .. flat-table::
1226     :header-rows:  0
1227     :stub-columns: 0
1228
1229
1230     -  .. row 1
1231
1232        -  EINVAL
1233
1234        -  attr is not a valid or supported attribute setting.
1235
1236
1237
1238 .. _AUDIO_SET_KARAOKE:
1239
1240 AUDIO_SET_KARAOKE
1241 =================
1242
1243 DESCRIPTION
1244
1245 This ioctl allows one to set the mixer settings for a karaoke DVD.
1246
1247 SYNOPSIS
1248
1249 int ioctl(fd, int request = AUDIO_SET_KARAOKE, audio_karaoke_t
1250 *karaoke);
1251
1252 PARAMETERS
1253
1254
1255
1256 .. flat-table::
1257     :header-rows:  0
1258     :stub-columns: 0
1259
1260
1261     -  .. row 1
1262
1263        -  int fd
1264
1265        -  File descriptor returned by a previous call to open().
1266
1267     -  .. row 2
1268
1269        -  int request
1270
1271        -  Equals AUDIO_SET_KARAOKE for this command.
1272
1273     -  .. row 3
1274
1275        -  audio_karaoke_t *karaoke
1276
1277        -  karaoke settings according to section ??.
1278
1279
1280 RETURN VALUE
1281
1282 On success 0 is returned, on error -1 and the ``errno`` variable is set
1283 appropriately. The generic error codes are described at the
1284 :ref:`Generic Error Codes <gen-errors>` chapter.
1285
1286
1287
1288 .. flat-table::
1289     :header-rows:  0
1290     :stub-columns: 0
1291
1292
1293     -  .. row 1
1294
1295        -  EINVAL
1296
1297        -  karaoke is not a valid or supported karaoke setting.
1298
1299
1300
1301
1302 .. ------------------------------------------------------------------------------
1303 .. This file was automatically converted from DocBook-XML with the dbxml
1304 .. library (https://github.com/return42/sphkerneldoc). The origin XML comes
1305 .. from the linux kernel, refer to:
1306 ..
1307 .. * https://github.com/torvalds/linux/tree/master/Documentation/DocBook
1308 .. ------------------------------------------------------------------------------