Based on kernel version 4.7.2. Page generated on 2016-08-22 22:44 EST.
1 <title>DVB Audio Device</title> 2 <para>The DVB audio device controls the MPEG2 audio decoder of the DVB hardware. It 3 can be accessed through <constant>/dev/dvb/adapter?/audio?</constant>. Data types and and 4 ioctl definitions can be accessed by including <constant>linux/dvb/audio.h</constant> in your 5 application. 6 </para> 7 <para>Please note that some DVB cards don’t have their own MPEG decoder, which results in 8 the omission of the audio and video device. 9 </para> 10 <para> 11 These ioctls were also used by V4L2 to control MPEG decoders implemented in V4L2. The use 12 of these ioctls for that purpose has been made obsolete and proper V4L2 ioctls or controls 13 have been created to replace that functionality.</para> 14 15 <section id="audio_data_types"> 16 <title>Audio Data Types</title> 17 <para>This section describes the structures, data types and defines used when talking to the 18 audio device. 19 </para> 20 21 <section id="audio-stream-source-t"> 22 <title>audio_stream_source_t</title> 23 <para>The audio stream source is set through the AUDIO_SELECT_SOURCE call and can take 24 the following values, depending on whether we are replaying from an internal (demux) or 25 external (user write) source. 26 </para> 27 <programlisting> 28 typedef enum { 29 AUDIO_SOURCE_DEMUX, 30 AUDIO_SOURCE_MEMORY 31 } audio_stream_source_t; 32 </programlisting> 33 <para>AUDIO_SOURCE_DEMUX selects the demultiplexer (fed either by the frontend or the 34 DVR device) as the source of the video stream. If AUDIO_SOURCE_MEMORY 35 is selected the stream comes from the application through the <constant>write()</constant> system 36 call. 37 </para> 38 39 </section> 40 <section id="audio-play-state-t"> 41 <title>audio_play_state_t</title> 42 <para>The following values can be returned by the AUDIO_GET_STATUS call representing the 43 state of audio playback. 44 </para> 45 <programlisting> 46 typedef enum { 47 AUDIO_STOPPED, 48 AUDIO_PLAYING, 49 AUDIO_PAUSED 50 } audio_play_state_t; 51 </programlisting> 52 53 </section> 54 <section id="audio-channel-select-t"> 55 <title>audio_channel_select_t</title> 56 <para>The audio channel selected via AUDIO_CHANNEL_SELECT is determined by the 57 following values. 58 </para> 59 <programlisting> 60 typedef enum { 61 AUDIO_STEREO, 62 AUDIO_MONO_LEFT, 63 AUDIO_MONO_RIGHT, 64 AUDIO_MONO, 65 AUDIO_STEREO_SWAPPED 66 } audio_channel_select_t; 67 </programlisting> 68 69 </section> 70 <section id="audio-status"> 71 <title>struct audio_status</title> 72 <para>The AUDIO_GET_STATUS call returns the following structure informing about various 73 states of the playback operation. 74 </para> 75 <programlisting> 76 typedef struct audio_status { 77 boolean AV_sync_state; 78 boolean mute_state; 79 audio_play_state_t play_state; 80 audio_stream_source_t stream_source; 81 audio_channel_select_t channel_select; 82 boolean bypass_mode; 83 audio_mixer_t mixer_state; 84 } audio_status_t; 85 </programlisting> 86 87 </section> 88 <section id="audio-mixer"> 89 <title>struct audio_mixer</title> 90 <para>The following structure is used by the AUDIO_SET_MIXER call to set the audio 91 volume. 92 </para> 93 <programlisting> 94 typedef struct audio_mixer { 95 unsigned int volume_left; 96 unsigned int volume_right; 97 } audio_mixer_t; 98 </programlisting> 99 100 </section> 101 <section id="audio_encodings"> 102 <title>audio encodings</title> 103 <para>A call to AUDIO_GET_CAPABILITIES returns an unsigned integer with the following 104 bits set according to the hardwares capabilities. 105 </para> 106 <programlisting> 107 #define AUDIO_CAP_DTS 1 108 #define AUDIO_CAP_LPCM 2 109 #define AUDIO_CAP_MP1 4 110 #define AUDIO_CAP_MP2 8 111 #define AUDIO_CAP_MP3 16 112 #define AUDIO_CAP_AAC 32 113 #define AUDIO_CAP_OGG 64 114 #define AUDIO_CAP_SDDS 128 115 #define AUDIO_CAP_AC3 256 116 </programlisting> 117 118 </section> 119 <section id="audio-karaoke"> 120 <title>struct audio_karaoke</title> 121 <para>The ioctl AUDIO_SET_KARAOKE uses the following format: 122 </para> 123 <programlisting> 124 typedef 125 struct audio_karaoke { 126 int vocal1; 127 int vocal2; 128 int melody; 129 } audio_karaoke_t; 130 </programlisting> 131 <para>If Vocal1 or Vocal2 are non-zero, they get mixed into left and right t at 70% each. If both, 132 Vocal1 and Vocal2 are non-zero, Vocal1 gets mixed into the left channel and Vocal2 into the 133 right channel at 100% each. Ff Melody is non-zero, the melody channel gets mixed into left 134 and right. 135 </para> 136 137 </section> 138 <section id="audio-attributes-t"> 139 <title>audio attributes</title> 140 <para>The following attributes can be set by a call to AUDIO_SET_ATTRIBUTES: 141 </para> 142 <programlisting> 143 typedef uint16_t audio_attributes_t; 144 /⋆ bits: descr. ⋆/ 145 /⋆ 15-13 audio coding mode (0=ac3, 2=mpeg1, 3=mpeg2ext, 4=LPCM, 6=DTS, ⋆/ 146 /⋆ 12 multichannel extension ⋆/ 147 /⋆ 11-10 audio type (0=not spec, 1=language included) ⋆/ 148 /⋆ 9- 8 audio application mode (0=not spec, 1=karaoke, 2=surround) ⋆/ 149 /⋆ 7- 6 Quantization / DRC (mpeg audio: 1=DRC exists)(lpcm: 0=16bit, ⋆/ 150 /⋆ 5- 4 Sample frequency fs (0=48kHz, 1=96kHz) ⋆/ 151 /⋆ 2- 0 number of audio channels (n+1 channels) ⋆/ 152 </programlisting> 153 </section></section> 154 <section id="audio_function_calls"> 155 <title>Audio Function Calls</title> 156 157 158 <section id="audio_fopen"> 159 <title>open()</title> 160 <para>DESCRIPTION 161 </para> 162 <informaltable><tgroup cols="1"><tbody><row><entry 163 align="char"> 164 <para>This system call opens a named audio device (e.g. /dev/dvb/adapter0/audio0) 165 for subsequent use. When an open() call has succeeded, the device will be ready 166 for use. The significance of blocking or non-blocking mode is described in the 167 documentation for functions where there is a difference. It does not affect the 168 semantics of the open() call itself. A device opened in blocking mode can later 169 be put into non-blocking mode (and vice versa) using the F_SETFL command 170 of the fcntl system call. This is a standard system call, documented in the Linux 171 manual page for fcntl. Only one user can open the Audio Device in O_RDWR 172 mode. All other attempts to open the device in this mode will fail, and an error 173 code will be returned. If the Audio Device is opened in O_RDONLY mode, the 174 only ioctl call that can be used is AUDIO_GET_STATUS. All other call will 175 return with an error code.</para> 176 </entry> 177 </row></tbody></tgroup></informaltable> 178 <para>SYNOPSIS 179 </para> 180 <informaltable><tgroup cols="1"><tbody><row><entry 181 align="char"> 182 <para>int open(const char ⋆deviceName, int flags);</para> 183 </entry> 184 </row></tbody></tgroup></informaltable> 185 <para>PARAMETERS 186 </para> 187 <informaltable><tgroup cols="2"><tbody><row><entry 188 align="char"> 189 <para>const char 190 *deviceName</para> 191 </entry><entry 192 align="char"> 193 <para>Name of specific audio device.</para> 194 </entry> 195 </row><row><entry 196 align="char"> 197 <para>int flags</para> 198 </entry><entry 199 align="char"> 200 <para>A bit-wise OR of the following flags:</para> 201 </entry> 202 </row><row><entry 203 align="char"> 204 </entry><entry 205 align="char"> 206 <para>O_RDONLY read-only access</para> 207 </entry> 208 </row><row><entry 209 align="char"> 210 </entry><entry 211 align="char"> 212 <para>O_RDWR read/write access</para> 213 </entry> 214 </row><row><entry 215 align="char"> 216 </entry><entry 217 align="char"> 218 <para>O_NONBLOCK open in non-blocking mode</para> 219 </entry> 220 </row><row><entry 221 align="char"> 222 </entry><entry 223 align="char"> 224 <para>(blocking mode is the default)</para> 225 </entry> 226 </row></tbody></tgroup></informaltable> 227 <para>RETURN VALUE</para> 228 <informaltable><tgroup cols="2"><tbody><row><entry 229 align="char"> 230 <para>ENODEV</para> 231 </entry><entry 232 align="char"> 233 <para>Device driver not loaded/available.</para> 234 </entry> 235 </row><row><entry 236 align="char"> 237 <para>EBUSY</para> 238 </entry><entry 239 align="char"> 240 <para>Device or resource busy.</para> 241 </entry> 242 </row><row><entry 243 align="char"> 244 <para>EINVAL</para> 245 </entry><entry 246 align="char"> 247 <para>Invalid argument.</para> 248 </entry> 249 </row></tbody></tgroup></informaltable> 250 251 </section> 252 <section id="audio_fclose"> 253 <title>close()</title> 254 <para>DESCRIPTION 255 </para> 256 <informaltable><tgroup cols="1"><tbody><row><entry 257 align="char"> 258 <para>This system call closes a previously opened audio device.</para> 259 </entry> 260 </row></tbody></tgroup></informaltable> 261 <para>SYNOPSIS 262 </para> 263 <informaltable><tgroup cols="1"><tbody><row><entry 264 align="char"> 265 <para>int close(int fd);</para> 266 </entry> 267 </row></tbody></tgroup></informaltable> 268 <para>PARAMETERS 269 </para> 270 <informaltable><tgroup cols="2"><tbody><row><entry 271 align="char"> 272 <para>int fd</para> 273 </entry><entry 274 align="char"> 275 <para>File descriptor returned by a previous call to open().</para> 276 </entry> 277 </row></tbody></tgroup></informaltable> 278 <para>RETURN VALUE</para> 279 <informaltable><tgroup cols="2"><tbody><row><entry 280 align="char"> 281 <para>EBADF</para> 282 </entry><entry 283 align="char"> 284 <para>fd is not a valid open file descriptor.</para> 285 </entry> 286 </row></tbody></tgroup></informaltable> 287 288 </section> 289 <section id="audio_fwrite"> 290 <title>write()</title> 291 <para>DESCRIPTION 292 </para> 293 <informaltable><tgroup cols="1"><tbody><row><entry 294 align="char"> 295 <para>This system call can only be used if AUDIO_SOURCE_MEMORY is selected 296 in the ioctl call AUDIO_SELECT_SOURCE. The data provided shall be in 297 PES format. If O_NONBLOCK is not specified the function will block until 298 buffer space is available. The amount of data to be transferred is implied by 299 count.</para> 300 </entry> 301 </row></tbody></tgroup></informaltable> 302 <para>SYNOPSIS 303 </para> 304 <informaltable><tgroup cols="1"><tbody><row><entry 305 align="char"> 306 <para>size_t write(int fd, const void ⋆buf, size_t count);</para> 307 </entry> 308 </row></tbody></tgroup></informaltable> 309 <para>PARAMETERS 310 </para> 311 <informaltable><tgroup cols="2"><tbody><row><entry 312 align="char"> 313 <para>int fd</para> 314 </entry><entry 315 align="char"> 316 <para>File descriptor returned by a previous call to open().</para> 317 </entry> 318 </row><row><entry 319 align="char"> 320 <para>void *buf</para> 321 </entry><entry 322 align="char"> 323 <para>Pointer to the buffer containing the PES data.</para> 324 </entry> 325 </row><row><entry 326 align="char"> 327 <para>size_t count</para> 328 </entry><entry 329 align="char"> 330 <para>Size of buf.</para> 331 </entry> 332 </row></tbody></tgroup></informaltable> 333 <para>RETURN VALUE</para> 334 <informaltable><tgroup cols="2"><tbody><row><entry 335 align="char"> 336 <para>EPERM</para> 337 </entry><entry 338 align="char"> 339 <para>Mode AUDIO_SOURCE_MEMORY not selected.</para> 340 </entry> 341 </row><row><entry 342 align="char"> 343 <para>ENOMEM</para> 344 </entry><entry 345 align="char"> 346 <para>Attempted to write more data than the internal buffer can 347 hold.</para> 348 </entry> 349 </row><row><entry 350 align="char"> 351 <para>EBADF</para> 352 </entry><entry 353 align="char"> 354 <para>fd is not a valid open file descriptor.</para> 355 </entry> 356 </row></tbody></tgroup></informaltable> 357 358 </section><section id="AUDIO_STOP" 359 role="subsection"><title>AUDIO_STOP</title> 360 <para>DESCRIPTION 361 </para> 362 <informaltable><tgroup cols="1"><tbody><row><entry 363 align="char"> 364 <para>This ioctl call asks the Audio Device to stop playing the current stream.</para> 365 </entry> 366 </row></tbody></tgroup></informaltable> 367 <para>SYNOPSIS 368 </para> 369 <informaltable><tgroup cols="1"><tbody><row><entry 370 align="char"> 371 <para>int ioctl(int fd, int request = AUDIO_STOP);</para> 372 </entry> 373 </row></tbody></tgroup></informaltable> 374 <para>PARAMETERS 375 </para> 376 <informaltable><tgroup cols="2"><tbody><row><entry 377 align="char"> 378 <para>int fd</para> 379 </entry><entry 380 align="char"> 381 <para>File descriptor returned by a previous call to open().</para> 382 </entry> 383 </row><row><entry 384 align="char"> 385 <para>int request</para> 386 </entry><entry 387 align="char"> 388 <para>Equals AUDIO_STOP for this command.</para> 389 </entry> 390 </row></tbody></tgroup></informaltable> 391 &return-value-dvb; 392 393 </section><section id="AUDIO_PLAY" 394 role="subsection"><title>AUDIO_PLAY</title> 395 <para>DESCRIPTION 396 </para> 397 <informaltable><tgroup cols="1"><tbody><row><entry 398 align="char"> 399 <para>This ioctl call asks the Audio Device to start playing an audio stream from the 400 selected source.</para> 401 </entry> 402 </row></tbody></tgroup></informaltable> 403 <para>SYNOPSIS 404 </para> 405 <informaltable><tgroup cols="1"><tbody><row><entry 406 align="char"> 407 <para>int ioctl(int fd, int request = AUDIO_PLAY);</para> 408 </entry> 409 </row></tbody></tgroup></informaltable> 410 <para>PARAMETERS 411 </para> 412 <informaltable><tgroup cols="2"><tbody><row><entry 413 align="char"> 414 <para>int fd</para> 415 </entry><entry 416 align="char"> 417 <para>File descriptor returned by a previous call to open().</para> 418 </entry> 419 </row><row><entry 420 align="char"> 421 <para>int request</para> 422 </entry><entry 423 align="char"> 424 <para>Equals AUDIO_PLAY for this command.</para> 425 </entry> 426 </row></tbody></tgroup></informaltable> 427 &return-value-dvb; 428 429 </section><section id="AUDIO_PAUSE" 430 role="subsection"><title>AUDIO_PAUSE</title> 431 <para>DESCRIPTION 432 </para> 433 <informaltable><tgroup cols="1"><tbody><row><entry 434 align="char"> 435 <para>This ioctl call suspends the audio stream being played. Decoding and playing 436 are paused. It is then possible to restart again decoding and playing process of 437 the audio stream using AUDIO_CONTINUE command.</para> 438 </entry> 439 </row><row><entry 440 align="char"> 441 <para>If AUDIO_SOURCE_MEMORY is selected in the ioctl call 442 AUDIO_SELECT_SOURCE, the DVB-subsystem will not decode (consume) 443 any more data until the ioctl call AUDIO_CONTINUE or AUDIO_PLAY is 444 performed.</para> 445 </entry> 446 </row></tbody></tgroup></informaltable> 447 <para>SYNOPSIS 448 </para> 449 <informaltable><tgroup cols="1"><tbody><row><entry 450 align="char"> 451 <para>int ioctl(int fd, int request = AUDIO_PAUSE);</para> 452 </entry> 453 </row></tbody></tgroup></informaltable> 454 <para>PARAMETERS 455 </para> 456 <informaltable><tgroup cols="2"><tbody><row><entry 457 align="char"> 458 <para>int fd</para> 459 </entry><entry 460 align="char"> 461 <para>File descriptor returned by a previous call to open().</para> 462 </entry> 463 </row><row><entry 464 align="char"> 465 <para>int request</para> 466 </entry><entry 467 align="char"> 468 <para>Equals AUDIO_PAUSE for this command.</para> 469 </entry> 470 </row></tbody></tgroup></informaltable> 471 &return-value-dvb; 472 473 </section><section id="AUDIO_CONTINUE" 474 role="subsection"><title>AUDIO_CONTINUE</title> 475 <para>DESCRIPTION 476 </para> 477 <informaltable><tgroup cols="1"><tbody><row><entry 478 align="char"> 479 <para>This ioctl restarts the decoding and playing process previously paused 480 with AUDIO_PAUSE command.</para> 481 </entry> 482 </row><row><entry 483 align="char"> 484 <para>It only works if the stream were previously stopped with AUDIO_PAUSE</para> 485 </entry> 486 </row></tbody></tgroup></informaltable> 487 <para>SYNOPSIS 488 </para> 489 <informaltable><tgroup cols="1"><tbody><row><entry 490 align="char"> 491 <para>int ioctl(int fd, int request = AUDIO_CONTINUE);</para> 492 </entry> 493 </row></tbody></tgroup></informaltable> 494 <para>PARAMETERS 495 </para> 496 <informaltable><tgroup cols="2"><tbody><row><entry 497 align="char"> 498 <para>int fd</para> 499 </entry><entry 500 align="char"> 501 <para>File descriptor returned by a previous call to open().</para> 502 </entry> 503 </row><row><entry 504 align="char"> 505 <para>int request</para> 506 </entry><entry 507 align="char"> 508 <para>Equals AUDIO_CONTINUE for this command.</para> 509 </entry> 510 </row></tbody></tgroup></informaltable> 511 &return-value-dvb; 512 513 </section><section id="AUDIO_SELECT_SOURCE" 514 role="subsection"><title>AUDIO_SELECT_SOURCE</title> 515 <para>DESCRIPTION 516 </para> 517 <informaltable><tgroup cols="1"><tbody><row><entry 518 align="char"> 519 <para>This ioctl call informs the audio device which source shall be used 520 for the input data. The possible sources are demux or memory. If 521 AUDIO_SOURCE_MEMORY is selected, the data is fed to the Audio Device 522 through the write command.</para> 523 </entry> 524 </row></tbody></tgroup></informaltable> 525 <para>SYNOPSIS 526 </para> 527 <informaltable><tgroup cols="1"><tbody><row><entry 528 align="char"> 529 <para>int ioctl(int fd, int request = AUDIO_SELECT_SOURCE, 530 audio_stream_source_t source);</para> 531 </entry> 532 </row></tbody></tgroup></informaltable> 533 <para>PARAMETERS 534 </para> 535 <informaltable><tgroup cols="2"><tbody><row><entry 536 align="char"> 537 <para>int fd</para> 538 </entry><entry 539 align="char"> 540 <para>File descriptor returned by a previous call to open().</para> 541 </entry> 542 </row><row><entry 543 align="char"> 544 <para>int request</para> 545 </entry><entry 546 align="char"> 547 <para>Equals AUDIO_SELECT_SOURCE for this command.</para> 548 </entry> 549 </row><row><entry 550 align="char"> 551 <para>audio_stream_source_t 552 source</para> 553 </entry><entry 554 align="char"> 555 <para>Indicates the source that shall be used for the Audio 556 stream.</para> 557 </entry> 558 </row></tbody></tgroup></informaltable> 559 &return-value-dvb; 560 561 </section><section id="AUDIO_SET_MUTE" 562 role="subsection"><title>AUDIO_SET_MUTE</title> 563 <para>DESCRIPTION 564 </para> 565 <para>This ioctl is for DVB devices only. To control a V4L2 decoder use the V4L2 566 &VIDIOC-DECODER-CMD; with the <constant>V4L2_DEC_CMD_START_MUTE_AUDIO</constant> flag instead.</para> 567 <informaltable><tgroup cols="1"><tbody><row><entry 568 align="char"> 569 <para>This ioctl call asks the audio device to mute the stream that is currently being 570 played.</para> 571 </entry> 572 </row></tbody></tgroup></informaltable> 573 <para>SYNOPSIS 574 </para> 575 <informaltable><tgroup cols="1"><tbody><row><entry 576 align="char"> 577 <para>int ioctl(int fd, int request = AUDIO_SET_MUTE, 578 boolean state);</para> 579 </entry> 580 </row></tbody></tgroup></informaltable> 581 <para>PARAMETERS 582 </para> 583 <informaltable><tgroup cols="2"><tbody><row><entry 584 align="char"> 585 <para>int fd</para> 586 </entry><entry 587 align="char"> 588 <para>File descriptor returned by a previous call to open().</para> 589 </entry> 590 </row><row><entry 591 align="char"> 592 <para>int request</para> 593 </entry><entry 594 align="char"> 595 <para>Equals AUDIO_SET_MUTE for this command.</para> 596 </entry> 597 </row><row><entry 598 align="char"> 599 <para>boolean state</para> 600 </entry><entry 601 align="char"> 602 <para>Indicates if audio device shall mute or not.</para> 603 </entry> 604 </row><row><entry 605 align="char"> 606 </entry><entry 607 align="char"> 608 <para>TRUE Audio Mute</para> 609 </entry> 610 </row><row><entry 611 align="char"> 612 </entry><entry 613 align="char"> 614 <para>FALSE Audio Un-mute</para> 615 </entry> 616 </row></tbody></tgroup></informaltable> 617 &return-value-dvb; 618 619 </section><section id="AUDIO_SET_AV_SYNC" 620 role="subsection"><title>AUDIO_SET_AV_SYNC</title> 621 <para>DESCRIPTION 622 </para> 623 <informaltable><tgroup cols="1"><tbody><row><entry 624 align="char"> 625 <para>This ioctl call asks the Audio Device to turn ON or OFF A/V synchronization.</para> 626 </entry> 627 </row></tbody></tgroup></informaltable> 628 <para>SYNOPSIS 629 </para> 630 <informaltable><tgroup cols="1"><tbody><row><entry 631 align="char"> 632 <para>int ioctl(int fd, int request = AUDIO_SET_AV_SYNC, 633 boolean state);</para> 634 </entry> 635 </row></tbody></tgroup></informaltable> 636 <para>PARAMETERS 637 </para> 638 <informaltable><tgroup cols="2"><tbody><row><entry 639 align="char"> 640 <para>int fd</para> 641 </entry><entry 642 align="char"> 643 <para>File descriptor returned by a previous call to open().</para> 644 </entry> 645 </row><row><entry 646 align="char"> 647 <para>int request</para> 648 </entry><entry 649 align="char"> 650 <para>Equals AUDIO_AV_SYNC for this command.</para> 651 </entry> 652 </row><row><entry 653 align="char"> 654 <para>boolean state</para> 655 </entry><entry 656 align="char"> 657 <para>Tells the DVB subsystem if A/V synchronization shall be 658 ON or OFF.</para> 659 </entry> 660 </row><row><entry 661 align="char"> 662 </entry><entry 663 align="char"> 664 <para>TRUE AV-sync ON</para> 665 </entry> 666 </row><row><entry 667 align="char"> 668 </entry><entry 669 align="char"> 670 <para>FALSE AV-sync OFF</para> 671 </entry> 672 </row></tbody></tgroup></informaltable> 673 &return-value-dvb; 674 675 </section><section id="AUDIO_SET_BYPASS_MODE" 676 role="subsection"><title>AUDIO_SET_BYPASS_MODE</title> 677 <para>DESCRIPTION 678 </para> 679 <informaltable><tgroup cols="1"><tbody><row><entry 680 align="char"> 681 <para>This ioctl call asks the Audio Device to bypass the Audio decoder and forward 682 the stream without decoding. This mode shall be used if streams that can’t be 683 handled by the DVB system shall be decoded. Dolby DigitalTM streams are 684 automatically forwarded by the DVB subsystem if the hardware can handle it.</para> 685 </entry> 686 </row></tbody></tgroup></informaltable> 687 <para>SYNOPSIS 688 </para> 689 <informaltable><tgroup cols="1"><tbody><row><entry 690 align="char"> 691 <para>int ioctl(int fd, int request = 692 AUDIO_SET_BYPASS_MODE, boolean mode);</para> 693 </entry> 694 </row></tbody></tgroup></informaltable> 695 <para>PARAMETERS 696 </para> 697 <informaltable><tgroup cols="2"><tbody><row><entry 698 align="char"> 699 <para>int fd</para> 700 </entry><entry 701 align="char"> 702 <para>File descriptor returned by a previous call to open().</para> 703 </entry> 704 </row><row><entry 705 align="char"> 706 <para>int request</para> 707 </entry><entry 708 align="char"> 709 <para>Equals AUDIO_SET_BYPASS_MODE for this 710 command.</para> 711 </entry> 712 </row><row><entry 713 align="char"> 714 <para>boolean mode</para> 715 </entry><entry 716 align="char"> 717 <para>Enables or disables the decoding of the current Audio 718 stream in the DVB subsystem.</para> 719 </entry> 720 </row><row><entry 721 align="char"> 722 </entry><entry 723 align="char"> 724 <para>TRUE Bypass is disabled</para> 725 </entry> 726 </row><row><entry 727 align="char"> 728 </entry><entry 729 align="char"> 730 <para>FALSE Bypass is enabled</para> 731 </entry> 732 </row></tbody></tgroup></informaltable> 733 &return-value-dvb; 734 735 </section><section id="AUDIO_CHANNEL_SELECT" 736 role="subsection"><title>AUDIO_CHANNEL_SELECT</title> 737 <para>DESCRIPTION 738 </para> 739 <para>This ioctl is for DVB devices only. To control a V4L2 decoder use the V4L2 740 <constant>V4L2_CID_MPEG_AUDIO_DEC_PLAYBACK</constant> control instead.</para> 741 <informaltable><tgroup cols="1"><tbody><row><entry 742 align="char"> 743 <para>This ioctl call asks the Audio Device to select the requested channel if possible.</para> 744 </entry> 745 </row></tbody></tgroup></informaltable> 746 <para>SYNOPSIS 747 </para> 748 <informaltable><tgroup cols="1"><tbody><row><entry 749 align="char"> 750 <para>int ioctl(int fd, int request = 751 AUDIO_CHANNEL_SELECT, audio_channel_select_t);</para> 752 </entry> 753 </row></tbody></tgroup></informaltable> 754 <para>PARAMETERS 755 </para> 756 <informaltable><tgroup cols="2"><tbody><row><entry 757 align="char"> 758 <para>int fd</para> 759 </entry><entry 760 align="char"> 761 <para>File descriptor returned by a previous call to open().</para> 762 </entry> 763 </row><row><entry 764 align="char"> 765 <para>int request</para> 766 </entry><entry 767 align="char"> 768 <para>Equals AUDIO_CHANNEL_SELECT for this 769 command.</para> 770 </entry> 771 </row><row><entry 772 align="char"> 773 <para>audio_channel_select_t 774 ch</para> 775 </entry><entry 776 align="char"> 777 <para>Select the output format of the audio (mono left/right, 778 stereo).</para> 779 </entry> 780 </row></tbody></tgroup></informaltable> 781 &return-value-dvb; 782 783 </section><section id="AUDIO_BILINGUAL_CHANNEL_SELECT" 784 role="subsection"><title>AUDIO_BILINGUAL_CHANNEL_SELECT</title> 785 <para>DESCRIPTION 786 </para> 787 <para>This ioctl is obsolete. Do not use in new drivers. It has been replaced by 788 the V4L2 <constant>V4L2_CID_MPEG_AUDIO_DEC_MULTILINGUAL_PLAYBACK</constant> control 789 for MPEG decoders controlled through V4L2.</para> 790 <informaltable><tgroup cols="1"><tbody><row><entry 791 align="char"> 792 <para>This ioctl call asks the Audio Device to select the requested channel for bilingual streams if possible.</para> 793 </entry> 794 </row></tbody></tgroup></informaltable> 795 <para>SYNOPSIS 796 </para> 797 <informaltable><tgroup cols="1"><tbody><row><entry 798 align="char"> 799 <para>int ioctl(int fd, int request = 800 AUDIO_BILINGUAL_CHANNEL_SELECT, audio_channel_select_t);</para> 801 </entry> 802 </row></tbody></tgroup></informaltable> 803 <para>PARAMETERS 804 </para> 805 <informaltable><tgroup cols="2"><tbody><row><entry 806 align="char"> 807 <para>int fd</para> 808 </entry><entry 809 align="char"> 810 <para>File descriptor returned by a previous call to open().</para> 811 </entry> 812 </row><row><entry 813 align="char"> 814 <para>int request</para> 815 </entry><entry 816 align="char"> 817 <para>Equals AUDIO_BILINGUAL_CHANNEL_SELECT for this 818 command.</para> 819 </entry> 820 </row><row><entry 821 align="char"> 822 <para>audio_channel_select_t 823 ch</para> 824 </entry><entry 825 align="char"> 826 <para>Select the output format of the audio (mono left/right, 827 stereo).</para> 828 </entry> 829 </row> 830 </tbody></tgroup></informaltable> 831 &return-value-dvb; 832 833 </section><section id="AUDIO_GET_PTS" 834 role="subsection"><title>AUDIO_GET_PTS</title> 835 <para>DESCRIPTION 836 </para> 837 <para>This ioctl is obsolete. Do not use in new drivers. If you need this functionality, 838 then please contact the linux-media mailing list (&v4l-ml;).</para> 839 <informaltable><tgroup cols="1"><tbody><row><entry 840 align="char"> 841 <para>This ioctl call asks the Audio Device to return the current PTS timestamp.</para> 842 </entry> 843 </row></tbody></tgroup></informaltable> 844 <para>SYNOPSIS 845 </para> 846 <informaltable><tgroup cols="1"><tbody><row><entry 847 align="char"> 848 <para>int ioctl(int fd, int request = 849 AUDIO_GET_PTS, __u64 *pts);</para> 850 </entry> 851 </row></tbody></tgroup></informaltable> 852 <para>PARAMETERS 853 </para> 854 <informaltable><tgroup cols="2"><tbody><row><entry 855 align="char"> 856 <para>int fd</para> 857 </entry><entry 858 align="char"> 859 <para>File descriptor returned by a previous call to open().</para> 860 </entry> 861 </row><row><entry 862 align="char"> 863 <para>int request</para> 864 </entry><entry 865 align="char"> 866 <para>Equals AUDIO_GET_PTS for this 867 command.</para> 868 </entry> 869 </row><row><entry 870 align="char"> 871 <para>__u64 *pts 872 </para> 873 </entry><entry 874 align="char"> 875 <para>Returns the 33-bit timestamp as defined in ITU T-REC-H.222.0 / ISO/IEC 13818-1. 876 </para> 877 <para> 878 The PTS should belong to the currently played 879 frame if possible, but may also be a value close to it 880 like the PTS of the last decoded frame or the last PTS 881 extracted by the PES parser.</para> 882 </entry> 883 </row></tbody></tgroup></informaltable> 884 &return-value-dvb; 885 886 </section><section id="AUDIO_GET_STATUS" 887 role="subsection"><title>AUDIO_GET_STATUS</title> 888 <para>DESCRIPTION 889 </para> 890 <informaltable><tgroup cols="1"><tbody><row><entry 891 align="char"> 892 <para>This ioctl call asks the Audio Device to return the current state of the Audio 893 Device.</para> 894 </entry> 895 </row></tbody></tgroup></informaltable> 896 <para>SYNOPSIS 897 </para> 898 <informaltable><tgroup cols="1"><tbody><row><entry 899 align="char"> 900 <para>int ioctl(int fd, int request = AUDIO_GET_STATUS, 901 struct audio_status ⋆status);</para> 902 </entry> 903 </row></tbody></tgroup></informaltable> 904 <para>PARAMETERS 905 </para> 906 <informaltable><tgroup cols="2"><tbody><row><entry 907 align="char"> 908 <para>int fd</para> 909 </entry><entry 910 align="char"> 911 <para>File descriptor returned by a previous call to open().</para> 912 </entry> 913 </row><row><entry 914 align="char"> 915 <para>int request</para> 916 </entry><entry 917 align="char"> 918 <para>Equals AUDIO_GET_STATUS for this command.</para> 919 </entry> 920 </row><row><entry 921 align="char"> 922 <para>struct audio_status 923 *status</para> 924 </entry><entry 925 align="char"> 926 <para>Returns the current state of Audio Device.</para> 927 </entry> 928 </row></tbody></tgroup></informaltable> 929 &return-value-dvb; 930 931 </section><section id="AUDIO_GET_CAPABILITIES" 932 role="subsection"><title>AUDIO_GET_CAPABILITIES</title> 933 <para>DESCRIPTION 934 </para> 935 <informaltable><tgroup cols="1"><tbody><row><entry 936 align="char"> 937 <para>This ioctl call asks the Audio Device to tell us about the decoding capabilities 938 of the audio hardware.</para> 939 </entry> 940 </row></tbody></tgroup></informaltable> 941 <para>SYNOPSIS 942 </para> 943 <informaltable><tgroup cols="1"><tbody><row><entry 944 align="char"> 945 <para>int ioctl(int fd, int request = 946 AUDIO_GET_CAPABILITIES, unsigned int ⋆cap);</para> 947 </entry> 948 </row></tbody></tgroup></informaltable> 949 <para>PARAMETERS 950 </para> 951 <informaltable><tgroup cols="2"><tbody><row><entry 952 align="char"> 953 <para>int fd</para> 954 </entry><entry 955 align="char"> 956 <para>File descriptor returned by a previous call to open().</para> 957 </entry> 958 </row><row><entry 959 align="char"> 960 <para>int request</para> 961 </entry><entry 962 align="char"> 963 <para>Equals AUDIO_GET_CAPABILITIES for this 964 command.</para> 965 </entry> 966 </row><row><entry 967 align="char"> 968 <para>unsigned int *cap</para> 969 </entry><entry 970 align="char"> 971 <para>Returns a bit array of supported sound formats.</para> 972 </entry> 973 </row></tbody></tgroup></informaltable> 974 &return-value-dvb; 975 976 </section><section id="AUDIO_CLEAR_BUFFER" 977 role="subsection"><title>AUDIO_CLEAR_BUFFER</title> 978 <para>DESCRIPTION 979 </para> 980 <informaltable><tgroup cols="1"><tbody><row><entry 981 align="char"> 982 <para>This ioctl call asks the Audio Device to clear all software and hardware buffers 983 of the audio decoder device.</para> 984 </entry> 985 </row></tbody></tgroup></informaltable> 986 <para>SYNOPSIS 987 </para> 988 <informaltable><tgroup cols="1"><tbody><row><entry 989 align="char"> 990 <para>int ioctl(int fd, int request = AUDIO_CLEAR_BUFFER);</para> 991 </entry> 992 </row></tbody></tgroup></informaltable> 993 <para>PARAMETERS 994 </para> 995 <informaltable><tgroup cols="2"><tbody><row><entry 996 align="char"> 997 <para>int fd</para> 998 </entry><entry 999 align="char"> 1000 <para>File descriptor returned by a previous call to open().</para> 1001 </entry> 1002 </row><row><entry 1003 align="char"> 1004 <para>int request</para> 1005 </entry><entry 1006 align="char"> 1007 <para>Equals AUDIO_CLEAR_BUFFER for this command.</para> 1008 </entry> 1009 </row></tbody></tgroup></informaltable> 1010 &return-value-dvb; 1011 1012 </section><section id="AUDIO_SET_ID" 1013 role="subsection"><title>AUDIO_SET_ID</title> 1014 <para>DESCRIPTION 1015 </para> 1016 <informaltable><tgroup cols="1"><tbody><row><entry 1017 align="char"> 1018 <para>This ioctl selects which sub-stream is to be decoded if a program or system 1019 stream is sent to the video device. If no audio stream type is set the id has to be 1020 in [0xC0,0xDF] for MPEG sound, in [0x80,0x87] for AC3 and in [0xA0,0xA7] 1021 for LPCM. More specifications may follow for other stream types. If the stream 1022 type is set the id just specifies the substream id of the audio stream and only 1023 the first 5 bits are recognized.</para> 1024 </entry> 1025 </row></tbody></tgroup></informaltable> 1026 <para>SYNOPSIS 1027 </para> 1028 <informaltable><tgroup cols="1"><tbody><row><entry 1029 align="char"> 1030 <para>int ioctl(int fd, int request = AUDIO_SET_ID, int 1031 id);</para> 1032 </entry> 1033 </row></tbody></tgroup></informaltable> 1034 <para>PARAMETERS 1035 </para> 1036 <informaltable><tgroup cols="2"><tbody><row><entry 1037 align="char"> 1038 <para>int fd</para> 1039 </entry><entry 1040 align="char"> 1041 <para>File descriptor returned by a previous call to open().</para> 1042 </entry> 1043 </row><row><entry 1044 align="char"> 1045 <para>int request</para> 1046 </entry><entry 1047 align="char"> 1048 <para>Equals AUDIO_SET_ID for this command.</para> 1049 </entry> 1050 </row><row><entry 1051 align="char"> 1052 <para>int id</para> 1053 </entry><entry 1054 align="char"> 1055 <para>audio sub-stream id</para> 1056 </entry> 1057 </row></tbody></tgroup></informaltable> 1058 &return-value-dvb; 1059 1060 </section><section id="AUDIO_SET_MIXER" 1061 role="subsection"><title>AUDIO_SET_MIXER</title> 1062 <para>DESCRIPTION 1063 </para> 1064 <informaltable><tgroup cols="1"><tbody><row><entry 1065 align="char"> 1066 <para>This ioctl lets you adjust the mixer settings of the audio decoder.</para> 1067 </entry> 1068 </row></tbody></tgroup></informaltable> 1069 <para>SYNOPSIS 1070 </para> 1071 <informaltable><tgroup cols="1"><tbody><row><entry 1072 align="char"> 1073 <para>int ioctl(int fd, int request = AUDIO_SET_MIXER, 1074 audio_mixer_t ⋆mix);</para> 1075 </entry> 1076 </row></tbody></tgroup></informaltable> 1077 <para>PARAMETERS 1078 </para> 1079 <informaltable><tgroup cols="2"><tbody><row><entry 1080 align="char"> 1081 <para>int fd</para> 1082 </entry><entry 1083 align="char"> 1084 <para>File descriptor returned by a previous call to open().</para> 1085 </entry> 1086 </row><row><entry 1087 align="char"> 1088 <para>int request</para> 1089 </entry><entry 1090 align="char"> 1091 <para>Equals AUDIO_SET_ID for this command.</para> 1092 </entry> 1093 </row><row><entry 1094 align="char"> 1095 <para>audio_mixer_t *mix</para> 1096 </entry><entry 1097 align="char"> 1098 <para>mixer settings.</para> 1099 </entry> 1100 </row></tbody></tgroup></informaltable> 1101 &return-value-dvb; 1102 1103 </section><section id="AUDIO_SET_STREAMTYPE" 1104 role="subsection"><title>AUDIO_SET_STREAMTYPE</title> 1105 <para>DESCRIPTION 1106 </para> 1107 <informaltable><tgroup cols="1"><tbody><row><entry 1108 align="char"> 1109 <para>This ioctl tells the driver which kind of audio stream to expect. This is useful 1110 if the stream offers several audio sub-streams like LPCM and AC3.</para> 1111 </entry> 1112 </row></tbody></tgroup></informaltable> 1113 <para>SYNOPSIS 1114 </para> 1115 <informaltable><tgroup cols="1"><tbody><row><entry 1116 align="char"> 1117 <para>int ioctl(fd, int request = AUDIO_SET_STREAMTYPE, 1118 int type);</para> 1119 </entry> 1120 </row></tbody></tgroup></informaltable> 1121 <para>PARAMETERS 1122 </para> 1123 <informaltable><tgroup cols="2"><tbody><row><entry 1124 align="char"> 1125 <para>int fd</para> 1126 </entry><entry 1127 align="char"> 1128 <para>File descriptor returned by a previous call to open().</para> 1129 </entry> 1130 </row><row><entry 1131 align="char"> 1132 <para>int request</para> 1133 </entry><entry 1134 align="char"> 1135 <para>Equals AUDIO_SET_STREAMTYPE for this 1136 command.</para> 1137 </entry> 1138 </row><row><entry 1139 align="char"> 1140 <para>int type</para> 1141 </entry><entry 1142 align="char"> 1143 <para>stream type</para> 1144 </entry> 1145 </row></tbody></tgroup></informaltable> 1146 &return-value-dvb; 1147 <informaltable><tgroup cols="2"><tbody><row><entry 1148 align="char"> 1149 <para>EINVAL</para> 1150 </entry><entry 1151 align="char"> 1152 <para>type is not a valid or supported stream type.</para> 1153 </entry> 1154 </row></tbody></tgroup></informaltable> 1155 1156 </section><section id="AUDIO_SET_EXT_ID" 1157 role="subsection"><title>AUDIO_SET_EXT_ID</title> 1158 <para>DESCRIPTION 1159 </para> 1160 <informaltable><tgroup cols="1"><tbody><row><entry 1161 align="char"> 1162 <para>This ioctl can be used to set the extension id for MPEG streams in DVD 1163 playback. Only the first 3 bits are recognized.</para> 1164 </entry> 1165 </row></tbody></tgroup></informaltable> 1166 <para>SYNOPSIS 1167 </para> 1168 <informaltable><tgroup cols="1"><tbody><row><entry 1169 align="char"> 1170 <para>int ioctl(fd, int request = AUDIO_SET_EXT_ID, int 1171 id);</para> 1172 </entry> 1173 </row></tbody></tgroup></informaltable> 1174 <para>PARAMETERS 1175 </para> 1176 <informaltable><tgroup cols="2"><tbody><row><entry 1177 align="char"> 1178 <para>int fd</para> 1179 </entry><entry 1180 align="char"> 1181 <para>File descriptor returned by a previous call to open().</para> 1182 </entry> 1183 </row><row><entry 1184 align="char"> 1185 <para>int request</para> 1186 </entry><entry 1187 align="char"> 1188 <para>Equals AUDIO_SET_EXT_ID for this command.</para> 1189 </entry> 1190 </row><row><entry 1191 align="char"> 1192 <para>int id</para> 1193 </entry><entry 1194 align="char"> 1195 <para>audio sub_stream_id</para> 1196 </entry> 1197 </row></tbody></tgroup></informaltable> 1198 &return-value-dvb; 1199 <informaltable><tgroup cols="2"><tbody><row><entry 1200 align="char"> 1201 <para>EINVAL</para> 1202 </entry><entry 1203 align="char"> 1204 <para>id is not a valid id.</para> 1205 </entry> 1206 </row></tbody></tgroup></informaltable> 1207 1208 </section><section id="AUDIO_SET_ATTRIBUTES" 1209 role="subsection"><title>AUDIO_SET_ATTRIBUTES</title> 1210 <para>DESCRIPTION 1211 </para> 1212 <informaltable><tgroup cols="1"><tbody><row><entry 1213 align="char"> 1214 <para>This ioctl is intended for DVD playback and allows you to set certain 1215 information about the audio stream.</para> 1216 </entry> 1217 </row></tbody></tgroup></informaltable> 1218 <para>SYNOPSIS 1219 </para> 1220 <informaltable><tgroup cols="1"><tbody><row><entry 1221 align="char"> 1222 <para>int ioctl(fd, int request = AUDIO_SET_ATTRIBUTES, 1223 audio_attributes_t attr );</para> 1224 </entry> 1225 </row></tbody></tgroup></informaltable> 1226 <para>PARAMETERS 1227 </para> 1228 <informaltable><tgroup cols="2"><tbody><row><entry 1229 align="char"> 1230 <para>int fd</para> 1231 </entry><entry 1232 align="char"> 1233 <para>File descriptor returned by a previous call to open().</para> 1234 </entry> 1235 </row><row><entry 1236 align="char"> 1237 <para>int request</para> 1238 </entry><entry 1239 align="char"> 1240 <para>Equals AUDIO_SET_ATTRIBUTES for this command.</para> 1241 </entry> 1242 </row><row><entry 1243 align="char"> 1244 <para>audio_attributes_t 1245 attr</para> 1246 </entry><entry 1247 align="char"> 1248 <para>audio attributes according to section ??</para> 1249 </entry> 1250 </row></tbody></tgroup></informaltable> 1251 &return-value-dvb; 1252 <informaltable><tgroup cols="2"><tbody><row><entry 1253 align="char"> 1254 <para>EINVAL</para> 1255 </entry><entry 1256 align="char"> 1257 <para>attr is not a valid or supported attribute setting.</para> 1258 </entry> 1259 </row></tbody></tgroup></informaltable> 1260 1261 </section><section id="AUDIO_SET_KARAOKE" 1262 role="subsection"><title>AUDIO_SET_KARAOKE</title> 1263 <para>DESCRIPTION 1264 </para> 1265 <informaltable><tgroup cols="1"><tbody><row><entry 1266 align="char"> 1267 <para>This ioctl allows one to set the mixer settings for a karaoke DVD.</para> 1268 </entry> 1269 </row></tbody></tgroup></informaltable> 1270 <para>SYNOPSIS 1271 </para> 1272 <informaltable><tgroup cols="1"><tbody><row><entry 1273 align="char"> 1274 <para>int ioctl(fd, int request = AUDIO_SET_KARAOKE, 1275 audio_karaoke_t ⋆karaoke);</para> 1276 </entry> 1277 </row></tbody></tgroup></informaltable> 1278 <para>PARAMETERS 1279 </para> 1280 <informaltable><tgroup cols="2"><tbody><row><entry 1281 align="char"> 1282 <para>int fd</para> 1283 </entry><entry 1284 align="char"> 1285 <para>File descriptor returned by a previous call to open().</para> 1286 </entry> 1287 </row><row><entry 1288 align="char"> 1289 <para>int request</para> 1290 </entry><entry 1291 align="char"> 1292 <para>Equals AUDIO_SET_KARAOKE for this 1293 command.</para> 1294 </entry> 1295 </row><row><entry 1296 align="char"> 1297 <para>audio_karaoke_t 1298 *karaoke</para> 1299 </entry><entry 1300 align="char"> 1301 <para>karaoke settings according to section ??.</para> 1302 </entry> 1303 </row></tbody></tgroup></informaltable> 1304 &return-value-dvb; 1305 <informaltable><tgroup cols="2"><tbody><row><entry 1306 align="char"> 1307 <para>EINVAL</para> 1308 </entry><entry 1309 align="char"> 1310 <para>karaoke is not a valid or supported karaoke setting.</para> 1311 </entry> 1312 </row></tbody></tgroup></informaltable> 1313 </section> 1314 </section>