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