1<title>DVB Demux Device</title> 2 3<para>The DVB demux device controls the filters of the DVB hardware/software. It can be 4accessed through <constant>/dev/adapter?/demux?</constant>. Data types and and ioctl definitions can be 5accessed by including <constant>linux/dvb/dmx.h</constant> in your application. 6</para> 7<section id="dmx_types"> 8<title>Demux Data Types</title> 9 10<section id="dmx-output-t"> 11<title>Output for the demux</title> 12 13<table pgwide="1" frame="none" id="dmx-output"> 14 <title>enum dmx_output</title> 15 <tgroup cols="2"> 16 &cs-def; 17 <thead> 18 <row> 19 <entry>ID</entry> 20 <entry>Description</entry> 21 </row> 22 </thead> 23 <tbody valign="top"> 24 <row> 25 <entry align="char" id="DMX-OUT-DECODER">DMX_OUT_DECODER</entry> 26 <entry>Streaming directly to decoder.</entry> 27 </row><row> 28 <entry align="char" id="DMX-OUT-TAP">DMX_OUT_TAP</entry> 29 <entry>Output going to a memory buffer (to be retrieved via the 30 read command). Delivers the stream output to the demux 31 device on which the ioctl is called.</entry> 32 </row><row> 33 <entry align="char" id="DMX-OUT-TS-TAP">DMX_OUT_TS_TAP</entry> 34 <entry>Output multiplexed into a new TS (to be retrieved by 35 reading from the logical DVR device). Routes output to the 36 logical DVR device <constant>/dev/dvb/adapter?/dvr?</constant>, 37 which delivers a TS multiplexed from all filters for which 38 <constant>DMX_OUT_TS_TAP</constant> was specified.</entry> 39 </row><row> 40 <entry align="char" id="DMX-OUT-TSDEMUX-TAP">DMX_OUT_TSDEMUX_TAP</entry> 41 <entry>Like &DMX-OUT-TS-TAP; but retrieved from the DMX 42 device.</entry> 43 </row> 44 </tbody> 45 </tgroup> 46</table> 47 48</section> 49 50<section id="dmx-input-t"> 51<title>dmx_input_t</title> 52<programlisting> 53typedef enum 54{ 55 DMX_IN_FRONTEND, /⋆ Input from a front-end device. ⋆/ 56 DMX_IN_DVR /⋆ Input from the logical DVR device. ⋆/ 57} dmx_input_t; 58</programlisting> 59</section> 60 61<section id="dmx-pes-type-t"> 62<title>dmx_pes_type_t</title> 63<programlisting> 64typedef enum 65{ 66 DMX_PES_AUDIO0, 67 DMX_PES_VIDEO0, 68 DMX_PES_TELETEXT0, 69 DMX_PES_SUBTITLE0, 70 DMX_PES_PCR0, 71 72 DMX_PES_AUDIO1, 73 DMX_PES_VIDEO1, 74 DMX_PES_TELETEXT1, 75 DMX_PES_SUBTITLE1, 76 DMX_PES_PCR1, 77 78 DMX_PES_AUDIO2, 79 DMX_PES_VIDEO2, 80 DMX_PES_TELETEXT2, 81 DMX_PES_SUBTITLE2, 82 DMX_PES_PCR2, 83 84 DMX_PES_AUDIO3, 85 DMX_PES_VIDEO3, 86 DMX_PES_TELETEXT3, 87 DMX_PES_SUBTITLE3, 88 DMX_PES_PCR3, 89 90 DMX_PES_OTHER 91} dmx_pes_type_t; 92</programlisting> 93</section> 94 95<section id="dmx-filter"> 96<title>struct dmx_filter</title> 97 <programlisting> 98 typedef struct dmx_filter 99{ 100 __u8 filter[DMX_FILTER_SIZE]; 101 __u8 mask[DMX_FILTER_SIZE]; 102 __u8 mode[DMX_FILTER_SIZE]; 103} dmx_filter_t; 104</programlisting> 105</section> 106 107<section id="dmx-sct-filter-params"> 108<title>struct dmx_sct_filter_params</title> 109<programlisting> 110struct dmx_sct_filter_params 111{ 112 __u16 pid; 113 dmx_filter_t filter; 114 __u32 timeout; 115 __u32 flags; 116#define DMX_CHECK_CRC 1 117#define DMX_ONESHOT 2 118#define DMX_IMMEDIATE_START 4 119#define DMX_KERNEL_CLIENT 0x8000 120}; 121</programlisting> 122</section> 123 124<section id="dmx-pes-filter-params"> 125<title>struct dmx_pes_filter_params</title> 126<programlisting> 127struct dmx_pes_filter_params 128{ 129 __u16 pid; 130 dmx_input_t input; 131 dmx_output_t output; 132 dmx_pes_type_t pes_type; 133 __u32 flags; 134}; 135</programlisting> 136</section> 137 138<section id="dmx-event"> 139<title>struct dmx_event</title> 140 <programlisting> 141 struct dmx_event 142 { 143 dmx_event_t event; 144 time_t timeStamp; 145 union 146 { 147 dmx_scrambling_status_t scrambling; 148 } u; 149 }; 150</programlisting> 151</section> 152 153<section id="dmx-stc"> 154<title>struct dmx_stc</title> 155<programlisting> 156struct dmx_stc { 157 unsigned int num; /⋆ input : which STC? 0..N ⋆/ 158 unsigned int base; /⋆ output: divisor for stc to get 90 kHz clock ⋆/ 159 __u64 stc; /⋆ output: stc in 'base'⋆90 kHz units ⋆/ 160}; 161</programlisting> 162</section> 163 164<section id="dmx-caps"> 165<title>struct dmx_caps</title> 166<programlisting> 167 typedef struct dmx_caps { 168 __u32 caps; 169 int num_decoders; 170} dmx_caps_t; 171</programlisting> 172</section> 173 174<section id="dmx-source-t"> 175<title>enum dmx_source_t</title> 176<programlisting> 177typedef enum { 178 DMX_SOURCE_FRONT0 = 0, 179 DMX_SOURCE_FRONT1, 180 DMX_SOURCE_FRONT2, 181 DMX_SOURCE_FRONT3, 182 DMX_SOURCE_DVR0 = 16, 183 DMX_SOURCE_DVR1, 184 DMX_SOURCE_DVR2, 185 DMX_SOURCE_DVR3 186} dmx_source_t; 187</programlisting> 188</section> 189 190</section> 191<section id="dmx_fcalls"> 192<title>Demux Function Calls</title> 193 194<section id="dmx_fopen"> 195<title>open()</title> 196<para>DESCRIPTION 197</para> 198<informaltable><tgroup cols="1"><tbody><row><entry 199 align="char"> 200<para>This system call, used with a device name of /dev/dvb/adapter0/demux0, 201 allocates a new filter and returns a handle which can be used for subsequent 202 control of that filter. This call has to be made for each filter to be used, i.e. every 203 returned file descriptor is a reference to a single filter. /dev/dvb/adapter0/dvr0 204 is a logical device to be used for retrieving Transport Streams for digital 205 video recording. When reading from this device a transport stream containing 206 the packets from all PES filters set in the corresponding demux device 207 (/dev/dvb/adapter0/demux0) having the output set to DMX_OUT_TS_TAP. A 208 recorded Transport Stream is replayed by writing to this device. </para> 209<para>The significance of blocking or non-blocking mode is described in the 210 documentation for functions where there is a difference. It does not affect the 211 semantics of the open() call itself. A device opened in blocking mode can later 212 be put into non-blocking mode (and vice versa) using the F_SETFL command 213 of the fcntl system call.</para> 214</entry> 215 </row></tbody></tgroup></informaltable> 216<para>SYNOPSIS 217</para> 218<informaltable><tgroup cols="1"><tbody><row><entry 219 align="char"> 220<para>int open(const char ⋆deviceName, int flags);</para> 221</entry> 222 </row></tbody></tgroup></informaltable> 223<para>PARAMETERS 224</para> 225<informaltable><tgroup cols="2"><tbody><row><entry 226 align="char"> 227<para>const char 228 *deviceName</para> 229</entry><entry 230 align="char"> 231<para>Name of demux device.</para> 232</entry> 233 </row><row><entry 234 align="char"> 235<para>int flags</para> 236</entry><entry 237 align="char"> 238<para>A bit-wise OR of the following flags:</para> 239</entry> 240 </row><row><entry 241 align="char"> 242</entry><entry 243 align="char"> 244<para>O_RDWR read/write access</para> 245</entry> 246 </row><row><entry 247 align="char"> 248</entry><entry 249 align="char"> 250<para>O_NONBLOCK open in non-blocking mode</para> 251</entry> 252 </row><row><entry 253 align="char"> 254</entry><entry 255 align="char"> 256<para>(blocking mode is the default)</para> 257</entry> 258 </row></tbody></tgroup></informaltable> 259<para>RETURN VALUE</para> 260<informaltable><tgroup cols="2"><tbody><row><entry 261 align="char"> 262<para>ENODEV</para> 263</entry><entry 264 align="char"> 265<para>Device driver not loaded/available.</para> 266</entry> 267 </row><row><entry 268 align="char"> 269<para>EINVAL</para> 270</entry><entry 271 align="char"> 272<para>Invalid argument.</para> 273</entry> 274 </row><row><entry 275 align="char"> 276<para>EMFILE</para> 277</entry><entry 278 align="char"> 279<para>“Too many open files”, i.e. no more filters available.</para> 280</entry> 281 </row><row><entry 282 align="char"> 283<para>ENOMEM</para> 284</entry><entry 285 align="char"> 286<para>The driver failed to allocate enough memory.</para> 287</entry> 288 </row></tbody></tgroup></informaltable> 289</section> 290 291<section id="dmx_fclose"> 292<title>close()</title> 293<para>DESCRIPTION 294</para> 295<informaltable><tgroup cols="1"><tbody><row><entry 296 align="char"> 297<para>This system call deactivates and deallocates a filter that was previously 298 allocated via the open() call.</para> 299</entry> 300 </row></tbody></tgroup></informaltable> 301<para>SYNOPSIS 302</para> 303<informaltable><tgroup cols="1"><tbody><row><entry 304 align="char"> 305<para>int close(int fd);</para> 306</entry> 307 </row></tbody></tgroup></informaltable> 308<para>PARAMETERS 309</para> 310<informaltable><tgroup cols="2"><tbody><row><entry 311 align="char"> 312<para>int fd</para> 313</entry><entry 314 align="char"> 315<para>File descriptor returned by a previous call to open().</para> 316</entry> 317 </row></tbody></tgroup></informaltable> 318<para>RETURN VALUE</para> 319<informaltable><tgroup cols="2"><tbody><row><entry 320 align="char"> 321<para>EBADF</para> 322</entry><entry 323 align="char"> 324<para>fd is not a valid open file descriptor.</para> 325</entry> 326 </row></tbody></tgroup></informaltable> 327</section> 328 329<section id="dmx_fread"> 330<title>read()</title> 331<para>DESCRIPTION 332</para> 333<informaltable><tgroup cols="1"><tbody><row><entry 334 align="char"> 335<para>This system call returns filtered data, which might be section or PES data. The 336 filtered data is transferred from the driver’s internal circular buffer to buf. The 337 maximum amount of data to be transferred is implied by count.</para> 338</entry> 339 </row><row><entry 340 align="char"> 341<para>When returning section data the driver always tries to return a complete single 342 section (even though buf would provide buffer space for more data). If the size 343 of the buffer is smaller than the section as much as possible will be returned, 344 and the remaining data will be provided in subsequent calls.</para> 345</entry> 346 </row><row><entry 347 align="char"> 348<para>The size of the internal buffer is 2 * 4096 bytes (the size of two maximum 349 sized sections) by default. The size of this buffer may be changed by using the 350 DMX_SET_BUFFER_SIZE function. If the buffer is not large enough, or if 351 the read operations are not performed fast enough, this may result in a buffer 352 overflow error. In this case EOVERFLOW will be returned, and the circular 353 buffer will be emptied. This call is blocking if there is no data to return, i.e. the 354 process will be put to sleep waiting for data, unless the O_NONBLOCK flag 355 is specified.</para> 356</entry> 357 </row><row><entry 358 align="char"> 359<para>Note that in order to be able to read, the filtering process has to be started 360 by defining either a section or a PES filter by means of the ioctl functions, 361 and then starting the filtering process via the DMX_START ioctl function 362 or by setting the DMX_IMMEDIATE_START flag. If the reading is done 363 from a logical DVR demux device, the data will constitute a Transport Stream 364 including the packets from all PES filters in the corresponding demux device 365 /dev/dvb/adapter0/demux0 having the output set to DMX_OUT_TS_TAP.</para> 366</entry> 367 </row></tbody></tgroup></informaltable> 368<para>SYNOPSIS 369</para> 370<informaltable><tgroup cols="1"><tbody><row><entry 371 align="char"> 372<para>size_t read(int fd, void ⋆buf, size_t count);</para> 373</entry> 374 </row></tbody></tgroup></informaltable> 375<para>PARAMETERS 376</para> 377<informaltable><tgroup cols="2"><tbody><row><entry 378 align="char"> 379<para>int fd</para> 380</entry><entry 381 align="char"> 382<para>File descriptor returned by a previous call to open().</para> 383</entry> 384 </row><row><entry 385 align="char"> 386<para>void *buf</para> 387</entry><entry 388 align="char"> 389<para>Pointer to the buffer to be used for returned filtered data.</para> 390</entry> 391 </row><row><entry 392 align="char"> 393<para>size_t count</para> 394</entry><entry 395 align="char"> 396<para>Size of buf.</para> 397</entry> 398 </row></tbody></tgroup></informaltable> 399<para>RETURN VALUE</para> 400<informaltable><tgroup cols="2"><tbody><row><entry 401 align="char"> 402<para>EWOULDBLOCK</para> 403</entry><entry 404 align="char"> 405<para>No data to return and O_NONBLOCK was specified.</para> 406</entry> 407 </row><row><entry 408 align="char"> 409<para>EBADF</para> 410</entry><entry 411 align="char"> 412<para>fd is not a valid open file descriptor.</para> 413</entry> 414 </row><row><entry 415 align="char"> 416<para>ECRC</para> 417</entry><entry 418 align="char"> 419<para>Last section had a CRC error - no data returned. The 420 buffer is flushed.</para> 421</entry> 422 </row><row><entry 423 align="char"> 424<para>EOVERFLOW</para> 425</entry><entry 426 align="char"> 427</entry> 428 </row><row><entry 429 align="char"> 430</entry><entry 431 align="char"> 432<para>The filtered data was not read from the buffer in due 433 time, resulting in non-read data being lost. The buffer is 434 flushed.</para> 435</entry> 436 </row><row><entry 437 align="char"> 438<para>ETIMEDOUT</para> 439</entry><entry 440 align="char"> 441<para>The section was not loaded within the stated timeout 442 period. See ioctl DMX_SET_FILTER for how to set a 443 timeout.</para> 444</entry> 445 </row><row><entry 446 align="char"> 447<para>EFAULT</para> 448</entry><entry 449 align="char"> 450<para>The driver failed to write to the callers buffer due to an 451 invalid *buf pointer.</para> 452</entry> 453 </row></tbody></tgroup></informaltable> 454</section> 455 456<section id="dmx_fwrite"> 457<title>write()</title> 458<para>DESCRIPTION 459</para> 460<informaltable><tgroup cols="1"><tbody><row><entry 461 align="char"> 462<para>This system call is only provided by the logical device /dev/dvb/adapter0/dvr0, 463 associated with the physical demux device that provides the actual DVR 464 functionality. It is used for replay of a digitally recorded Transport Stream. 465 Matching filters have to be defined in the corresponding physical demux 466 device, /dev/dvb/adapter0/demux0. The amount of data to be transferred is 467 implied by count.</para> 468</entry> 469 </row></tbody></tgroup></informaltable> 470<para>SYNOPSIS 471</para> 472<informaltable><tgroup cols="1"><tbody><row><entry 473 align="char"> 474<para>ssize_t write(int fd, const void ⋆buf, size_t 475 count);</para> 476</entry> 477 </row></tbody></tgroup></informaltable> 478<para>PARAMETERS 479</para> 480<informaltable><tgroup cols="2"><tbody><row><entry 481 align="char"> 482<para>int fd</para> 483</entry><entry 484 align="char"> 485<para>File descriptor returned by a previous call to open().</para> 486</entry> 487 </row><row><entry 488 align="char"> 489<para>void *buf</para> 490</entry><entry 491 align="char"> 492<para>Pointer to the buffer containing the Transport Stream.</para> 493</entry> 494 </row><row><entry 495 align="char"> 496<para>size_t count</para> 497</entry><entry 498 align="char"> 499<para>Size of buf.</para> 500</entry> 501 </row></tbody></tgroup></informaltable> 502<para>RETURN VALUE</para> 503<informaltable><tgroup cols="2"><tbody><row><entry 504 align="char"> 505<para>EWOULDBLOCK</para> 506</entry><entry 507 align="char"> 508<para>No data was written. This 509 might happen if O_NONBLOCK was specified and there 510 is no more buffer space available (if O_NONBLOCK is 511 not specified the function will block until buffer space is 512 available).</para> 513</entry> 514 </row><row><entry 515 align="char"> 516<para>EBUSY</para> 517</entry><entry 518 align="char"> 519<para>This error code indicates that there are conflicting 520 requests. The corresponding demux device is setup to 521 receive data from the front- end. Make sure that these 522 filters are stopped and that the filters with input set to 523 DMX_IN_DVR are started.</para> 524</entry> 525 </row><row><entry 526 align="char"> 527<para>EBADF</para> 528</entry><entry 529 align="char"> 530<para>fd is not a valid open file descriptor.</para> 531</entry> 532 </row></tbody></tgroup></informaltable> 533</section> 534 535<section id="DMX_START"> 536<title>DMX_START</title> 537<para>DESCRIPTION 538</para> 539<informaltable><tgroup cols="1"><tbody><row><entry 540 align="char"> 541<para>This ioctl call is used to start the actual filtering operation defined via the ioctl 542 calls DMX_SET_FILTER or DMX_SET_PES_FILTER.</para> 543</entry> 544 </row></tbody></tgroup></informaltable> 545<para>SYNOPSIS 546</para> 547<informaltable><tgroup cols="1"><tbody><row><entry 548 align="char"> 549<para>int ioctl( int fd, int request = DMX_START);</para> 550</entry> 551 </row></tbody></tgroup></informaltable> 552<para>PARAMETERS 553</para> 554<informaltable><tgroup cols="2"><tbody><row><entry 555 align="char"> 556<para>int fd</para> 557</entry><entry 558 align="char"> 559<para>File descriptor returned by a previous call to open().</para> 560</entry> 561 </row><row><entry 562 align="char"> 563<para>int request</para> 564</entry><entry 565 align="char"> 566<para>Equals DMX_START for this command.</para> 567</entry> 568 </row></tbody></tgroup></informaltable> 569&return-value-dvb; 570<informaltable><tgroup cols="2"><tbody><row><entry 571 align="char"> 572<para>EINVAL</para> 573</entry><entry 574 align="char"> 575<para>Invalid argument, i.e. no filtering parameters provided via 576 the DMX_SET_FILTER or DMX_SET_PES_FILTER 577 functions.</para> 578</entry> 579 </row><row><entry 580 align="char"> 581<para>EBUSY</para> 582</entry><entry 583 align="char"> 584<para>This error code indicates that there are conflicting 585 requests. There are active filters filtering data from 586 another input source. Make sure that these filters are 587 stopped before starting this filter.</para> 588</entry> 589 </row></tbody></tgroup></informaltable> 590</section> 591 592<section id="DMX_STOP"> 593<title>DMX_STOP</title> 594<para>DESCRIPTION 595</para> 596<informaltable><tgroup cols="1"><tbody><row><entry 597 align="char"> 598<para>This ioctl call is used to stop the actual filtering operation defined via the 599 ioctl calls DMX_SET_FILTER or DMX_SET_PES_FILTER and started via 600 the DMX_START command.</para> 601</entry> 602 </row></tbody></tgroup></informaltable> 603<para>SYNOPSIS 604</para> 605<informaltable><tgroup cols="1"><tbody><row><entry 606 align="char"> 607<para>int ioctl( int fd, int request = DMX_STOP);</para> 608</entry> 609 </row></tbody></tgroup></informaltable> 610<para>PARAMETERS 611</para> 612<informaltable><tgroup cols="2"><tbody><row><entry 613 align="char"> 614<para>int fd</para> 615</entry><entry 616 align="char"> 617<para>File descriptor returned by a previous call to open().</para> 618</entry> 619 </row><row><entry 620 align="char"> 621<para>int request</para> 622</entry><entry 623 align="char"> 624<para>Equals DMX_STOP for this command.</para> 625</entry> 626 </row></tbody></tgroup></informaltable> 627&return-value-dvb; 628</section> 629 630<section id="DMX_SET_FILTER"> 631<title>DMX_SET_FILTER</title> 632<para>DESCRIPTION 633</para> 634<informaltable><tgroup cols="1"><tbody><row><entry 635 align="char"> 636<para>This ioctl call sets up a filter according to the filter and mask parameters 637 provided. A timeout may be defined stating number of seconds to wait for a 638 section to be loaded. A value of 0 means that no timeout should be applied. 639 Finally there is a flag field where it is possible to state whether a section should 640 be CRC-checked, whether the filter should be a ”one-shot” filter, i.e. if the 641 filtering operation should be stopped after the first section is received, and 642 whether the filtering operation should be started immediately (without waiting 643 for a DMX_START ioctl call). If a filter was previously set-up, this filter will 644 be canceled, and the receive buffer will be flushed.</para> 645</entry> 646 </row></tbody></tgroup></informaltable> 647<para>SYNOPSIS 648</para> 649<informaltable><tgroup cols="1"><tbody><row><entry 650 align="char"> 651<para>int ioctl( int fd, int request = DMX_SET_FILTER, 652 struct dmx_sct_filter_params ⋆params);</para> 653</entry> 654 </row></tbody></tgroup></informaltable> 655<para>PARAMETERS 656</para> 657<informaltable><tgroup cols="2"><tbody><row><entry 658 align="char"> 659<para>int fd</para> 660</entry><entry 661 align="char"> 662<para>File descriptor returned by a previous call to open().</para> 663</entry> 664 </row><row><entry 665 align="char"> 666<para>int request</para> 667</entry><entry 668 align="char"> 669<para>Equals DMX_SET_FILTER for this command.</para> 670</entry> 671 </row><row><entry 672 align="char"> 673<para>struct 674 dmx_sct_filter_params 675 *params</para> 676</entry><entry 677 align="char"> 678<para>Pointer to structure containing filter parameters.</para> 679</entry> 680 </row></tbody></tgroup></informaltable> 681&return-value-dvb; 682</section> 683 684<section id="DMX_SET_PES_FILTER"> 685<title>DMX_SET_PES_FILTER</title> 686<para>DESCRIPTION 687</para> 688<informaltable><tgroup cols="1"><tbody><row><entry 689 align="char"> 690<para>This ioctl call sets up a PES filter according to the parameters provided. By a 691 PES filter is meant a filter that is based just on the packet identifier (PID), i.e. 692 no PES header or payload filtering capability is supported.</para> 693</entry> 694 </row><row><entry 695 align="char"> 696<para>The transport stream destination for the filtered output may be set. Also the 697 PES type may be stated in order to be able to e.g. direct a video stream directly 698 to the video decoder. Finally there is a flag field where it is possible to state 699 whether the filtering operation should be started immediately (without waiting 700 for a DMX_START ioctl call). If a filter was previously set-up, this filter will 701 be cancelled, and the receive buffer will be flushed.</para> 702</entry> 703 </row></tbody></tgroup></informaltable> 704<para>SYNOPSIS 705</para> 706<informaltable><tgroup cols="1"><tbody><row><entry 707 align="char"> 708<para>int ioctl( int fd, int request = DMX_SET_PES_FILTER, 709 struct dmx_pes_filter_params ⋆params);</para> 710</entry> 711 </row></tbody></tgroup></informaltable> 712<para>PARAMETERS 713</para> 714<informaltable><tgroup cols="2"><tbody><row><entry 715 align="char"> 716<para>int fd</para> 717</entry><entry 718 align="char"> 719<para>File descriptor returned by a previous call to open().</para> 720</entry> 721 </row><row><entry 722 align="char"> 723<para>int request</para> 724</entry><entry 725 align="char"> 726<para>Equals DMX_SET_PES_FILTER for this command.</para> 727</entry> 728 </row><row><entry 729 align="char"> 730<para>struct 731 dmx_pes_filter_params 732 *params</para> 733</entry><entry 734 align="char"> 735<para>Pointer to structure containing filter parameters.</para> 736</entry> 737 </row></tbody></tgroup></informaltable> 738&return-value-dvb; 739<informaltable><tgroup cols="2"><tbody><row><entry 740 align="char"> 741<para>EBUSY</para> 742</entry><entry 743 align="char"> 744<para>This error code indicates that there are conflicting 745 requests. There are active filters filtering data from 746 another input source. Make sure that these filters are 747 stopped before starting this filter.</para> 748</entry> 749 </row></tbody></tgroup></informaltable> 750</section> 751 752<section id="DMX_SET_BUFFER_SIZE"> 753<title>DMX_SET_BUFFER_SIZE</title> 754<para>DESCRIPTION 755</para> 756<informaltable><tgroup cols="1"><tbody><row><entry 757 align="char"> 758<para>This ioctl call is used to set the size of the circular buffer used for filtered data. 759 The default size is two maximum sized sections, i.e. if this function is not called 760 a buffer size of 2 * 4096 bytes will be used.</para> 761</entry> 762 </row></tbody></tgroup></informaltable> 763<para>SYNOPSIS 764</para> 765<informaltable><tgroup cols="1"><tbody><row><entry 766 align="char"> 767<para>int ioctl( int fd, int request = 768 DMX_SET_BUFFER_SIZE, unsigned long size);</para> 769</entry> 770 </row></tbody></tgroup></informaltable> 771<para>PARAMETERS 772</para> 773<informaltable><tgroup cols="2"><tbody><row><entry 774 align="char"> 775<para>int fd</para> 776</entry><entry 777 align="char"> 778<para>File descriptor returned by a previous call to open().</para> 779</entry> 780 </row><row><entry 781 align="char"> 782<para>int request</para> 783</entry><entry 784 align="char"> 785<para>Equals DMX_SET_BUFFER_SIZE for this command.</para> 786</entry> 787 </row><row><entry 788 align="char"> 789<para>unsigned long size</para> 790</entry><entry 791 align="char"> 792<para>Size of circular buffer.</para> 793</entry> 794 </row></tbody></tgroup></informaltable> 795&return-value-dvb; 796</section> 797 798<section id="DMX_GET_EVENT"> 799<title>DMX_GET_EVENT</title> 800<para>DESCRIPTION 801</para> 802<informaltable><tgroup cols="1"><tbody><row><entry 803 align="char"> 804<para>This ioctl call returns an event if available. If an event is not available, 805 the behavior depends on whether the device is in blocking or non-blocking 806 mode. In the latter case, the call fails immediately with errno set to 807 EWOULDBLOCK. In the former case, the call blocks until an event becomes 808 available.</para> 809</entry> 810 </row><row><entry 811 align="char"> 812<para>The standard Linux poll() and/or select() system calls can be used with the 813 device file descriptor to watch for new events. For select(), the file descriptor 814 should be included in the exceptfds argument, and for poll(), POLLPRI should 815 be specified as the wake-up condition. Only the latest event for each filter is 816 saved.</para> 817</entry> 818 </row></tbody></tgroup></informaltable> 819<para>SYNOPSIS 820</para> 821<informaltable><tgroup cols="1"><tbody><row><entry 822 align="char"> 823<para>int ioctl( int fd, int request = DMX_GET_EVENT, 824 struct dmx_event ⋆ev);</para> 825</entry> 826 </row></tbody></tgroup></informaltable> 827<para>PARAMETERS 828</para> 829<informaltable><tgroup cols="2"><tbody><row><entry 830 align="char"> 831<para>int fd</para> 832</entry><entry 833 align="char"> 834<para>File descriptor returned by a previous call to open().</para> 835</entry> 836 </row><row><entry 837 align="char"> 838<para>int request</para> 839</entry><entry 840 align="char"> 841<para>Equals DMX_GET_EVENT for this command.</para> 842</entry> 843 </row><row><entry 844 align="char"> 845<para>struct dmx_event *ev</para> 846</entry><entry 847 align="char"> 848<para>Pointer to the location where the event is to be stored.</para> 849</entry> 850 </row></tbody></tgroup></informaltable> 851&return-value-dvb; 852<informaltable><tgroup cols="2"><tbody><row><entry 853 align="char"> 854<para>EWOULDBLOCK</para> 855</entry><entry 856 align="char"> 857<para>There is no event pending, and the device is in 858 non-blocking mode.</para> 859</entry> 860 </row></tbody></tgroup></informaltable> 861</section> 862 863<section id="DMX_GET_STC"> 864<title>DMX_GET_STC</title> 865<para>DESCRIPTION 866</para> 867<informaltable><tgroup cols="1"><tbody><row><entry 868 align="char"> 869<para>This ioctl call returns the current value of the system time counter (which is driven 870 by a PES filter of type DMX_PES_PCR). Some hardware supports more than one 871 STC, so you must specify which one by setting the num field of stc before the ioctl 872 (range 0...n). The result is returned in form of a ratio with a 64 bit numerator 873 and a 32 bit denominator, so the real 90kHz STC value is stc->stc / 874 stc->base 875 .</para> 876</entry> 877 </row></tbody></tgroup></informaltable> 878<para>SYNOPSIS 879</para> 880<informaltable><tgroup cols="1"><tbody><row><entry 881 align="char"> 882<para>int ioctl( int fd, int request = DMX_GET_STC, struct 883 dmx_stc ⋆stc);</para> 884</entry> 885 </row></tbody></tgroup></informaltable> 886<para>PARAMETERS 887</para> 888<informaltable><tgroup cols="2"><tbody><row><entry 889 align="char"> 890<para>int fd</para> 891</entry><entry 892 align="char"> 893<para>File descriptor returned by a previous call to open().</para> 894</entry> 895 </row><row><entry 896 align="char"> 897<para>int request</para> 898</entry><entry 899 align="char"> 900<para>Equals DMX_GET_STC for this command.</para> 901</entry> 902 </row><row><entry 903 align="char"> 904<para>struct dmx_stc *stc</para> 905</entry><entry 906 align="char"> 907<para>Pointer to the location where the stc is to be stored.</para> 908</entry> 909 </row></tbody></tgroup></informaltable> 910&return-value-dvb; 911<informaltable><tgroup cols="2"><tbody><row><entry 912 align="char"> 913<para>EINVAL</para> 914</entry><entry 915 align="char"> 916<para>Invalid stc number.</para> 917</entry> 918 </row></tbody></tgroup></informaltable> 919 </section> 920 921<section id="DMX_GET_PES_PIDS" 922role="subsection"><title>DMX_GET_PES_PIDS</title> 923<para>DESCRIPTION 924</para> 925<informaltable><tgroup cols="1"><tbody><row><entry 926 align="char"> 927<para>This ioctl is undocumented. Documentation is welcome.</para> 928</entry> 929 </row></tbody></tgroup></informaltable> 930<para>SYNOPSIS 931</para> 932<informaltable><tgroup cols="1"><tbody><row><entry 933 align="char"> 934<para>int ioctl(fd, int request = DMX_GET_PES_PIDS, 935 __u16[5]);</para> 936</entry> 937 </row></tbody></tgroup></informaltable> 938<para>PARAMETERS 939</para> 940<informaltable><tgroup cols="2"><tbody><row><entry 941 align="char"> 942<para>int fd</para> 943</entry><entry 944 align="char"> 945<para>File descriptor returned by a previous call to open().</para> 946</entry> 947 </row><row><entry 948 align="char"> 949<para>int request</para> 950</entry><entry 951 align="char"> 952<para>Equals DMX_GET_PES_PIDS for this command.</para> 953</entry> 954 </row><row><entry 955 align="char"> 956<para>__u16[5] 957</para> 958</entry><entry 959 align="char"> 960<para>Undocumented.</para> 961</entry> 962 </row></tbody></tgroup></informaltable> 963&return-value-dvb; 964</section> 965 966<section id="DMX_GET_CAPS" 967role="subsection"><title>DMX_GET_CAPS</title> 968<para>DESCRIPTION 969</para> 970<informaltable><tgroup cols="1"><tbody><row><entry 971 align="char"> 972<para>This ioctl is undocumented. Documentation is welcome.</para> 973</entry> 974 </row></tbody></tgroup></informaltable> 975<para>SYNOPSIS 976</para> 977<informaltable><tgroup cols="1"><tbody><row><entry 978 align="char"> 979<para>int ioctl(fd, int request = DMX_GET_CAPS, 980 dmx_caps_t *);</para> 981</entry> 982 </row></tbody></tgroup></informaltable> 983<para>PARAMETERS 984</para> 985<informaltable><tgroup cols="2"><tbody><row><entry 986 align="char"> 987<para>int fd</para> 988</entry><entry 989 align="char"> 990<para>File descriptor returned by a previous call to open().</para> 991</entry> 992 </row><row><entry 993 align="char"> 994<para>int request</para> 995</entry><entry 996 align="char"> 997<para>Equals DMX_GET_CAPS for this command.</para> 998</entry> 999 </row><row><entry 1000 align="char"> 1001<para>dmx_caps_t * 1002</para> 1003</entry><entry 1004 align="char"> 1005<para>Undocumented.</para> 1006</entry> 1007 </row></tbody></tgroup></informaltable> 1008&return-value-dvb; 1009</section> 1010 1011<section id="DMX_SET_SOURCE" 1012role="subsection"><title>DMX_SET_SOURCE</title> 1013<para>DESCRIPTION 1014</para> 1015<informaltable><tgroup cols="1"><tbody><row><entry 1016 align="char"> 1017<para>This ioctl is undocumented. Documentation is welcome.</para> 1018</entry> 1019 </row></tbody></tgroup></informaltable> 1020<para>SYNOPSIS 1021</para> 1022<informaltable><tgroup cols="1"><tbody><row><entry 1023 align="char"> 1024<para>int ioctl(fd, int request = DMX_SET_SOURCE, 1025 dmx_source_t *);</para> 1026</entry> 1027 </row></tbody></tgroup></informaltable> 1028<para>PARAMETERS 1029</para> 1030<informaltable><tgroup cols="2"><tbody><row><entry 1031 align="char"> 1032<para>int fd</para> 1033</entry><entry 1034 align="char"> 1035<para>File descriptor returned by a previous call to open().</para> 1036</entry> 1037 </row><row><entry 1038 align="char"> 1039<para>int request</para> 1040</entry><entry 1041 align="char"> 1042<para>Equals DMX_SET_SOURCE for this command.</para> 1043</entry> 1044 </row><row><entry 1045 align="char"> 1046<para>dmx_source_t * 1047</para> 1048</entry><entry 1049 align="char"> 1050<para>Undocumented.</para> 1051</entry> 1052 </row></tbody></tgroup></informaltable> 1053&return-value-dvb; 1054</section> 1055 1056<section id="DMX_ADD_PID" 1057role="subsection"><title>DMX_ADD_PID</title> 1058<para>DESCRIPTION 1059</para> 1060<informaltable><tgroup cols="1"><tbody><row><entry 1061 align="char"> 1062<para>This ioctl call allows to add multiple PIDs to a transport stream filter 1063previously set up with DMX_SET_PES_FILTER and output equal to DMX_OUT_TSDEMUX_TAP. 1064</para></entry></row><row><entry align="char"><para> 1065It is used by readers of /dev/dvb/adapterX/demuxY. 1066</para></entry></row><row><entry align="char"><para> 1067It may be called at any time, i.e. before or after the first filter on the 1068shared file descriptor was started. It makes it possible to record multiple 1069services without the need to de-multiplex or re-multiplex TS packets.</para> 1070</entry> 1071 </row></tbody></tgroup></informaltable> 1072<para>SYNOPSIS 1073</para> 1074<informaltable><tgroup cols="1"><tbody><row><entry 1075 align="char"> 1076<para>int ioctl(fd, int request = DMX_ADD_PID, 1077 __u16 *);</para> 1078</entry> 1079 </row></tbody></tgroup></informaltable> 1080<para>PARAMETERS 1081</para> 1082<informaltable><tgroup cols="2"><tbody><row><entry 1083 align="char"> 1084<para>int fd</para> 1085</entry><entry 1086 align="char"> 1087<para>File descriptor returned by a previous call to open().</para> 1088</entry> 1089 </row><row><entry 1090 align="char"> 1091<para>int request</para> 1092</entry><entry 1093 align="char"> 1094<para>Equals DMX_ADD_PID for this command.</para> 1095</entry> 1096 </row><row><entry 1097 align="char"> 1098<para>__u16 * 1099</para> 1100</entry><entry 1101 align="char"> 1102<para>PID number to be filtered.</para> 1103</entry> 1104 </row></tbody></tgroup></informaltable> 1105&return-value-dvb; 1106</section> 1107 1108<section id="DMX_REMOVE_PID" 1109role="subsection"><title>DMX_REMOVE_PID</title> 1110<para>DESCRIPTION 1111</para> 1112<informaltable><tgroup cols="1"><tbody><row><entry 1113 align="char"> 1114<para>This ioctl call allows to remove a PID when multiple PIDs are set on a 1115transport stream filter, e. g. a filter previously set up with output equal to 1116DMX_OUT_TSDEMUX_TAP, created via either DMX_SET_PES_FILTER or DMX_ADD_PID. 1117</para></entry></row><row><entry align="char"><para> 1118It is used by readers of /dev/dvb/adapterX/demuxY. 1119</para></entry></row><row><entry align="char"><para> 1120It may be called at any time, i.e. before or after the first filter on the 1121shared file descriptor was started. It makes it possible to record multiple 1122services without the need to de-multiplex or re-multiplex TS packets.</para> 1123</entry> 1124 </row></tbody></tgroup></informaltable> 1125<para>SYNOPSIS 1126</para> 1127<informaltable><tgroup cols="1"><tbody><row><entry 1128 align="char"> 1129<para>int ioctl(fd, int request = DMX_REMOVE_PID, 1130 __u16 *);</para> 1131</entry> 1132 </row></tbody></tgroup></informaltable> 1133<para>PARAMETERS 1134</para> 1135<informaltable><tgroup cols="2"><tbody><row><entry 1136 align="char"> 1137<para>int fd</para> 1138</entry><entry 1139 align="char"> 1140<para>File descriptor returned by a previous call to open().</para> 1141</entry> 1142 </row><row><entry 1143 align="char"> 1144<para>int request</para> 1145</entry><entry 1146 align="char"> 1147<para>Equals DMX_REMOVE_PID for this command.</para> 1148</entry> 1149 </row><row><entry 1150 align="char"> 1151<para>__u16 * 1152</para> 1153</entry><entry 1154 align="char"> 1155<para>PID of the PES filter to be removed.</para> 1156</entry> 1157 </row></tbody></tgroup></informaltable> 1158&return-value-dvb; 1159</section> 1160 1161 1162</section> 1163