Documentation/DocBook/media/dvb/demux.xml

   1 <title>DVB Demux Device</title>
   2
   3 <para>The DVB demux device controls the filters of the DVB hardware/software. It can be
   4 accessed through <constant>/dev/adapter?/demux?</constant>. Data types and and ioctl definitions can be
   5 accessed 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>dmx_output_t</title>
  12 <programlisting>
  13 typedef enum
  14 {
  15         DMX_OUT_DECODER, /&#x22C6; Streaming directly to decoder. &#x22C6;/
  16         DMX_OUT_TAP,     /&#x22C6; Output going to a memory buffer &#x22C6;/
  17                          /&#x22C6; (to be retrieved via the read command).&#x22C6;/
  18         DMX_OUT_TS_TAP,  /&#x22C6; Output multiplexed into a new TS  &#x22C6;/
  19                          /&#x22C6; (to be retrieved by reading from the &#x22C6;/
  20                          /&#x22C6; logical DVR device).                 &#x22C6;/
  21         DMX_OUT_TSDEMUX_TAP /&#x22C6; Like TS_TAP but retrieved from the DMX device &#x22C6;/
  22 } dmx_output_t;
  23 </programlisting>
  24 <para><constant>DMX_OUT_TAP</constant> delivers the stream output to the demux device on which the ioctl is
  25 called.
  26 </para>
  27 <para><constant>DMX_OUT_TS_TAP</constant> routes output to the logical DVR device <constant>/dev/dvb/adapter?/dvr?</constant>,
  28 which delivers a TS multiplexed from all filters for which <constant>DMX_OUT_TS_TAP</constant> was
  29 specified.
  30 </para>
  31 </section>
  32
  33 <section id="dmx-input-t">
  34 <title>dmx_input_t</title>
  35 <programlisting>
  36 typedef enum
  37 {
  38         DMX_IN_FRONTEND, /&#x22C6; Input from a front-end device.  &#x22C6;/
  39         DMX_IN_DVR       /&#x22C6; Input from the logical DVR device.  &#x22C6;/
  40 } dmx_input_t;
  41 </programlisting>
  42 </section>
  43
  44 <section id="dmx-pes-type-t">
  45 <title>dmx_pes_type_t</title>
  46 <programlisting>
  47 typedef enum
  48 {
  49         DMX_PES_AUDIO0,
  50         DMX_PES_VIDEO0,
  51         DMX_PES_TELETEXT0,
  52         DMX_PES_SUBTITLE0,
  53         DMX_PES_PCR0,
  54
  55         DMX_PES_AUDIO1,
  56         DMX_PES_VIDEO1,
  57         DMX_PES_TELETEXT1,
  58         DMX_PES_SUBTITLE1,
  59         DMX_PES_PCR1,
  60
  61         DMX_PES_AUDIO2,
  62         DMX_PES_VIDEO2,
  63         DMX_PES_TELETEXT2,
  64         DMX_PES_SUBTITLE2,
  65         DMX_PES_PCR2,
  66
  67         DMX_PES_AUDIO3,
  68         DMX_PES_VIDEO3,
  69         DMX_PES_TELETEXT3,
  70         DMX_PES_SUBTITLE3,
  71         DMX_PES_PCR3,
  72
  73         DMX_PES_OTHER
  74 } dmx_pes_type_t;
  75 </programlisting>
  76 </section>
  77
  78 <section id="dmx-filter">
  79 <title>struct dmx_filter</title>
  80  <programlisting>
  81  typedef struct dmx_filter
  82 {
  83         __u8  filter[DMX_FILTER_SIZE];
  84         __u8  mask[DMX_FILTER_SIZE];
  85         __u8  mode[DMX_FILTER_SIZE];
  86 } dmx_filter_t;
  87 </programlisting>
  88 </section>
  89
  90 <section id="dmx-sct-filter-params">
  91 <title>struct dmx_sct_filter_params</title>
  92 <programlisting>
  93 struct dmx_sct_filter_params
  94 {
  95         __u16          pid;
  96         dmx_filter_t   filter;
  97         __u32          timeout;
  98         __u32          flags;
  99 #define DMX_CHECK_CRC       1
 100 #define DMX_ONESHOT         2
 101 #define DMX_IMMEDIATE_START 4
 102 #define DMX_KERNEL_CLIENT   0x8000
 103 };
 104 </programlisting>
 105 </section>
 106
 107 <section id="dmx-pes-filter-params">
 108 <title>struct dmx_pes_filter_params</title>
 109 <programlisting>
 110 struct dmx_pes_filter_params
 111 {
 112         __u16          pid;
 113         dmx_input_t    input;
 114         dmx_output_t   output;
 115         dmx_pes_type_t pes_type;
 116         __u32          flags;
 117 };
 118 </programlisting>
 119 </section>
 120
 121 <section id="dmx-event">
 122 <title>struct dmx_event</title>
 123  <programlisting>
 124  struct dmx_event
 125  {
 126          dmx_event_t          event;
 127          time_t               timeStamp;
 128          union
 129          {
 130                  dmx_scrambling_status_t scrambling;
 131          } u;
 132  };
 133 </programlisting>
 134 </section>
 135
 136 <section id="dmx-stc">
 137 <title>struct dmx_stc</title>
 138 <programlisting>
 139 struct dmx_stc {
 140         unsigned int num;       /&#x22C6; input : which STC? 0..N &#x22C6;/
 141         unsigned int base;      /&#x22C6; output: divisor for stc to get 90 kHz clock &#x22C6;/
 142         __u64 stc;              /&#x22C6; output: stc in 'base'&#x22C6;90 kHz units &#x22C6;/
 143 };
 144 </programlisting>
 145 </section>
 146
 147 <section id="dmx-caps">
 148 <title>struct dmx_caps</title>
 149 <programlisting>
 150  typedef struct dmx_caps {
 151         __u32 caps;
 152         int num_decoders;
 153 } dmx_caps_t;
 154 </programlisting>
 155 </section>
 156
 157 <section id="dmx-source-t">
 158 <title>enum dmx_source_t</title>
 159 <programlisting>
 160 typedef enum {
 161         DMX_SOURCE_FRONT0 = 0,
 162         DMX_SOURCE_FRONT1,
 163         DMX_SOURCE_FRONT2,
 164         DMX_SOURCE_FRONT3,
 165         DMX_SOURCE_DVR0   = 16,
 166         DMX_SOURCE_DVR1,
 167         DMX_SOURCE_DVR2,
 168         DMX_SOURCE_DVR3
 169 } dmx_source_t;
 170 </programlisting>
 171 </section>
 172
 173 </section>
 174 <section id="dmx_fcalls">
 175 <title>Demux Function Calls</title>
 176
 177 <section id="dmx_fopen">
 178 <title>open()</title>
 179 <para>DESCRIPTION
 180 </para>
 181 <informaltable><tgroup cols="1"><tbody><row><entry
 182  align="char">
 183 <para>This system call, used with a device name of /dev/dvb/adapter0/demux0,
 184  allocates a new filter and returns a handle which can be used for subsequent
 185  control of that filter. This call has to be made for each filter to be used, i.e. every
 186  returned file descriptor is a reference to a single filter. /dev/dvb/adapter0/dvr0
 187  is a logical device to be used for retrieving Transport Streams for digital
 188  video recording. When reading from this device a transport stream containing
 189  the packets from all PES filters set in the corresponding demux device
 190  (/dev/dvb/adapter0/demux0) having the output set to DMX_OUT_TS_TAP. A
 191  recorded Transport Stream is replayed by writing to this device. </para>
 192 <para>The significance of blocking or non-blocking mode is described in the
 193  documentation for functions where there is a difference. It does not affect the
 194  semantics of the open() call itself. A device opened in blocking mode can later
 195  be put into non-blocking mode (and vice versa) using the F_SETFL command
 196  of the fcntl system call.</para>
 197 </entry>
 198  </row></tbody></tgroup></informaltable>
 199 <para>SYNOPSIS
 200 </para>
 201 <informaltable><tgroup cols="1"><tbody><row><entry
 202  align="char">
 203 <para>int open(const char &#x22C6;deviceName, int flags);</para>
 204 </entry>
 205  </row></tbody></tgroup></informaltable>
 206 <para>PARAMETERS
 207 </para>
 208 <informaltable><tgroup cols="2"><tbody><row><entry
 209  align="char">
 210 <para>const char
 211  *deviceName</para>
 212 </entry><entry
 213  align="char">
 214 <para>Name of demux device.</para>
 215 </entry>
 216  </row><row><entry
 217  align="char">
 218 <para>int flags</para>
 219 </entry><entry
 220  align="char">
 221 <para>A bit-wise OR of the following flags:</para>
 222 </entry>
 223  </row><row><entry
 224  align="char">
 225 </entry><entry
 226  align="char">
 227 <para>O_RDWR read/write access</para>
 228 </entry>
 229  </row><row><entry
 230  align="char">
 231 </entry><entry
 232  align="char">
 233 <para>O_NONBLOCK open in non-blocking mode</para>
 234 </entry>
 235  </row><row><entry
 236  align="char">
 237 </entry><entry
 238  align="char">
 239 <para>(blocking mode is the default)</para>
 240 </entry>
 241  </row></tbody></tgroup></informaltable>
 242 <para>RETURN VALUE</para>
 243 <informaltable><tgroup cols="2"><tbody><row><entry
 244  align="char">
 245 <para>ENODEV</para>
 246 </entry><entry
 247  align="char">
 248 <para>Device driver not loaded/available.</para>
 249 </entry>
 250  </row><row><entry
 251  align="char">
 252 <para>EINVAL</para>
 253 </entry><entry
 254  align="char">
 255 <para>Invalid argument.</para>
 256 </entry>
 257  </row><row><entry
 258  align="char">
 259 <para>EMFILE</para>
 260 </entry><entry
 261  align="char">
 262 <para>&#8220;Too many open files&#8221;, i.e. no more filters available.</para>
 263 </entry>
 264  </row><row><entry
 265  align="char">
 266 <para>ENOMEM</para>
 267 </entry><entry
 268  align="char">
 269 <para>The driver failed to allocate enough memory.</para>
 270 </entry>
 271  </row></tbody></tgroup></informaltable>
 272 </section>
 273
 274 <section id="dmx_fclose">
 275 <title>close()</title>
 276 <para>DESCRIPTION
 277 </para>
 278 <informaltable><tgroup cols="1"><tbody><row><entry
 279  align="char">
 280 <para>This system call deactivates and deallocates a filter that was previously
 281  allocated via the open() call.</para>
 282 </entry>
 283  </row></tbody></tgroup></informaltable>
 284 <para>SYNOPSIS
 285 </para>
 286 <informaltable><tgroup cols="1"><tbody><row><entry
 287  align="char">
 288 <para>int close(int fd);</para>
 289 </entry>
 290  </row></tbody></tgroup></informaltable>
 291 <para>PARAMETERS
 292 </para>
 293 <informaltable><tgroup cols="2"><tbody><row><entry
 294  align="char">
 295 <para>int fd</para>
 296 </entry><entry
 297  align="char">
 298 <para>File descriptor returned by a previous call to open().</para>
 299 </entry>
 300  </row></tbody></tgroup></informaltable>
 301 <para>RETURN VALUE</para>
 302 <informaltable><tgroup cols="2"><tbody><row><entry
 303  align="char">
 304 <para>EBADF</para>
 305 </entry><entry
 306  align="char">
 307 <para>fd is not a valid open file descriptor.</para>
 308 </entry>
 309  </row></tbody></tgroup></informaltable>
 310 </section>
 311
 312 <section id="dmx_fread">
 313 <title>read()</title>
 314 <para>DESCRIPTION
 315 </para>
 316 <informaltable><tgroup cols="1"><tbody><row><entry
 317  align="char">
 318 <para>This system call returns filtered data, which might be section or PES data. The
 319  filtered data is transferred from the driver&#8217;s internal circular buffer to buf. The
 320  maximum amount of data to be transferred is implied by count.</para>
 321 </entry>
 322  </row><row><entry
 323  align="char">
 324 <para>When returning section data the driver always tries to return a complete single
 325  section (even though buf would provide buffer space for more data). If the size
 326  of the buffer is smaller than the section as much as possible will be returned,
 327  and the remaining data will be provided in subsequent calls.</para>
 328 </entry>
 329  </row><row><entry
 330  align="char">
 331 <para>The size of the internal buffer is 2 * 4096 bytes (the size of two maximum
 332  sized sections) by default. The size of this buffer may be changed by using the
 333  DMX_SET_BUFFER_SIZE function. If the buffer is not large enough, or if
 334  the read operations are not performed fast enough, this may result in a buffer
 335  overflow error. In this case EOVERFLOW will be returned, and the circular
 336  buffer will be emptied. This call is blocking if there is no data to return, i.e. the
 337  process will be put to sleep waiting for data, unless the O_NONBLOCK flag
 338  is specified.</para>
 339 </entry>
 340  </row><row><entry
 341  align="char">
 342 <para>Note that in order to be able to read, the filtering process has to be started
 343  by defining either a section or a PES filter by means of the ioctl functions,
 344  and then starting the filtering process via the DMX_START ioctl function
 345  or by setting the DMX_IMMEDIATE_START flag. If the reading is done
 346  from a logical DVR demux device, the data will constitute a Transport Stream
 347  including the packets from all PES filters in the corresponding demux device
 348  /dev/dvb/adapter0/demux0 having the output set to DMX_OUT_TS_TAP.</para>
 349 </entry>
 350  </row></tbody></tgroup></informaltable>
 351 <para>SYNOPSIS
 352 </para>
 353 <informaltable><tgroup cols="1"><tbody><row><entry
 354  align="char">
 355 <para>size_t read(int fd, void &#x22C6;buf, size_t count);</para>
 356 </entry>
 357  </row></tbody></tgroup></informaltable>
 358 <para>PARAMETERS
 359 </para>
 360 <informaltable><tgroup cols="2"><tbody><row><entry
 361  align="char">
 362 <para>int fd</para>
 363 </entry><entry
 364  align="char">
 365 <para>File descriptor returned by a previous call to open().</para>
 366 </entry>
 367  </row><row><entry
 368  align="char">
 369 <para>void *buf</para>
 370 </entry><entry
 371  align="char">
 372 <para>Pointer to the buffer to be used for returned filtered data.</para>
 373 </entry>
 374  </row><row><entry
 375  align="char">
 376 <para>size_t count</para>
 377 </entry><entry
 378  align="char">
 379 <para>Size of buf.</para>
 380 </entry>
 381  </row></tbody></tgroup></informaltable>
 382 <para>RETURN VALUE</para>
 383 <informaltable><tgroup cols="2"><tbody><row><entry
 384  align="char">
 385 <para>EWOULDBLOCK</para>
 386 </entry><entry
 387  align="char">
 388 <para>No data to return and O_NONBLOCK was specified.</para>
 389 </entry>
 390  </row><row><entry
 391  align="char">
 392 <para>EBADF</para>
 393 </entry><entry
 394  align="char">
 395 <para>fd is not a valid open file descriptor.</para>
 396 </entry>
 397  </row><row><entry
 398  align="char">
 399 <para>ECRC</para>
 400 </entry><entry
 401  align="char">
 402 <para>Last section had a CRC error - no data returned. The
 403  buffer is flushed.</para>
 404 </entry>
 405  </row><row><entry
 406  align="char">
 407 <para>EOVERFLOW</para>
 408 </entry><entry
 409  align="char">
 410 </entry>
 411  </row><row><entry
 412  align="char">
 413 </entry><entry
 414  align="char">
 415 <para>The filtered data was not read from the buffer in due
 416  time, resulting in non-read data being lost. The buffer is
 417  flushed.</para>
 418 </entry>
 419  </row><row><entry
 420  align="char">
 421 <para>ETIMEDOUT</para>
 422 </entry><entry
 423  align="char">
 424 <para>The section was not loaded within the stated timeout
 425  period. See ioctl DMX_SET_FILTER for how to set a
 426  timeout.</para>
 427 </entry>
 428  </row><row><entry
 429  align="char">
 430 <para>EFAULT</para>
 431 </entry><entry
 432  align="char">
 433 <para>The driver failed to write to the callers buffer due to an
 434  invalid *buf pointer.</para>
 435 </entry>
 436  </row></tbody></tgroup></informaltable>
 437 </section>
 438
 439 <section id="dmx_fwrite">
 440 <title>write()</title>
 441 <para>DESCRIPTION
 442 </para>
 443 <informaltable><tgroup cols="1"><tbody><row><entry
 444  align="char">
 445 <para>This system call is only provided by the logical device /dev/dvb/adapter0/dvr0,
 446  associated with the physical demux device that provides the actual DVR
 447  functionality. It is used for replay of a digitally recorded Transport Stream.
 448  Matching filters have to be defined in the corresponding physical demux
 449  device, /dev/dvb/adapter0/demux0. The amount of data to be transferred is
 450  implied by count.</para>
 451 </entry>
 452  </row></tbody></tgroup></informaltable>
 453 <para>SYNOPSIS
 454 </para>
 455 <informaltable><tgroup cols="1"><tbody><row><entry
 456  align="char">
 457 <para>ssize_t write(int fd, const void &#x22C6;buf, size_t
 458  count);</para>
 459 </entry>
 460  </row></tbody></tgroup></informaltable>
 461 <para>PARAMETERS
 462 </para>
 463 <informaltable><tgroup cols="2"><tbody><row><entry
 464  align="char">
 465 <para>int fd</para>
 466 </entry><entry
 467  align="char">
 468 <para>File descriptor returned by a previous call to open().</para>
 469 </entry>
 470  </row><row><entry
 471  align="char">
 472 <para>void *buf</para>
 473 </entry><entry
 474  align="char">
 475 <para>Pointer to the buffer containing the Transport Stream.</para>
 476 </entry>
 477  </row><row><entry
 478  align="char">
 479 <para>size_t count</para>
 480 </entry><entry
 481  align="char">
 482 <para>Size of buf.</para>
 483 </entry>
 484  </row></tbody></tgroup></informaltable>
 485 <para>RETURN VALUE</para>
 486 <informaltable><tgroup cols="2"><tbody><row><entry
 487  align="char">
 488 <para>EWOULDBLOCK</para>
 489 </entry><entry
 490  align="char">
 491 <para>No data was written. This
 492  might happen if O_NONBLOCK was specified and there
 493  is no more buffer space available (if O_NONBLOCK is
 494  not specified the function will block until buffer space is
 495  available).</para>
 496 </entry>
 497  </row><row><entry
 498  align="char">
 499 <para>EBUSY</para>
 500 </entry><entry
 501  align="char">
 502 <para>This error code indicates that there are conflicting
 503  requests. The corresponding demux device is setup to
 504  receive data from the front- end. Make sure that these
 505  filters are stopped and that the filters with input set to
 506  DMX_IN_DVR are started.</para>
 507 </entry>
 508  </row><row><entry
 509  align="char">
 510 <para>EBADF</para>
 511 </entry><entry
 512  align="char">
 513 <para>fd is not a valid open file descriptor.</para>
 514 </entry>
 515  </row></tbody></tgroup></informaltable>
 516 </section>
 517
 518 <section id="DMX_START">
 519 <title>DMX_START</title>
 520 <para>DESCRIPTION
 521 </para>
 522 <informaltable><tgroup cols="1"><tbody><row><entry
 523  align="char">
 524 <para>This ioctl call is used to start the actual filtering operation defined via the ioctl
 525  calls DMX_SET_FILTER or DMX_SET_PES_FILTER.</para>
 526 </entry>
 527  </row></tbody></tgroup></informaltable>
 528 <para>SYNOPSIS
 529 </para>
 530 <informaltable><tgroup cols="1"><tbody><row><entry
 531  align="char">
 532 <para>int ioctl( int fd, int request = DMX_START);</para>
 533 </entry>
 534  </row></tbody></tgroup></informaltable>
 535 <para>PARAMETERS
 536 </para>
 537 <informaltable><tgroup cols="2"><tbody><row><entry
 538  align="char">
 539 <para>int fd</para>
 540 </entry><entry
 541  align="char">
 542 <para>File descriptor returned by a previous call to open().</para>
 543 </entry>
 544  </row><row><entry
 545  align="char">
 546 <para>int request</para>
 547 </entry><entry
 548  align="char">
 549 <para>Equals DMX_START for this command.</para>
 550 </entry>
 551  </row></tbody></tgroup></informaltable>
 552 &return-value-dvb;
 553 <informaltable><tgroup cols="2"><tbody><row><entry
 554  align="char">
 555 <para>EINVAL</para>
 556 </entry><entry
 557  align="char">
 558 <para>Invalid argument, i.e. no filtering parameters provided via
 559  the DMX_SET_FILTER or DMX_SET_PES_FILTER
 560  functions.</para>
 561 </entry>
 562  </row><row><entry
 563  align="char">
 564 <para>EBUSY</para>
 565 </entry><entry
 566  align="char">
 567 <para>This error code indicates that there are conflicting
 568  requests. There are active filters filtering data from
 569  another input source. Make sure that these filters are
 570  stopped before starting this filter.</para>
 571 </entry>
 572  </row></tbody></tgroup></informaltable>
 573 </section>
 574
 575 <section id="DMX_STOP">
 576 <title>DMX_STOP</title>
 577 <para>DESCRIPTION
 578 </para>
 579 <informaltable><tgroup cols="1"><tbody><row><entry
 580  align="char">
 581 <para>This ioctl call is used to stop the actual filtering operation defined via the
 582  ioctl calls DMX_SET_FILTER or DMX_SET_PES_FILTER and started via
 583  the DMX_START command.</para>
 584 </entry>
 585  </row></tbody></tgroup></informaltable>
 586 <para>SYNOPSIS
 587 </para>
 588 <informaltable><tgroup cols="1"><tbody><row><entry
 589  align="char">
 590 <para>int ioctl( int fd, int request = DMX_STOP);</para>
 591 </entry>
 592  </row></tbody></tgroup></informaltable>
 593 <para>PARAMETERS
 594 </para>
 595 <informaltable><tgroup cols="2"><tbody><row><entry
 596  align="char">
 597 <para>int fd</para>
 598 </entry><entry
 599  align="char">
 600 <para>File descriptor returned by a previous call to open().</para>
 601 </entry>
 602  </row><row><entry
 603  align="char">
 604 <para>int request</para>
 605 </entry><entry
 606  align="char">
 607 <para>Equals DMX_STOP for this command.</para>
 608 </entry>
 609  </row></tbody></tgroup></informaltable>
 610 &return-value-dvb;
 611 </section>
 612
 613 <section id="DMX_SET_FILTER">
 614 <title>DMX_SET_FILTER</title>
 615 <para>DESCRIPTION
 616 </para>
 617 <informaltable><tgroup cols="1"><tbody><row><entry
 618  align="char">
 619 <para>This ioctl call sets up a filter according to the filter and mask parameters
 620  provided. A timeout may be defined stating number of seconds to wait for a
 621  section to be loaded. A value of 0 means that no timeout should be applied.
 622  Finally there is a flag field where it is possible to state whether a section should
 623  be CRC-checked, whether the filter should be a &#8221;one-shot&#8221; filter, i.e. if the
 624  filtering operation should be stopped after the first section is received, and
 625  whether the filtering operation should be started immediately (without waiting
 626  for a DMX_START ioctl call). If a filter was previously set-up, this filter will
 627  be canceled, and the receive buffer will be flushed.</para>
 628 </entry>
 629  </row></tbody></tgroup></informaltable>
 630 <para>SYNOPSIS
 631 </para>
 632 <informaltable><tgroup cols="1"><tbody><row><entry
 633  align="char">
 634 <para>int ioctl( int fd, int request = DMX_SET_FILTER,
 635  struct dmx_sct_filter_params &#x22C6;params);</para>
 636 </entry>
 637  </row></tbody></tgroup></informaltable>
 638 <para>PARAMETERS
 639 </para>
 640 <informaltable><tgroup cols="2"><tbody><row><entry
 641  align="char">
 642 <para>int fd</para>
 643 </entry><entry
 644  align="char">
 645 <para>File descriptor returned by a previous call to open().</para>
 646 </entry>
 647  </row><row><entry
 648  align="char">
 649 <para>int request</para>
 650 </entry><entry
 651  align="char">
 652 <para>Equals DMX_SET_FILTER for this command.</para>
 653 </entry>
 654  </row><row><entry
 655  align="char">
 656 <para>struct
 657  dmx_sct_filter_params
 658  *params</para>
 659 </entry><entry
 660  align="char">
 661 <para>Pointer to structure containing filter parameters.</para>
 662 </entry>
 663  </row></tbody></tgroup></informaltable>
 664 &return-value-dvb;
 665 </section>
 666
 667 <section id="DMX_SET_PES_FILTER">
 668 <title>DMX_SET_PES_FILTER</title>
 669 <para>DESCRIPTION
 670 </para>
 671 <informaltable><tgroup cols="1"><tbody><row><entry
 672  align="char">
 673 <para>This ioctl call sets up a PES filter according to the parameters provided. By a
 674  PES filter is meant a filter that is based just on the packet identifier (PID), i.e.
 675  no PES header or payload filtering capability is supported.</para>
 676 </entry>
 677  </row><row><entry
 678  align="char">
 679 <para>The transport stream destination for the filtered output may be set. Also the
 680  PES type may be stated in order to be able to e.g. direct a video stream directly
 681  to the video decoder. Finally there is a flag field where it is possible to state
 682  whether the filtering operation should be started immediately (without waiting
 683  for a DMX_START ioctl call). If a filter was previously set-up, this filter will
 684  be cancelled, and the receive buffer will be flushed.</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 = DMX_SET_PES_FILTER,
 692  struct dmx_pes_filter_params &#x22C6;params);</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 DMX_SET_PES_FILTER for this command.</para>
 710 </entry>
 711  </row><row><entry
 712  align="char">
 713 <para>struct
 714  dmx_pes_filter_params
 715  *params</para>
 716 </entry><entry
 717  align="char">
 718 <para>Pointer to structure containing filter parameters.</para>
 719 </entry>
 720  </row></tbody></tgroup></informaltable>
 721 &return-value-dvb;
 722 <informaltable><tgroup cols="2"><tbody><row><entry
 723  align="char">
 724 <para>EBUSY</para>
 725 </entry><entry
 726  align="char">
 727 <para>This error code indicates that there are conflicting
 728  requests. There are active filters filtering data from
 729  another input source. Make sure that these filters are
 730  stopped before starting this filter.</para>
 731 </entry>
 732  </row></tbody></tgroup></informaltable>
 733 </section>
 734
 735 <section id="DMX_SET_BUFFER_SIZE">
 736 <title>DMX_SET_BUFFER_SIZE</title>
 737 <para>DESCRIPTION
 738 </para>
 739 <informaltable><tgroup cols="1"><tbody><row><entry
 740  align="char">
 741 <para>This ioctl call is used to set the size of the circular buffer used for filtered data.
 742  The default size is two maximum sized sections, i.e. if this function is not called
 743  a buffer size of 2 * 4096 bytes will be used.</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  DMX_SET_BUFFER_SIZE, unsigned long size);</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 DMX_SET_BUFFER_SIZE for this command.</para>
 769 </entry>
 770  </row><row><entry
 771  align="char">
 772 <para>unsigned long size</para>
 773 </entry><entry
 774  align="char">
 775 <para>Size of circular buffer.</para>
 776 </entry>
 777  </row></tbody></tgroup></informaltable>
 778 &return-value-dvb;
 779 </section>
 780
 781 <section id="DMX_GET_EVENT">
 782 <title>DMX_GET_EVENT</title>
 783 <para>DESCRIPTION
 784 </para>
 785 <informaltable><tgroup cols="1"><tbody><row><entry
 786  align="char">
 787 <para>This ioctl call returns an event if available. If an event is not available,
 788  the behavior depends on whether the device is in blocking or non-blocking
 789  mode. In the latter case, the call fails immediately with errno set to
 790  EWOULDBLOCK. In the former case, the call blocks until an event becomes
 791  available.</para>
 792 </entry>
 793  </row><row><entry
 794  align="char">
 795 <para>The standard Linux poll() and/or select() system calls can be used with the
 796  device file descriptor to watch for new events. For select(), the file descriptor
 797  should be included in the exceptfds argument, and for poll(), POLLPRI should
 798  be specified as the wake-up condition. Only the latest event for each filter is
 799  saved.</para>
 800 </entry>
 801  </row></tbody></tgroup></informaltable>
 802 <para>SYNOPSIS
 803 </para>
 804 <informaltable><tgroup cols="1"><tbody><row><entry
 805  align="char">
 806 <para>int ioctl( int fd, int request = DMX_GET_EVENT,
 807  struct dmx_event &#x22C6;ev);</para>
 808 </entry>
 809  </row></tbody></tgroup></informaltable>
 810 <para>PARAMETERS
 811 </para>
 812 <informaltable><tgroup cols="2"><tbody><row><entry
 813  align="char">
 814 <para>int fd</para>
 815 </entry><entry
 816  align="char">
 817 <para>File descriptor returned by a previous call to open().</para>
 818 </entry>
 819  </row><row><entry
 820  align="char">
 821 <para>int request</para>
 822 </entry><entry
 823  align="char">
 824 <para>Equals DMX_GET_EVENT for this command.</para>
 825 </entry>
 826  </row><row><entry
 827  align="char">
 828 <para>struct dmx_event *ev</para>
 829 </entry><entry
 830  align="char">
 831 <para>Pointer to the location where the event is to be stored.</para>
 832 </entry>
 833  </row></tbody></tgroup></informaltable>
 834 &return-value-dvb;
 835 <informaltable><tgroup cols="2"><tbody><row><entry
 836  align="char">
 837 <para>EWOULDBLOCK</para>
 838 </entry><entry
 839  align="char">
 840 <para>There is no event pending, and the device is in
 841  non-blocking mode.</para>
 842 </entry>
 843  </row></tbody></tgroup></informaltable>
 844 </section>
 845
 846 <section id="DMX_GET_STC">
 847 <title>DMX_GET_STC</title>
 848 <para>DESCRIPTION
 849 </para>
 850 <informaltable><tgroup cols="1"><tbody><row><entry
 851  align="char">
 852 <para>This ioctl call returns the current value of the system time counter (which is driven
 853  by a PES filter of type DMX_PES_PCR). Some hardware supports more than one
 854  STC, so you must specify which one by setting the num field of stc before the ioctl
 855  (range 0...n). The result is returned in form of a ratio with a 64 bit numerator
 856  and a 32 bit denominator, so the real 90kHz STC value is stc-&#x003E;stc /
 857  stc-&#x003E;base
 858  .</para>
 859 </entry>
 860  </row></tbody></tgroup></informaltable>
 861 <para>SYNOPSIS
 862 </para>
 863 <informaltable><tgroup cols="1"><tbody><row><entry
 864  align="char">
 865 <para>int ioctl( int fd, int request = DMX_GET_STC, struct
 866  dmx_stc &#x22C6;stc);</para>
 867 </entry>
 868  </row></tbody></tgroup></informaltable>
 869 <para>PARAMETERS
 870 </para>
 871 <informaltable><tgroup cols="2"><tbody><row><entry
 872  align="char">
 873 <para>int fd</para>
 874 </entry><entry
 875  align="char">
 876 <para>File descriptor returned by a previous call to open().</para>
 877 </entry>
 878  </row><row><entry
 879  align="char">
 880 <para>int request</para>
 881 </entry><entry
 882  align="char">
 883 <para>Equals DMX_GET_STC for this command.</para>
 884 </entry>
 885  </row><row><entry
 886  align="char">
 887 <para>struct dmx_stc *stc</para>
 888 </entry><entry
 889  align="char">
 890 <para>Pointer to the location where the stc is to be stored.</para>
 891 </entry>
 892  </row></tbody></tgroup></informaltable>
 893 &return-value-dvb;
 894 <informaltable><tgroup cols="2"><tbody><row><entry
 895  align="char">
 896 <para>EINVAL</para>
 897 </entry><entry
 898  align="char">
 899 <para>Invalid stc number.</para>
 900 </entry>
 901  </row></tbody></tgroup></informaltable>
 902  </section>
 903
 904 <section id="DMX_GET_PES_PIDS"
 905 role="subsection"><title>DMX_GET_PES_PIDS</title>
 906 <para>DESCRIPTION
 907 </para>
 908 <informaltable><tgroup cols="1"><tbody><row><entry
 909  align="char">
 910 <para>This ioctl is undocumented. Documentation is welcome.</para>
 911 </entry>
 912  </row></tbody></tgroup></informaltable>
 913 <para>SYNOPSIS
 914 </para>
 915 <informaltable><tgroup cols="1"><tbody><row><entry
 916  align="char">
 917 <para>int ioctl(fd, int request = DMX_GET_PES_PIDS,
 918  __u16[5]);</para>
 919 </entry>
 920  </row></tbody></tgroup></informaltable>
 921 <para>PARAMETERS
 922 </para>
 923 <informaltable><tgroup cols="2"><tbody><row><entry
 924  align="char">
 925 <para>int fd</para>
 926 </entry><entry
 927  align="char">
 928 <para>File descriptor returned by a previous call to open().</para>
 929 </entry>
 930  </row><row><entry
 931  align="char">
 932 <para>int request</para>
 933 </entry><entry
 934  align="char">
 935 <para>Equals DMX_GET_PES_PIDS for this command.</para>
 936 </entry>
 937  </row><row><entry
 938  align="char">
 939 <para>__u16[5]
 940 </para>
 941 </entry><entry
 942  align="char">
 943 <para>Undocumented.</para>
 944 </entry>
 945  </row></tbody></tgroup></informaltable>
 946 &return-value-dvb;
 947 </section>
 948
 949 <section id="DMX_GET_CAPS"
 950 role="subsection"><title>DMX_GET_CAPS</title>
 951 <para>DESCRIPTION
 952 </para>
 953 <informaltable><tgroup cols="1"><tbody><row><entry
 954  align="char">
 955 <para>This ioctl is undocumented. Documentation is welcome.</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(fd, int request = DMX_GET_CAPS,
 963  dmx_caps_t *);</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 DMX_GET_CAPS for this command.</para>
 981 </entry>
 982  </row><row><entry
 983  align="char">
 984 <para>dmx_caps_t *
 985 </para>
 986 </entry><entry
 987  align="char">
 988 <para>Undocumented.</para>
 989 </entry>
 990  </row></tbody></tgroup></informaltable>
 991 &return-value-dvb;
 992 </section>
 993
 994 <section id="DMX_SET_SOURCE"
 995 role="subsection"><title>DMX_SET_SOURCE</title>
 996 <para>DESCRIPTION
 997 </para>
 998 <informaltable><tgroup cols="1"><tbody><row><entry
 999  align="char">
1000 <para>This ioctl is undocumented. Documentation is welcome.</para>
1001 </entry>
1002  </row></tbody></tgroup></informaltable>
1003 <para>SYNOPSIS
1004 </para>
1005 <informaltable><tgroup cols="1"><tbody><row><entry
1006  align="char">
1007 <para>int ioctl(fd, int request = DMX_SET_SOURCE,
1008  dmx_source_t *);</para>
1009 </entry>
1010  </row></tbody></tgroup></informaltable>
1011 <para>PARAMETERS
1012 </para>
1013 <informaltable><tgroup cols="2"><tbody><row><entry
1014  align="char">
1015 <para>int fd</para>
1016 </entry><entry
1017  align="char">
1018 <para>File descriptor returned by a previous call to open().</para>
1019 </entry>
1020  </row><row><entry
1021  align="char">
1022 <para>int request</para>
1023 </entry><entry
1024  align="char">
1025 <para>Equals DMX_SET_SOURCE for this command.</para>
1026 </entry>
1027  </row><row><entry
1028  align="char">
1029 <para>dmx_source_t *
1030 </para>
1031 </entry><entry
1032  align="char">
1033 <para>Undocumented.</para>
1034 </entry>
1035  </row></tbody></tgroup></informaltable>
1036 &return-value-dvb;
1037 </section>
1038
1039 <section id="DMX_ADD_PID"
1040 role="subsection"><title>DMX_ADD_PID</title>
1041 <para>DESCRIPTION
1042 </para>
1043 <informaltable><tgroup cols="1"><tbody><row><entry
1044  align="char">
1045 <para>This ioctl call allows to add multiple PIDs to a transport stream filter
1046 previously set up with DMX_SET_PES_FILTER and output equal to DMX_OUT_TSDEMUX_TAP.
1047 </para></entry></row><row><entry align="char"><para>
1048 It is used by readers of /dev/dvb/adapterX/demuxY.
1049 </para></entry></row><row><entry align="char"><para>
1050 It may be called at any time, i.e. before or after the first filter on the
1051 shared file descriptor was started. It makes it possible to record multiple
1052 services without the need to de-multiplex or re-multiplex TS packets.</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 = DMX_ADD_PID,
1060  __u16 *);</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 DMX_ADD_PID for this command.</para>
1078 </entry>
1079  </row><row><entry
1080  align="char">
1081 <para>__u16 *
1082 </para>
1083 </entry><entry
1084  align="char">
1085 <para>PID number to be filtered.</para>
1086 </entry>
1087  </row></tbody></tgroup></informaltable>
1088 &return-value-dvb;
1089 </section>
1090
1091 <section id="DMX_REMOVE_PID"
1092 role="subsection"><title>DMX_REMOVE_PID</title>
1093 <para>DESCRIPTION
1094 </para>
1095 <informaltable><tgroup cols="1"><tbody><row><entry
1096  align="char">
1097 <para>This ioctl call allows to remove a PID when multiple PIDs are set on a
1098 transport stream filter, e. g. a filter previously set up with output equal to
1099 DMX_OUT_TSDEMUX_TAP, created via either DMX_SET_PES_FILTER or DMX_ADD_PID.
1100 </para></entry></row><row><entry align="char"><para>
1101 It is used by readers of /dev/dvb/adapterX/demuxY.
1102 </para></entry></row><row><entry align="char"><para>
1103 It may be called at any time, i.e. before or after the first filter on the
1104 shared file descriptor was started. It makes it possible to record multiple
1105 services without the need to de-multiplex or re-multiplex TS packets.</para>
1106 </entry>
1107  </row></tbody></tgroup></informaltable>
1108 <para>SYNOPSIS
1109 </para>
1110 <informaltable><tgroup cols="1"><tbody><row><entry
1111  align="char">
1112 <para>int ioctl(fd, int request = DMX_REMOVE_PID,
1113  __u16 *);</para>
1114 </entry>
1115  </row></tbody></tgroup></informaltable>
1116 <para>PARAMETERS
1117 </para>
1118 <informaltable><tgroup cols="2"><tbody><row><entry
1119  align="char">
1120 <para>int fd</para>
1121 </entry><entry
1122  align="char">
1123 <para>File descriptor returned by a previous call to open().</para>
1124 </entry>
1125  </row><row><entry
1126  align="char">
1127 <para>int request</para>
1128 </entry><entry
1129  align="char">
1130 <para>Equals DMX_REMOVE_PID for this command.</para>
1131 </entry>
1132  </row><row><entry
1133  align="char">
1134 <para>__u16 *
1135 </para>
1136 </entry><entry
1137  align="char">
1138 <para>PID of the PES filter to be removed.</para>
1139 </entry>
1140  </row></tbody></tgroup></informaltable>
1141 &return-value-dvb;
1142 </section>
1143
1144
1145 </section>