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Based on kernel version 3.16. Page generated on 2014-08-06 21:38 EST.

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 <emphasis role="tt">/dev/adapter0/demux0</emphasis>. Data types and and ioctl definitions can be
5	accessed by including <emphasis role="tt">linux/dvb/dmx.h</emphasis> 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><emphasis role="tt">DMX_OUT_TAP</emphasis> delivers the stream output to the demux device on which the ioctl is
25	called.
26	</para>
27	<para><emphasis role="tt">DMX_OUT_TS_TAP</emphasis> routes output to the logical DVR device <emphasis role="tt">/dev/dvb/adapter0/dvr0</emphasis>,
28	which delivers a TS multiplexed from all filters for which <emphasis role="tt">DMX_OUT_TS_TAP</emphasis> 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>
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