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Based on kernel version 3.13. Page generated on 2014-01-20 22:02 EST.

1	<refentry id="vidioc-enumstd">
2	  <refmeta>
3	    <refentrytitle>ioctl VIDIOC_ENUMSTD</refentrytitle>
4	    &manvol;
5	  </refmeta>
6	
7	  <refnamediv>
8	    <refname>VIDIOC_ENUMSTD</refname>
9	    <refpurpose>Enumerate supported video standards</refpurpose>
10	  </refnamediv>
11	
12	  <refsynopsisdiv>
13	    <funcsynopsis>
14	      <funcprototype>
15		<funcdef>int <function>ioctl</function></funcdef>
16		<paramdef>int <parameter>fd</parameter></paramdef>
17		<paramdef>int <parameter>request</parameter></paramdef>
18		<paramdef>struct v4l2_standard *<parameter>argp</parameter></paramdef>
19	      </funcprototype>
20	    </funcsynopsis>
21	  </refsynopsisdiv>
22	
23	  <refsect1>
24	    <title>Arguments</title>
25	
26	    <variablelist>
27	      <varlistentry>
28		<term><parameter>fd</parameter></term>
29		<listitem>
30		  <para>&fd;</para>
31		</listitem>
32	      </varlistentry>
33	      <varlistentry>
34		<term><parameter>request</parameter></term>
35		<listitem>
36		  <para>VIDIOC_ENUMSTD</para>
37		</listitem>
38	      </varlistentry>
39	      <varlistentry>
40		<term><parameter>argp</parameter></term>
41		<listitem>
42		  <para></para>
43		</listitem>
44	      </varlistentry>
45	    </variablelist>
46	  </refsect1>
47	
48	  <refsect1>
49	    <title>Description</title>
50	
51	    <para>To query the attributes of a video standard,
52	especially a custom (driver defined) one, applications initialize the
53	<structfield>index</structfield> field of &v4l2-standard; and call the
54	<constant>VIDIOC_ENUMSTD</constant> ioctl with a pointer to this
55	structure. Drivers fill the rest of the structure or return an
56	&EINVAL; when the index is out of bounds. To enumerate all standards
57	applications shall begin  at index zero, incrementing by one until the
58	driver returns <errorcode>EINVAL</errorcode>. Drivers may enumerate a
59	different set of standards after switching the video input or
60	output.<footnote>
61		<para>The supported standards may overlap and we need an
62	unambiguous set to find the current standard returned by
63	<constant>VIDIOC_G_STD</constant>.</para>
64	      </footnote></para>
65	
66	    <table pgwide="1" frame="none" id="v4l2-standard">
67	      <title>struct <structname>v4l2_standard</structname></title>
68	      <tgroup cols="3">
69		&cs-str;
70		<tbody valign="top">
71		  <row>
72		    <entry>__u32</entry>
73		    <entry><structfield>index</structfield></entry>
74		    <entry>Number of the video standard, set by the
75	application.</entry>
76		  </row>
77		  <row>
78		    <entry>&v4l2-std-id;</entry>
79		    <entry><structfield>id</structfield></entry>
80		    <entry>The bits in this field identify the standard as
81	one of the common standards listed in <xref linkend="v4l2-std-id" />,
82	or if bits 32 to 63 are set as custom standards. Multiple bits can be
83	set if the hardware does not distinguish between these standards,
84	however separate indices do not indicate the opposite. The
85	<structfield>id</structfield> must be unique. No other enumerated
86	<structname>v4l2_standard</structname> structure, for this input or
87	output anyway, can contain the same set of bits.</entry>
88		  </row>
89		  <row>
90		    <entry>__u8</entry>
91		    <entry><structfield>name</structfield>[24]</entry>
92		    <entry>Name of the standard, a NUL-terminated ASCII
93	string, for example: "PAL-B/G", "NTSC Japan". This information is
94	intended for the user.</entry>
95		  </row>
96		  <row>
97		    <entry>&v4l2-fract;</entry>
98		    <entry><structfield>frameperiod</structfield></entry>
99		    <entry>The frame period (not field period) is numerator
100	/ denominator. For example M/NTSC has a frame period of 1001 /
101	30000 seconds.</entry>
102		  </row>
103		  <row>
104		    <entry>__u32</entry>
105		    <entry><structfield>framelines</structfield></entry>
106		    <entry>Total lines per frame including blanking,
107	e.&nbsp;g. 625 for B/PAL.</entry>
108		  </row>
109		  <row>
110		    <entry>__u32</entry>
111		    <entry><structfield>reserved</structfield>[4]</entry>
112		    <entry>Reserved for future extensions. Drivers must set
113	the array to zero.</entry>
114		  </row>
115		</tbody>
116	      </tgroup>
117	    </table>
118	
119	    <table pgwide="1" frame="none" id="v4l2-fract">
120	      <title>struct <structname>v4l2_fract</structname></title>
121	      <tgroup cols="3">
122		&cs-str;
123		<tbody valign="top">
124		  <row>
125		    <entry>__u32</entry>
126		    <entry><structfield>numerator</structfield></entry>
127		    <entry></entry>
128		  </row>
129		  <row>
130		    <entry>__u32</entry>
131		    <entry><structfield>denominator</structfield></entry>
132		    <entry></entry>
133		  </row>
134		</tbody>
135	      </tgroup>
136	    </table>
137	
138	    <table pgwide="1" frame="none" id="v4l2-std-id">
139	      <title>typedef <structname>v4l2_std_id</structname></title>
140	      <tgroup cols="3">
141		&cs-str;
142		<tbody valign="top">
143		  <row>
144		    <entry>__u64</entry>
145		    <entry><structfield>v4l2_std_id</structfield></entry>
146		    <entry>This type is a set, each bit representing another
147	video standard as listed below and in <xref
148	linkend="video-standards" />. The 32 most significant bits are reserved
149	for custom (driver defined) video standards.</entry>
150		  </row>
151		</tbody>
152	      </tgroup>
153	    </table>
154	
155	    <para><programlisting>
156	#define V4L2_STD_PAL_B          ((v4l2_std_id)0x00000001)
157	#define V4L2_STD_PAL_B1         ((v4l2_std_id)0x00000002)
158	#define V4L2_STD_PAL_G          ((v4l2_std_id)0x00000004)
159	#define V4L2_STD_PAL_H          ((v4l2_std_id)0x00000008)
160	#define V4L2_STD_PAL_I          ((v4l2_std_id)0x00000010)
161	#define V4L2_STD_PAL_D          ((v4l2_std_id)0x00000020)
162	#define V4L2_STD_PAL_D1         ((v4l2_std_id)0x00000040)
163	#define V4L2_STD_PAL_K          ((v4l2_std_id)0x00000080)
164	
165	#define V4L2_STD_PAL_M          ((v4l2_std_id)0x00000100)
166	#define V4L2_STD_PAL_N          ((v4l2_std_id)0x00000200)
167	#define V4L2_STD_PAL_Nc         ((v4l2_std_id)0x00000400)
168	#define V4L2_STD_PAL_60         ((v4l2_std_id)0x00000800)
169	</programlisting></para><para><constant>V4L2_STD_PAL_60</constant> is
170	a hybrid standard with 525 lines, 60 Hz refresh rate, and PAL color
171	modulation with a 4.43 MHz color subcarrier. Some PAL video recorders
172	can play back NTSC tapes in this mode for display on a 50/60 Hz agnostic
173	PAL TV.</para><para><programlisting>
174	#define V4L2_STD_NTSC_M         ((v4l2_std_id)0x00001000)
175	#define V4L2_STD_NTSC_M_JP      ((v4l2_std_id)0x00002000)
176	#define V4L2_STD_NTSC_443       ((v4l2_std_id)0x00004000)
177	</programlisting></para><para><constant>V4L2_STD_NTSC_443</constant>
178	is a hybrid standard with 525 lines, 60 Hz refresh rate, and NTSC
179	color modulation with a 4.43 MHz color
180	subcarrier.</para><para><programlisting>
181	#define V4L2_STD_NTSC_M_KR      ((v4l2_std_id)0x00008000)
182	
183	#define V4L2_STD_SECAM_B        ((v4l2_std_id)0x00010000)
184	#define V4L2_STD_SECAM_D        ((v4l2_std_id)0x00020000)
185	#define V4L2_STD_SECAM_G        ((v4l2_std_id)0x00040000)
186	#define V4L2_STD_SECAM_H        ((v4l2_std_id)0x00080000)
187	#define V4L2_STD_SECAM_K        ((v4l2_std_id)0x00100000)
188	#define V4L2_STD_SECAM_K1       ((v4l2_std_id)0x00200000)
189	#define V4L2_STD_SECAM_L        ((v4l2_std_id)0x00400000)
190	#define V4L2_STD_SECAM_LC       ((v4l2_std_id)0x00800000)
191	
192	/* ATSC/HDTV */
193	#define V4L2_STD_ATSC_8_VSB     ((v4l2_std_id)0x01000000)
194	#define V4L2_STD_ATSC_16_VSB    ((v4l2_std_id)0x02000000)
195	</programlisting></para><para><!-- ATSC proposal by Mark McClelland,
196	video4linux-list@redhat.com on 17 Oct 2002
197	--><constant>V4L2_STD_ATSC_8_VSB</constant> and
198	<constant>V4L2_STD_ATSC_16_VSB</constant> are U.S. terrestrial digital
199	TV standards. Presently the V4L2 API does not support digital TV. See
200	also the Linux DVB API at <ulink
201	url="http://linuxtv.org">http://linuxtv.org</ulink>.</para>
202	<para><programlisting>
203	#define V4L2_STD_PAL_BG         (V4L2_STD_PAL_B         |\
204					 V4L2_STD_PAL_B1        |\
205					 V4L2_STD_PAL_G)
206	#define V4L2_STD_B              (V4L2_STD_PAL_B         |\
207					 V4L2_STD_PAL_B1        |\
208					 V4L2_STD_SECAM_B)
209	#define V4L2_STD_GH             (V4L2_STD_PAL_G         |\
210					 V4L2_STD_PAL_H         |\
211					 V4L2_STD_SECAM_G       |\
212					 V4L2_STD_SECAM_H)
213	#define V4L2_STD_PAL_DK         (V4L2_STD_PAL_D         |\
214					 V4L2_STD_PAL_D1        |\
215					 V4L2_STD_PAL_K)
216	#define V4L2_STD_PAL            (V4L2_STD_PAL_BG        |\
217					 V4L2_STD_PAL_DK        |\
218					 V4L2_STD_PAL_H         |\
219					 V4L2_STD_PAL_I)
220	#define V4L2_STD_NTSC           (V4L2_STD_NTSC_M        |\
221					 V4L2_STD_NTSC_M_JP     |\
222					 V4L2_STD_NTSC_M_KR)
223	#define V4L2_STD_MN             (V4L2_STD_PAL_M         |\
224					 V4L2_STD_PAL_N         |\
225					 V4L2_STD_PAL_Nc        |\
226					 V4L2_STD_NTSC)
227	#define V4L2_STD_SECAM_DK       (V4L2_STD_SECAM_D       |\
228					 V4L2_STD_SECAM_K       |\
229					 V4L2_STD_SECAM_K1)
230	#define V4L2_STD_DK             (V4L2_STD_PAL_DK        |\
231					 V4L2_STD_SECAM_DK)
232	
233	#define V4L2_STD_SECAM          (V4L2_STD_SECAM_B       |\
234					 V4L2_STD_SECAM_G       |\
235					 V4L2_STD_SECAM_H       |\
236					 V4L2_STD_SECAM_DK      |\
237					 V4L2_STD_SECAM_L       |\
238					 V4L2_STD_SECAM_LC)
239	
240	#define V4L2_STD_525_60         (V4L2_STD_PAL_M         |\
241					 V4L2_STD_PAL_60        |\
242					 V4L2_STD_NTSC          |\
243					 V4L2_STD_NTSC_443)
244	#define V4L2_STD_625_50         (V4L2_STD_PAL           |\
245					 V4L2_STD_PAL_N         |\
246					 V4L2_STD_PAL_Nc        |\
247					 V4L2_STD_SECAM)
248	
249	#define V4L2_STD_UNKNOWN        0
250	#define V4L2_STD_ALL            (V4L2_STD_525_60        |\
251					 V4L2_STD_625_50)
252	</programlisting></para>
253	
254	    <table pgwide="1" id="video-standards" orient="land">
255	      <title>Video Standards (based on [<xref linkend="itu470" />])</title>
256	      <tgroup cols="12" colsep="1" rowsep="1" align="center">
257		<colspec colname="c1" align="left" />
258		<colspec colname="c2" />
259		<colspec colname="c3" />
260		<colspec colname="c4" />
261		<colspec colname="c5" />
262		<colspec colnum="7" colname="c7" />
263		<colspec colnum="9" colname="c9" />
264		<colspec colnum="12" colname="c12" />
265		<spanspec namest="c2" nameend="c3" spanname="m" align="center" />
266		<spanspec namest="c4" nameend="c12" spanname="x" align="center" />
267		<spanspec namest="c5" nameend="c7" spanname="b" align="center" />
268		<spanspec namest="c9" nameend="c12" spanname="s" align="center" />
269		<thead>
270		  <row>
271		    <entry>Characteristics</entry>
272		    <entry><para>M/NTSC<footnote><para>Japan uses a standard
273	similar to M/NTSC
274	(V4L2_STD_NTSC_M_JP).</para></footnote></para></entry>
275		    <entry>M/PAL</entry>
276		    <entry><para>N/PAL<footnote><para> The values in
277	brackets apply to the combination N/PAL a.k.a.
278	N<subscript>C</subscript> used in Argentina
279	(V4L2_STD_PAL_Nc).</para></footnote></para></entry>
280		    <entry align="center">B, B1, G/PAL</entry>
281		    <entry align="center">D, D1, K/PAL</entry>
282		    <entry align="center">H/PAL</entry>
283		    <entry align="center">I/PAL</entry>
284		    <entry align="center">B, G/SECAM</entry>
285		    <entry align="center">D, K/SECAM</entry>
286		    <entry align="center">K1/SECAM</entry>
287		    <entry align="center">L/SECAM</entry>
288		  </row>
289		</thead>
290		<tbody valign="top">
291		  <row>
292		    <entry>Frame lines</entry>
293		    <entry spanname="m">525</entry>
294		    <entry spanname="x">625</entry>
295		  </row>
296		  <row>
297		    <entry>Frame period (s)</entry>
298		    <entry spanname="m">1001/30000</entry>
299		    <entry spanname="x">1/25</entry>
300		  </row>
301		  <row>
302		    <entry>Chrominance sub-carrier frequency (Hz)</entry>
303		    <entry>3579545 &plusmn;&nbsp;10</entry>
304		    <entry>3579611.49 &plusmn;&nbsp;10</entry>
305		    <entry>4433618.75 &plusmn;&nbsp;5 (3582056.25
306	&plusmn;&nbsp;5)</entry>
307		    <entry spanname="b">4433618.75 &plusmn;&nbsp;5</entry>
308		    <entry>4433618.75 &plusmn;&nbsp;1</entry>
309		    <entry spanname="s">f<subscript>OR</subscript>&nbsp;=
310	4406250 &plusmn;&nbsp;2000, f<subscript>OB</subscript>&nbsp;= 4250000
311	&plusmn;&nbsp;2000</entry>
312		  </row>
313		  <row>
314		    <entry>Nominal radio-frequency channel bandwidth
315	(MHz)</entry>
316		    <entry>6</entry>
317		    <entry>6</entry>
318		    <entry>6</entry>
319		    <entry>B: 7; B1, G: 8</entry>
320		    <entry>8</entry>
321		    <entry>8</entry>
322		    <entry>8</entry>
323		    <entry>8</entry>
324		    <entry>8</entry>
325		    <entry>8</entry>
326		    <entry>8</entry>
327		  </row>
328		  <row>
329		    <entry>Sound carrier relative to vision carrier
330	(MHz)</entry>
331		    <entry>+&nbsp;4.5</entry>
332		    <entry>+&nbsp;4.5</entry>
333		    <entry>+&nbsp;4.5</entry>
334		    <entry><para>+&nbsp;5.5 &plusmn;&nbsp;0.001
335	<footnote><para>In the Federal Republic of Germany, Austria, Italy,
336	the Netherlands, Slovakia and Switzerland a system of two sound
337	carriers is used, the frequency of the second carrier being
338	242.1875&nbsp;kHz above the frequency of the first sound carrier. For
339	stereophonic sound transmissions a similar system is used in
340	Australia.</para></footnote> <footnote><para>New Zealand uses a sound
341	carrier displaced 5.4996 &plusmn;&nbsp;0.0005 MHz from the vision
342	carrier.</para></footnote> <footnote><para>In Denmark, Finland, New
343	Zealand, Sweden and Spain a system of two sound carriers is used. In
344	Iceland, Norway and Poland the same system is being introduced. The
345	second carrier is 5.85&nbsp;MHz above the vision carrier and is DQPSK
346	modulated with 728&nbsp;kbit/s sound and data multiplex. (NICAM
347	system)</para></footnote> <footnote><para>In the United Kingdom, a
348	system of two sound carriers is used. The second sound carrier is
349	6.552&nbsp;MHz above the vision carrier and is DQPSK modulated with a
350	728&nbsp;kbit/s sound and data multiplex able to carry two sound
351	channels. (NICAM system)</para></footnote></para></entry>
352		    <entry>+&nbsp;6.5 &plusmn;&nbsp;0.001</entry>
353		    <entry>+&nbsp;5.5</entry>
354		    <entry>+&nbsp;5.9996 &plusmn;&nbsp;0.0005</entry>
355		    <entry>+&nbsp;5.5 &plusmn;&nbsp;0.001</entry>
356		    <entry>+&nbsp;6.5 &plusmn;&nbsp;0.001</entry>
357		    <entry>+&nbsp;6.5</entry>
358		    <entry><para>+&nbsp;6.5 <footnote><para>In France, a
359	digital carrier 5.85 MHz away from the vision carrier may be used in
360	addition to the main sound carrier. It is modulated in differentially
361	encoded QPSK with a 728 kbit/s sound and data multiplexer capable of
362	carrying two sound channels. (NICAM
363	system)</para></footnote></para></entry>
364		  </row>
365		</tbody>
366	      </tgroup>
367	    </table>
368	  </refsect1>
369	
370	  <refsect1>
371	    &return-value;
372	
373	    <variablelist>
374	      <varlistentry>
375		<term><errorcode>EINVAL</errorcode></term>
376		<listitem>
377		  <para>The &v4l2-standard; <structfield>index</structfield>
378	is out of bounds.</para>
379		</listitem>
380	      </varlistentry>
381	      <varlistentry>
382		<term><errorcode>ENODATA</errorcode></term>
383		<listitem>
384		  <para>Standard video timings are not supported for this input or output.</para>
385		</listitem>
386	      </varlistentry>
387	    </variablelist>
388	  </refsect1>
389	</refentry>
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