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8e080c2e MCC |
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. 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 | |
991ce92f | 201 | url="https://linuxtv.org">https://linuxtv.org</ulink>.</para> |
8e080c2e MCC |
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 ± 10</entry> | |
304 | <entry>3579611.49 ± 10</entry> | |
305 | <entry>4433618.75 ± 5 (3582056.25 | |
306 | ± 5)</entry> | |
307 | <entry spanname="b">4433618.75 ± 5</entry> | |
308 | <entry>4433618.75 ± 1</entry> | |
309 | <entry spanname="s">f<subscript>OR</subscript> = | |
310 | 4406250 ± 2000, f<subscript>OB</subscript> = 4250000 | |
311 | ± 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>+ 4.5</entry> | |
332 | <entry>+ 4.5</entry> | |
333 | <entry>+ 4.5</entry> | |
334 | <entry><para>+ 5.5 ± 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 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 ± 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 MHz above the vision carrier and is DQPSK | |
346 | modulated with 728 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 MHz above the vision carrier and is DQPSK modulated with a | |
350 | 728 kbit/s sound and data multiplex able to carry two sound | |
351 | channels. (NICAM system)</para></footnote></para></entry> | |
352 | <entry>+ 6.5 ± 0.001</entry> | |
353 | <entry>+ 5.5</entry> | |
354 | <entry>+ 5.9996 ± 0.0005</entry> | |
355 | <entry>+ 5.5 ± 0.001</entry> | |
356 | <entry>+ 6.5 ± 0.001</entry> | |
357 | <entry>+ 6.5</entry> | |
358 | <entry><para>+ 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> | |
663dc7f3 HV |
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> | |
8e080c2e MCC |
387 | </variablelist> |
388 | </refsect1> | |
389 | </refentry> |