| Mauro Carvalho Chehab | 8e080c2 | 2009-09-13 22:16:04 -0300 | [diff] [blame] | 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 |
| 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 ± 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> |
| 381 | </variablelist> |
| 382 | </refsect1> |
| 383 | </refentry> |
| 384 | |
| 385 | <!-- |
| 386 | Local Variables: |
| 387 | mode: sgml |
| 388 | sgml-parent-document: "v4l2.sgml" |
| 389 | indent-tabs-mode: nil |
| 390 | End: |
| 391 | --> |