Based on kernel version 4.7.2. Page generated on 2016-08-22 22:45 EST.
1 <refentry id="vidioc-g-tuner"> 2 <refmeta> 3 <refentrytitle>ioctl VIDIOC_G_TUNER, VIDIOC_S_TUNER</refentrytitle> 4 &manvol; 5 </refmeta> 6 7 <refnamediv> 8 <refname>VIDIOC_G_TUNER</refname> 9 <refname>VIDIOC_S_TUNER</refname> 10 <refpurpose>Get or set tuner attributes</refpurpose> 11 </refnamediv> 12 13 <refsynopsisdiv> 14 <funcsynopsis> 15 <funcprototype> 16 <funcdef>int <function>ioctl</function></funcdef> 17 <paramdef>int <parameter>fd</parameter></paramdef> 18 <paramdef>int <parameter>request</parameter></paramdef> 19 <paramdef>struct v4l2_tuner 20 *<parameter>argp</parameter></paramdef> 21 </funcprototype> 22 </funcsynopsis> 23 <funcsynopsis> 24 <funcprototype> 25 <funcdef>int <function>ioctl</function></funcdef> 26 <paramdef>int <parameter>fd</parameter></paramdef> 27 <paramdef>int <parameter>request</parameter></paramdef> 28 <paramdef>const struct v4l2_tuner 29 *<parameter>argp</parameter></paramdef> 30 </funcprototype> 31 </funcsynopsis> 32 </refsynopsisdiv> 33 34 <refsect1> 35 <title>Arguments</title> 36 37 <variablelist> 38 <varlistentry> 39 <term><parameter>fd</parameter></term> 40 <listitem> 41 <para>&fd;</para> 42 </listitem> 43 </varlistentry> 44 <varlistentry> 45 <term><parameter>request</parameter></term> 46 <listitem> 47 <para>VIDIOC_G_TUNER, VIDIOC_S_TUNER</para> 48 </listitem> 49 </varlistentry> 50 <varlistentry> 51 <term><parameter>argp</parameter></term> 52 <listitem> 53 <para></para> 54 </listitem> 55 </varlistentry> 56 </variablelist> 57 </refsect1> 58 59 <refsect1> 60 <title>Description</title> 61 62 <para>To query the attributes of a tuner applications initialize the 63 <structfield>index</structfield> field and zero out the 64 <structfield>reserved</structfield> array of a &v4l2-tuner; and call the 65 <constant>VIDIOC_G_TUNER</constant> ioctl with a pointer to this 66 structure. Drivers fill the rest of the structure or return an 67 &EINVAL; when the index is out of bounds. To enumerate all tuners 68 applications shall begin at index zero, incrementing by one until the 69 driver returns <errorcode>EINVAL</errorcode>.</para> 70 71 <para>Tuners have two writable properties, the audio mode and 72 the radio frequency. To change the audio mode, applications initialize 73 the <structfield>index</structfield>, 74 <structfield>audmode</structfield> and 75 <structfield>reserved</structfield> fields and call the 76 <constant>VIDIOC_S_TUNER</constant> ioctl. This will 77 <emphasis>not</emphasis> change the current tuner, which is determined 78 by the current video input. Drivers may choose a different audio mode 79 if the requested mode is invalid or unsupported. Since this is a 80 <!-- FIXME -->write-only ioctl, it does not return the actually 81 selected audio mode.</para> 82 83 <para><link linkend="sdr">SDR</link> specific tuner types are 84 <constant>V4L2_TUNER_SDR</constant> and <constant>V4L2_TUNER_RF</constant>. 85 For SDR devices <structfield>audmode</structfield> field must be 86 initialized to zero. 87 The term 'tuner' means SDR receiver in this context.</para> 88 89 <para>To change the radio frequency the &VIDIOC-S-FREQUENCY; ioctl 90 is available.</para> 91 92 <table pgwide="1" frame="none" id="v4l2-tuner"> 93 <title>struct <structname>v4l2_tuner</structname></title> 94 <tgroup cols="3"> 95 <colspec colname="c1" colwidth="1*" /> 96 <colspec colname="c2" colwidth="1*" /> 97 <colspec colname="c3" colwidth="1*" /> 98 <colspec colname="c4" colwidth="1*" /> 99 <spanspec spanname="hspan" namest="c3" nameend="c4" /> 100 <tbody valign="top"> 101 <row> 102 <entry>__u32</entry> 103 <entry><structfield>index</structfield></entry> 104 <entry spanname="hspan">Identifies the tuner, set by the 105 application.</entry> 106 </row> 107 <row> 108 <entry>__u8</entry> 109 <entry><structfield>name</structfield>[32]</entry> 110 <entry spanname="hspan"><para>Name of the tuner, a 111 NUL-terminated ASCII string. This information is intended for the 112 user.<!-- FIXME Video inputs already have a name, the purpose of this 113 field is not quite clear.--></para></entry> 114 </row> 115 <row> 116 <entry>__u32</entry> 117 <entry><structfield>type</structfield></entry> 118 <entry spanname="hspan">Type of the tuner, see <xref 119 linkend="v4l2-tuner-type" />.</entry> 120 </row> 121 <row> 122 <entry>__u32</entry> 123 <entry><structfield>capability</structfield></entry> 124 <entry spanname="hspan"><para>Tuner capability flags, see 125 <xref linkend="tuner-capability" />. Audio flags indicate the ability 126 to decode audio subprograms. They will <emphasis>not</emphasis> 127 change, for example with the current video standard.</para><para>When 128 the structure refers to a radio tuner the 129 <constant>V4L2_TUNER_CAP_LANG1</constant>, 130 <constant>V4L2_TUNER_CAP_LANG2</constant> and 131 <constant>V4L2_TUNER_CAP_NORM</constant> flags can't be used.</para> 132 <para>If multiple frequency bands are supported, then 133 <structfield>capability</structfield> is the union of all 134 <structfield>capability</structfield> fields of each &v4l2-frequency-band;. 135 </para></entry> 136 </row> 137 <row> 138 <entry>__u32</entry> 139 <entry><structfield>rangelow</structfield></entry> 140 <entry spanname="hspan">The lowest tunable frequency in 141 units of 62.5 kHz, or if the <structfield>capability</structfield> 142 flag <constant>V4L2_TUNER_CAP_LOW</constant> is set, in units of 62.5 143 Hz, or if the <structfield>capability</structfield> flag 144 <constant>V4L2_TUNER_CAP_1HZ</constant> is set, in units of 1 Hz. 145 If multiple frequency bands are supported, then 146 <structfield>rangelow</structfield> is the lowest frequency 147 of all the frequency bands.</entry> 148 </row> 149 <row> 150 <entry>__u32</entry> 151 <entry><structfield>rangehigh</structfield></entry> 152 <entry spanname="hspan">The highest tunable frequency in 153 units of 62.5 kHz, or if the <structfield>capability</structfield> 154 flag <constant>V4L2_TUNER_CAP_LOW</constant> is set, in units of 62.5 155 Hz, or if the <structfield>capability</structfield> flag 156 <constant>V4L2_TUNER_CAP_1HZ</constant> is set, in units of 1 Hz. 157 If multiple frequency bands are supported, then 158 <structfield>rangehigh</structfield> is the highest frequency 159 of all the frequency bands.</entry> 160 </row> 161 <row> 162 <entry>__u32</entry> 163 <entry><structfield>rxsubchans</structfield></entry> 164 <entry spanname="hspan"><para>Some tuners or audio 165 decoders can determine the received audio subprograms by analyzing 166 audio carriers, pilot tones or other indicators. To pass this 167 information drivers set flags defined in <xref 168 linkend="tuner-rxsubchans" /> in this field. For 169 example:</para></entry> 170 </row> 171 <row> 172 <entry></entry> 173 <entry></entry> 174 <entry><constant>V4L2_TUNER_SUB_MONO</constant></entry> 175 <entry>receiving mono audio</entry> 176 </row> 177 <row> 178 <entry></entry> 179 <entry></entry> 180 <entry><constant>STEREO | SAP</constant></entry> 181 <entry>receiving stereo audio and a secondary audio 182 program</entry> 183 </row> 184 <row> 185 <entry></entry> 186 <entry></entry> 187 <entry><constant>MONO | STEREO</constant></entry> 188 <entry>receiving mono or stereo audio, the hardware cannot 189 distinguish</entry> 190 </row> 191 <row> 192 <entry></entry> 193 <entry></entry> 194 <entry><constant>LANG1 | LANG2</constant></entry> 195 <entry>receiving bilingual audio</entry> 196 </row> 197 <row> 198 <entry></entry> 199 <entry></entry> 200 <entry><constant>MONO | STEREO | LANG1 | LANG2</constant></entry> 201 <entry>receiving mono, stereo or bilingual 202 audio</entry> 203 </row> 204 <row> 205 <entry></entry> 206 <entry></entry> 207 <entry spanname="hspan"><para>When the 208 <constant>V4L2_TUNER_CAP_STEREO</constant>, 209 <constant>_LANG1</constant>, <constant>_LANG2</constant> or 210 <constant>_SAP</constant> flag is cleared in the 211 <structfield>capability</structfield> field, the corresponding 212 <constant>V4L2_TUNER_SUB_</constant> flag must not be set 213 here.</para><para>This field is valid only if this is the tuner of the 214 current video input, or when the structure refers to a radio 215 tuner.</para></entry> 216 </row> 217 <row> 218 <entry>__u32</entry> 219 <entry><structfield>audmode</structfield></entry> 220 <entry spanname="hspan"><para>The selected audio mode, see 221 <xref linkend="tuner-audmode" /> for valid values. The audio mode does 222 not affect audio subprogram detection, and like a <link 223 linkend="control">control</link> it does not automatically change 224 unless the requested mode is invalid or unsupported. See <xref 225 linkend="tuner-matrix" /> for possible results when 226 the selected and received audio programs do not 227 match.</para><para>Currently this is the only field of struct 228 <structname>v4l2_tuner</structname> applications can 229 change.</para></entry> 230 </row> 231 <row> 232 <entry>__u32</entry> 233 <entry><structfield>signal</structfield></entry> 234 <entry spanname="hspan">The signal strength if known, ranging 235 from 0 to 65535. Higher values indicate a better signal.</entry> 236 </row> 237 <row> 238 <entry>__s32</entry> 239 <entry><structfield>afc</structfield></entry> 240 <entry spanname="hspan">Automatic frequency control: When the 241 <structfield>afc</structfield> value is negative, the frequency is too 242 low, when positive too high.<!-- FIXME need example what to do when it never 243 settles at zero, &ie; range is what? --></entry> 244 </row> 245 <row> 246 <entry>__u32</entry> 247 <entry><structfield>reserved</structfield>[4]</entry> 248 <entry spanname="hspan">Reserved for future extensions. Drivers and 249 applications must set the array to zero.</entry> 250 </row> 251 </tbody> 252 </tgroup> 253 </table> 254 255 <table pgwide="1" frame="none" id="v4l2-tuner-type"> 256 <title>enum v4l2_tuner_type</title> 257 <tgroup cols="3"> 258 &cs-def; 259 <tbody valign="top"> 260 <row> 261 <entry><constant>V4L2_TUNER_RADIO</constant></entry> 262 <entry>1</entry> 263 <entry></entry> 264 </row> 265 <row> 266 <entry><constant>V4L2_TUNER_ANALOG_TV</constant></entry> 267 <entry>2</entry> 268 <entry></entry> 269 </row> 270 <row> 271 <entry><constant>V4L2_TUNER_SDR</constant></entry> 272 <entry>4</entry> 273 <entry></entry> 274 </row> 275 <row> 276 <entry><constant>V4L2_TUNER_RF</constant></entry> 277 <entry>5</entry> 278 <entry></entry> 279 </row> 280 </tbody> 281 </tgroup> 282 </table> 283 284 <table pgwide="1" frame="none" id="tuner-capability"> 285 <title>Tuner and Modulator Capability Flags</title> 286 <tgroup cols="3"> 287 &cs-def; 288 <tbody valign="top"> 289 <row> 290 <entry><constant>V4L2_TUNER_CAP_LOW</constant></entry> 291 <entry>0x0001</entry> 292 <entry>When set, tuning frequencies are expressed in units of 293 62.5 Hz instead of 62.5 kHz.</entry> 294 </row> 295 <row> 296 <entry><constant>V4L2_TUNER_CAP_NORM</constant></entry> 297 <entry>0x0002</entry> 298 <entry>This is a multi-standard tuner; the video standard 299 can or must be switched. (B/G PAL tuners for example are typically not 300 considered multi-standard because the video standard is automatically 301 determined from the frequency band.) The set of supported video 302 standards is available from the &v4l2-input; pointing to this tuner, 303 see the description of ioctl &VIDIOC-ENUMINPUT; for details. Only 304 <constant>V4L2_TUNER_ANALOG_TV</constant> tuners can have this capability.</entry> 305 </row> 306 <row> 307 <entry><constant>V4L2_TUNER_CAP_HWSEEK_BOUNDED</constant></entry> 308 <entry>0x0004</entry> 309 <entry>If set, then this tuner supports the hardware seek functionality 310 where the seek stops when it reaches the end of the frequency range.</entry> 311 </row> 312 <row> 313 <entry><constant>V4L2_TUNER_CAP_HWSEEK_WRAP</constant></entry> 314 <entry>0x0008</entry> 315 <entry>If set, then this tuner supports the hardware seek functionality 316 where the seek wraps around when it reaches the end of the frequency range.</entry> 317 </row> 318 <row> 319 <entry><constant>V4L2_TUNER_CAP_STEREO</constant></entry> 320 <entry>0x0010</entry> 321 <entry>Stereo audio reception is supported.</entry> 322 </row> 323 <row> 324 <entry><constant>V4L2_TUNER_CAP_LANG1</constant></entry> 325 <entry>0x0040</entry> 326 <entry>Reception of the primary language of a bilingual 327 audio program is supported. Bilingual audio is a feature of 328 two-channel systems, transmitting the primary language monaural on the 329 main audio carrier and a secondary language monaural on a second 330 carrier. Only 331 <constant>V4L2_TUNER_ANALOG_TV</constant> tuners can have this capability.</entry> 332 </row> 333 <row> 334 <entry><constant>V4L2_TUNER_CAP_LANG2</constant></entry> 335 <entry>0x0020</entry> 336 <entry>Reception of the secondary language of a bilingual 337 audio program is supported. Only 338 <constant>V4L2_TUNER_ANALOG_TV</constant> tuners can have this capability.</entry> 339 </row> 340 <row> 341 <entry><constant>V4L2_TUNER_CAP_SAP</constant></entry> 342 <entry>0x0020</entry> 343 <entry><para>Reception of a secondary audio program is 344 supported. This is a feature of the BTSC system which accompanies the 345 NTSC video standard. Two audio carriers are available for mono or 346 stereo transmissions of a primary language, and an independent third 347 carrier for a monaural secondary language. Only 348 <constant>V4L2_TUNER_ANALOG_TV</constant> tuners can have this capability.</para><para>Note the 349 <constant>V4L2_TUNER_CAP_LANG2</constant> and 350 <constant>V4L2_TUNER_CAP_SAP</constant> flags are synonyms. 351 <constant>V4L2_TUNER_CAP_SAP</constant> applies when the tuner 352 supports the <constant>V4L2_STD_NTSC_M</constant> video 353 standard.</para><!-- FIXME what if PAL+NTSC and Bi but not SAP? --></entry> 354 </row> 355 <row> 356 <entry><constant>V4L2_TUNER_CAP_RDS</constant></entry> 357 <entry>0x0080</entry> 358 <entry>RDS capture is supported. This capability is only valid for 359 radio tuners.</entry> 360 </row> 361 <row> 362 <entry><constant>V4L2_TUNER_CAP_RDS_BLOCK_IO</constant></entry> 363 <entry>0x0100</entry> 364 <entry>The RDS data is passed as unparsed RDS blocks.</entry> 365 </row> 366 <row> 367 <entry><constant>V4L2_TUNER_CAP_RDS_CONTROLS</constant></entry> 368 <entry>0x0200</entry> 369 <entry>The RDS data is parsed by the hardware and set via controls.</entry> 370 </row> 371 <row> 372 <entry><constant>V4L2_TUNER_CAP_FREQ_BANDS</constant></entry> 373 <entry>0x0400</entry> 374 <entry>The &VIDIOC-ENUM-FREQ-BANDS; ioctl can be used to enumerate 375 the available frequency bands.</entry> 376 </row> 377 <row> 378 <entry><constant>V4L2_TUNER_CAP_HWSEEK_PROG_LIM</constant></entry> 379 <entry>0x0800</entry> 380 <entry>The range to search when using the hardware seek functionality 381 is programmable, see &VIDIOC-S-HW-FREQ-SEEK; for details.</entry> 382 </row> 383 <row> 384 <entry><constant>V4L2_TUNER_CAP_1HZ</constant></entry> 385 <entry>0x1000</entry> 386 <entry>When set, tuning frequencies are expressed in units of 1 Hz instead of 62.5 kHz.</entry> 387 </row> 388 </tbody> 389 </tgroup> 390 </table> 391 392 <table pgwide="1" frame="none" id="tuner-rxsubchans"> 393 <title>Tuner Audio Reception Flags</title> 394 <tgroup cols="3"> 395 &cs-def; 396 <tbody valign="top"> 397 <row> 398 <entry><constant>V4L2_TUNER_SUB_MONO</constant></entry> 399 <entry>0x0001</entry> 400 <entry>The tuner receives a mono audio signal.</entry> 401 </row> 402 <row> 403 <entry><constant>V4L2_TUNER_SUB_STEREO</constant></entry> 404 <entry>0x0002</entry> 405 <entry>The tuner receives a stereo audio signal.</entry> 406 </row> 407 <row> 408 <entry><constant>V4L2_TUNER_SUB_LANG1</constant></entry> 409 <entry>0x0008</entry> 410 <entry>The tuner receives the primary language of a 411 bilingual audio signal. Drivers must clear this flag when the current 412 video standard is <constant>V4L2_STD_NTSC_M</constant>.</entry> 413 </row> 414 <row> 415 <entry><constant>V4L2_TUNER_SUB_LANG2</constant></entry> 416 <entry>0x0004</entry> 417 <entry>The tuner receives the secondary language of a 418 bilingual audio signal (or a second audio program).</entry> 419 </row> 420 <row> 421 <entry><constant>V4L2_TUNER_SUB_SAP</constant></entry> 422 <entry>0x0004</entry> 423 <entry>The tuner receives a Second Audio Program. Note the 424 <constant>V4L2_TUNER_SUB_LANG2</constant> and 425 <constant>V4L2_TUNER_SUB_SAP</constant> flags are synonyms. The 426 <constant>V4L2_TUNER_SUB_SAP</constant> flag applies when the 427 current video standard is <constant>V4L2_STD_NTSC_M</constant>.</entry> 428 </row> 429 <row> 430 <entry><constant>V4L2_TUNER_SUB_RDS</constant></entry> 431 <entry>0x0010</entry> 432 <entry>The tuner receives an RDS channel.</entry> 433 </row> 434 </tbody> 435 </tgroup> 436 </table> 437 438 <table pgwide="1" frame="none" id="tuner-audmode"> 439 <title>Tuner Audio Modes</title> 440 <tgroup cols="3"> 441 &cs-def; 442 <tbody valign="top"> 443 <row> 444 <entry><constant>V4L2_TUNER_MODE_MONO</constant></entry> 445 <entry>0</entry> 446 <entry>Play mono audio. When the tuner receives a stereo 447 signal this a down-mix of the left and right channel. When the tuner 448 receives a bilingual or SAP signal this mode selects the primary 449 language.</entry> 450 </row> 451 <row> 452 <entry><constant>V4L2_TUNER_MODE_STEREO</constant></entry> 453 <entry>1</entry> 454 <entry><para>Play stereo audio. When the tuner receives 455 bilingual audio it may play different languages on the left and right 456 channel or the primary language is played on both channels.</para><para>Playing 457 different languages in this mode is 458 deprecated. New drivers should do this only in 459 <constant>MODE_LANG1_LANG2</constant>.</para><para>When the tuner 460 receives no stereo signal or does not support stereo reception the 461 driver shall fall back to <constant>MODE_MONO</constant>.</para></entry> 462 </row> 463 <row> 464 <entry><constant>V4L2_TUNER_MODE_LANG1</constant></entry> 465 <entry>3</entry> 466 <entry>Play the primary language, mono or stereo. Only 467 <constant>V4L2_TUNER_ANALOG_TV</constant> tuners support this 468 mode.</entry> 469 </row> 470 <row> 471 <entry><constant>V4L2_TUNER_MODE_LANG2</constant></entry> 472 <entry>2</entry> 473 <entry>Play the secondary language, mono. When the tuner 474 receives no bilingual audio or SAP, or their reception is not 475 supported the driver shall fall back to mono or stereo mode. Only 476 <constant>V4L2_TUNER_ANALOG_TV</constant> tuners support this 477 mode.</entry> 478 </row> 479 <row> 480 <entry><constant>V4L2_TUNER_MODE_SAP</constant></entry> 481 <entry>2</entry> 482 <entry>Play the Second Audio Program. When the tuner 483 receives no bilingual audio or SAP, or their reception is not 484 supported the driver shall fall back to mono or stereo mode. Only 485 <constant>V4L2_TUNER_ANALOG_TV</constant> tuners support this mode. 486 Note the <constant>V4L2_TUNER_MODE_LANG2</constant> and 487 <constant>V4L2_TUNER_MODE_SAP</constant> are synonyms.</entry> 488 </row> 489 <row> 490 <entry><constant>V4L2_TUNER_MODE_LANG1_LANG2</constant></entry> 491 <entry>4</entry> 492 <entry>Play the primary language on the left channel, the 493 secondary language on the right channel. When the tuner receives no 494 bilingual audio or SAP, it shall fall back to 495 <constant>MODE_LANG1</constant> or <constant>MODE_MONO</constant>. 496 Only <constant>V4L2_TUNER_ANALOG_TV</constant> tuners support this 497 mode.</entry> 498 </row> 499 </tbody> 500 </tgroup> 501 </table> 502 503 <table pgwide="1" frame="all" id="tuner-matrix"> 504 <title>Tuner Audio Matrix</title> 505 <tgroup cols="6" align="center"> 506 <colspec align="left" /> 507 <colspec colname="c2" colwidth="1*" /> 508 <colspec colwidth="1*" /> 509 <colspec colwidth="1*" /> 510 <colspec colnum="6" colname="c6" colwidth="1*" /> 511 <spanspec namest="c2" nameend="c6" spanname="hspan" align="center" /> 512 <thead> 513 <row> 514 <entry></entry> 515 <entry spanname="hspan">Selected 516 <constant>V4L2_TUNER_MODE_</constant></entry> 517 </row> 518 <row> 519 <entry>Received <constant>V4L2_TUNER_SUB_</constant></entry> 520 <entry><constant>MONO</constant></entry> 521 <entry><constant>STEREO</constant></entry> 522 <entry><constant>LANG1</constant></entry> 523 <entry><constant>LANG2 = SAP</constant></entry> 524 <entry><constant>LANG1_LANG2</constant><footnote><para>This 525 mode has been added in Linux 2.6.17 and may not be supported by older 526 drivers.</para></footnote></entry> 527 </row> 528 </thead> 529 <tbody valign="top"> 530 <row> 531 <entry><constant>MONO</constant></entry> 532 <entry>Mono</entry> 533 <entry>Mono/Mono</entry> 534 <entry>Mono</entry> 535 <entry>Mono</entry> 536 <entry>Mono/Mono</entry> 537 </row> 538 <row> 539 <entry><constant>MONO | SAP</constant></entry> 540 <entry>Mono</entry> 541 <entry>Mono/Mono</entry> 542 <entry>Mono</entry> 543 <entry>SAP</entry> 544 <entry>Mono/SAP (preferred) or Mono/Mono</entry> 545 </row> 546 <row> 547 <entry><constant>STEREO</constant></entry> 548 <entry>L+R</entry> 549 <entry>L/R</entry> 550 <entry>Stereo L/R (preferred) or Mono L+R</entry> 551 <entry>Stereo L/R (preferred) or Mono L+R</entry> 552 <entry>L/R (preferred) or L+R/L+R</entry> 553 </row> 554 <row> 555 <entry><constant>STEREO | SAP</constant></entry> 556 <entry>L+R</entry> 557 <entry>L/R</entry> 558 <entry>Stereo L/R (preferred) or Mono L+R</entry> 559 <entry>SAP</entry> 560 <entry>L+R/SAP (preferred) or L/R or L+R/L+R</entry> 561 </row> 562 <row> 563 <entry><constant>LANG1 | LANG2</constant></entry> 564 <entry>Language 1</entry> 565 <entry>Lang1/Lang2 (deprecated<footnote><para>Playback of 566 both languages in <constant>MODE_STEREO</constant> is deprecated. In 567 the future drivers should produce only the primary language in this 568 mode. Applications should request 569 <constant>MODE_LANG1_LANG2</constant> to record both languages or a 570 stereo signal.</para></footnote>) or 571 Lang1/Lang1</entry> 572 <entry>Language 1</entry> 573 <entry>Language 2</entry> 574 <entry>Lang1/Lang2 (preferred) or Lang1/Lang1</entry> 575 </row> 576 </tbody> 577 </tgroup> 578 </table> 579 </refsect1> 580 581 <refsect1> 582 &return-value; 583 584 <variablelist> 585 <varlistentry> 586 <term><errorcode>EINVAL</errorcode></term> 587 <listitem> 588 <para>The &v4l2-tuner; <structfield>index</structfield> is 589 out of bounds.</para> 590 </listitem> 591 </varlistentry> 592 </variablelist> 593 </refsect1> 594 </refentry>
