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1 <section id="control">
2 <title>User Controls</title>
4 <para>Devices typically have a number of user-settable controls
5 such as brightness, saturation and so on, which would be presented to
6 the user on a graphical user interface. But, different devices
7 will have different controls available, and furthermore, the range of
8 possible values, and the default value will vary from device to
9 device. The control ioctls provide the information and a mechanism to
10 create a nice user interface for these controls that will work
11 correctly with any device.</para>
13 <para>All controls are accessed using an ID value. V4L2 defines
14 several IDs for specific purposes. Drivers can also implement their
15 own custom controls using <constant>V4L2_CID_PRIVATE_BASE</constant>
16 and higher values. The pre-defined control IDs have the prefix
17 <constant>V4L2_CID_</constant>, and are listed in <xref
18 linkend="control-id" />. The ID is used when querying the attributes of
19 a control, and when getting or setting the current value.</para>
21 <para>Generally applications should present controls to the user
22 without assumptions about their purpose. Each control comes with a
23 name string the user is supposed to understand. When the purpose is
24 non-intuitive the driver writer should provide a user manual, a user
25 interface plug-in or a driver specific panel application. Predefined
26 IDs were introduced to change a few controls programmatically, for
27 example to mute a device during a channel switch.</para>
29 <para>Drivers may enumerate different controls after switching
30 the current video input or output, tuner or modulator, or audio input
31 or output. Different in the sense of other bounds, another default and
32 current value, step size or other menu items. A control with a certain
33 <emphasis>custom</emphasis> ID can also change name and
34 type.<footnote>
35 <para>It will be more convenient for applications if drivers
36 make use of the <constant>V4L2_CTRL_FLAG_DISABLED</constant> flag, but
37 that was never required.</para>
38 </footnote> Control values are stored globally, they do not
39 change when switching except to stay within the reported bounds. They
40 also do not change ⪚ when the device is opened or closed, when the
41 tuner radio frequency is changed or generally never without
42 application request. Since V4L2 specifies no event mechanism, panel
43 applications intended to cooperate with other panel applications (be
44 they built into a larger application, as a TV viewer) may need to
45 regularly poll control values to update their user
46 interface.<footnote>
47 <para>Applications could call an ioctl to request events.
48 After another process called &VIDIOC-S-CTRL; or another ioctl changing
49 shared properties the &func-select; function would indicate
50 readability until any ioctl (querying the properties) is
51 called.</para>
52 </footnote></para>
54 <para>
55 All controls use machine endianness.
56 </para>
58 <table pgwide="1" frame="none" id="control-id">
59 <title>Control IDs</title>
60 <tgroup cols="3">
61 &cs-def;
62 <thead>
63 <row>
64 <entry>ID</entry>
65 <entry>Type</entry>
66 <entry>Description</entry>
67 </row>
68 </thead>
69 <tbody valign="top">
70 <row>
71 <entry><constant>V4L2_CID_BASE</constant></entry>
72 <entry></entry>
73 <entry>First predefined ID, equal to
74 <constant>V4L2_CID_BRIGHTNESS</constant>.</entry>
75 </row>
76 <row>
77 <entry><constant>V4L2_CID_USER_BASE</constant></entry>
78 <entry></entry>
79 <entry>Synonym of <constant>V4L2_CID_BASE</constant>.</entry>
80 </row>
81 <row>
82 <entry><constant>V4L2_CID_BRIGHTNESS</constant></entry>
83 <entry>integer</entry>
84 <entry>Picture brightness, or more precisely, the black
85 level.</entry>
86 </row>
87 <row>
88 <entry><constant>V4L2_CID_CONTRAST</constant></entry>
89 <entry>integer</entry>
90 <entry>Picture contrast or luma gain.</entry>
91 </row>
92 <row>
93 <entry><constant>V4L2_CID_SATURATION</constant></entry>
94 <entry>integer</entry>
95 <entry>Picture color saturation or chroma gain.</entry>
96 </row>
97 <row>
98 <entry><constant>V4L2_CID_HUE</constant></entry>
99 <entry>integer</entry>
100 <entry>Hue or color balance.</entry>
101 </row>
102 <row>
103 <entry><constant>V4L2_CID_AUDIO_VOLUME</constant></entry>
104 <entry>integer</entry>
105 <entry>Overall audio volume. Note some drivers also
106 provide an OSS or ALSA mixer interface.</entry>
107 </row>
108 <row>
109 <entry><constant>V4L2_CID_AUDIO_BALANCE</constant></entry>
110 <entry>integer</entry>
111 <entry>Audio stereo balance. Minimum corresponds to all
112 the way left, maximum to right.</entry>
113 </row>
114 <row>
115 <entry><constant>V4L2_CID_AUDIO_BASS</constant></entry>
116 <entry>integer</entry>
117 <entry>Audio bass adjustment.</entry>
118 </row>
119 <row>
120 <entry><constant>V4L2_CID_AUDIO_TREBLE</constant></entry>
121 <entry>integer</entry>
122 <entry>Audio treble adjustment.</entry>
123 </row>
124 <row>
125 <entry><constant>V4L2_CID_AUDIO_MUTE</constant></entry>
126 <entry>boolean</entry>
127 <entry>Mute audio, &ie; set the volume to zero, however
128 without affecting <constant>V4L2_CID_AUDIO_VOLUME</constant>. Like
129 ALSA drivers, V4L2 drivers must mute at load time to avoid excessive
130 noise. Actually the entire device should be reset to a low power
131 consumption state.</entry>
132 </row>
133 <row>
134 <entry><constant>V4L2_CID_AUDIO_LOUDNESS</constant></entry>
135 <entry>boolean</entry>
136 <entry>Loudness mode (bass boost).</entry>
137 </row>
138 <row>
139 <entry><constant>V4L2_CID_BLACK_LEVEL</constant></entry>
140 <entry>integer</entry>
141 <entry>Another name for brightness (not a synonym of
142 <constant>V4L2_CID_BRIGHTNESS</constant>). This control is deprecated
143 and should not be used in new drivers and applications.</entry>
144 </row>
145 <row>
146 <entry><constant>V4L2_CID_AUTO_WHITE_BALANCE</constant></entry>
147 <entry>boolean</entry>
148 <entry>Automatic white balance (cameras).</entry>
149 </row>
150 <row>
151 <entry><constant>V4L2_CID_DO_WHITE_BALANCE</constant></entry>
152 <entry>button</entry>
153 <entry>This is an action control. When set (the value is
154 ignored), the device will do a white balance and then hold the current
155 setting. Contrast this with the boolean
156 <constant>V4L2_CID_AUTO_WHITE_BALANCE</constant>, which, when
157 activated, keeps adjusting the white balance.</entry>
158 </row>
159 <row>
160 <entry><constant>V4L2_CID_RED_BALANCE</constant></entry>
161 <entry>integer</entry>
162 <entry>Red chroma balance.</entry>
163 </row>
164 <row>
165 <entry><constant>V4L2_CID_BLUE_BALANCE</constant></entry>
166 <entry>integer</entry>
167 <entry>Blue chroma balance.</entry>
168 </row>
169 <row>
170 <entry><constant>V4L2_CID_GAMMA</constant></entry>
171 <entry>integer</entry>
172 <entry>Gamma adjust.</entry>
173 </row>
174 <row>
175 <entry><constant>V4L2_CID_WHITENESS</constant></entry>
176 <entry>integer</entry>
177 <entry>Whiteness for grey-scale devices. This is a synonym
178 for <constant>V4L2_CID_GAMMA</constant>. This control is deprecated
179 and should not be used in new drivers and applications.</entry>
180 </row>
181 <row>
182 <entry><constant>V4L2_CID_EXPOSURE</constant></entry>
183 <entry>integer</entry>
184 <entry>Exposure (cameras). [Unit?]</entry>
185 </row>
186 <row>
187 <entry><constant>V4L2_CID_AUTOGAIN</constant></entry>
188 <entry>boolean</entry>
189 <entry>Automatic gain/exposure control.</entry>
190 </row>
191 <row>
192 <entry><constant>V4L2_CID_GAIN</constant></entry>
193 <entry>integer</entry>
194 <entry>Gain control.</entry>
195 </row>
196 <row>
197 <entry><constant>V4L2_CID_HFLIP</constant></entry>
198 <entry>boolean</entry>
199 <entry>Mirror the picture horizontally.</entry>
200 </row>
201 <row>
202 <entry><constant>V4L2_CID_VFLIP</constant></entry>
203 <entry>boolean</entry>
204 <entry>Mirror the picture vertically.</entry>
205 </row>
206 <row>
207 <entry><constant>V4L2_CID_HCENTER_DEPRECATED</constant> (formerly <constant>V4L2_CID_HCENTER</constant>)</entry>
208 <entry>integer</entry>
209 <entry>Horizontal image centering. This control is
210 deprecated. New drivers and applications should use the <link
211 linkend="camera-controls">Camera class controls</link>
212 <constant>V4L2_CID_PAN_ABSOLUTE</constant>,
213 <constant>V4L2_CID_PAN_RELATIVE</constant> and
214 <constant>V4L2_CID_PAN_RESET</constant> instead.</entry>
215 </row>
216 <row>
217 <entry><constant>V4L2_CID_VCENTER_DEPRECATED</constant>
218 (formerly <constant>V4L2_CID_VCENTER</constant>)</entry>
219 <entry>integer</entry>
220 <entry>Vertical image centering. Centering is intended to
221 <emphasis>physically</emphasis> adjust cameras. For image cropping see
222 <xref linkend="crop" />, for clipping <xref linkend="overlay" />. This
223 control is deprecated. New drivers and applications should use the
224 <link linkend="camera-controls">Camera class controls</link>
225 <constant>V4L2_CID_TILT_ABSOLUTE</constant>,
226 <constant>V4L2_CID_TILT_RELATIVE</constant> and
227 <constant>V4L2_CID_TILT_RESET</constant> instead.</entry>
228 </row>
229 <row id="v4l2-power-line-frequency">
230 <entry><constant>V4L2_CID_POWER_LINE_FREQUENCY</constant></entry>
231 <entry>enum</entry>
232 <entry>Enables a power line frequency filter to avoid
233 flicker. Possible values for <constant>enum v4l2_power_line_frequency</constant> are:
234 <constant>V4L2_CID_POWER_LINE_FREQUENCY_DISABLED</constant> (0),
235 <constant>V4L2_CID_POWER_LINE_FREQUENCY_50HZ</constant> (1),
236 <constant>V4L2_CID_POWER_LINE_FREQUENCY_60HZ</constant> (2) and
237 <constant>V4L2_CID_POWER_LINE_FREQUENCY_AUTO</constant> (3).</entry>
238 </row>
239 <row>
240 <entry><constant>V4L2_CID_HUE_AUTO</constant></entry>
241 <entry>boolean</entry>
242 <entry>Enables automatic hue control by the device. The
243 effect of setting <constant>V4L2_CID_HUE</constant> while automatic
244 hue control is enabled is undefined, drivers should ignore such
245 request.</entry>
246 </row>
247 <row>
248 <entry><constant>V4L2_CID_WHITE_BALANCE_TEMPERATURE</constant></entry>
249 <entry>integer</entry>
250 <entry>This control specifies the white balance settings
251 as a color temperature in Kelvin. A driver should have a minimum of
252 2800 (incandescent) to 6500 (daylight). For more information about
253 color temperature see <ulink
254 url="http://en.wikipedia.org/wiki/Color_temperature">Wikipedia</ulink>.</entry>
255 </row>
256 <row>
257 <entry><constant>V4L2_CID_SHARPNESS</constant></entry>
258 <entry>integer</entry>
259 <entry>Adjusts the sharpness filters in a camera. The
260 minimum value disables the filters, higher values give a sharper
261 picture.</entry>
262 </row>
263 <row>
264 <entry><constant>V4L2_CID_BACKLIGHT_COMPENSATION</constant></entry>
265 <entry>integer</entry>
266 <entry>Adjusts the backlight compensation in a camera. The
267 minimum value disables backlight compensation.</entry>
268 </row>
269 <row>
270 <entry><constant>V4L2_CID_CHROMA_AGC</constant></entry>
271 <entry>boolean</entry>
272 <entry>Chroma automatic gain control.</entry>
273 </row>
274 <row>
275 <entry><constant>V4L2_CID_CHROMA_GAIN</constant></entry>
276 <entry>integer</entry>
277 <entry>Adjusts the Chroma gain control (for use when chroma AGC
278 is disabled).</entry>
279 </row>
280 <row>
281 <entry><constant>V4L2_CID_COLOR_KILLER</constant></entry>
282 <entry>boolean</entry>
283 <entry>Enable the color killer (&ie; force a black & white image in case of a weak video signal).</entry>
284 </row>
285 <row id="v4l2-colorfx">
286 <entry><constant>V4L2_CID_COLORFX</constant></entry>
287 <entry>enum</entry>
288 <entry>Selects a color effect. Possible values for
289 <constant>enum v4l2_colorfx</constant> are:
290 <constant>V4L2_COLORFX_NONE</constant> (0),
291 <constant>V4L2_COLORFX_BW</constant> (1),
292 <constant>V4L2_COLORFX_SEPIA</constant> (2),
293 <constant>V4L2_COLORFX_NEGATIVE</constant> (3),
294 <constant>V4L2_COLORFX_EMBOSS</constant> (4),
295 <constant>V4L2_COLORFX_SKETCH</constant> (5),
296 <constant>V4L2_COLORFX_SKY_BLUE</constant> (6),
297 <constant>V4L2_COLORFX_GRASS_GREEN</constant> (7),
298 <constant>V4L2_COLORFX_SKIN_WHITEN</constant> (8) and
299 <constant>V4L2_COLORFX_VIVID</constant> (9).</entry>
300 </row>
301 <row>
302 <entry><constant>V4L2_CID_ROTATE</constant></entry>
303 <entry>integer</entry>
304 <entry>Rotates the image by specified angle. Common angles are 90,
305 270 and 180. Rotating the image to 90 and 270 will reverse the height
306 and width of the display window. It is necessary to set the new height and
307 width of the picture using the &VIDIOC-S-FMT; ioctl according to
308 the rotation angle selected.</entry>
309 </row>
310 <row>
311 <entry><constant>V4L2_CID_BG_COLOR</constant></entry>
312 <entry>integer</entry>
313 <entry>Sets the background color on the current output device.
314 Background color needs to be specified in the RGB24 format. The
315 supplied 32 bit value is interpreted as bits 0-7 Red color information,
316 bits 8-15 Green color information, bits 16-23 Blue color
317 information and bits 24-31 must be zero.</entry>
318 </row>
319 <row>
320 <entry><constant>V4L2_CID_ILLUMINATORS_1</constant>
321 <constant>V4L2_CID_ILLUMINATORS_2</constant></entry>
322 <entry>boolean</entry>
323 <entry>Switch on or off the illuminator 1 or 2 of the device
324 (usually a microscope).</entry>
325 </row>
326 <row>
327 <entry><constant>V4L2_CID_LASTP1</constant></entry>
328 <entry></entry>
329 <entry>End of the predefined control IDs (currently
330 <constant>V4L2_CID_ILLUMINATORS_2</constant> + 1).</entry>
331 </row>
332 <row>
333 <entry><constant>V4L2_CID_MIN_BUFFERS_FOR_CAPTURE</constant></entry>
334 <entry>integer</entry>
335 <entry>This is a read-only control that can be read by the application
336 and used as a hint to determine the number of CAPTURE buffers to pass to REQBUFS.
337 The value is the minimum number of CAPTURE buffers that is necessary for hardware
338 to work.</entry>
339 </row>
340 <row>
341 <entry><constant>V4L2_CID_MIN_BUFFERS_FOR_OUTPUT</constant></entry>
342 <entry>integer</entry>
343 <entry>This is a read-only control that can be read by the application
344 and used as a hint to determine the number of OUTPUT buffers to pass to REQBUFS.
345 The value is the minimum number of OUTPUT buffers that is necessary for hardware
346 to work.</entry>
347 </row>
348 <row>
349 <entry><constant>V4L2_CID_PRIVATE_BASE</constant></entry>
350 <entry></entry>
351 <entry>ID of the first custom (driver specific) control.
352 Applications depending on particular custom controls should check the
353 driver name and version, see <xref linkend="querycap" />.</entry>
354 </row>
355 </tbody>
356 </tgroup>
357 </table>
359 <para>Applications can enumerate the available controls with the
360 &VIDIOC-QUERYCTRL; and &VIDIOC-QUERYMENU; ioctls, get and set a
361 control value with the &VIDIOC-G-CTRL; and &VIDIOC-S-CTRL; ioctls.
362 Drivers must implement <constant>VIDIOC_QUERYCTRL</constant>,
363 <constant>VIDIOC_G_CTRL</constant> and
364 <constant>VIDIOC_S_CTRL</constant> when the device has one or more
365 controls, <constant>VIDIOC_QUERYMENU</constant> when it has one or
366 more menu type controls.</para>
368 <example>
369 <title>Enumerating all controls</title>
371 <programlisting>
372 &v4l2-queryctrl; queryctrl;
373 &v4l2-querymenu; querymenu;
375 static void
376 enumerate_menu (void)
377 {
378 printf (" Menu items:\n");
380 memset (&querymenu, 0, sizeof (querymenu));
381 querymenu.id = queryctrl.id;
383 for (querymenu.index = queryctrl.minimum;
384 querymenu.index <= queryctrl.maximum;
385 querymenu.index++) {
386 if (0 == ioctl (fd, &VIDIOC-QUERYMENU;, &querymenu)) {
387 printf (" %s\n", querymenu.name);
388 }
389 }
390 }
392 memset (&queryctrl, 0, sizeof (queryctrl));
394 for (queryctrl.id = V4L2_CID_BASE;
395 queryctrl.id < V4L2_CID_LASTP1;
396 queryctrl.id++) {
397 if (0 == ioctl (fd, &VIDIOC-QUERYCTRL;, &queryctrl)) {
398 if (queryctrl.flags & V4L2_CTRL_FLAG_DISABLED)
399 continue;
401 printf ("Control %s\n", queryctrl.name);
403 if (queryctrl.type == V4L2_CTRL_TYPE_MENU)
404 enumerate_menu ();
405 } else {
406 if (errno == EINVAL)
407 continue;
409 perror ("VIDIOC_QUERYCTRL");
410 exit (EXIT_FAILURE);
411 }
412 }
414 for (queryctrl.id = V4L2_CID_PRIVATE_BASE;;
415 queryctrl.id++) {
416 if (0 == ioctl (fd, &VIDIOC-QUERYCTRL;, &queryctrl)) {
417 if (queryctrl.flags & V4L2_CTRL_FLAG_DISABLED)
418 continue;
420 printf ("Control %s\n", queryctrl.name);
422 if (queryctrl.type == V4L2_CTRL_TYPE_MENU)
423 enumerate_menu ();
424 } else {
425 if (errno == EINVAL)
426 break;
428 perror ("VIDIOC_QUERYCTRL");
429 exit (EXIT_FAILURE);
430 }
431 }
432 </programlisting>
433 </example>
435 <example>
436 <title>Changing controls</title>
438 <programlisting>
439 &v4l2-queryctrl; queryctrl;
440 &v4l2-control; control;
442 memset (&queryctrl, 0, sizeof (queryctrl));
443 queryctrl.id = V4L2_CID_BRIGHTNESS;
445 if (-1 == ioctl (fd, &VIDIOC-QUERYCTRL;, &queryctrl)) {
446 if (errno != EINVAL) {
447 perror ("VIDIOC_QUERYCTRL");
448 exit (EXIT_FAILURE);
449 } else {
450 printf ("V4L2_CID_BRIGHTNESS is not supported\n");
451 }
452 } else if (queryctrl.flags & V4L2_CTRL_FLAG_DISABLED) {
453 printf ("V4L2_CID_BRIGHTNESS is not supported\n");
454 } else {
455 memset (&control, 0, sizeof (control));
456 control.id = V4L2_CID_BRIGHTNESS;
457 control.value = queryctrl.default_value;
459 if (-1 == ioctl (fd, &VIDIOC-S-CTRL;, &control)) {
460 perror ("VIDIOC_S_CTRL");
461 exit (EXIT_FAILURE);
462 }
463 }
465 memset (&control, 0, sizeof (control));
466 control.id = V4L2_CID_CONTRAST;
468 if (0 == ioctl (fd, &VIDIOC-G-CTRL;, &control)) {
469 control.value += 1;
471 /* The driver may clamp the value or return ERANGE, ignored here */
473 if (-1 == ioctl (fd, &VIDIOC-S-CTRL;, &control)
474 && errno != ERANGE) {
475 perror ("VIDIOC_S_CTRL");
476 exit (EXIT_FAILURE);
477 }
478 /* Ignore if V4L2_CID_CONTRAST is unsupported */
479 } else if (errno != EINVAL) {
480 perror ("VIDIOC_G_CTRL");
481 exit (EXIT_FAILURE);
482 }
484 control.id = V4L2_CID_AUDIO_MUTE;
485 control.value = TRUE; /* silence */
487 /* Errors ignored */
488 ioctl (fd, VIDIOC_S_CTRL, &control);
489 </programlisting>
490 </example>
491 </section>
493 <section id="extended-controls">
494 <title>Extended Controls</title>
496 <section>
497 <title>Introduction</title>
499 <para>The control mechanism as originally designed was meant
500 to be used for user settings (brightness, saturation, etc). However,
501 it turned out to be a very useful model for implementing more
502 complicated driver APIs where each driver implements only a subset of
503 a larger API.</para>
505 <para>The MPEG encoding API was the driving force behind
506 designing and implementing this extended control mechanism: the MPEG
507 standard is quite large and the currently supported hardware MPEG
508 encoders each only implement a subset of this standard. Further more,
509 many parameters relating to how the video is encoded into an MPEG
510 stream are specific to the MPEG encoding chip since the MPEG standard
511 only defines the format of the resulting MPEG stream, not how the
512 video is actually encoded into that format.</para>
514 <para>Unfortunately, the original control API lacked some
515 features needed for these new uses and so it was extended into the
516 (not terribly originally named) extended control API.</para>
518 <para>Even though the MPEG encoding API was the first effort
519 to use the Extended Control API, nowadays there are also other classes
520 of Extended Controls, such as Camera Controls and FM Transmitter Controls.
521 The Extended Controls API as well as all Extended Controls classes are
522 described in the following text.</para>
523 </section>
525 <section>
526 <title>The Extended Control API</title>
528 <para>Three new ioctls are available: &VIDIOC-G-EXT-CTRLS;,
529 &VIDIOC-S-EXT-CTRLS; and &VIDIOC-TRY-EXT-CTRLS;. These ioctls act on
530 arrays of controls (as opposed to the &VIDIOC-G-CTRL; and
531 &VIDIOC-S-CTRL; ioctls that act on a single control). This is needed
532 since it is often required to atomically change several controls at
533 once.</para>
535 <para>Each of the new ioctls expects a pointer to a
536 &v4l2-ext-controls;. This structure contains a pointer to the control
537 array, a count of the number of controls in that array and a control
538 class. Control classes are used to group similar controls into a
539 single class. For example, control class
540 <constant>V4L2_CTRL_CLASS_USER</constant> contains all user controls
541 (&ie; all controls that can also be set using the old
542 <constant>VIDIOC_S_CTRL</constant> ioctl). Control class
543 <constant>V4L2_CTRL_CLASS_MPEG</constant> contains all controls
544 relating to MPEG encoding, etc.</para>
546 <para>All controls in the control array must belong to the
547 specified control class. An error is returned if this is not the
548 case.</para>
550 <para>It is also possible to use an empty control array (count
551 == 0) to check whether the specified control class is
552 supported.</para>
554 <para>The control array is a &v4l2-ext-control; array. The
555 <structname>v4l2_ext_control</structname> structure is very similar to
556 &v4l2-control;, except for the fact that it also allows for 64-bit
557 values and pointers to be passed.</para>
559 <para>It is important to realize that due to the flexibility of
560 controls it is necessary to check whether the control you want to set
561 actually is supported in the driver and what the valid range of values
562 is. So use the &VIDIOC-QUERYCTRL; and &VIDIOC-QUERYMENU; ioctls to
563 check this. Also note that it is possible that some of the menu
564 indices in a control of type <constant>V4L2_CTRL_TYPE_MENU</constant>
565 may not be supported (<constant>VIDIOC_QUERYMENU</constant> will
566 return an error). A good example is the list of supported MPEG audio
567 bitrates. Some drivers only support one or two bitrates, others
568 support a wider range.</para>
570 <para>
571 All controls use machine endianness.
572 </para>
573 </section>
575 <section>
576 <title>Enumerating Extended Controls</title>
578 <para>The recommended way to enumerate over the extended
579 controls is by using &VIDIOC-QUERYCTRL; in combination with the
580 <constant>V4L2_CTRL_FLAG_NEXT_CTRL</constant> flag:</para>
582 <informalexample>
583 <programlisting>
584 &v4l2-queryctrl; qctrl;
586 qctrl.id = V4L2_CTRL_FLAG_NEXT_CTRL;
587 while (0 == ioctl (fd, &VIDIOC-QUERYCTRL;, &qctrl)) {
588 /* ... */
589 qctrl.id |= V4L2_CTRL_FLAG_NEXT_CTRL;
590 }
591 </programlisting>
592 </informalexample>
594 <para>The initial control ID is set to 0 ORed with the
595 <constant>V4L2_CTRL_FLAG_NEXT_CTRL</constant> flag. The
596 <constant>VIDIOC_QUERYCTRL</constant> ioctl will return the first
597 control with a higher ID than the specified one. When no such controls
598 are found an error is returned.</para>
600 <para>If you want to get all controls within a specific control
601 class, then you can set the initial
602 <structfield>qctrl.id</structfield> value to the control class and add
603 an extra check to break out of the loop when a control of another
604 control class is found:</para>
606 <informalexample>
607 <programlisting>
608 qctrl.id = V4L2_CTRL_CLASS_MPEG | V4L2_CTRL_FLAG_NEXT_CTRL;
609 while (0 == ioctl (fd, &VIDIOC-QUERYCTRL;, &qctrl)) {
610 if (V4L2_CTRL_ID2CLASS (qctrl.id) != V4L2_CTRL_CLASS_MPEG)
611 break;
612 /* ... */
613 qctrl.id |= V4L2_CTRL_FLAG_NEXT_CTRL;
614 }
615 </programlisting>
616 </informalexample>
618 <para>The 32-bit <structfield>qctrl.id</structfield> value is
619 subdivided into three bit ranges: the top 4 bits are reserved for
620 flags (⪚ <constant>V4L2_CTRL_FLAG_NEXT_CTRL</constant>) and are not
621 actually part of the ID. The remaining 28 bits form the control ID, of
622 which the most significant 12 bits define the control class and the
623 least significant 16 bits identify the control within the control
624 class. It is guaranteed that these last 16 bits are always non-zero
625 for controls. The range of 0x1000 and up are reserved for
626 driver-specific controls. The macro
627 <constant>V4L2_CTRL_ID2CLASS(id)</constant> returns the control class
628 ID based on a control ID.</para>
630 <para>If the driver does not support extended controls, then
631 <constant>VIDIOC_QUERYCTRL</constant> will fail when used in
632 combination with <constant>V4L2_CTRL_FLAG_NEXT_CTRL</constant>. In
633 that case the old method of enumerating control should be used (see
634 1.8). But if it is supported, then it is guaranteed to enumerate over
635 all controls, including driver-private controls.</para>
636 </section>
638 <section>
639 <title>Creating Control Panels</title>
641 <para>It is possible to create control panels for a graphical
642 user interface where the user can select the various controls.
643 Basically you will have to iterate over all controls using the method
644 described above. Each control class starts with a control of type
645 <constant>V4L2_CTRL_TYPE_CTRL_CLASS</constant>.
646 <constant>VIDIOC_QUERYCTRL</constant> will return the name of this
647 control class which can be used as the title of a tab page within a
648 control panel.</para>
650 <para>The flags field of &v4l2-queryctrl; also contains hints on
651 the behavior of the control. See the &VIDIOC-QUERYCTRL; documentation
652 for more details.</para>
653 </section>
655 <section id="mpeg-controls">
656 <title>MPEG Control Reference</title>
658 <para>Below all controls within the MPEG control class are
659 described. First the generic controls, then controls specific for
660 certain hardware.</para>
662 <section>
663 <title>Generic MPEG Controls</title>
665 <table pgwide="1" frame="none" id="mpeg-control-id">
666 <title>MPEG Control IDs</title>
667 <tgroup cols="4">
668 <colspec colname="c1" colwidth="1*" />
669 <colspec colname="c2" colwidth="6*" />
670 <colspec colname="c3" colwidth="2*" />
671 <colspec colname="c4" colwidth="6*" />
672 <spanspec namest="c1" nameend="c2" spanname="id" />
673 <spanspec namest="c2" nameend="c4" spanname="descr" />
674 <thead>
675 <row>
676 <entry spanname="id" align="left">ID</entry>
677 <entry align="left">Type</entry>
678 </row><row rowsep="1"><entry spanname="descr" align="left">Description</entry>
679 </row>
680 </thead>
681 <tbody valign="top">
682 <row><entry></entry></row>
683 <row>
684 <entry spanname="id"><constant>V4L2_CID_MPEG_CLASS</constant> </entry>
685 <entry>class</entry>
686 </row><row><entry spanname="descr">The MPEG class
687 descriptor. Calling &VIDIOC-QUERYCTRL; for this control will return a
688 description of this control class. This description can be used as the
689 caption of a Tab page in a GUI, for example.</entry>
690 </row>
691 <row><entry></entry></row>
692 <row id="v4l2-mpeg-stream-type">
693 <entry spanname="id"><constant>V4L2_CID_MPEG_STREAM_TYPE</constant> </entry>
694 <entry>enum v4l2_mpeg_stream_type</entry>
695 </row><row><entry spanname="descr">The MPEG-1, -2 or -4
696 output stream type. One cannot assume anything here. Each hardware
697 MPEG encoder tends to support different subsets of the available MPEG
698 stream types. This control is specific to multiplexed MPEG streams.
699 The currently defined stream types are:</entry>
700 </row>
701 <row>
702 <entrytbl spanname="descr" cols="2">
703 <tbody valign="top">
704 <row>
705 <entry><constant>V4L2_MPEG_STREAM_TYPE_MPEG2_PS</constant> </entry>
706 <entry>MPEG-2 program stream</entry>
707 </row>
708 <row>
709 <entry><constant>V4L2_MPEG_STREAM_TYPE_MPEG2_TS</constant> </entry>
710 <entry>MPEG-2 transport stream</entry>
711 </row>
712 <row>
713 <entry><constant>V4L2_MPEG_STREAM_TYPE_MPEG1_SS</constant> </entry>
714 <entry>MPEG-1 system stream</entry>
715 </row>
716 <row>
717 <entry><constant>V4L2_MPEG_STREAM_TYPE_MPEG2_DVD</constant> </entry>
718 <entry>MPEG-2 DVD-compatible stream</entry>
719 </row>
720 <row>
721 <entry><constant>V4L2_MPEG_STREAM_TYPE_MPEG1_VCD</constant> </entry>
722 <entry>MPEG-1 VCD-compatible stream</entry>
723 </row>
724 <row>
725 <entry><constant>V4L2_MPEG_STREAM_TYPE_MPEG2_SVCD</constant> </entry>
726 <entry>MPEG-2 SVCD-compatible stream</entry>
727 </row>
728 </tbody>
729 </entrytbl>
730 </row>
731 <row><entry></entry></row>
732 <row>
733 <entry spanname="id"><constant>V4L2_CID_MPEG_STREAM_PID_PMT</constant> </entry>
734 <entry>integer</entry>
735 </row><row><entry spanname="descr">Program Map Table
736 Packet ID for the MPEG transport stream (default 16)</entry>
737 </row>
738 <row><entry></entry></row>
739 <row>
740 <entry spanname="id"><constant>V4L2_CID_MPEG_STREAM_PID_AUDIO</constant> </entry>
741 <entry>integer</entry>
742 </row><row><entry spanname="descr">Audio Packet ID for
743 the MPEG transport stream (default 256)</entry>
744 </row>
745 <row><entry></entry></row>
746 <row>
747 <entry spanname="id"><constant>V4L2_CID_MPEG_STREAM_PID_VIDEO</constant> </entry>
748 <entry>integer</entry>
749 </row><row><entry spanname="descr">Video Packet ID for
750 the MPEG transport stream (default 260)</entry>
751 </row>
752 <row><entry></entry></row>
753 <row>
754 <entry spanname="id"><constant>V4L2_CID_MPEG_STREAM_PID_PCR</constant> </entry>
755 <entry>integer</entry>
756 </row><row><entry spanname="descr">Packet ID for the
757 MPEG transport stream carrying PCR fields (default 259)</entry>
758 </row>
759 <row><entry></entry></row>
760 <row>
761 <entry spanname="id"><constant>V4L2_CID_MPEG_STREAM_PES_ID_AUDIO</constant> </entry>
762 <entry>integer</entry>
763 </row><row><entry spanname="descr">Audio ID for MPEG
764 PES</entry>
765 </row>
766 <row><entry></entry></row>
767 <row>
768 <entry spanname="id"><constant>V4L2_CID_MPEG_STREAM_PES_ID_VIDEO</constant> </entry>
769 <entry>integer</entry>
770 </row><row><entry spanname="descr">Video ID for MPEG
771 PES</entry>
772 </row>
773 <row><entry></entry></row>
774 <row id="v4l2-mpeg-stream-vbi-fmt">
775 <entry spanname="id"><constant>V4L2_CID_MPEG_STREAM_VBI_FMT</constant> </entry>
776 <entry>enum v4l2_mpeg_stream_vbi_fmt</entry>
777 </row><row><entry spanname="descr">Some cards can embed
778 VBI data (⪚ Closed Caption, Teletext) into the MPEG stream. This
779 control selects whether VBI data should be embedded, and if so, what
780 embedding method should be used. The list of possible VBI formats
781 depends on the driver. The currently defined VBI format types
782 are:</entry>
783 </row>
784 <row>
785 <entrytbl spanname="descr" cols="2">
786 <tbody valign="top">
787 <row>
788 <entry><constant>V4L2_MPEG_STREAM_VBI_FMT_NONE</constant> </entry>
789 <entry>No VBI in the MPEG stream</entry>
790 </row>
791 <row>
792 <entry><constant>V4L2_MPEG_STREAM_VBI_FMT_IVTV</constant> </entry>
793 <entry>VBI in private packets, IVTV format (documented
794 in the kernel sources in the file <filename>Documentation/video4linux/cx2341x/README.vbi</filename>)</entry>
795 </row>
796 </tbody>
797 </entrytbl>
798 </row>
799 <row><entry></entry></row>
800 <row id="v4l2-mpeg-audio-sampling-freq">
801 <entry spanname="id"><constant>V4L2_CID_MPEG_AUDIO_SAMPLING_FREQ</constant> </entry>
802 <entry>enum v4l2_mpeg_audio_sampling_freq</entry>
803 </row><row><entry spanname="descr">MPEG Audio sampling
804 frequency. Possible values are:</entry>
805 </row>
806 <row>
807 <entrytbl spanname="descr" cols="2">
808 <tbody valign="top">
809 <row>
810 <entry><constant>V4L2_MPEG_AUDIO_SAMPLING_FREQ_44100</constant> </entry>
811 <entry>44.1 kHz</entry>
812 </row>
813 <row>
814 <entry><constant>V4L2_MPEG_AUDIO_SAMPLING_FREQ_48000</constant> </entry>
815 <entry>48 kHz</entry>
816 </row>
817 <row>
818 <entry><constant>V4L2_MPEG_AUDIO_SAMPLING_FREQ_32000</constant> </entry>
819 <entry>32 kHz</entry>
820 </row>
821 </tbody>
822 </entrytbl>
823 </row>
824 <row><entry></entry></row>
825 <row id="v4l2-mpeg-audio-encoding">
826 <entry spanname="id"><constant>V4L2_CID_MPEG_AUDIO_ENCODING</constant> </entry>
827 <entry>enum v4l2_mpeg_audio_encoding</entry>
828 </row><row><entry spanname="descr">MPEG Audio encoding.
829 This control is specific to multiplexed MPEG streams.
830 Possible values are:</entry>
831 </row>
832 <row>
833 <entrytbl spanname="descr" cols="2">
834 <tbody valign="top">
835 <row>
836 <entry><constant>V4L2_MPEG_AUDIO_ENCODING_LAYER_1</constant> </entry>
837 <entry>MPEG-1/2 Layer I encoding</entry>
838 </row>
839 <row>
840 <entry><constant>V4L2_MPEG_AUDIO_ENCODING_LAYER_2</constant> </entry>
841 <entry>MPEG-1/2 Layer II encoding</entry>
842 </row>
843 <row>
844 <entry><constant>V4L2_MPEG_AUDIO_ENCODING_LAYER_3</constant> </entry>
845 <entry>MPEG-1/2 Layer III encoding</entry>
846 </row>
847 <row>
848 <entry><constant>V4L2_MPEG_AUDIO_ENCODING_AAC</constant> </entry>
849 <entry>MPEG-2/4 AAC (Advanced Audio Coding)</entry>
850 </row>
851 <row>
852 <entry><constant>V4L2_MPEG_AUDIO_ENCODING_AC3</constant> </entry>
853 <entry>AC-3 aka ATSC A/52 encoding</entry>
854 </row>
855 </tbody>
856 </entrytbl>
857 </row>
858 <row><entry></entry></row>
859 <row id="v4l2-mpeg-audio-l1-bitrate">
860 <entry spanname="id"><constant>V4L2_CID_MPEG_AUDIO_L1_BITRATE</constant> </entry>
861 <entry>enum v4l2_mpeg_audio_l1_bitrate</entry>
862 </row><row><entry spanname="descr">MPEG-1/2 Layer I bitrate.
863 Possible values are:</entry>
864 </row>
865 <row>
866 <entrytbl spanname="descr" cols="2">
867 <tbody valign="top">
868 <row>
869 <entry><constant>V4L2_MPEG_AUDIO_L1_BITRATE_32K</constant> </entry>
870 <entry>32 kbit/s</entry></row>
871 <row>
872 <entry><constant>V4L2_MPEG_AUDIO_L1_BITRATE_64K</constant> </entry>
873 <entry>64 kbit/s</entry>
874 </row>
875 <row>
876 <entry><constant>V4L2_MPEG_AUDIO_L1_BITRATE_96K</constant> </entry>
877 <entry>96 kbit/s</entry>
878 </row>
879 <row>
880 <entry><constant>V4L2_MPEG_AUDIO_L1_BITRATE_128K</constant> </entry>
881 <entry>128 kbit/s</entry>
882 </row>
883 <row>
884 <entry><constant>V4L2_MPEG_AUDIO_L1_BITRATE_160K</constant> </entry>
885 <entry>160 kbit/s</entry>
886 </row>
887 <row>
888 <entry><constant>V4L2_MPEG_AUDIO_L1_BITRATE_192K</constant> </entry>
889 <entry>192 kbit/s</entry>
890 </row>
891 <row>
892 <entry><constant>V4L2_MPEG_AUDIO_L1_BITRATE_224K</constant> </entry>
893 <entry>224 kbit/s</entry>
894 </row>
895 <row>
896 <entry><constant>V4L2_MPEG_AUDIO_L1_BITRATE_256K</constant> </entry>
897 <entry>256 kbit/s</entry>
898 </row>
899 <row>
900 <entry><constant>V4L2_MPEG_AUDIO_L1_BITRATE_288K</constant> </entry>
901 <entry>288 kbit/s</entry>
902 </row>
903 <row>
904 <entry><constant>V4L2_MPEG_AUDIO_L1_BITRATE_320K</constant> </entry>
905 <entry>320 kbit/s</entry>
906 </row>
907 <row>
908 <entry><constant>V4L2_MPEG_AUDIO_L1_BITRATE_352K</constant> </entry>
909 <entry>352 kbit/s</entry>
910 </row>
911 <row>
912 <entry><constant>V4L2_MPEG_AUDIO_L1_BITRATE_384K</constant> </entry>
913 <entry>384 kbit/s</entry>
914 </row>
915 <row>
916 <entry><constant>V4L2_MPEG_AUDIO_L1_BITRATE_416K</constant> </entry>
917 <entry>416 kbit/s</entry>
918 </row>
919 <row>
920 <entry><constant>V4L2_MPEG_AUDIO_L1_BITRATE_448K</constant> </entry>
921 <entry>448 kbit/s</entry>
922 </row>
923 </tbody>
924 </entrytbl>
925 </row>
926 <row><entry></entry></row>
927 <row id="v4l2-mpeg-audio-l2-bitrate">
928 <entry spanname="id"><constant>V4L2_CID_MPEG_AUDIO_L2_BITRATE</constant> </entry>
929 <entry>enum v4l2_mpeg_audio_l2_bitrate</entry>
930 </row><row><entry spanname="descr">MPEG-1/2 Layer II bitrate.
931 Possible values are:</entry>
932 </row>
933 <row>
934 <entrytbl spanname="descr" cols="2">
935 <tbody valign="top">
936 <row>
937 <entry><constant>V4L2_MPEG_AUDIO_L2_BITRATE_32K</constant> </entry>
938 <entry>32 kbit/s</entry>
939 </row>
940 <row>
941 <entry><constant>V4L2_MPEG_AUDIO_L2_BITRATE_48K</constant> </entry>
942 <entry>48 kbit/s</entry>
943 </row>
944 <row>
945 <entry><constant>V4L2_MPEG_AUDIO_L2_BITRATE_56K</constant> </entry>
946 <entry>56 kbit/s</entry>
947 </row>
948 <row>
949 <entry><constant>V4L2_MPEG_AUDIO_L2_BITRATE_64K</constant> </entry>
950 <entry>64 kbit/s</entry>
951 </row>
952 <row>
953 <entry><constant>V4L2_MPEG_AUDIO_L2_BITRATE_80K</constant> </entry>
954 <entry>80 kbit/s</entry>
955 </row>
956 <row>
957 <entry><constant>V4L2_MPEG_AUDIO_L2_BITRATE_96K</constant> </entry>
958 <entry>96 kbit/s</entry>
959 </row>
960 <row>
961 <entry><constant>V4L2_MPEG_AUDIO_L2_BITRATE_112K</constant> </entry>
962 <entry>112 kbit/s</entry>
963 </row>
964 <row>
965 <entry><constant>V4L2_MPEG_AUDIO_L2_BITRATE_128K</constant> </entry>
966 <entry>128 kbit/s</entry>
967 </row>
968 <row>
969 <entry><constant>V4L2_MPEG_AUDIO_L2_BITRATE_160K</constant> </entry>
970 <entry>160 kbit/s</entry>
971 </row>
972 <row>
973 <entry><constant>V4L2_MPEG_AUDIO_L2_BITRATE_192K</constant> </entry>
974 <entry>192 kbit/s</entry>
975 </row>
976 <row>
977 <entry><constant>V4L2_MPEG_AUDIO_L2_BITRATE_224K</constant> </entry>
978 <entry>224 kbit/s</entry>
979 </row>
980 <row>
981 <entry><constant>V4L2_MPEG_AUDIO_L2_BITRATE_256K</constant> </entry>
982 <entry>256 kbit/s</entry>
983 </row>
984 <row>
985 <entry><constant>V4L2_MPEG_AUDIO_L2_BITRATE_320K</constant> </entry>
986 <entry>320 kbit/s</entry>
987 </row>
988 <row>
989 <entry><constant>V4L2_MPEG_AUDIO_L2_BITRATE_384K</constant> </entry>
990 <entry>384 kbit/s</entry>
991 </row>
992 </tbody>
993 </entrytbl>
994 </row>
995 <row><entry></entry></row>
996 <row id="v4l2-mpeg-audio-l3-bitrate">
997 <entry spanname="id"><constant>V4L2_CID_MPEG_AUDIO_L3_BITRATE</constant> </entry>
998 <entry>enum v4l2_mpeg_audio_l3_bitrate</entry>
999 </row><row><entry spanname="descr">MPEG-1/2 Layer III bitrate.
1000 Possible values are:</entry>
1001 </row>
1002 <row>
1003 <entrytbl spanname="descr" cols="2">
1004 <tbody valign="top">
1005 <row>
1006 <entry><constant>V4L2_MPEG_AUDIO_L3_BITRATE_32K</constant> </entry>
1007 <entry>32 kbit/s</entry>
1008 </row>
1009 <row>
1010 <entry><constant>V4L2_MPEG_AUDIO_L3_BITRATE_40K</constant> </entry>
1011 <entry>40 kbit/s</entry>
1012 </row>
1013 <row>
1014 <entry><constant>V4L2_MPEG_AUDIO_L3_BITRATE_48K</constant> </entry>
1015 <entry>48 kbit/s</entry>
1016 </row>
1017 <row>
1018 <entry><constant>V4L2_MPEG_AUDIO_L3_BITRATE_56K</constant> </entry>
1019 <entry>56 kbit/s</entry>
1020 </row>
1021 <row>
1022 <entry><constant>V4L2_MPEG_AUDIO_L3_BITRATE_64K</constant> </entry>
1023 <entry>64 kbit/s</entry>
1024 </row>
1025 <row>
1026 <entry><constant>V4L2_MPEG_AUDIO_L3_BITRATE_80K</constant> </entry>
1027 <entry>80 kbit/s</entry>
1028 </row>
1029 <row>
1030 <entry><constant>V4L2_MPEG_AUDIO_L3_BITRATE_96K</constant> </entry>
1031 <entry>96 kbit/s</entry>
1032 </row>
1033 <row>
1034 <entry><constant>V4L2_MPEG_AUDIO_L3_BITRATE_112K</constant> </entry>
1035 <entry>112 kbit/s</entry>
1036 </row>
1037 <row>
1038 <entry><constant>V4L2_MPEG_AUDIO_L3_BITRATE_128K</constant> </entry>
1039 <entry>128 kbit/s</entry>
1040 </row>
1041 <row>
1042 <entry><constant>V4L2_MPEG_AUDIO_L3_BITRATE_160K</constant> </entry>
1043 <entry>160 kbit/s</entry>
1044 </row>
1045 <row>
1046 <entry><constant>V4L2_MPEG_AUDIO_L3_BITRATE_192K</constant> </entry>
1047 <entry>192 kbit/s</entry>
1048 </row>
1049 <row>
1050 <entry><constant>V4L2_MPEG_AUDIO_L3_BITRATE_224K</constant> </entry>
1051 <entry>224 kbit/s</entry>
1052 </row>
1053 <row>
1054 <entry><constant>V4L2_MPEG_AUDIO_L3_BITRATE_256K</constant> </entry>
1055 <entry>256 kbit/s</entry>
1056 </row>
1057 <row>
1058 <entry><constant>V4L2_MPEG_AUDIO_L3_BITRATE_320K</constant> </entry>
1059 <entry>320 kbit/s</entry>
1060 </row>
1061 </tbody>
1062 </entrytbl>
1063 </row>
1064 <row><entry></entry></row>
1065 <row>
1066 <entry spanname="id"><constant>V4L2_CID_MPEG_AUDIO_AAC_BITRATE</constant> </entry>
1067 <entry>integer</entry>
1068 </row><row><entry spanname="descr">AAC bitrate in bits per second.</entry>
1069 </row>
1070 <row><entry></entry></row>
1071 <row id="v4l2-mpeg-audio-ac3-bitrate">
1072 <entry spanname="id"><constant>V4L2_CID_MPEG_AUDIO_AC3_BITRATE</constant> </entry>
1073 <entry>enum v4l2_mpeg_audio_ac3_bitrate</entry>
1074 </row><row><entry spanname="descr">AC-3 bitrate.
1075 Possible values are:</entry>
1076 </row>
1077 <row>
1078 <entrytbl spanname="descr" cols="2">
1079 <tbody valign="top">
1080 <row>
1081 <entry><constant>V4L2_MPEG_AUDIO_AC3_BITRATE_32K</constant> </entry>
1082 <entry>32 kbit/s</entry>
1083 </row>
1084 <row>
1085 <entry><constant>V4L2_MPEG_AUDIO_AC3_BITRATE_40K</constant> </entry>
1086 <entry>40 kbit/s</entry>
1087 </row>
1088 <row>
1089 <entry><constant>V4L2_MPEG_AUDIO_AC3_BITRATE_48K</constant> </entry>
1090 <entry>48 kbit/s</entry>
1091 </row>
1092 <row>
1093 <entry><constant>V4L2_MPEG_AUDIO_AC3_BITRATE_56K</constant> </entry>
1094 <entry>56 kbit/s</entry>
1095 </row>
1096 <row>
1097 <entry><constant>V4L2_MPEG_AUDIO_AC3_BITRATE_64K</constant> </entry>
1098 <entry>64 kbit/s</entry>
1099 </row>
1100 <row>
1101 <entry><constant>V4L2_MPEG_AUDIO_AC3_BITRATE_80K</constant> </entry>
1102 <entry>80 kbit/s</entry>
1103 </row>
1104 <row>
1105 <entry><constant>V4L2_MPEG_AUDIO_AC3_BITRATE_96K</constant> </entry>
1106 <entry>96 kbit/s</entry>
1107 </row>
1108 <row>
1109 <entry><constant>V4L2_MPEG_AUDIO_AC3_BITRATE_112K</constant> </entry>
1110 <entry>112 kbit/s</entry>
1111 </row>
1112 <row>
1113 <entry><constant>V4L2_MPEG_AUDIO_AC3_BITRATE_128K</constant> </entry>
1114 <entry>128 kbit/s</entry>
1115 </row>
1116 <row>
1117 <entry><constant>V4L2_MPEG_AUDIO_AC3_BITRATE_160K</constant> </entry>
1118 <entry>160 kbit/s</entry>
1119 </row>
1120 <row>
1121 <entry><constant>V4L2_MPEG_AUDIO_AC3_BITRATE_192K</constant> </entry>
1122 <entry>192 kbit/s</entry>
1123 </row>
1124 <row>
1125 <entry><constant>V4L2_MPEG_AUDIO_AC3_BITRATE_224K</constant> </entry>
1126 <entry>224 kbit/s</entry>
1127 </row>
1128 <row>
1129 <entry><constant>V4L2_MPEG_AUDIO_AC3_BITRATE_256K</constant> </entry>
1130 <entry>256 kbit/s</entry>
1131 </row>
1132 <row>
1133 <entry><constant>V4L2_MPEG_AUDIO_AC3_BITRATE_320K</constant> </entry>
1134 <entry>320 kbit/s</entry>
1135 </row>
1136 <row>
1137 <entry><constant>V4L2_MPEG_AUDIO_AC3_BITRATE_384K</constant> </entry>
1138 <entry>384 kbit/s</entry>
1139 </row>
1140 <row>
1141 <entry><constant>V4L2_MPEG_AUDIO_AC3_BITRATE_448K</constant> </entry>
1142 <entry>448 kbit/s</entry>
1143 </row>
1144 <row>
1145 <entry><constant>V4L2_MPEG_AUDIO_AC3_BITRATE_512K</constant> </entry>
1146 <entry>512 kbit/s</entry>
1147 </row>
1148 <row>
1149 <entry><constant>V4L2_MPEG_AUDIO_AC3_BITRATE_576K</constant> </entry>
1150 <entry>576 kbit/s</entry>
1151 </row>
1152 <row>
1153 <entry><constant>V4L2_MPEG_AUDIO_AC3_BITRATE_640K</constant> </entry>
1154 <entry>640 kbit/s</entry>
1155 </row>
1156 </tbody>
1157 </entrytbl>
1158 </row>
1159 <row><entry></entry></row>
1160 <row id="v4l2-mpeg-audio-mode">
1161 <entry spanname="id"><constant>V4L2_CID_MPEG_AUDIO_MODE</constant> </entry>
1162 <entry>enum v4l2_mpeg_audio_mode</entry>
1163 </row><row><entry spanname="descr">MPEG Audio mode.
1164 Possible values are:</entry>
1165 </row>
1166 <row>
1167 <entrytbl spanname="descr" cols="2">
1168 <tbody valign="top">
1169 <row>
1170 <entry><constant>V4L2_MPEG_AUDIO_MODE_STEREO</constant> </entry>
1171 <entry>Stereo</entry>
1172 </row>
1173 <row>
1174 <entry><constant>V4L2_MPEG_AUDIO_MODE_JOINT_STEREO</constant> </entry>
1175 <entry>Joint Stereo</entry>
1176 </row>
1177 <row>
1178 <entry><constant>V4L2_MPEG_AUDIO_MODE_DUAL</constant> </entry>
1179 <entry>Bilingual</entry>
1180 </row>
1181 <row>
1182 <entry><constant>V4L2_MPEG_AUDIO_MODE_MONO</constant> </entry>
1183 <entry>Mono</entry>
1184 </row>
1185 </tbody>
1186 </entrytbl>
1187 </row>
1188 <row><entry></entry></row>
1189 <row id="v4l2-mpeg-audio-mode-extension">
1190 <entry spanname="id"><constant>V4L2_CID_MPEG_AUDIO_MODE_EXTENSION</constant> </entry>
1191 <entry>enum v4l2_mpeg_audio_mode_extension</entry>
1192 </row><row><entry spanname="descr">Joint Stereo
1193 audio mode extension. In Layer I and II they indicate which subbands
1194 are in intensity stereo. All other subbands are coded in stereo. Layer
1195 III is not (yet) supported. Possible values
1196 are:</entry>
1197 </row>
1198 <row>
1199 <entrytbl spanname="descr" cols="2">
1200 <tbody valign="top">
1201 <row>
1202 <entry><constant>V4L2_MPEG_AUDIO_MODE_EXTENSION_BOUND_4</constant> </entry>
1203 <entry>Subbands 4-31 in intensity stereo</entry>
1204 </row>
1205 <row>
1206 <entry><constant>V4L2_MPEG_AUDIO_MODE_EXTENSION_BOUND_8</constant> </entry>
1207 <entry>Subbands 8-31 in intensity stereo</entry>
1208 </row>
1209 <row>
1210 <entry><constant>V4L2_MPEG_AUDIO_MODE_EXTENSION_BOUND_12</constant> </entry>
1211 <entry>Subbands 12-31 in intensity stereo</entry>
1212 </row>
1213 <row>
1214 <entry><constant>V4L2_MPEG_AUDIO_MODE_EXTENSION_BOUND_16</constant> </entry>
1215 <entry>Subbands 16-31 in intensity stereo</entry>
1216 </row>
1217 </tbody>
1218 </entrytbl>
1219 </row>
1220 <row><entry></entry></row>
1221 <row id="v4l2-mpeg-audio-emphasis">
1222 <entry spanname="id"><constant>V4L2_CID_MPEG_AUDIO_EMPHASIS</constant> </entry>
1223 <entry>enum v4l2_mpeg_audio_emphasis</entry>
1224 </row><row><entry spanname="descr">Audio Emphasis.
1225 Possible values are:</entry>
1226 </row>
1227 <row>
1228 <entrytbl spanname="descr" cols="2">
1229 <tbody valign="top">
1230 <row>
1231 <entry><constant>V4L2_MPEG_AUDIO_EMPHASIS_NONE</constant> </entry>
1232 <entry>None</entry>
1233 </row>
1234 <row>
1235 <entry><constant>V4L2_MPEG_AUDIO_EMPHASIS_50_DIV_15_uS</constant> </entry>
1236 <entry>50/15 microsecond emphasis</entry>
1237 </row>
1238 <row>
1239 <entry><constant>V4L2_MPEG_AUDIO_EMPHASIS_CCITT_J17</constant> </entry>
1240 <entry>CCITT J.17</entry>
1241 </row>
1242 </tbody>
1243 </entrytbl>
1244 </row>
1245 <row><entry></entry></row>
1246 <row id="v4l2-mpeg-audio-crc">
1247 <entry spanname="id"><constant>V4L2_CID_MPEG_AUDIO_CRC</constant> </entry>
1248 <entry>enum v4l2_mpeg_audio_crc</entry>
1249 </row><row><entry spanname="descr">CRC method. Possible
1250 values are:</entry>
1251 </row>
1252 <row>
1253 <entrytbl spanname="descr" cols="2">
1254 <tbody valign="top">
1255 <row>
1256 <entry><constant>V4L2_MPEG_AUDIO_CRC_NONE</constant> </entry>
1257 <entry>None</entry>
1258 </row>
1259 <row>
1260 <entry><constant>V4L2_MPEG_AUDIO_CRC_CRC16</constant> </entry>
1261 <entry>16 bit parity check</entry>
1262 </row>
1263 </tbody>
1264 </entrytbl>
1265 </row>
1266 <row><entry></entry></row>
1267 <row>
1268 <entry spanname="id"><constant>V4L2_CID_MPEG_AUDIO_MUTE</constant> </entry>
1269 <entry>boolean</entry>
1270 </row><row><entry spanname="descr">Mutes the audio when
1271 capturing. This is not done by muting audio hardware, which can still
1272 produce a slight hiss, but in the encoder itself, guaranteeing a fixed
1273 and reproducible audio bitstream. 0 = unmuted, 1 = muted.</entry>
1274 </row>
1275 <row><entry></entry></row>
1276 <row id="v4l2-mpeg-video-encoding">
1277 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_ENCODING</constant> </entry>
1278 <entry>enum v4l2_mpeg_video_encoding</entry>
1279 </row><row><entry spanname="descr">MPEG Video encoding
1280 method. This control is specific to multiplexed MPEG streams.
1281 Possible values are:</entry>
1282 </row>
1283 <row>
1284 <entrytbl spanname="descr" cols="2">
1285 <tbody valign="top">
1286 <row>
1287 <entry><constant>V4L2_MPEG_VIDEO_ENCODING_MPEG_1</constant> </entry>
1288 <entry>MPEG-1 Video encoding</entry>
1289 </row>
1290 <row>
1291 <entry><constant>V4L2_MPEG_VIDEO_ENCODING_MPEG_2</constant> </entry>
1292 <entry>MPEG-2 Video encoding</entry>
1293 </row>
1294 <row>
1295 <entry><constant>V4L2_MPEG_VIDEO_ENCODING_MPEG_4_AVC</constant> </entry>
1296 <entry>MPEG-4 AVC (H.264) Video encoding</entry>
1297 </row>
1298 </tbody>
1299 </entrytbl>
1300 </row>
1301 <row><entry></entry></row>
1302 <row id="v4l2-mpeg-video-aspect">
1303 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_ASPECT</constant> </entry>
1304 <entry>enum v4l2_mpeg_video_aspect</entry>
1305 </row><row><entry spanname="descr">Video aspect.
1306 Possible values are:</entry>
1307 </row>
1308 <row>
1309 <entrytbl spanname="descr" cols="2">
1310 <tbody valign="top">
1311 <row>
1312 <entry><constant>V4L2_MPEG_VIDEO_ASPECT_1x1</constant> </entry>
1313 </row>
1314 <row>
1315 <entry><constant>V4L2_MPEG_VIDEO_ASPECT_4x3</constant> </entry>
1316 </row>
1317 <row>
1318 <entry><constant>V4L2_MPEG_VIDEO_ASPECT_16x9</constant> </entry>
1319 </row>
1320 <row>
1321 <entry><constant>V4L2_MPEG_VIDEO_ASPECT_221x100</constant> </entry>
1322 </row>
1323 </tbody>
1324 </entrytbl>
1325 </row>
1326 <row><entry></entry></row>
1327 <row>
1328 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_B_FRAMES</constant> </entry>
1329 <entry>integer</entry>
1330 </row><row><entry spanname="descr">Number of B-Frames
1331 (default 2)</entry>
1332 </row>
1333 <row><entry></entry></row>
1334 <row>
1335 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_GOP_SIZE</constant> </entry>
1336 <entry>integer</entry>
1337 </row><row><entry spanname="descr">GOP size (default
1338 12)</entry>
1339 </row>
1340 <row><entry></entry></row>
1341 <row>
1342 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_GOP_CLOSURE</constant> </entry>
1343 <entry>boolean</entry>
1344 </row><row><entry spanname="descr">GOP closure (default
1345 1)</entry>
1346 </row>
1347 <row><entry></entry></row>
1348 <row>
1349 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_PULLDOWN</constant> </entry>
1350 <entry>boolean</entry>
1351 </row><row><entry spanname="descr">Enable 3:2 pulldown
1352 (default 0)</entry>
1353 </row>
1354 <row><entry></entry></row>
1355 <row id="v4l2-mpeg-video-bitrate-mode">
1356 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_BITRATE_MODE</constant> </entry>
1357 <entry>enum v4l2_mpeg_video_bitrate_mode</entry>
1358 </row><row><entry spanname="descr">Video bitrate mode.
1359 Possible values are:</entry>
1360 </row>
1361 <row>
1362 <entrytbl spanname="descr" cols="2">
1363 <tbody valign="top">
1364 <row>
1365 <entry><constant>V4L2_MPEG_VIDEO_BITRATE_MODE_VBR</constant> </entry>
1366 <entry>Variable bitrate</entry>
1367 </row>
1368 <row>
1369 <entry><constant>V4L2_MPEG_VIDEO_BITRATE_MODE_CBR</constant> </entry>
1370 <entry>Constant bitrate</entry>
1371 </row>
1372 </tbody>
1373 </entrytbl>
1374 </row>
1375 <row><entry></entry></row>
1376 <row>
1377 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_BITRATE</constant> </entry>
1378 <entry>integer</entry>
1379 </row><row><entry spanname="descr">Video bitrate in bits
1380 per second.</entry>
1381 </row>
1382 <row><entry></entry></row>
1383 <row>
1384 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_BITRATE_PEAK</constant> </entry>
1385 <entry>integer</entry>
1386 </row><row><entry spanname="descr">Peak video bitrate in
1387 bits per second. Must be larger or equal to the average video bitrate.
1388 It is ignored if the video bitrate mode is set to constant
1389 bitrate.</entry>
1390 </row>
1391 <row><entry></entry></row>
1392 <row>
1393 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_TEMPORAL_DECIMATION</constant> </entry>
1394 <entry>integer</entry>
1395 </row><row><entry spanname="descr">For every captured
1396 frame, skip this many subsequent frames (default 0).</entry>
1397 </row>
1398 <row><entry></entry></row>
1399 <row>
1400 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_MUTE</constant> </entry>
1401 <entry>boolean</entry>
1402 </row>
1403 <row><entry spanname="descr">"Mutes" the video to a
1404 fixed color when capturing. This is useful for testing, to produce a
1405 fixed video bitstream. 0 = unmuted, 1 = muted.</entry>
1406 </row>
1407 <row><entry></entry></row>
1408 <row>
1409 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_MUTE_YUV</constant> </entry>
1410 <entry>integer</entry>
1411 </row><row><entry spanname="descr">Sets the "mute" color
1412 of the video. The supplied 32-bit integer is interpreted as follows (bit
1413 0 = least significant bit):</entry>
1414 </row>
1415 <row>
1416 <entrytbl spanname="descr" cols="2">
1417 <tbody valign="top">
1418 <row>
1419 <entry>Bit 0:7</entry>
1420 <entry>V chrominance information</entry>
1421 </row>
1422 <row>
1423 <entry>Bit 8:15</entry>
1424 <entry>U chrominance information</entry>
1425 </row>
1426 <row>
1427 <entry>Bit 16:23</entry>
1428 <entry>Y luminance information</entry>
1429 </row>
1430 <row>
1431 <entry>Bit 24:31</entry>
1432 <entry>Must be zero.</entry>
1433 </row>
1434 </tbody>
1435 </entrytbl>
1436 </row>
1439 <row><entry></entry></row>
1440 <row>
1441 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_DECODER_SLICE_INTERFACE</constant> </entry>
1442 <entry>boolean</entry>
1443 </row>
1444 <row><entry spanname="descr">If enabled the decoder expects to receive a single slice per buffer, otherwise
1445 the decoder expects a single frame in per buffer. Applicable to the decoder, all codecs.
1446 </entry>
1447 </row>
1449 <row><entry></entry></row>
1450 <row>
1451 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_H264_VUI_SAR_ENABLE</constant> </entry>
1452 <entry>boolean</entry>
1453 </row>
1454 <row><entry spanname="descr">Enable writing sample aspect ratio in the Video Usability Information.
1455 Applicable to the H264 encoder.</entry>
1456 </row>
1458 <row><entry></entry></row>
1459 <row id="v4l2-mpeg-video-h264-vui-sar-idc">
1460 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_H264_VUI_SAR_IDC</constant> </entry>
1461 <entry>enum v4l2_mpeg_video_h264_vui_sar_idc</entry>
1462 </row>
1463 <row><entry spanname="descr">VUI sample aspect ratio indicator for H.264 encoding. The value
1464 is defined in the table E-1 in the standard. Applicable to the H264 encoder.</entry>
1465 </row>
1466 <row>
1467 <entrytbl spanname="descr" cols="2">
1468 <tbody valign="top">
1470 <row>
1471 <entry><constant>V4L2_MPEG_VIDEO_H264_VUI_SAR_IDC_UNSPECIFIED</constant> </entry>
1472 <entry>Unspecified</entry>
1473 </row>
1474 <row>
1475 <entry><constant>V4L2_MPEG_VIDEO_H264_VUI_SAR_IDC_1x1</constant> </entry>
1476 <entry>1x1</entry>
1477 </row>
1478 <row>
1479 <entry><constant>V4L2_MPEG_VIDEO_H264_VUI_SAR_IDC_12x11</constant> </entry>
1480 <entry>12x11</entry>
1481 </row>
1482 <row>
1483 <entry><constant>V4L2_MPEG_VIDEO_H264_VUI_SAR_IDC_10x11</constant> </entry>
1484 <entry>10x11</entry>
1485 </row>
1486 <row>
1487 <entry><constant>V4L2_MPEG_VIDEO_H264_VUI_SAR_IDC_16x11</constant> </entry>
1488 <entry>16x11</entry>
1489 </row>
1490 <row>
1491 <entry><constant>V4L2_MPEG_VIDEO_H264_VUI_SAR_IDC_40x33</constant> </entry>
1492 <entry>40x33</entry>
1493 </row>
1494 <row>
1495 <entry><constant>V4L2_MPEG_VIDEO_H264_VUI_SAR_IDC_24x11</constant> </entry>
1496 <entry>24x11</entry>
1497 </row>
1498 <row>
1499 <entry><constant>V4L2_MPEG_VIDEO_H264_VUI_SAR_IDC_20x11</constant> </entry>
1500 <entry>20x11</entry>
1501 </row>
1502 <row>
1503 <entry><constant>V4L2_MPEG_VIDEO_H264_VUI_SAR_IDC_32x11</constant> </entry>
1504 <entry>32x11</entry>
1505 </row>
1506 <row>
1507 <entry><constant>V4L2_MPEG_VIDEO_H264_VUI_SAR_IDC_80x33</constant> </entry>
1508 <entry>80x33</entry>
1509 </row>
1510 <row>
1511 <entry><constant>V4L2_MPEG_VIDEO_H264_VUI_SAR_IDC_18x11</constant> </entry>
1512 <entry>18x11</entry>
1513 </row>
1514 <row>
1515 <entry><constant>V4L2_MPEG_VIDEO_H264_VUI_SAR_IDC_15x11</constant> </entry>
1516 <entry>15x11</entry>
1517 </row>
1518 <row>
1519 <entry><constant>V4L2_MPEG_VIDEO_H264_VUI_SAR_IDC_64x33</constant> </entry>
1520 <entry>64x33</entry>
1521 </row>
1522 <row>
1523 <entry><constant>V4L2_MPEG_VIDEO_H264_VUI_SAR_IDC_160x99</constant> </entry>
1524 <entry>160x99</entry>
1525 </row>
1526 <row>
1527 <entry><constant>V4L2_MPEG_VIDEO_H264_VUI_SAR_IDC_4x3</constant> </entry>
1528 <entry>4x3</entry>
1529 </row>
1530 <row>
1531 <entry><constant>V4L2_MPEG_VIDEO_H264_VUI_SAR_IDC_3x2</constant> </entry>
1532 <entry>3x2</entry>
1533 </row>
1534 <row>
1535 <entry><constant>V4L2_MPEG_VIDEO_H264_VUI_SAR_IDC_2x1</constant> </entry>
1536 <entry>2x1</entry>
1537 </row>
1538 <row>
1539 <entry><constant>V4L2_MPEG_VIDEO_H264_VUI_SAR_IDC_EXTENDED</constant> </entry>
1540 <entry>Extended SAR</entry>
1541 </row>
1542 </tbody>
1543 </entrytbl>
1544 </row>
1546 <row><entry></entry></row>
1547 <row>
1548 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_H264_VUI_EXT_SAR_WIDTH</constant> </entry>
1549 <entry>integer</entry>
1550 </row>
1551 <row><entry spanname="descr">Extended sample aspect ratio width for H.264 VUI encoding.
1552 Applicable to the H264 encoder.</entry>
1553 </row>
1555 <row><entry></entry></row>
1556 <row>
1557 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_H264_VUI_EXT_SAR_HEIGHT</constant> </entry>
1558 <entry>integer</entry>
1559 </row>
1560 <row><entry spanname="descr">Extended sample aspect ratio height for H.264 VUI encoding.
1561 Applicable to the H264 encoder.</entry>
1562 </row>
1564 <row><entry></entry></row>
1565 <row id="v4l2-mpeg-video-h264-level">
1566 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_H264_LEVEL</constant> </entry>
1567 <entry>enum v4l2_mpeg_video_h264_level</entry>
1568 </row>
1569 <row><entry spanname="descr">The level information for the H264 video elementary stream.
1570 Applicable to the H264 encoder.
1571 Possible values are:</entry>
1572 </row>
1573 <row>
1574 <entrytbl spanname="descr" cols="2">
1575 <tbody valign="top">
1576 <row>
1577 <entry><constant>V4L2_MPEG_VIDEO_H264_LEVEL_1_0</constant> </entry>
1578 <entry>Level 1.0</entry>
1579 </row>
1580 <row>
1581 <entry><constant>V4L2_MPEG_VIDEO_H264_LEVEL_1B</constant> </entry>
1582 <entry>Level 1B</entry>
1583 </row>
1584 <row>
1585 <entry><constant>V4L2_MPEG_VIDEO_H264_LEVEL_1_1</constant> </entry>
1586 <entry>Level 1.1</entry>
1587 </row>
1588 <row>
1589 <entry><constant>V4L2_MPEG_VIDEO_H264_LEVEL_1_2</constant> </entry>
1590 <entry>Level 1.2</entry>
1591 </row>
1592 <row>
1593 <entry><constant>V4L2_MPEG_VIDEO_H264_LEVEL_1_3</constant> </entry>
1594 <entry>Level 1.3</entry>
1595 </row>
1596 <row>
1597 <entry><constant>V4L2_MPEG_VIDEO_H264_LEVEL_2_0</constant> </entry>
1598 <entry>Level 2.0</entry>
1599 </row>
1600 <row>
1601 <entry><constant>V4L2_MPEG_VIDEO_H264_LEVEL_2_1</constant> </entry>
1602 <entry>Level 2.1</entry>
1603 </row>
1604 <row>
1605 <entry><constant>V4L2_MPEG_VIDEO_H264_LEVEL_2_2</constant> </entry>
1606 <entry>Level 2.2</entry>
1607 </row>
1608 <row>
1609 <entry><constant>V4L2_MPEG_VIDEO_H264_LEVEL_3_0</constant> </entry>
1610 <entry>Level 3.0</entry>
1611 </row>
1612 <row>
1613 <entry><constant>V4L2_MPEG_VIDEO_H264_LEVEL_3_1</constant> </entry>
1614 <entry>Level 3.1</entry>
1615 </row>
1616 <row>
1617 <entry><constant>V4L2_MPEG_VIDEO_H264_LEVEL_3_2</constant> </entry>
1618 <entry>Level 3.2</entry>
1619 </row>
1620 <row>
1621 <entry><constant>V4L2_MPEG_VIDEO_H264_LEVEL_4_0</constant> </entry>
1622 <entry>Level 4.0</entry>
1623 </row>
1624 <row>
1625 <entry><constant>V4L2_MPEG_VIDEO_H264_LEVEL_4_1</constant> </entry>
1626 <entry>Level 4.1</entry>
1627 </row>
1628 <row>
1629 <entry><constant>V4L2_MPEG_VIDEO_H264_LEVEL_4_2</constant> </entry>
1630 <entry>Level 4.2</entry>
1631 </row>
1632 <row>
1633 <entry><constant>V4L2_MPEG_VIDEO_H264_LEVEL_5_0</constant> </entry>
1634 <entry>Level 5.0</entry>
1635 </row>
1636 <row>
1637 <entry><constant>V4L2_MPEG_VIDEO_H264_LEVEL_5_1</constant> </entry>
1638 <entry>Level 5.1</entry>
1639 </row>
1640 </tbody>
1641 </entrytbl>
1642 </row>
1644 <row><entry></entry></row>
1645 <row id="v4l2-mpeg-video-mpeg4-level">
1646 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_MPEG4_LEVEL</constant> </entry>
1647 <entry>enum v4l2_mpeg_video_mpeg4_level</entry>
1648 </row>
1649 <row><entry spanname="descr">The level information for the MPEG4 elementary stream.
1650 Applicable to the MPEG4 encoder.
1651 Possible values are:</entry>
1652 </row>
1653 <row>
1654 <entrytbl spanname="descr" cols="2">
1655 <tbody valign="top">
1656 <row>
1657 <entry><constant>V4L2_MPEG_VIDEO_LEVEL_0</constant> </entry>
1658 <entry>Level 0</entry>
1659 </row>
1660 <row>
1661 <entry><constant>V4L2_MPEG_VIDEO_LEVEL_0B</constant> </entry>
1662 <entry>Level 0b</entry>
1663 </row>
1664 <row>
1665 <entry><constant>V4L2_MPEG_VIDEO_LEVEL_1</constant> </entry>
1666 <entry>Level 1</entry>
1667 </row>
1668 <row>
1669 <entry><constant>V4L2_MPEG_VIDEO_LEVEL_2</constant> </entry>
1670 <entry>Level 2</entry>
1671 </row>
1672 <row>
1673 <entry><constant>V4L2_MPEG_VIDEO_LEVEL_3</constant> </entry>
1674 <entry>Level 3</entry>
1675 </row>
1676 <row>
1677 <entry><constant>V4L2_MPEG_VIDEO_LEVEL_3B</constant> </entry>
1678 <entry>Level 3b</entry>
1679 </row>
1680 <row>
1681 <entry><constant>V4L2_MPEG_VIDEO_LEVEL_4</constant> </entry>
1682 <entry>Level 4</entry>
1683 </row>
1684 <row>
1685 <entry><constant>V4L2_MPEG_VIDEO_LEVEL_5</constant> </entry>
1686 <entry>Level 5</entry>
1687 </row>
1688 </tbody>
1689 </entrytbl>
1690 </row>
1692 <row><entry></entry></row>
1693 <row id="v4l2-mpeg-video-h264-profile">
1694 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_H264_PROFILE</constant> </entry>
1695 <entry>enum v4l2_mpeg_video_h264_profile</entry>
1696 </row>
1697 <row><entry spanname="descr">The profile information for H264.
1698 Applicable to the H264 encoder.
1699 Possible values are:</entry>
1700 </row>
1701 <row>
1702 <entrytbl spanname="descr" cols="2">
1703 <tbody valign="top">
1704 <row>
1705 <entry><constant>V4L2_MPEG_VIDEO_H264_PROFILE_BASELINE</constant> </entry>
1706 <entry>Baseline profile</entry>
1707 </row>
1708 <row>
1709 <entry><constant>V4L2_MPEG_VIDEO_H264_PROFILE_CONSTRAINED_BASELINE</constant> </entry>
1710 <entry>Constrained Baseline profile</entry>
1711 </row>
1712 <row>
1713 <entry><constant>V4L2_MPEG_VIDEO_H264_PROFILE_MAIN</constant> </entry>
1714 <entry>Main profile</entry>
1715 </row>
1716 <row>
1717 <entry><constant>V4L2_MPEG_VIDEO_H264_PROFILE_EXTENDED</constant> </entry>
1718 <entry>Extended profile</entry>
1719 </row>
1720 <row>
1721 <entry><constant>V4L2_MPEG_VIDEO_H264_PROFILE_HIGH</constant> </entry>
1722 <entry>High profile</entry>
1723 </row>
1724 <row>
1725 <entry><constant>V4L2_MPEG_VIDEO_H264_PROFILE_HIGH_10</constant> </entry>
1726 <entry>High 10 profile</entry>
1727 </row>
1728 <row>
1729 <entry><constant>V4L2_MPEG_VIDEO_H264_PROFILE_HIGH_422</constant> </entry>
1730 <entry>High 422 profile</entry>
1731 </row>
1732 <row>
1733 <entry><constant>V4L2_MPEG_VIDEO_H264_PROFILE_HIGH_444_PREDICTIVE</constant> </entry>
1734 <entry>High 444 Predictive profile</entry>
1735 </row>
1736 <row>
1737 <entry><constant>V4L2_MPEG_VIDEO_H264_PROFILE_HIGH_10_INTRA</constant> </entry>
1738 <entry>High 10 Intra profile</entry>
1739 </row>
1740 <row>
1741 <entry><constant>V4L2_MPEG_VIDEO_H264_PROFILE_HIGH_422_INTRA</constant> </entry>
1742 <entry>High 422 Intra profile</entry>
1743 </row>
1744 <row>
1745 <entry><constant>V4L2_MPEG_VIDEO_H264_PROFILE_HIGH_444_INTRA</constant> </entry>
1746 <entry>High 444 Intra profile</entry>
1747 </row>
1748 <row>
1749 <entry><constant>V4L2_MPEG_VIDEO_H264_PROFILE_CAVLC_444_INTRA</constant> </entry>
1750 <entry>CAVLC 444 Intra profile</entry>
1751 </row>
1752 <row>
1753 <entry><constant>V4L2_MPEG_VIDEO_H264_PROFILE_SCALABLE_BASELINE</constant> </entry>
1754 <entry>Scalable Baseline profile</entry>
1755 </row>
1756 <row>
1757 <entry><constant>V4L2_MPEG_VIDEO_H264_PROFILE_SCALABLE_HIGH</constant> </entry>
1758 <entry>Scalable High profile</entry>
1759 </row>
1760 <row>
1761 <entry><constant>V4L2_MPEG_VIDEO_H264_PROFILE_SCALABLE_HIGH_INTRA</constant> </entry>
1762 <entry>Scalable High Intra profile</entry>
1763 </row>
1764 <row>
1765 <entry><constant>V4L2_MPEG_VIDEO_H264_PROFILE_STEREO_HIGH</constant> </entry>
1766 <entry>Stereo High profile</entry>
1767 </row>
1768 <row>
1769 <entry><constant>V4L2_MPEG_VIDEO_H264_PROFILE_MULTIVIEW_HIGH</constant> </entry>
1770 <entry>Multiview High profile</entry>
1771 </row>
1773 </tbody>
1774 </entrytbl>
1775 </row>
1777 <row><entry></entry></row>
1778 <row id="v4l2-mpeg-video-mpeg4-profile">
1779 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_MPEG4_PROFILE</constant> </entry>
1780 <entry>enum v4l2_mpeg_video_mpeg4_profile</entry>
1781 </row>
1782 <row><entry spanname="descr">The profile information for MPEG4.
1783 Applicable to the MPEG4 encoder.
1784 Possible values are:</entry>
1785 </row>
1786 <row>
1787 <entrytbl spanname="descr" cols="2">
1788 <tbody valign="top">
1789 <row>
1790 <entry><constant>V4L2_MPEG_VIDEO_PROFILE_SIMPLE</constant> </entry>
1791 <entry>Simple profile</entry>
1792 </row>
1793 <row>
1794 <entry><constant>V4L2_MPEG_VIDEO_PROFILE_ADVANCED_SIMPLE</constant> </entry>
1795 <entry>Advanced Simple profile</entry>
1796 </row>
1797 <row>
1798 <entry><constant>V4L2_MPEG_VIDEO_PROFILE_CORE</constant> </entry>
1799 <entry>Core profile</entry>
1800 </row>
1801 <row>
1802 <entry><constant>V4L2_MPEG_VIDEO_PROFILE_SIMPLE_SCALABLE</constant> </entry>
1803 <entry>Simple Scalable profile</entry>
1804 </row>
1805 <row>
1806 <entry><constant>V4L2_MPEG_VIDEO_PROFILE_ADVANCED_CODING_EFFICIENCY</constant> </entry>
1807 <entry></entry>
1808 </row>
1809 </tbody>
1810 </entrytbl>
1811 </row>
1813 <row><entry></entry></row>
1814 <row>
1815 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_MAX_REF_PIC</constant> </entry>
1816 <entry>integer</entry>
1817 </row>
1818 <row><entry spanname="descr">The maximum number of reference pictures used for encoding.
1819 Applicable to the encoder.
1820 </entry>
1821 </row>
1823 <row><entry></entry></row>
1824 <row id="v4l2-mpeg-video-multi-slice-mode">
1825 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_MULTI_SLICE_MODE</constant> </entry>
1826 <entry>enum v4l2_mpeg_video_multi_slice_mode</entry>
1827 </row>
1828 <row><entry spanname="descr">Determines how the encoder should handle division of frame into slices.
1829 Applicable to the encoder.
1830 Possible values are:</entry>
1831 </row>
1832 <row>
1833 <entrytbl spanname="descr" cols="2">
1834 <tbody valign="top">
1835 <row>
1836 <entry><constant>V4L2_MPEG_VIDEO_MULTI_SLICE_MODE_SINGLE</constant> </entry>
1837 <entry>Single slice per frame.</entry>
1838 </row>
1839 <row>
1840 <entry><constant>V4L2_MPEG_VIDEO_MULTI_SLICE_MODE_MAX_MB</constant> </entry>
1841 <entry>Multiple slices with set maximum number of macroblocks per slice.</entry>
1842 </row>
1843 <row>
1844 <entry><constant>V4L2_MPEG_VIDEO_MULTI_SLICE_MODE_MAX_BYTES</constant> </entry>
1845 <entry>Multiple slice with set maximum size in bytes per slice.</entry>
1846 </row>
1847 </tbody>
1848 </entrytbl>
1849 </row>
1851 <row><entry></entry></row>
1852 <row>
1853 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_MULTI_SLICE_MAX_MB</constant> </entry>
1854 <entry>integer</entry>
1855 </row>
1856 <row><entry spanname="descr">The maximum number of macroblocks in a slice. Used when
1857 <constant>V4L2_CID_MPEG_VIDEO_MULTI_SLICE_MODE</constant> is set to <constant>V4L2_MPEG_VIDEO_MULTI_SLICE_MODE_MAX_MB</constant>.
1858 Applicable to the encoder.</entry>
1859 </row>
1861 <row><entry></entry></row>
1862 <row>
1863 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_MULTI_SLICE_MAX_BYTES</constant> </entry>
1864 <entry>integer</entry>
1865 </row>
1866 <row><entry spanname="descr">The maximum size of a slice in bytes. Used when
1867 <constant>V4L2_CID_MPEG_VIDEO_MULTI_SLICE_MODE</constant> is set to <constant>V4L2_MPEG_VIDEO_MULTI_SLICE_MODE_MAX_BYTES</constant>.
1868 Applicable to the encoder.</entry>
1869 </row>
1871 <row><entry></entry></row>
1872 <row id="v4l2-mpeg-video-h264-loop-filter-mode">
1873 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_H264_LOOP_FILTER_MODE</constant> </entry>
1874 <entry>enum v4l2_mpeg_video_h264_loop_filter_mode</entry>
1875 </row>
1876 <row><entry spanname="descr">Loop filter mode for H264 encoder.
1877 Possible values are:</entry>
1878 </row>
1879 <row>
1880 <entrytbl spanname="descr" cols="2">
1881 <tbody valign="top">
1882 <row>
1883 <entry><constant>V4L2_MPEG_VIDEO_H264_LOOP_FILTER_MODE_ENABLED</constant> </entry>
1884 <entry>Loop filter is enabled.</entry>
1885 </row>
1886 <row>
1887 <entry><constant>V4L2_MPEG_VIDEO_H264_LOOP_FILTER_MODE_DISABLED</constant> </entry>
1888 <entry>Loop filter is disabled.</entry>
1889 </row>
1890 <row>
1891 <entry><constant>V4L2_MPEG_VIDEO_H264_LOOP_FILTER_MODE_DISABLED_AT_SLICE_BOUNDARY</constant> </entry>
1892 <entry>Loop filter is disabled at the slice boundary.</entry>
1893 </row>
1894 </tbody>
1895 </entrytbl>
1896 </row>
1898 <row><entry></entry></row>
1899 <row>
1900 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_H264_LOOP_FILTER_ALPHA</constant> </entry>
1901 <entry>integer</entry>
1902 </row>
1903 <row><entry spanname="descr">Loop filter alpha coefficient, defined in the H264 standard.
1904 Applicable to the H264 encoder.</entry>
1905 </row>
1907 <row><entry></entry></row>
1908 <row>
1909 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_H264_LOOP_FILTER_BETA</constant> </entry>
1910 <entry>integer</entry>
1911 </row>
1912 <row><entry spanname="descr">Loop filter beta coefficient, defined in the H264 standard.
1913 Applicable to the H264 encoder.</entry>
1914 </row>
1916 <row><entry></entry></row>
1917 <row id="v4l2-mpeg-video-h264-entropy-mode">
1918 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_H264_ENTROPY_MODE</constant> </entry>
1919 <entry>enum v4l2_mpeg_video_h264_entropy_mode</entry>
1920 </row>
1921 <row><entry spanname="descr">Entropy coding mode for H264 - CABAC/CAVALC.
1922 Applicable to the H264 encoder.
1923 Possible values are:</entry>
1924 </row>
1925 <row>
1926 <entrytbl spanname="descr" cols="2">
1927 <tbody valign="top">
1928 <row>
1929 <entry><constant>V4L2_MPEG_VIDEO_H264_ENTROPY_MODE_CAVLC</constant> </entry>
1930 <entry>Use CAVLC entropy coding.</entry>
1931 </row>
1932 <row>
1933 <entry><constant>V4L2_MPEG_VIDEO_H264_ENTROPY_MODE_CABAC</constant> </entry>
1934 <entry>Use CABAC entropy coding.</entry>
1935 </row>
1936 </tbody>
1937 </entrytbl>
1938 </row>
1940 <row><entry></entry></row>
1941 <row>
1942 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_H264_8X8_TRANSFORM</constant> </entry>
1943 <entry>boolean</entry>
1944 </row>
1945 <row><entry spanname="descr">Enable 8X8 transform for H264. Applicable to the H264 encoder.</entry>
1946 </row>
1948 <row><entry></entry></row>
1949 <row>
1950 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_CYCLIC_INTRA_REFRESH_MB</constant> </entry>
1951 <entry>integer</entry>
1952 </row>
1953 <row><entry spanname="descr">Cyclic intra macroblock refresh. This is the number of continuous macroblocks
1954 refreshed every frame. Each frame a succesive set of macroblocks is refreshed until the cycle completes and starts from the
1955 top of the frame. Applicable to H264, H263 and MPEG4 encoder.</entry>
1956 </row>
1958 <row><entry></entry></row>
1959 <row>
1960 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_FRAME_RC_ENABLE</constant> </entry>
1961 <entry>boolean</entry>
1962 </row>
1963 <row><entry spanname="descr">Frame level rate control enable.
1964 If this control is disabled then the quantization parameter for each frame type is constant and set with appropriate controls
1965 (e.g. <constant>V4L2_CID_MPEG_VIDEO_H263_I_FRAME_QP</constant>).
1966 If frame rate control is enabled then quantization parameter is adjusted to meet the chosen bitrate. Minimum and maximum value
1967 for the quantization parameter can be set with appropriate controls (e.g. <constant>V4L2_CID_MPEG_VIDEO_H263_MIN_QP</constant>).
1968 Applicable to encoders.</entry>
1969 </row>
1971 <row><entry></entry></row>
1972 <row>
1973 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_MB_RC_ENABLE</constant> </entry>
1974 <entry>boolean</entry>
1975 </row>
1976 <row><entry spanname="descr">Macroblock level rate control enable.
1977 Applicable to the MPEG4 and H264 encoders.</entry>
1978 </row>
1980 <row><entry></entry></row>
1981 <row>
1982 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_MPEG4_QPEL</constant> </entry>
1983 <entry>boolean</entry>
1984 </row>
1985 <row><entry spanname="descr">Quarter pixel motion estimation for MPEG4. Applicable to the MPEG4 encoder.</entry>
1986 </row>
1988 <row><entry></entry></row>
1989 <row>
1990 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_H263_I_FRAME_QP</constant> </entry>
1991 <entry>integer</entry>
1992 </row>
1993 <row><entry spanname="descr">Quantization parameter for an I frame for H263. Valid range: from 1 to 31.</entry>
1994 </row>
1996 <row><entry></entry></row>
1997 <row>
1998 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_H263_MIN_QP</constant> </entry>
1999 <entry>integer</entry>
2000 </row>
2001 <row><entry spanname="descr">Minimum quantization parameter for H263. Valid range: from 1 to 31.</entry>
2002 </row>
2004 <row><entry></entry></row>
2005 <row>
2006 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_H263_MAX_QP</constant> </entry>
2007 <entry>integer</entry>
2008 </row>
2009 <row><entry spanname="descr">Maximum quantization parameter for H263. Valid range: from 1 to 31.</entry>
2010 </row>
2012 <row><entry></entry></row>
2013 <row>
2014 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_H263_P_FRAME_QP</constant> </entry>
2015 <entry>integer</entry>
2016 </row>
2017 <row><entry spanname="descr">Quantization parameter for an P frame for H263. Valid range: from 1 to 31.</entry>
2018 </row>
2020 <row><entry></entry></row>
2021 <row>
2022 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_H263_B_FRAME_QP</constant> </entry>
2023 <entry>integer</entry>
2024 </row>
2025 <row><entry spanname="descr">Quantization parameter for an B frame for H263. Valid range: from 1 to 31.</entry>
2026 </row>
2028 <row><entry></entry></row>
2029 <row>
2030 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_H264_I_FRAME_QP</constant> </entry>
2031 <entry>integer</entry>
2032 </row>
2033 <row><entry spanname="descr">Quantization parameter for an I frame for H264. Valid range: from 0 to 51.</entry>
2034 </row>
2036 <row><entry></entry></row>
2037 <row>
2038 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_H264_MIN_QP</constant> </entry>
2039 <entry>integer</entry>
2040 </row>
2041 <row><entry spanname="descr">Minimum quantization parameter for H264. Valid range: from 0 to 51.</entry>
2042 </row>
2044 <row><entry></entry></row>
2045 <row>
2046 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_H264_MAX_QP</constant> </entry>
2047 <entry>integer</entry>
2048 </row>
2049 <row><entry spanname="descr">Maximum quantization parameter for H264. Valid range: from 0 to 51.</entry>
2050 </row>
2052 <row><entry></entry></row>
2053 <row>
2054 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_H264_P_FRAME_QP</constant> </entry>
2055 <entry>integer</entry>
2056 </row>
2057 <row><entry spanname="descr">Quantization parameter for an P frame for H264. Valid range: from 0 to 51.</entry>
2058 </row>
2060 <row><entry></entry></row>
2061 <row>
2062 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_H264_B_FRAME_QP</constant> </entry>
2063 <entry>integer</entry>
2064 </row>
2065 <row><entry spanname="descr">Quantization parameter for an B frame for H264. Valid range: from 0 to 51.</entry>
2066 </row>
2068 <row><entry></entry></row>
2069 <row>
2070 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_MPEG4_I_FRAME_QP</constant> </entry>
2071 <entry>integer</entry>
2072 </row>
2073 <row><entry spanname="descr">Quantization parameter for an I frame for MPEG4. Valid range: from 1 to 31.</entry>
2074 </row>
2076 <row><entry></entry></row>
2077 <row>
2078 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_MPEG4_MIN_QP</constant> </entry>
2079 <entry>integer</entry>
2080 </row>
2081 <row><entry spanname="descr">Minimum quantization parameter for MPEG4. Valid range: from 1 to 31.</entry>
2082 </row>
2084 <row><entry></entry></row>
2085 <row>
2086 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_MPEG4_MAX_QP</constant> </entry>
2087 <entry>integer</entry>
2088 </row>
2089 <row><entry spanname="descr">Maximum quantization parameter for MPEG4. Valid range: from 1 to 31.</entry>
2090 </row>
2092 <row><entry></entry></row>
2093 <row>
2094 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_MPEG4_P_FRAME_QP</constant> </entry>
2095 <entry>integer</entry>
2096 </row>
2097 <row><entry spanname="descr">Quantization parameter for an P frame for MPEG4. Valid range: from 1 to 31.</entry>
2098 </row>
2100 <row><entry></entry></row>
2101 <row>
2102 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_MPEG4_B_FRAME_QP</constant> </entry>
2103 <entry>integer</entry>
2104 </row>
2105 <row><entry spanname="descr">Quantization parameter for an B frame for MPEG4. Valid range: from 1 to 31.</entry>
2106 </row>
2108 <row><entry></entry></row>
2109 <row>
2110 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_VBV_SIZE</constant> </entry>
2111 <entry>integer</entry>
2112 </row>
2113 <row><entry spanname="descr">The Video Buffer Verifier size in kilobytes, it is used as a limitation of frame skip.
2114 The VBV is defined in the standard as a mean to verify that the produced stream will be succesfully decoded.
2115 The standard describes it as "Part of a hypothetical decoder that is conceptually connected to the
2116 output of the encoder. Its purpose is to provide a constraint on the variability of the data rate that an
2117 encoder or editing process may produce.".
2118 Applicable to the MPEG1, MPEG2, MPEG4 encoders.</entry>
2119 </row>
2121 <row><entry></entry></row>
2122 <row>
2123 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_H264_CPB_SIZE</constant> </entry>
2124 <entry>integer</entry>
2125 </row>
2126 <row><entry spanname="descr">The Coded Picture Buffer size in kilobytes, it is used as a limitation of frame skip.
2127 The CPB is defined in the H264 standard as a mean to verify that the produced stream will be succesfully decoded.
2128 Applicable to the H264 encoder.</entry>
2129 </row>
2131 <row><entry></entry></row>
2132 <row>
2133 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_H264_I_PERIOD</constant> </entry>
2134 <entry>integer</entry>
2135 </row>
2136 <row><entry spanname="descr">Period between I-frames in the open GOP for H264. In case of an open GOP
2137 this is the period between two I-frames. The period between IDR (Instantaneous Decoding Refresh) frames is taken from the GOP_SIZE control.
2138 An IDR frame, which stands for Instantaneous Decoding Refresh is an I-frame after which no prior frames are
2139 referenced. This means that a stream can be restarted from an IDR frame without the need to store or decode any
2140 previous frames. Applicable to the H264 encoder.</entry>
2141 </row>
2143 <row><entry></entry></row>
2144 <row id="v4l2-mpeg-video-header-mode">
2145 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_HEADER_MODE</constant> </entry>
2146 <entry>enum v4l2_mpeg_video_header_mode</entry>
2147 </row>
2148 <row><entry spanname="descr">Determines whether the header is returned as the first buffer or is
2149 it returned together with the first frame. Applicable to encoders.
2150 Possible values are:</entry>
2151 </row>
2152 <row>
2153 <entrytbl spanname="descr" cols="2">
2154 <tbody valign="top">
2155 <row>
2156 <entry><constant>V4L2_MPEG_VIDEO_HEADER_MODE_SEPARATE</constant> </entry>
2157 <entry>The stream header is returned separately in the first buffer.</entry>
2158 </row>
2159 <row>
2160 <entry><constant>V4L2_MPEG_VIDEO_HEADER_MODE_JOINED_WITH_1ST_FRAME</constant> </entry>
2161 <entry>The stream header is returned together with the first encoded frame.</entry>
2162 </row>
2163 </tbody>
2164 </entrytbl>
2165 </row>
2166 <row><entry></entry></row>
2167 <row>
2168 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_DECODER_MPEG4_DEBLOCK_FILTER</constant> </entry>
2169 <entry>boolean</entry>
2170 </row><row><entry spanname="descr">Enabled the deblocking post processing filter for MPEG4 decoder.
2171 Applicable to the MPEG4 decoder.</entry>
2172 </row>
2173 <row><entry></entry></row>
2174 <row>
2175 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_MPEG4_VOP_TIME_RES</constant> </entry>
2176 <entry>integer</entry>
2177 </row><row><entry spanname="descr">vop_time_increment_resolution value for MPEG4. Applicable to the MPEG4 encoder.</entry>
2178 </row>
2179 <row><entry></entry></row>
2180 <row>
2181 <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_MPEG4_VOP_TIME_INC</constant> </entry>
2182 <entry>integer</entry>
2183 </row><row><entry spanname="descr">vop_time_increment value for MPEG4. Applicable to the MPEG4 encoder.</entry>
2184 </row>
2186 </tbody>
2187 </tgroup>
2188 </table>
2189 </section>
2191 <section>
2192 <title>MFC 5.1 MPEG Controls</title>
2194 <para>The following MPEG class controls deal with MPEG
2195 decoding and encoding settings that are specific to the Multi Format Codec 5.1 device present
2196 in the S5P family of SoCs by Samsung.
2197 </para>
2199 <table pgwide="1" frame="none" id="mfc51-control-id">
2200 <title>MFC 5.1 Control IDs</title>
2201 <tgroup cols="4">
2202 <colspec colname="c1" colwidth="1*" />
2203 <colspec colname="c2" colwidth="6*" />
2204 <colspec colname="c3" colwidth="2*" />
2205 <colspec colname="c4" colwidth="6*" />
2206 <spanspec namest="c1" nameend="c2" spanname="id" />
2207 <spanspec namest="c2" nameend="c4" spanname="descr" />
2208 <thead>
2209 <row>
2210 <entry spanname="id" align="left">ID</entry>
2211 <entry align="left">Type</entry>
2212 </row><row><entry spanname="descr" align="left">Description</entry>
2213 </row>
2214 </thead>
2215 <tbody valign="top">
2216 <row><entry></entry></row>
2217 <row>
2218 <entry spanname="id"><constant>V4L2_CID_MPEG_MFC51_VIDEO_DECODER_H264_DISPLAY_DELAY_ENABLE</constant> </entry>
2219 <entry>integer</entry>
2220 </row><row><entry spanname="descr">If the display delay is enabled then the decoder has to return a
2221 CAPTURE buffer after processing a certain number of OUTPUT buffers. If this number is low, then it may result in
2222 buffers not being dequeued in display order. In addition hardware may still use those buffers as reference, thus
2223 application should not write to those buffers. This feature can be used for example for generating thumbnails of videos.
2224 Applicable to the H264 decoder.
2225 </entry>
2226 </row>
2227 <row><entry></entry></row>
2228 <row>
2229 <entry spanname="id"><constant>V4L2_CID_MPEG_MFC51_VIDEO_DECODER_H264_DISPLAY_DELAY</constant> </entry>
2230 <entry>integer</entry>
2231 </row><row><entry spanname="descr">Display delay value for H264 decoder.
2232 The decoder is forced to return a decoded frame after the set 'display delay' number of frames. If this number is
2233 low it may result in frames returned out of dispaly order, in addition the hardware may still be using the returned buffer
2234 as a reference picture for subsequent frames.
2235 </entry>
2236 </row>
2237 <row><entry></entry></row>
2238 <row>
2239 <entry spanname="id"><constant>V4L2_CID_MPEG_MFC51_VIDEO_H264_NUM_REF_PIC_FOR_P</constant> </entry>
2240 <entry>integer</entry>
2241 </row><row><entry spanname="descr">The number of reference pictures used for encoding a P picture.
2242 Applicable to the H264 encoder.</entry>
2243 </row>
2244 <row><entry></entry></row>
2245 <row>
2246 <entry spanname="id"><constant>V4L2_CID_MPEG_MFC51_VIDEO_PADDING</constant> </entry>
2247 <entry>boolean</entry>
2248 </row><row><entry spanname="descr">Padding enable in the encoder - use a color instead of repeating border pixels.
2249 Applicable to encoders.</entry>
2250 </row>
2251 <row><entry></entry></row>
2252 <row>
2253 <entry spanname="id"><constant>V4L2_CID_MPEG_MFC51_VIDEO_PADDING_YUV</constant> </entry>
2254 <entry>integer</entry>
2255 </row><row><entry spanname="descr">Padding color in the encoder. Applicable to encoders. The supplied 32-bit integer is interpreted as follows (bit
2256 0 = least significant bit):</entry>
2257 </row>
2258 <row>
2259 <entrytbl spanname="descr" cols="2">
2260 <tbody valign="top">
2261 <row>
2262 <entry>Bit 0:7</entry>
2263 <entry>V chrominance information</entry>
2264 </row>
2265 <row>
2266 <entry>Bit 8:15</entry>
2267 <entry>U chrominance information</entry>
2268 </row>
2269 <row>
2270 <entry>Bit 16:23</entry>
2271 <entry>Y luminance information</entry>
2272 </row>
2273 <row>
2274 <entry>Bit 24:31</entry>
2275 <entry>Must be zero.</entry>
2276 </row>
2277 </tbody>
2278 </entrytbl>
2279 </row>
2280 <row><entry></entry></row>
2281 <row>
2282 <entry spanname="id"><constant>V4L2_CID_MPEG_MFC51_VIDEO_RC_REACTION_COEFF</constant> </entry>
2283 <entry>integer</entry>
2284 </row><row><entry spanname="descr">Reaction coefficient for MFC rate control. Applicable to encoders.
2285 <para>Note 1: Valid only when the frame level RC is enabled.</para>
2286 <para>Note 2: For tight CBR, this field must be small (ex. 2 ~ 10).
2287 For VBR, this field must be large (ex. 100 ~ 1000).</para>
2288 <para>Note 3: It is not recommended to use the greater number than FRAME_RATE * (10^9 / BIT_RATE).</para>
2289 </entry>
2290 </row>
2291 <row><entry></entry></row>
2292 <row>
2293 <entry spanname="id"><constant>V4L2_CID_MPEG_MFC51_VIDEO_H264_ADAPTIVE_RC_DARK</constant> </entry>
2294 <entry>boolean</entry>
2295 </row><row><entry spanname="descr">Adaptive rate control for dark region.
2296 Valid only when H.264 and macroblock level RC is enabled (<constant>V4L2_CID_MPEG_VIDEO_MB_RC_ENABLE</constant>).
2297 Applicable to the H264 encoder.</entry>
2298 </row>
2299 <row><entry></entry></row>
2300 <row>
2301 <entry spanname="id"><constant>V4L2_CID_MPEG_MFC51_VIDEO_H264_ADAPTIVE_RC_SMOOTH</constant> </entry>
2302 <entry>boolean</entry>
2303 </row><row><entry spanname="descr">Adaptive rate control for smooth region.
2304 Valid only when H.264 and macroblock level RC is enabled (<constant>V4L2_CID_MPEG_VIDEO_MB_RC_ENABLE</constant>).
2305 Applicable to the H264 encoder.</entry>
2306 </row>
2307 <row><entry></entry></row>
2308 <row>
2309 <entry spanname="id"><constant>V4L2_CID_MPEG_MFC51_VIDEO_H264_ADAPTIVE_RC_STATIC</constant> </entry>
2310 <entry>boolean</entry>
2311 </row><row><entry spanname="descr">Adaptive rate control for static region.
2312 Valid only when H.264 and macroblock level RC is enabled (<constant>V4L2_CID_MPEG_VIDEO_MB_RC_ENABLE</constant>).
2313 Applicable to the H264 encoder.</entry>
2314 </row>
2315 <row><entry></entry></row>
2316 <row>
2317 <entry spanname="id"><constant>V4L2_CID_MPEG_MFC51_VIDEO_H264_ADAPTIVE_RC_ACTIVITY</constant> </entry>
2318 <entry>boolean</entry>
2319 </row><row><entry spanname="descr">Adaptive rate control for activity region.
2320 Valid only when H.264 and macroblock level RC is enabled (<constant>V4L2_CID_MPEG_VIDEO_MB_RC_ENABLE</constant>).
2321 Applicable to the H264 encoder.</entry>
2322 </row>
2323 <row><entry></entry></row>
2324 <row id="v4l2-mpeg-mfc51-video-frame-skip-mode">
2325 <entry spanname="id"><constant>V4L2_CID_MPEG_MFC51_VIDEO_FRAME_SKIP_MODE</constant> </entry>
2326 <entry>enum v4l2_mpeg_mfc51_video_frame_skip_mode</entry>
2327 </row>
2328 <row><entry spanname="descr">
2329 Indicates in what conditions the encoder should skip frames. If encoding a frame would cause the encoded stream to be larger then
2330 a chosen data limit then the frame will be skipped.
2331 Possible values are:</entry>
2332 </row>
2333 <row>
2334 <entrytbl spanname="descr" cols="2">
2335 <tbody valign="top">
2336 <row>
2337 <entry><constant>V4L2_MPEG_MFC51_FRAME_SKIP_MODE_DISABLED</constant> </entry>
2338 <entry>Frame skip mode is disabled.</entry>
2339 </row>
2340 <row>
2341 <entry><constant>V4L2_MPEG_MFC51_FRAME_SKIP_MODE_LEVEL_LIMIT</constant> </entry>
2342 <entry>Frame skip mode enabled and buffer limit is set by the chosen level and is defined by the standard.</entry>
2343 </row>
2344 <row>
2345 <entry><constant>V4L2_MPEG_MFC51_FRAME_SKIP_MODE_BUF_LIMIT</constant> </entry>
2346 <entry>Frame skip mode enabled and buffer limit is set by the VBV (MPEG1/2/4) or CPB (H264) buffer size control.</entry>
2347 </row>
2348 </tbody>
2349 </entrytbl>
2350 </row>
2351 <row><entry></entry></row>
2352 <row>
2353 <entry spanname="id"><constant>V4L2_CID_MPEG_MFC51_VIDEO_RC_FIXED_TARGET_BIT</constant> </entry>
2354 <entry>integer</entry>
2355 </row><row><entry spanname="descr">Enable rate-control with fixed target bit.
2356 If this setting is enabled, then the rate control logic of the encoder will calculate the average bitrate
2357 for a GOP and keep it below or equal the set bitrate target. Otherwise the rate control logic calculates the
2358 overall average bitrate for the stream and keeps it below or equal to the set bitrate. In the first case
2359 the average bitrate for the whole stream will be smaller then the set bitrate. This is caused because the
2360 average is calculated for smaller number of frames, on the other hand enabling this setting will ensure that
2361 the stream will meet tight bandwidth contraints. Applicable to encoders.
2362 </entry>
2363 </row>
2364 <row><entry></entry></row>
2365 <row id="v4l2-mpeg-mfc51-video-force-frame-type">
2366 <entry spanname="id"><constant>V4L2_CID_MPEG_MFC51_VIDEO_FORCE_FRAME_TYPE</constant> </entry>
2367 <entry>enum v4l2_mpeg_mfc51_video_force_frame_type</entry>
2368 </row>
2369 <row><entry spanname="descr">Force a frame type for the next queued buffer. Applicable to encoders.
2370 Possible values are:</entry>
2371 </row>
2372 <row>
2373 <entrytbl spanname="descr" cols="2">
2374 <tbody valign="top">
2375 <row>
2376 <entry><constant>V4L2_MPEG_MFC51_FORCE_FRAME_TYPE_DISABLED</constant> </entry>
2377 <entry>Forcing a specific frame type disabled.</entry>
2378 </row>
2379 <row>
2380 <entry><constant>V4L2_MPEG_MFC51_FORCE_FRAME_TYPE_I_FRAME</constant> </entry>
2381 <entry>Force an I-frame.</entry>
2382 </row>
2383 <row>
2384 <entry><constant>V4L2_MPEG_MFC51_FORCE_FRAME_TYPE_NOT_CODED</constant> </entry>
2385 <entry>Force a non-coded frame.</entry>
2386 </row>
2387 </tbody>
2388 </entrytbl>
2389 </row>
2390 </tbody>
2391 </tgroup>
2392 </table>
2393 </section>
2395 <section>
2396 <title>CX2341x MPEG Controls</title>
2398 <para>The following MPEG class controls deal with MPEG
2399 encoding settings that are specific to the Conexant CX23415 and
2400 CX23416 MPEG encoding chips.</para>
2402 <table pgwide="1" frame="none" id="cx2341x-control-id">
2403 <title>CX2341x Control IDs</title>
2404 <tgroup cols="4">
2405 <colspec colname="c1" colwidth="1*" />
2406 <colspec colname="c2" colwidth="6*" />
2407 <colspec colname="c3" colwidth="2*" />
2408 <colspec colname="c4" colwidth="6*" />
2409 <spanspec namest="c1" nameend="c2" spanname="id" />
2410 <spanspec namest="c2" nameend="c4" spanname="descr" />
2411 <thead>
2412 <row>
2413 <entry spanname="id" align="left">ID</entry>
2414 <entry align="left">Type</entry>
2415 </row><row><entry spanname="descr" align="left">Description</entry>
2416 </row>
2417 </thead>
2418 <tbody valign="top">
2419 <row><entry></entry></row>
2420 <row id="v4l2-mpeg-cx2341x-video-spatial-filter-mode">
2421 <entry spanname="id"><constant>V4L2_CID_MPEG_CX2341X_VIDEO_SPATIAL_FILTER_MODE</constant> </entry>
2422 <entry>enum v4l2_mpeg_cx2341x_video_spatial_filter_mode</entry>
2423 </row><row><entry spanname="descr">Sets the Spatial
2424 Filter mode (default <constant>MANUAL</constant>). Possible values
2425 are:</entry>
2426 </row>
2427 <row>
2428 <entrytbl spanname="descr" cols="2">
2429 <tbody valign="top">
2430 <row>
2431 <entry><constant>V4L2_MPEG_CX2341X_VIDEO_SPATIAL_FILTER_MODE_MANUAL</constant> </entry>
2432 <entry>Choose the filter manually</entry>
2433 </row>
2434 <row>
2435 <entry><constant>V4L2_MPEG_CX2341X_VIDEO_SPATIAL_FILTER_MODE_AUTO</constant> </entry>
2436 <entry>Choose the filter automatically</entry>
2437 </row>
2438 </tbody>
2439 </entrytbl>
2440 </row>
2441 <row><entry></entry></row>
2442 <row>
2443 <entry spanname="id"><constant>V4L2_CID_MPEG_CX2341X_VIDEO_SPATIAL_FILTER</constant> </entry>
2444 <entry>integer (0-15)</entry>
2445 </row><row><entry spanname="descr">The setting for the
2446 Spatial Filter. 0 = off, 15 = maximum. (Default is 0.)</entry>
2447 </row>
2448 <row><entry></entry></row>
2449 <row id="luma-spatial-filter-type">
2450 <entry spanname="id"><constant>V4L2_CID_MPEG_CX2341X_VIDEO_LUMA_SPATIAL_FILTER_TYPE</constant> </entry>
2451 <entry>enum v4l2_mpeg_cx2341x_video_luma_spatial_filter_type</entry>
2452 </row><row><entry spanname="descr">Select the algorithm
2453 to use for the Luma Spatial Filter (default
2454 <constant>1D_HOR</constant>). Possible values:</entry>
2455 </row>
2456 <row>
2457 <entrytbl spanname="descr" cols="2">
2458 <tbody valign="top">
2459 <row>
2460 <entry><constant>V4L2_MPEG_CX2341X_VIDEO_LUMA_SPATIAL_FILTER_TYPE_OFF</constant> </entry>
2461 <entry>No filter</entry>
2462 </row>
2463 <row>
2464 <entry><constant>V4L2_MPEG_CX2341X_VIDEO_LUMA_SPATIAL_FILTER_TYPE_1D_HOR</constant> </entry>
2465 <entry>One-dimensional horizontal</entry>
2466 </row>
2467 <row>
2468 <entry><constant>V4L2_MPEG_CX2341X_VIDEO_LUMA_SPATIAL_FILTER_TYPE_1D_VERT</constant> </entry>
2469 <entry>One-dimensional vertical</entry>
2470 </row>
2471 <row>
2472 <entry><constant>V4L2_MPEG_CX2341X_VIDEO_LUMA_SPATIAL_FILTER_TYPE_2D_HV_SEPARABLE</constant> </entry>
2473 <entry>Two-dimensional separable</entry>
2474 </row>
2475 <row>
2476 <entry><constant>V4L2_MPEG_CX2341X_VIDEO_LUMA_SPATIAL_FILTER_TYPE_2D_SYM_NON_SEPARABLE</constant> </entry>
2477 <entry>Two-dimensional symmetrical
2478 non-separable</entry>
2479 </row>
2480 </tbody>
2481 </entrytbl>
2482 </row>
2483 <row><entry></entry></row>
2484 <row id="chroma-spatial-filter-type">
2485 <entry spanname="id"><constant>V4L2_CID_MPEG_CX2341X_VIDEO_CHROMA_SPATIAL_FILTER_TYPE</constant> </entry>
2486 <entry>enum v4l2_mpeg_cx2341x_video_chroma_spatial_filter_type</entry>
2487 </row><row><entry spanname="descr">Select the algorithm
2488 for the Chroma Spatial Filter (default <constant>1D_HOR</constant>).
2489 Possible values are:</entry>
2490 </row>
2491 <row>
2492 <entrytbl spanname="descr" cols="2">
2493 <tbody valign="top">
2494 <row>
2495 <entry><constant>V4L2_MPEG_CX2341X_VIDEO_CHROMA_SPATIAL_FILTER_TYPE_OFF</constant> </entry>
2496 <entry>No filter</entry>
2497 </row>
2498 <row>
2499 <entry><constant>V4L2_MPEG_CX2341X_VIDEO_CHROMA_SPATIAL_FILTER_TYPE_1D_HOR</constant> </entry>
2500 <entry>One-dimensional horizontal</entry>
2501 </row>
2502 </tbody>
2503 </entrytbl>
2504 </row>
2505 <row><entry></entry></row>
2506 <row id="v4l2-mpeg-cx2341x-video-temporal-filter-mode">
2507 <entry spanname="id"><constant>V4L2_CID_MPEG_CX2341X_VIDEO_TEMPORAL_FILTER_MODE</constant> </entry>
2508 <entry>enum v4l2_mpeg_cx2341x_video_temporal_filter_mode</entry>
2509 </row><row><entry spanname="descr">Sets the Temporal
2510 Filter mode (default <constant>MANUAL</constant>). Possible values
2511 are:</entry>
2512 </row>
2513 <row>
2514 <entrytbl spanname="descr" cols="2">
2515 <tbody valign="top">
2516 <row>
2517 <entry><constant>V4L2_MPEG_CX2341X_VIDEO_TEMPORAL_FILTER_MODE_MANUAL</constant> </entry>
2518 <entry>Choose the filter manually</entry>
2519 </row>
2520 <row>
2521 <entry><constant>V4L2_MPEG_CX2341X_VIDEO_TEMPORAL_FILTER_MODE_AUTO</constant> </entry>
2522 <entry>Choose the filter automatically</entry>
2523 </row>
2524 </tbody>
2525 </entrytbl>
2526 </row>
2527 <row><entry></entry></row>
2528 <row>
2529 <entry spanname="id"><constant>V4L2_CID_MPEG_CX2341X_VIDEO_TEMPORAL_FILTER</constant> </entry>
2530 <entry>integer (0-31)</entry>
2531 </row><row><entry spanname="descr">The setting for the
2532 Temporal Filter. 0 = off, 31 = maximum. (Default is 8 for full-scale
2533 capturing and 0 for scaled capturing.)</entry>
2534 </row>
2535 <row><entry></entry></row>
2536 <row id="v4l2-mpeg-cx2341x-video-median-filter-type">
2537 <entry spanname="id"><constant>V4L2_CID_MPEG_CX2341X_VIDEO_MEDIAN_FILTER_TYPE</constant> </entry>
2538 <entry>enum v4l2_mpeg_cx2341x_video_median_filter_type</entry>
2539 </row><row><entry spanname="descr">Median Filter Type
2540 (default <constant>OFF</constant>). Possible values are:</entry>
2541 </row>
2542 <row>
2543 <entrytbl spanname="descr" cols="2">
2544 <tbody valign="top">
2545 <row>
2546 <entry><constant>V4L2_MPEG_CX2341X_VIDEO_MEDIAN_FILTER_TYPE_OFF</constant> </entry>
2547 <entry>No filter</entry>
2548 </row>
2549 <row>
2550 <entry><constant>V4L2_MPEG_CX2341X_VIDEO_MEDIAN_FILTER_TYPE_HOR</constant> </entry>
2551 <entry>Horizontal filter</entry>
2552 </row>
2553 <row>
2554 <entry><constant>V4L2_MPEG_CX2341X_VIDEO_MEDIAN_FILTER_TYPE_VERT</constant> </entry>
2555 <entry>Vertical filter</entry>
2556 </row>
2557 <row>
2558 <entry><constant>V4L2_MPEG_CX2341X_VIDEO_MEDIAN_FILTER_TYPE_HOR_VERT</constant> </entry>
2559 <entry>Horizontal and vertical filter</entry>
2560 </row>
2561 <row>
2562 <entry><constant>V4L2_MPEG_CX2341X_VIDEO_MEDIAN_FILTER_TYPE_DIAG</constant> </entry>
2563 <entry>Diagonal filter</entry>
2564 </row>
2565 </tbody>
2566 </entrytbl>
2567 </row>
2568 <row><entry></entry></row>
2569 <row>
2570 <entry spanname="id"><constant>V4L2_CID_MPEG_CX2341X_VIDEO_LUMA_MEDIAN_FILTER_BOTTOM</constant> </entry>
2571 <entry>integer (0-255)</entry>
2572 </row><row><entry spanname="descr">Threshold above which
2573 the luminance median filter is enabled (default 0)</entry>
2574 </row>
2575 <row><entry></entry></row>
2576 <row>
2577 <entry spanname="id"><constant>V4L2_CID_MPEG_CX2341X_VIDEO_LUMA_MEDIAN_FILTER_TOP</constant> </entry>
2578 <entry>integer (0-255)</entry>
2579 </row><row><entry spanname="descr">Threshold below which
2580 the luminance median filter is enabled (default 255)</entry>
2581 </row>
2582 <row><entry></entry></row>
2583 <row>
2584 <entry spanname="id"><constant>V4L2_CID_MPEG_CX2341X_VIDEO_CHROMA_MEDIAN_FILTER_BOTTOM</constant> </entry>
2585 <entry>integer (0-255)</entry>
2586 </row><row><entry spanname="descr">Threshold above which
2587 the chroma median filter is enabled (default 0)</entry>
2588 </row>
2589 <row><entry></entry></row>
2590 <row>
2591 <entry spanname="id"><constant>V4L2_CID_MPEG_CX2341X_VIDEO_CHROMA_MEDIAN_FILTER_TOP</constant> </entry>
2592 <entry>integer (0-255)</entry>
2593 </row><row><entry spanname="descr">Threshold below which
2594 the chroma median filter is enabled (default 255)</entry>
2595 </row>
2596 <row><entry></entry></row>
2597 <row>
2598 <entry spanname="id"><constant>V4L2_CID_MPEG_CX2341X_STREAM_INSERT_NAV_PACKETS</constant> </entry>
2599 <entry>boolean</entry>
2600 </row>
2601 <row><entry spanname="descr">The CX2341X MPEG encoder
2602 can insert one empty MPEG-2 PES packet into the stream between every
2603 four video frames. The packet size is 2048 bytes, including the
2604 packet_start_code_prefix and stream_id fields. The stream_id is 0xBF
2605 (private stream 2). The payload consists of 0x00 bytes, to be filled
2606 in by the application. 0 = do not insert, 1 = insert packets.</entry>
2607 </row>
2608 </tbody>
2609 </tgroup>
2610 </table>
2611 </section>
2612 </section>
2614 <section id="camera-controls">
2615 <title>Camera Control Reference</title>
2617 <para>The Camera class includes controls for mechanical (or
2618 equivalent digital) features of a device such as controllable lenses
2619 or sensors.</para>
2621 <table pgwide="1" frame="none" id="camera-control-id">
2622 <title>Camera Control IDs</title>
2623 <tgroup cols="4">
2624 <colspec colname="c1" colwidth="1*" />
2625 <colspec colname="c2" colwidth="6*" />
2626 <colspec colname="c3" colwidth="2*" />
2627 <colspec colname="c4" colwidth="6*" />
2628 <spanspec namest="c1" nameend="c2" spanname="id" />
2629 <spanspec namest="c2" nameend="c4" spanname="descr" />
2630 <thead>
2631 <row>
2632 <entry spanname="id" align="left">ID</entry>
2633 <entry align="left">Type</entry>
2634 </row><row rowsep="1"><entry spanname="descr" align="left">Description</entry>
2635 </row>
2636 </thead>
2637 <tbody valign="top">
2638 <row><entry></entry></row>
2639 <row>
2640 <entry spanname="id"><constant>V4L2_CID_CAMERA_CLASS</constant> </entry>
2641 <entry>class</entry>
2642 </row><row><entry spanname="descr">The Camera class
2643 descriptor. Calling &VIDIOC-QUERYCTRL; for this control will return a
2644 description of this control class.</entry>
2645 </row>
2646 <row><entry></entry></row>
2648 <row id="v4l2-exposure-auto-type">
2649 <entry spanname="id"><constant>V4L2_CID_EXPOSURE_AUTO</constant> </entry>
2650 <entry>enum v4l2_exposure_auto_type</entry>
2651 </row><row><entry spanname="descr">Enables automatic
2652 adjustments of the exposure time and/or iris aperture. The effect of
2653 manual changes of the exposure time or iris aperture while these
2654 features are enabled is undefined, drivers should ignore such
2655 requests. Possible values are:</entry>
2656 </row>
2657 <row>
2658 <entrytbl spanname="descr" cols="2">
2659 <tbody valign="top">
2660 <row>
2661 <entry><constant>V4L2_EXPOSURE_AUTO</constant> </entry>
2662 <entry>Automatic exposure time, automatic iris
2663 aperture.</entry>
2664 </row>
2665 <row>
2666 <entry><constant>V4L2_EXPOSURE_MANUAL</constant> </entry>
2667 <entry>Manual exposure time, manual iris.</entry>
2668 </row>
2669 <row>
2670 <entry><constant>V4L2_EXPOSURE_SHUTTER_PRIORITY</constant> </entry>
2671 <entry>Manual exposure time, auto iris.</entry>
2672 </row>
2673 <row>
2674 <entry><constant>V4L2_EXPOSURE_APERTURE_PRIORITY</constant> </entry>
2675 <entry>Auto exposure time, manual iris.</entry>
2676 </row>
2677 </tbody>
2678 </entrytbl>
2679 </row>
2680 <row><entry></entry></row>
2682 <row>
2683 <entry spanname="id"><constant>V4L2_CID_EXPOSURE_ABSOLUTE</constant> </entry>
2684 <entry>integer</entry>
2685 </row><row><entry spanname="descr">Determines the exposure
2686 time of the camera sensor. The exposure time is limited by the frame
2687 interval. Drivers should interpret the values as 100 µs units,
2688 where the value 1 stands for 1/10000th of a second, 10000 for 1 second
2689 and 100000 for 10 seconds.</entry>
2690 </row>
2691 <row><entry></entry></row>
2693 <row>
2694 <entry spanname="id"><constant>V4L2_CID_EXPOSURE_AUTO_PRIORITY</constant> </entry>
2695 <entry>boolean</entry>
2696 </row><row><entry spanname="descr">When
2697 <constant>V4L2_CID_EXPOSURE_AUTO</constant> is set to
2698 <constant>AUTO</constant> or <constant>APERTURE_PRIORITY</constant>,
2699 this control determines if the device may dynamically vary the frame
2700 rate. By default this feature is disabled (0) and the frame rate must
2701 remain constant.</entry>
2702 </row>
2703 <row><entry></entry></row>
2705 <row>
2706 <entry spanname="id"><constant>V4L2_CID_PAN_RELATIVE</constant> </entry>
2707 <entry>integer</entry>
2708 </row><row><entry spanname="descr">This control turns the
2709 camera horizontally by the specified amount. The unit is undefined. A
2710 positive value moves the camera to the right (clockwise when viewed
2711 from above), a negative value to the left. A value of zero does not
2712 cause motion. This is a write-only control.</entry>
2713 </row>
2714 <row><entry></entry></row>
2716 <row>
2717 <entry spanname="id"><constant>V4L2_CID_TILT_RELATIVE</constant> </entry>
2718 <entry>integer</entry>
2719 </row><row><entry spanname="descr">This control turns the
2720 camera vertically by the specified amount. The unit is undefined. A
2721 positive value moves the camera up, a negative value down. A value of
2722 zero does not cause motion. This is a write-only control.</entry>
2723 </row>
2724 <row><entry></entry></row>
2726 <row>
2727 <entry spanname="id"><constant>V4L2_CID_PAN_RESET</constant> </entry>
2728 <entry>button</entry>
2729 </row><row><entry spanname="descr">When this control is set,
2730 the camera moves horizontally to the default position.</entry>
2731 </row>
2732 <row><entry></entry></row>
2734 <row>
2735 <entry spanname="id"><constant>V4L2_CID_TILT_RESET</constant> </entry>
2736 <entry>button</entry>
2737 </row><row><entry spanname="descr">When this control is set,
2738 the camera moves vertically to the default position.</entry>
2739 </row>
2740 <row><entry></entry></row>
2742 <row>
2743 <entry spanname="id"><constant>V4L2_CID_PAN_ABSOLUTE</constant> </entry>
2744 <entry>integer</entry>
2745 </row><row><entry spanname="descr">This control
2746 turns the camera horizontally to the specified position. Positive
2747 values move the camera to the right (clockwise when viewed from above),
2748 negative values to the left. Drivers should interpret the values as arc
2749 seconds, with valid values between -180 * 3600 and +180 * 3600
2750 inclusive.</entry>
2751 </row>
2752 <row><entry></entry></row>
2754 <row>
2755 <entry spanname="id"><constant>V4L2_CID_TILT_ABSOLUTE</constant> </entry>
2756 <entry>integer</entry>
2757 </row><row><entry spanname="descr">This control
2758 turns the camera vertically to the specified position. Positive values
2759 move the camera up, negative values down. Drivers should interpret the
2760 values as arc seconds, with valid values between -180 * 3600 and +180
2761 * 3600 inclusive.</entry>
2762 </row>
2763 <row><entry></entry></row>
2765 <row>
2766 <entry spanname="id"><constant>V4L2_CID_FOCUS_ABSOLUTE</constant> </entry>
2767 <entry>integer</entry>
2768 </row><row><entry spanname="descr">This control sets the
2769 focal point of the camera to the specified position. The unit is
2770 undefined. Positive values set the focus closer to the camera,
2771 negative values towards infinity.</entry>
2772 </row>
2773 <row><entry></entry></row>
2775 <row>
2776 <entry spanname="id"><constant>V4L2_CID_FOCUS_RELATIVE</constant> </entry>
2777 <entry>integer</entry>
2778 </row><row><entry spanname="descr">This control moves the
2779 focal point of the camera by the specified amount. The unit is
2780 undefined. Positive values move the focus closer to the camera,
2781 negative values towards infinity. This is a write-only control.</entry>
2782 </row>
2783 <row><entry></entry></row>
2785 <row>
2786 <entry spanname="id"><constant>V4L2_CID_FOCUS_AUTO</constant> </entry>
2787 <entry>boolean</entry>
2788 </row><row><entry spanname="descr">Enables automatic focus
2789 adjustments. The effect of manual focus adjustments while this feature
2790 is enabled is undefined, drivers should ignore such requests.</entry>
2791 </row>
2792 <row><entry></entry></row>
2794 <row>
2795 <entry spanname="id"><constant>V4L2_CID_ZOOM_ABSOLUTE</constant> </entry>
2796 <entry>integer</entry>
2797 </row><row><entry spanname="descr">Specify the objective lens
2798 focal length as an absolute value. The zoom unit is driver-specific and its
2799 value should be a positive integer.</entry>
2800 </row>
2801 <row><entry></entry></row>
2803 <row>
2804 <entry spanname="id"><constant>V4L2_CID_ZOOM_RELATIVE</constant> </entry>
2805 <entry>integer</entry>
2806 </row><row><entry spanname="descr">Specify the objective lens
2807 focal length relatively to the current value. Positive values move the zoom
2808 lens group towards the telephoto direction, negative values towards the
2809 wide-angle direction. The zoom unit is driver-specific. This is a write-only control.</entry>
2810 </row>
2811 <row><entry></entry></row>
2813 <row>
2814 <entry spanname="id"><constant>V4L2_CID_ZOOM_CONTINUOUS</constant> </entry>
2815 <entry>integer</entry>
2816 </row><row><entry spanname="descr">Move the objective lens group
2817 at the specified speed until it reaches physical device limits or until an
2818 explicit request to stop the movement. A positive value moves the zoom lens
2819 group towards the telephoto direction. A value of zero stops the zoom lens
2820 group movement. A negative value moves the zoom lens group towards the
2821 wide-angle direction. The zoom speed unit is driver-specific.</entry>
2822 </row>
2823 <row><entry></entry></row>
2825 <row>
2826 <entry spanname="id"><constant>V4L2_CID_IRIS_ABSOLUTE</constant> </entry>
2827 <entry>integer</entry>
2828 </row><row><entry spanname="descr">This control sets the
2829 camera's aperture to the specified value. The unit is undefined.
2830 Larger values open the iris wider, smaller values close it.</entry>
2831 </row>
2832 <row><entry></entry></row>
2834 <row>
2835 <entry spanname="id"><constant>V4L2_CID_IRIS_RELATIVE</constant> </entry>
2836 <entry>integer</entry>
2837 </row><row><entry spanname="descr">This control modifies the
2838 camera's aperture by the specified amount. The unit is undefined.
2839 Positive values open the iris one step further, negative values close
2840 it one step further. This is a write-only control.</entry>
2841 </row>
2842 <row><entry></entry></row>
2844 <row>
2845 <entry spanname="id"><constant>V4L2_CID_PRIVACY</constant> </entry>
2846 <entry>boolean</entry>
2847 </row><row><entry spanname="descr">Prevent video from being acquired
2848 by the camera. When this control is set to <constant>TRUE</constant> (1), no
2849 image can be captured by the camera. Common means to enforce privacy are
2850 mechanical obturation of the sensor and firmware image processing, but the
2851 device is not restricted to these methods. Devices that implement the privacy
2852 control must support read access and may support write access.</entry>
2853 </row>
2855 <row>
2856 <entry spanname="id"><constant>V4L2_CID_BAND_STOP_FILTER</constant> </entry>
2857 <entry>integer</entry>
2858 </row><row><entry spanname="descr">Switch the band-stop filter of a
2859 camera sensor on or off, or specify its strength. Such band-stop filters can
2860 be used, for example, to filter out the fluorescent light component.</entry>
2861 </row>
2862 <row><entry></entry></row>
2863 </tbody>
2864 </tgroup>
2865 </table>
2866 </section>
2868 <section id="fm-tx-controls">
2869 <title>FM Transmitter Control Reference</title>
2871 <para>The FM Transmitter (FM_TX) class includes controls for common features of
2872 FM transmissions capable devices. Currently this class includes parameters for audio
2873 compression, pilot tone generation, audio deviation limiter, RDS transmission and
2874 tuning power features.</para>
2876 <table pgwide="1" frame="none" id="fm-tx-control-id">
2877 <title>FM_TX Control IDs</title>
2879 <tgroup cols="4">
2880 <colspec colname="c1" colwidth="1*" />
2881 <colspec colname="c2" colwidth="6*" />
2882 <colspec colname="c3" colwidth="2*" />
2883 <colspec colname="c4" colwidth="6*" />
2884 <spanspec namest="c1" nameend="c2" spanname="id" />
2885 <spanspec namest="c2" nameend="c4" spanname="descr" />
2886 <thead>
2887 <row>
2888 <entry spanname="id" align="left">ID</entry>
2889 <entry align="left">Type</entry>
2890 </row><row rowsep="1"><entry spanname="descr" align="left">Description</entry>
2891 </row>
2892 </thead>
2893 <tbody valign="top">
2894 <row><entry></entry></row>
2895 <row>
2896 <entry spanname="id"><constant>V4L2_CID_FM_TX_CLASS</constant> </entry>
2897 <entry>class</entry>
2898 </row><row><entry spanname="descr">The FM_TX class
2899 descriptor. Calling &VIDIOC-QUERYCTRL; for this control will return a
2900 description of this control class.</entry>
2901 </row>
2902 <row>
2903 <entry spanname="id"><constant>V4L2_CID_RDS_TX_DEVIATION</constant> </entry>
2904 <entry>integer</entry>
2905 </row>
2906 <row><entry spanname="descr">Configures RDS signal frequency deviation level in Hz.
2907 The range and step are driver-specific.</entry>
2908 </row>
2909 <row>
2910 <entry spanname="id"><constant>V4L2_CID_RDS_TX_PI</constant> </entry>
2911 <entry>integer</entry>
2912 </row>
2913 <row><entry spanname="descr">Sets the RDS Programme Identification field
2914 for transmission.</entry>
2915 </row>
2916 <row>
2917 <entry spanname="id"><constant>V4L2_CID_RDS_TX_PTY</constant> </entry>
2918 <entry>integer</entry>
2919 </row>
2920 <row><entry spanname="descr">Sets the RDS Programme Type field for transmission.
2921 This encodes up to 31 pre-defined programme types.</entry>
2922 </row>
2923 <row>
2924 <entry spanname="id"><constant>V4L2_CID_RDS_TX_PS_NAME</constant> </entry>
2925 <entry>string</entry>
2926 </row>
2927 <row><entry spanname="descr">Sets the Programme Service name (PS_NAME) for transmission.
2928 It is intended for static display on a receiver. It is the primary aid to listeners in programme service
2929 identification and selection. In Annex E of <xref linkend="en50067" />, the RDS specification,
2930 there is a full description of the correct character encoding for Programme Service name strings.
2931 Also from RDS specification, PS is usually a single eight character text. However, it is also possible
2932 to find receivers which can scroll strings sized as 8 x N characters. So, this control must be configured
2933 with steps of 8 characters. The result is it must always contain a string with size multiple of 8.</entry>
2934 </row>
2935 <row>
2936 <entry spanname="id"><constant>V4L2_CID_RDS_TX_RADIO_TEXT</constant> </entry>
2937 <entry>string</entry>
2938 </row>
2939 <row><entry spanname="descr">Sets the Radio Text info for transmission. It is a textual description of
2940 what is being broadcasted. RDS Radio Text can be applied when broadcaster wishes to transmit longer PS names,
2941 programme-related information or any other text. In these cases, RadioText should be used in addition to
2942 <constant>V4L2_CID_RDS_TX_PS_NAME</constant>. The encoding for Radio Text strings is also fully described
2943 in Annex E of <xref linkend="en50067" />. The length of Radio Text strings depends on which RDS Block is being
2944 used to transmit it, either 32 (2A block) or 64 (2B block). However, it is also possible
2945 to find receivers which can scroll strings sized as 32 x N or 64 x N characters. So, this control must be configured
2946 with steps of 32 or 64 characters. The result is it must always contain a string with size multiple of 32 or 64. </entry>
2947 </row>
2948 <row>
2949 <entry spanname="id"><constant>V4L2_CID_AUDIO_LIMITER_ENABLED</constant> </entry>
2950 <entry>boolean</entry>
2951 </row>
2952 <row><entry spanname="descr">Enables or disables the audio deviation limiter feature.
2953 The limiter is useful when trying to maximize the audio volume, minimize receiver-generated
2954 distortion and prevent overmodulation.
2955 </entry>
2956 </row>
2957 <row>
2958 <entry spanname="id"><constant>V4L2_CID_AUDIO_LIMITER_RELEASE_TIME</constant> </entry>
2959 <entry>integer</entry>
2960 </row>
2961 <row><entry spanname="descr">Sets the audio deviation limiter feature release time.
2962 Unit is in useconds. Step and range are driver-specific.</entry>
2963 </row>
2964 <row>
2965 <entry spanname="id"><constant>V4L2_CID_AUDIO_LIMITER_DEVIATION</constant> </entry>
2966 <entry>integer</entry>
2967 </row>
2968 <row><entry spanname="descr">Configures audio frequency deviation level in Hz.
2969 The range and step are driver-specific.</entry>
2970 </row>
2971 <row>
2972 <entry spanname="id"><constant>V4L2_CID_AUDIO_COMPRESSION_ENABLED</constant> </entry>
2973 <entry>boolean</entry>
2974 </row>
2975 <row><entry spanname="descr">Enables or disables the audio compression feature.
2976 This feature amplifies signals below the threshold by a fixed gain and compresses audio
2977 signals above the threshold by the ratio of Threshold/(Gain + Threshold).</entry>
2978 </row>
2979 <row>
2980 <entry spanname="id"><constant>V4L2_CID_AUDIO_COMPRESSION_GAIN</constant> </entry>
2981 <entry>integer</entry>
2982 </row>
2983 <row><entry spanname="descr">Sets the gain for audio compression feature. It is
2984 a dB value. The range and step are driver-specific.</entry>
2985 </row>
2986 <row>
2987 <entry spanname="id"><constant>V4L2_CID_AUDIO_COMPRESSION_THRESHOLD</constant> </entry>
2988 <entry>integer</entry>
2989 </row>
2990 <row><entry spanname="descr">Sets the threshold level for audio compression freature.
2991 It is a dB value. The range and step are driver-specific.</entry>
2992 </row>
2993 <row>
2994 <entry spanname="id"><constant>V4L2_CID_AUDIO_COMPRESSION_ATTACK_TIME</constant> </entry>
2995 <entry>integer</entry>
2996 </row>
2997 <row><entry spanname="descr">Sets the attack time for audio compression feature.
2998 It is a useconds value. The range and step are driver-specific.</entry>
2999 </row>
3000 <row>
3001 <entry spanname="id"><constant>V4L2_CID_AUDIO_COMPRESSION_RELEASE_TIME</constant> </entry>
3002 <entry>integer</entry>
3003 </row>
3004 <row><entry spanname="descr">Sets the release time for audio compression feature.
3005 It is a useconds value. The range and step are driver-specific.</entry>
3006 </row>
3007 <row>
3008 <entry spanname="id"><constant>V4L2_CID_PILOT_TONE_ENABLED</constant> </entry>
3009 <entry>boolean</entry>
3010 </row>
3011 <row><entry spanname="descr">Enables or disables the pilot tone generation feature.</entry>
3012 </row>
3013 <row>
3014 <entry spanname="id"><constant>V4L2_CID_PILOT_TONE_DEVIATION</constant> </entry>
3015 <entry>integer</entry>
3016 </row>
3017 <row><entry spanname="descr">Configures pilot tone frequency deviation level. Unit is
3018 in Hz. The range and step are driver-specific.</entry>
3019 </row>
3020 <row>
3021 <entry spanname="id"><constant>V4L2_CID_PILOT_TONE_FREQUENCY</constant> </entry>
3022 <entry>integer</entry>
3023 </row>
3024 <row><entry spanname="descr">Configures pilot tone frequency value. Unit is
3025 in Hz. The range and step are driver-specific.</entry>
3026 </row>
3027 <row>
3028 <entry spanname="id"><constant>V4L2_CID_TUNE_PREEMPHASIS</constant> </entry>
3029 <entry>integer</entry>
3030 </row>
3031 <row id="v4l2-preemphasis"><entry spanname="descr">Configures the pre-emphasis value for broadcasting.
3032 A pre-emphasis filter is applied to the broadcast to accentuate the high audio frequencies.
3033 Depending on the region, a time constant of either 50 or 75 useconds is used. The enum v4l2_preemphasis
3034 defines possible values for pre-emphasis. Here they are:</entry>
3035 </row><row>
3036 <entrytbl spanname="descr" cols="2">
3037 <tbody valign="top">
3038 <row>
3039 <entry><constant>V4L2_PREEMPHASIS_DISABLED</constant> </entry>
3040 <entry>No pre-emphasis is applied.</entry>
3041 </row>
3042 <row>
3043 <entry><constant>V4L2_PREEMPHASIS_50_uS</constant> </entry>
3044 <entry>A pre-emphasis of 50 uS is used.</entry>
3045 </row>
3046 <row>
3047 <entry><constant>V4L2_PREEMPHASIS_75_uS</constant> </entry>
3048 <entry>A pre-emphasis of 75 uS is used.</entry>
3049 </row>
3050 </tbody>
3051 </entrytbl>
3053 </row>
3054 <row>
3055 <entry spanname="id"><constant>V4L2_CID_TUNE_POWER_LEVEL</constant> </entry>
3056 <entry>integer</entry>
3057 </row>
3058 <row><entry spanname="descr">Sets the output power level for signal transmission.
3059 Unit is in dBuV. Range and step are driver-specific.</entry>
3060 </row>
3061 <row>
3062 <entry spanname="id"><constant>V4L2_CID_TUNE_ANTENNA_CAPACITOR</constant> </entry>
3063 <entry>integer</entry>
3064 </row>
3065 <row><entry spanname="descr">This selects the value of antenna tuning capacitor
3066 manually or automatically if set to zero. Unit, range and step are driver-specific.</entry>
3067 </row>
3068 <row><entry></entry></row>
3069 </tbody>
3070 </tgroup>
3071 </table>
3073 <para>For more details about RDS specification, refer to
3074 <xref linkend="en50067" /> document, from CENELEC.</para>
3075 </section>
3077 <section id="flash-controls">
3078 <title>Flash Control Reference</title>
3080 <note>
3081 <title>Experimental</title>
3083 <para>This is an <link linkend="experimental">experimental</link>
3084 interface and may change in the future.</para>
3085 </note>
3087 <para>
3088 The V4L2 flash controls are intended to provide generic access
3089 to flash controller devices. Flash controller devices are
3090 typically used in digital cameras.
3091 </para>
3093 <para>
3094 The interface can support both LED and xenon flash devices. As
3095 of writing this, there is no xenon flash driver using this
3096 interface.
3097 </para>
3099 <section id="flash-controls-use-cases">
3100 <title>Supported use cases</title>
3102 <section>
3103 <title>Unsynchronised LED flash (software strobe)</title>
3105 <para>
3106 Unsynchronised LED flash is controlled directly by the
3107 host as the sensor. The flash must be enabled by the host
3108 before the exposure of the image starts and disabled once
3109 it ends. The host is fully responsible for the timing of
3110 the flash.
3111 </para>
3113 <para>Example of such device: Nokia N900.</para>
3114 </section>
3116 <section>
3117 <title>Synchronised LED flash (hardware strobe)</title>
3119 <para>
3120 The synchronised LED flash is pre-programmed by the host
3121 (power and timeout) but controlled by the sensor through a
3122 strobe signal from the sensor to the flash.
3123 </para>
3125 <para>
3126 The sensor controls the flash duration and timing. This
3127 information typically must be made available to the
3128 sensor.
3129 </para>
3131 </section>
3133 <section>
3134 <title>LED flash as torch</title>
3136 <para>
3137 LED flash may be used as torch in conjunction with another
3138 use case involving camera or individually.
3139 </para>
3141 </section>
3143 </section>
3145 <table pgwide="1" frame="none" id="flash-control-id">
3146 <title>Flash Control IDs</title>
3148 <tgroup cols="4">
3149 <colspec colname="c1" colwidth="1*" />
3150 <colspec colname="c2" colwidth="6*" />
3151 <colspec colname="c3" colwidth="2*" />
3152 <colspec colname="c4" colwidth="6*" />
3153 <spanspec namest="c1" nameend="c2" spanname="id" />
3154 <spanspec namest="c2" nameend="c4" spanname="descr" />
3155 <thead>
3156 <row>
3157 <entry spanname="id" align="left">ID</entry>
3158 <entry align="left">Type</entry>
3159 </row><row rowsep="1"><entry spanname="descr" align="left">Description</entry>
3160 </row>
3161 </thead>
3162 <tbody valign="top">
3163 <row><entry></entry></row>
3164 <row>
3165 <entry spanname="id"><constant>V4L2_CID_FLASH_CLASS</constant></entry>
3166 <entry>class</entry>
3167 </row>
3168 <row>
3169 <entry spanname="descr">The FLASH class descriptor.</entry>
3170 </row>
3171 <row>
3172 <entry spanname="id"><constant>V4L2_CID_FLASH_LED_MODE</constant></entry>
3173 <entry>menu</entry>
3174 </row>
3175 <row id="v4l2-flash-led-mode">
3176 <entry spanname="descr">Defines the mode of the flash LED,
3177 the high-power white LED attached to the flash controller.
3178 Setting this control may not be possible in presence of
3179 some faults. See V4L2_CID_FLASH_FAULT.</entry>
3180 </row>
3181 <row>
3182 <entrytbl spanname="descr" cols="2">
3183 <tbody valign="top">
3184 <row>
3185 <entry><constant>V4L2_FLASH_LED_MODE_NONE</constant></entry>
3186 <entry>Off.</entry>
3187 </row>
3188 <row>
3189 <entry><constant>V4L2_FLASH_LED_MODE_FLASH</constant></entry>
3190 <entry>Flash mode.</entry>
3191 </row>
3192 <row>
3193 <entry><constant>V4L2_FLASH_LED_MODE_TORCH</constant></entry>
3194 <entry>Torch mode. See V4L2_CID_FLASH_TORCH_INTENSITY.</entry>
3195 </row>
3196 </tbody>
3197 </entrytbl>
3198 </row>
3199 <row>
3200 <entry spanname="id"><constant>V4L2_CID_FLASH_STROBE_SOURCE</constant></entry>
3201 <entry>menu</entry>
3202 </row>
3203 <row id="v4l2-flash-strobe-source"><entry
3204 spanname="descr">Defines the source of the flash LED
3205 strobe.</entry>
3206 </row>
3207 <row>
3208 <entrytbl spanname="descr" cols="2">
3209 <tbody valign="top">
3210 <row>
3211 <entry><constant>V4L2_FLASH_STROBE_SOURCE_SOFTWARE</constant></entry>
3212 <entry>The flash strobe is triggered by using
3213 the V4L2_CID_FLASH_STROBE control.</entry>
3214 </row>
3215 <row>
3216 <entry><constant>V4L2_FLASH_STROBE_SOURCE_EXTERNAL</constant></entry>
3217 <entry>The flash strobe is triggered by an
3218 external source. Typically this is a sensor,
3219 which makes it possible to synchronises the
3220 flash strobe start to exposure start.</entry>
3221 </row>
3222 </tbody>
3223 </entrytbl>
3224 </row>
3225 <row>
3226 <entry spanname="id"><constant>V4L2_CID_FLASH_STROBE</constant></entry>
3227 <entry>button</entry>
3228 </row>
3229 <row>
3230 <entry spanname="descr">Strobe flash. Valid when
3231 V4L2_CID_FLASH_LED_MODE is set to
3232 V4L2_FLASH_LED_MODE_FLASH and V4L2_CID_FLASH_STROBE_SOURCE
3233 is set to V4L2_FLASH_STROBE_SOURCE_SOFTWARE. Setting this
3234 control may not be possible in presence of some faults.
3235 See V4L2_CID_FLASH_FAULT.</entry>
3236 </row>
3237 <row>
3238 <entry spanname="id"><constant>V4L2_CID_FLASH_STROBE_STOP</constant></entry>
3239 <entry>button</entry>
3240 </row>
3241 <row><entry spanname="descr">Stop flash strobe immediately.</entry>
3242 </row>
3243 <row>
3244 <entry spanname="id"><constant>V4L2_CID_FLASH_STROBE_STATUS</constant></entry>
3245 <entry>boolean</entry>
3246 </row>
3247 <row>
3248 <entry spanname="descr">Strobe status: whether the flash
3249 is strobing at the moment or not. This is a read-only
3250 control.</entry>
3251 </row>
3252 <row>
3253 <entry spanname="id"><constant>V4L2_CID_FLASH_TIMEOUT</constant></entry>
3254 <entry>integer</entry>
3255 </row>
3256 <row>
3257 <entry spanname="descr">Hardware timeout for flash. The
3258 flash strobe is stopped after this period of time has
3259 passed from the start of the strobe.</entry>
3260 </row>
3261 <row>
3262 <entry spanname="id"><constant>V4L2_CID_FLASH_INTENSITY</constant></entry>
3263 <entry>integer</entry>
3264 </row>
3265 <row>
3266 <entry spanname="descr">Intensity of the flash strobe when
3267 the flash LED is in flash mode
3268 (V4L2_FLASH_LED_MODE_FLASH). The unit should be milliamps
3269 (mA) if possible.</entry>
3270 </row>
3271 <row>
3272 <entry spanname="id"><constant>V4L2_CID_FLASH_TORCH_INTENSITY</constant></entry>
3273 <entry>integer</entry>
3274 </row>
3275 <row>
3276 <entry spanname="descr">Intensity of the flash LED in
3277 torch mode (V4L2_FLASH_LED_MODE_TORCH). The unit should be
3278 milliamps (mA) if possible. Setting this control may not
3279 be possible in presence of some faults. See
3280 V4L2_CID_FLASH_FAULT.</entry>
3281 </row>
3282 <row>
3283 <entry spanname="id"><constant>V4L2_CID_FLASH_INDICATOR_INTENSITY</constant></entry>
3284 <entry>integer</entry>
3285 </row>
3286 <row>
3287 <entry spanname="descr">Intensity of the indicator LED.
3288 The indicator LED may be fully independent of the flash
3289 LED. The unit should be microamps (uA) if possible.</entry>
3290 </row>
3291 <row>
3292 <entry spanname="id"><constant>V4L2_CID_FLASH_FAULT</constant></entry>
3293 <entry>bitmask</entry>
3294 </row>
3295 <row>
3296 <entry spanname="descr">Faults related to the flash. The
3297 faults tell about specific problems in the flash chip
3298 itself or the LEDs attached to it. Faults may prevent
3299 further use of some of the flash controls. In particular,
3300 V4L2_CID_FLASH_LED_MODE is set to V4L2_FLASH_LED_MODE_NONE
3301 if the fault affects the flash LED. Exactly which faults
3302 have such an effect is chip dependent. Reading the faults
3303 resets the control and returns the chip to a usable state
3304 if possible.</entry>
3305 </row>
3306 <row>
3307 <entrytbl spanname="descr" cols="2">
3308 <tbody valign="top">
3309 <row>
3310 <entry><constant>V4L2_FLASH_FAULT_OVER_VOLTAGE</constant></entry>
3311 <entry>Flash controller voltage to the flash LED
3312 has exceeded the limit specific to the flash
3313 controller.</entry>
3314 </row>
3315 <row>
3316 <entry><constant>V4L2_FLASH_FAULT_TIMEOUT</constant></entry>
3317 <entry>The flash strobe was still on when
3318 the timeout set by the user ---
3319 V4L2_CID_FLASH_TIMEOUT control --- has expired.
3320 Not all flash controllers may set this in all
3321 such conditions.</entry>
3322 </row>
3323 <row>
3324 <entry><constant>V4L2_FLASH_FAULT_OVER_TEMPERATURE</constant></entry>
3325 <entry>The flash controller has overheated.</entry>
3326 </row>
3327 <row>
3328 <entry><constant>V4L2_FLASH_FAULT_SHORT_CIRCUIT</constant></entry>
3329 <entry>The short circuit protection of the flash
3330 controller has been triggered.</entry>
3331 </row>
3332 </tbody>
3333 </entrytbl>
3334 </row>
3335 <row>
3336 <entry spanname="id"><constant>V4L2_CID_FLASH_CHARGE</constant></entry>
3337 <entry>boolean</entry>
3338 </row>
3339 <row><entry spanname="descr">Enable or disable charging of the xenon
3340 flash capacitor.</entry>
3341 </row>
3342 <row>
3343 <entry spanname="id"><constant>V4L2_CID_FLASH_READY</constant></entry>
3344 <entry>boolean</entry>
3345 </row>
3346 <row>
3347 <entry spanname="descr">Is the flash ready to strobe?
3348 Xenon flashes require their capacitors charged before
3349 strobing. LED flashes often require a cooldown period
3350 after strobe during which another strobe will not be
3351 possible. This is a read-only control.</entry>
3352 </row>
3353 <row><entry></entry></row>
3354 </tbody>
3355 </tgroup>
3356 </table>
3358 </section>
3359 </section>