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1 <section id="control">
2 <title>User Controls</title>
3
4 <para>Devices typically have a number of user-settable controls
5such as brightness, saturation and so on, which would be presented to
6the user on a graphical user interface. But, different devices
7will have different controls available, and furthermore, the range of
8possible values, and the default value will vary from device to
9device. The control ioctls provide the information and a mechanism to
10create a nice user interface for these controls that will work
11correctly with any device.</para>
12
13 <para>All controls are accessed using an ID value. V4L2 defines
14several IDs for specific purposes. Drivers can also implement their
15own custom controls using <constant>V4L2_CID_PRIVATE_BASE</constant>
16and higher values. The pre-defined control IDs have the prefix
17<constant>V4L2_CID_</constant>, and are listed in <xref
18linkend="control-id" />. The ID is used when querying the attributes of
19a control, and when getting or setting the current value.</para>
20
21 <para>Generally applications should present controls to the user
22without assumptions about their purpose. Each control comes with a
23name string the user is supposed to understand. When the purpose is
24non-intuitive the driver writer should provide a user manual, a user
25interface plug-in or a driver specific panel application. Predefined
26IDs were introduced to change a few controls programmatically, for
27example to mute a device during a channel switch.</para>
28
29 <para>Drivers may enumerate different controls after switching
30the current video input or output, tuner or modulator, or audio input
31or output. Different in the sense of other bounds, another default and
32current value, step size or other menu items. A control with a certain
33<emphasis>custom</emphasis> ID can also change name and
34type.<footnote>
35 <para>It will be more convenient for applications if drivers
36make use of the <constant>V4L2_CTRL_FLAG_DISABLED</constant> flag, but
37that was never required.</para>
38 </footnote> Control values are stored globally, they do not
39change when switching except to stay within the reported bounds. They
40also do not change ⪚ when the device is opened or closed, when the
41tuner radio frequency is changed or generally never without
42application request. Since V4L2 specifies no event mechanism, panel
43applications intended to cooperate with other panel applications (be
44they built into a larger application, as a TV viewer) may need to
45regularly poll control values to update their user
46interface.<footnote>
47 <para>Applications could call an ioctl to request events.
48After another process called &VIDIOC-S-CTRL; or another ioctl changing
49shared properties the &func-select; function would indicate
50readability until any ioctl (querying the properties) is
51called.</para>
52 </footnote></para>
53
54 <para>
55 All controls use machine endianness.
56 </para>
57
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
85level.</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
106provide 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
112the 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
128without affecting <constant>V4L2_CID_AUDIO_VOLUME</constant>. Like
129ALSA drivers, V4L2 drivers must mute at load time to avoid excessive
130noise. Actually the entire device should be reset to a low power
131consumption 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
143and 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
154ignored), the device will do a white balance and then hold the current
155setting. Contrast this with the boolean
156<constant>V4L2_CID_AUTO_WHITE_BALANCE</constant>, which, when
157activated, 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
178for <constant>V4L2_CID_GAMMA</constant>. This control is deprecated
179and 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
210deprecated. New drivers and applications should use the <link
211linkend="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
223control 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
233flicker. 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
243effect of setting <constant>V4L2_CID_HUE</constant> while automatic
244hue control is enabled is undefined, drivers should ignore such
245request.</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
251as a color temperature in Kelvin. A driver should have a minimum of
2522800 (incandescent) to 6500 (daylight). For more information about
253color temperature see <ulink
254url="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
260minimum value disables the filters, higher values give a sharper
261picture.</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
267minimum 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
336and used as a hint to determine the number of CAPTURE buffers to pass to REQBUFS.
337The value is the minimum number of CAPTURE buffers that is necessary for hardware
338to 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
344and used as a hint to determine the number of OUTPUT buffers to pass to REQBUFS.
345The value is the minimum number of OUTPUT buffers that is necessary for hardware
346to 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.
352Applications depending on particular custom controls should check the
353driver name and version, see <xref linkend="querycap" />.</entry>
354 </row>
355 </tbody>
356 </tgroup>
357 </table>
358
359 <para>Applications can enumerate the available controls with the
360&VIDIOC-QUERYCTRL; and &VIDIOC-QUERYMENU; ioctls, get and set a
361control value with the &VIDIOC-G-CTRL; and &VIDIOC-S-CTRL; ioctls.
362Drivers 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
365controls, <constant>VIDIOC_QUERYMENU</constant> when it has one or
366more menu type controls.</para>
367
368 <example>
369 <title>Enumerating all controls</title>
370
371 <programlisting>
372&v4l2-queryctrl; queryctrl;
373&v4l2-querymenu; querymenu;
374
375static void
376enumerate_menu (void)
377{
378 printf (" Menu items:\n");
379
380 memset (&querymenu, 0, sizeof (querymenu));
381 querymenu.id = queryctrl.id;
382
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}
391
392memset (&queryctrl, 0, sizeof (queryctrl));
393
394for (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;
400
401 printf ("Control %s\n", queryctrl.name);
402
403 if (queryctrl.type == V4L2_CTRL_TYPE_MENU)
404 enumerate_menu ();
405 } else {
406 if (errno == EINVAL)
407 continue;
408
409 perror ("VIDIOC_QUERYCTRL");
410 exit (EXIT_FAILURE);
411 }
412}
413
414for (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;
419
420 printf ("Control %s\n", queryctrl.name);
421
422 if (queryctrl.type == V4L2_CTRL_TYPE_MENU)
423 enumerate_menu ();
424 } else {
425 if (errno == EINVAL)
426 break;
427
428 perror ("VIDIOC_QUERYCTRL");
429 exit (EXIT_FAILURE);
430 }
431}
432</programlisting>
433 </example>
434
435 <example>
436 <title>Changing controls</title>
437
438 <programlisting>
439&v4l2-queryctrl; queryctrl;
440&v4l2-control; control;
441
442memset (&queryctrl, 0, sizeof (queryctrl));
443queryctrl.id = V4L2_CID_BRIGHTNESS;
444
445if (-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;
458
459 if (-1 == ioctl (fd, &VIDIOC-S-CTRL;, &control)) {
460 perror ("VIDIOC_S_CTRL");
461 exit (EXIT_FAILURE);
462 }
463}
464
465memset (&control, 0, sizeof (control));
466control.id = V4L2_CID_CONTRAST;
467
468if (0 == ioctl (fd, &VIDIOC-G-CTRL;, &control)) {
469 control.value += 1;
470
471 /* The driver may clamp the value or return ERANGE, ignored here */
472
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}
483
484control.id = V4L2_CID_AUDIO_MUTE;
485control.value = TRUE; /* silence */
486
487/* Errors ignored */
488ioctl (fd, VIDIOC_S_CTRL, &control);
489</programlisting>
490 </example>
491 </section>
492
493 <section id="extended-controls">
494 <title>Extended Controls</title>
495
496 <section>
497 <title>Introduction</title>
498
499 <para>The control mechanism as originally designed was meant
500to be used for user settings (brightness, saturation, etc). However,
501it turned out to be a very useful model for implementing more
502complicated driver APIs where each driver implements only a subset of
503a larger API.</para>
504
505 <para>The MPEG encoding API was the driving force behind
506designing and implementing this extended control mechanism: the MPEG
507standard is quite large and the currently supported hardware MPEG
508encoders each only implement a subset of this standard. Further more,
509many parameters relating to how the video is encoded into an MPEG
510stream are specific to the MPEG encoding chip since the MPEG standard
511only defines the format of the resulting MPEG stream, not how the
512video is actually encoded into that format.</para>
513
514 <para>Unfortunately, the original control API lacked some
515features needed for these new uses and so it was extended into the
516(not terribly originally named) extended control API.</para>
517
518 <para>Even though the MPEG encoding API was the first effort
519to use the Extended Control API, nowadays there are also other classes
520of Extended Controls, such as Camera Controls and FM Transmitter Controls.
521The Extended Controls API as well as all Extended Controls classes are
522described in the following text.</para>
523 </section>
524
525 <section>
526 <title>The Extended Control API</title>
527
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
530arrays of controls (as opposed to the &VIDIOC-G-CTRL; and
531&VIDIOC-S-CTRL; ioctls that act on a single control). This is needed
532since it is often required to atomically change several controls at
533once.</para>
534
535 <para>Each of the new ioctls expects a pointer to a
536&v4l2-ext-controls;. This structure contains a pointer to the control
537array, a count of the number of controls in that array and a control
538class. Control classes are used to group similar controls into a
539single 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
544relating to MPEG encoding, etc.</para>
545
546 <para>All controls in the control array must belong to the
547specified control class. An error is returned if this is not the
548case.</para>
549
550 <para>It is also possible to use an empty control array (count
551== 0) to check whether the specified control class is
552supported.</para>
553
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
557values and pointers to be passed.</para>
558
559 <para>It is important to realize that due to the flexibility of
560controls it is necessary to check whether the control you want to set
561actually is supported in the driver and what the valid range of values
562is. So use the &VIDIOC-QUERYCTRL; and &VIDIOC-QUERYMENU; ioctls to
563check this. Also note that it is possible that some of the menu
564indices in a control of type <constant>V4L2_CTRL_TYPE_MENU</constant>
565may not be supported (<constant>VIDIOC_QUERYMENU</constant> will
566return an error). A good example is the list of supported MPEG audio
567bitrates. Some drivers only support one or two bitrates, others
568support a wider range.</para>
569
570 <para>
571 All controls use machine endianness.
572 </para>
573 </section>
574
575 <section>
576 <title>Enumerating Extended Controls</title>
577
578 <para>The recommended way to enumerate over the extended
579controls is by using &VIDIOC-QUERYCTRL; in combination with the
580<constant>V4L2_CTRL_FLAG_NEXT_CTRL</constant> flag:</para>
581
582 <informalexample>
583 <programlisting>
584&v4l2-queryctrl; qctrl;
585
586qctrl.id = V4L2_CTRL_FLAG_NEXT_CTRL;
587while (0 == ioctl (fd, &VIDIOC-QUERYCTRL;, &qctrl)) {
588 /* ... */
589 qctrl.id |= V4L2_CTRL_FLAG_NEXT_CTRL;
590}
591</programlisting>
592 </informalexample>
593
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
597control with a higher ID than the specified one. When no such controls
598are found an error is returned.</para>
599
600 <para>If you want to get all controls within a specific control
601class, then you can set the initial
602<structfield>qctrl.id</structfield> value to the control class and add
603an extra check to break out of the loop when a control of another
604control class is found:</para>
605
606 <informalexample>
607 <programlisting>
608qctrl.id = V4L2_CTRL_CLASS_MPEG | V4L2_CTRL_FLAG_NEXT_CTRL;
609while (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>
617
618 <para>The 32-bit <structfield>qctrl.id</structfield> value is
619subdivided into three bit ranges: the top 4 bits are reserved for
620flags (⪚ <constant>V4L2_CTRL_FLAG_NEXT_CTRL</constant>) and are not
621actually part of the ID. The remaining 28 bits form the control ID, of
622which the most significant 12 bits define the control class and the
623least significant 16 bits identify the control within the control
624class. It is guaranteed that these last 16 bits are always non-zero
625for controls. The range of 0x1000 and up are reserved for
626driver-specific controls. The macro
627<constant>V4L2_CTRL_ID2CLASS(id)</constant> returns the control class
628ID based on a control ID.</para>
629
630 <para>If the driver does not support extended controls, then
631<constant>VIDIOC_QUERYCTRL</constant> will fail when used in
632combination with <constant>V4L2_CTRL_FLAG_NEXT_CTRL</constant>. In
633that case the old method of enumerating control should be used (see
6341.8). But if it is supported, then it is guaranteed to enumerate over
635all controls, including driver-private controls.</para>
636 </section>
637
638 <section>
639 <title>Creating Control Panels</title>
640
641 <para>It is possible to create control panels for a graphical
642user interface where the user can select the various controls.
643Basically you will have to iterate over all controls using the method
644described 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
647control class which can be used as the title of a tab page within a
648control panel.</para>
649
650 <para>The flags field of &v4l2-queryctrl; also contains hints on
651the behavior of the control. See the &VIDIOC-QUERYCTRL; documentation
652for more details.</para>
653 </section>
654
655 <section id="mpeg-controls">
656 <title>MPEG Control Reference</title>
657
658 <para>Below all controls within the MPEG control class are
659described. First the generic controls, then controls specific for
660certain hardware.</para>
661
662 <section>
663 <title>Generic MPEG Controls</title>
664
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
687descriptor. Calling &VIDIOC-QUERYCTRL; for this control will return a
688description of this control class. This description can be used as the
689caption 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
696output stream type. One cannot assume anything here. Each hardware
697MPEG encoder tends to support different subsets of the available MPEG
698stream types. This control is specific to multiplexed MPEG streams.
699The 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
736Packet 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
743the 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
750the 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
757MPEG 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
764PES</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
771PES</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
778VBI data (⪚ Closed Caption, Teletext) into the MPEG stream. This
779control selects whether VBI data should be embedded, and if so, what
780embedding method should be used. The list of possible VBI formats
781depends on the driver. The currently defined VBI format types
782are:</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
794in 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
804frequency. 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.
829This control is specific to multiplexed MPEG streams.
830Possible 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.
863Possible 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.
931Possible 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.
1000Possible 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.
1075Possible 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.
1164Possible 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
1193audio mode extension. In Layer I and II they indicate which subbands
1194are in intensity stereo. All other subbands are coded in stereo. Layer
1195III is not (yet) supported. Possible values
1196are:</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.
1225Possible 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
1250values 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
1271capturing. This is not done by muting audio hardware, which can still
1272produce a slight hiss, but in the encoder itself, guaranteeing a fixed
1273and 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
1280method. This control is specific to multiplexed MPEG streams.
1281Possible 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.
1306Possible 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
133812)</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
13451)</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.
1359Possible 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
1380per 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
1387bits per second. Must be larger or equal to the average video bitrate.
1388It is ignored if the video bitrate mode is set to constant
1389bitrate.</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
1396frame, 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
1404fixed color when capturing. This is useful for testing, to produce a
1405fixed 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
1412of the video. The supplied 32-bit integer is interpreted as follows (bit
14130 = 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>
1437
1438
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
1445the decoder expects a single frame in per buffer. Applicable to the decoder, all codecs.
1446</entry>
1447 </row>
1448
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.
1455Applicable to the H264 encoder.</entry>
1456 </row>
1457
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
1464is 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">
1469
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>
1545
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.
1552Applicable to the H264 encoder.</entry>
1553 </row>
1554
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.
1561Applicable to the H264 encoder.</entry>
1562 </row>
1563
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.
1570Applicable to the H264 encoder.
1571Possible 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>
1643
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.
1650Applicable to the MPEG4 encoder.
1651Possible 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>
1691
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.
1698Applicable to the H264 encoder.
1699Possible 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>
1772
1773 </tbody>
1774 </entrytbl>
1775 </row>
1776
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.
1783Applicable to the MPEG4 encoder.
1784Possible 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>
1812
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.
1819Applicable to the encoder.
1820</entry>
1821 </row>
1822
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.
1829Applicable to the encoder.
1830Possible 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>
1850
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>.
1858Applicable to the encoder.</entry>
1859 </row>
1860
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>.
1868Applicable to the encoder.</entry>
1869 </row>
1870
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.
1877Possible 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>
1897
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.
1904Applicable to the H264 encoder.</entry>
1905 </row>
1906
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.
1913Applicable to the H264 encoder.</entry>
1914 </row>
1915
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.
1922Applicable to the H264 encoder.
1923Possible 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>
1939
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>
1947
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
1954refreshed every frame. Each frame a succesive set of macroblocks is refreshed until the cycle completes and starts from the
1955top of the frame. Applicable to H264, H263 and MPEG4 encoder.</entry>
1956 </row>
1957
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.
1964If 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>).
1966If frame rate control is enabled then quantization parameter is adjusted to meet the chosen bitrate. Minimum and maximum value
1967for the quantization parameter can be set with appropriate controls (e.g. <constant>V4L2_CID_MPEG_VIDEO_H263_MIN_QP</constant>).
1968Applicable to encoders.</entry>
1969 </row>
1970
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.
1977Applicable to the MPEG4 and H264 encoders.</entry>
1978 </row>
1979
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>
1987
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>
1995
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>
2003
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>
2011
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>
2019
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>
2027
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>
2035
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>
2043
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>
2051
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>
2059
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>
2067
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>
2075
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>
2083
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>
2091
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>
2099
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>
2107
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.
2114The VBV is defined in the standard as a mean to verify that the produced stream will be succesfully decoded.
2115The standard describes it as "Part of a hypothetical decoder that is conceptually connected to the
2116output of the encoder. Its purpose is to provide a constraint on the variability of the data rate that an
2117encoder or editing process may produce.".
2118Applicable to the MPEG1, MPEG2, MPEG4 encoders.</entry>
2119 </row>
2120
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.
2127The CPB is defined in the H264 standard as a mean to verify that the produced stream will be succesfully decoded.
2128Applicable to the H264 encoder.</entry>
2129 </row>
2130
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
2137this is the period between two I-frames. The period between IDR (Instantaneous Decoding Refresh) frames is taken from the GOP_SIZE control.
2138An IDR frame, which stands for Instantaneous Decoding Refresh is an I-frame after which no prior frames are
2139referenced. This means that a stream can be restarted from an IDR frame without the need to store or decode any
2140previous frames. Applicable to the H264 encoder.</entry>
2141 </row>
2142
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
2149it returned together with the first frame. Applicable to encoders.
2150Possible 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.
2171Applicable 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>
2185
2186 </tbody>
2187 </tgroup>
2188 </table>
2189 </section>
2190
2191 <section>
2192 <title>MFC 5.1 MPEG Controls</title>
2193
2194 <para>The following MPEG class controls deal with MPEG
2195decoding and encoding settings that are specific to the Multi Format Codec 5.1 device present
2196in the S5P family of SoCs by Samsung.
2197</para>
2198
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
2221CAPTURE buffer after processing a certain number of OUTPUT buffers. If this number is low, then it may result in
2222buffers not being dequeued in display order. In addition hardware may still use those buffers as reference, thus
2223application should not write to those buffers. This feature can be used for example for generating thumbnails of videos.
2224Applicable 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.
2232The decoder is forced to return a decoded frame after the set 'display delay' number of frames. If this number is
2233low it may result in frames returned out of dispaly order, in addition the hardware may still be using the returned buffer
2234as 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.
2242Applicable 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.
2249Applicable 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
22560 = 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).
2287For 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.
2296Valid only when H.264 and macroblock level RC is enabled (<constant>V4L2_CID_MPEG_VIDEO_MB_RC_ENABLE</constant>).
2297Applicable 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.
2304Valid only when H.264 and macroblock level RC is enabled (<constant>V4L2_CID_MPEG_VIDEO_MB_RC_ENABLE</constant>).
2305Applicable 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.
2312Valid only when H.264 and macroblock level RC is enabled (<constant>V4L2_CID_MPEG_VIDEO_MB_RC_ENABLE</constant>).
2313Applicable 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.
2320Valid only when H.264 and macroblock level RC is enabled (<constant>V4L2_CID_MPEG_VIDEO_MB_RC_ENABLE</constant>).
2321Applicable 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">
2329Indicates in what conditions the encoder should skip frames. If encoding a frame would cause the encoded stream to be larger then
2330a chosen data limit then the frame will be skipped.
2331Possible 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.
2356If this setting is enabled, then the rate control logic of the encoder will calculate the average bitrate
2357for a GOP and keep it below or equal the set bitrate target. Otherwise the rate control logic calculates the
2358overall average bitrate for the stream and keeps it below or equal to the set bitrate. In the first case
2359the average bitrate for the whole stream will be smaller then the set bitrate. This is caused because the
2360average is calculated for smaller number of frames, on the other hand enabling this setting will ensure that
2361the 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.
2370Possible 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>
2394
2395 <section>
2396 <title>CX2341x MPEG Controls</title>
2397
2398 <para>The following MPEG class controls deal with MPEG
2399encoding settings that are specific to the Conexant CX23415 and
2400CX23416 MPEG encoding chips.</para>
2401
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
2424Filter mode (default <constant>MANUAL</constant>). Possible values
2425are:</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
2446Spatial 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
2453to 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
2478non-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
2488for the Chroma Spatial Filter (default <constant>1D_HOR</constant>).
2489Possible 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
2510Filter mode (default <constant>MANUAL</constant>). Possible values
2511are:</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
2532Temporal Filter. 0 = off, 31 = maximum. (Default is 8 for full-scale
2533capturing 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
2573the 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
2580the 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
2587the 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
2594the 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
2602can insert one empty MPEG-2 PES packet into the stream between every
2603four video frames. The packet size is 2048 bytes, including the
2604packet_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
2606in by the application. 0 = do not insert, 1 = insert packets.</entry>
2607 </row>
2608 </tbody>
2609 </tgroup>
2610 </table>
2611 </section>
2612 </section>
2613
2614 <section id="camera-controls">
2615 <title>Camera Control Reference</title>
2616
2617 <para>The Camera class includes controls for mechanical (or
2618equivalent digital) features of a device such as controllable lenses
2619or sensors.</para>
2620
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
2643descriptor. Calling &VIDIOC-QUERYCTRL; for this control will return a
2644description of this control class.</entry>
2645 </row>
2646 <row><entry></entry></row>
2647
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
2652adjustments of the exposure time and/or iris aperture. The effect of
2653manual changes of the exposure time or iris aperture while these
2654features are enabled is undefined, drivers should ignore such
2655requests. 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
2663aperture.</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>
2681
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
2686time of the camera sensor. The exposure time is limited by the frame
2687interval. Drivers should interpret the values as 100 µs units,
2688where the value 1 stands for 1/10000th of a second, 10000 for 1 second
2689and 100000 for 10 seconds.</entry>
2690 </row>
2691 <row><entry></entry></row>
2692
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>,
2699this control determines if the device may dynamically vary the frame
2700rate. By default this feature is disabled (0) and the frame rate must
2701remain constant.</entry>
2702 </row>
2703 <row><entry></entry></row>
2704
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
2709camera horizontally by the specified amount. The unit is undefined. A
2710positive value moves the camera to the right (clockwise when viewed
2711from above), a negative value to the left. A value of zero does not
2712cause motion. This is a write-only control.</entry>
2713 </row>
2714 <row><entry></entry></row>
2715
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
2720camera vertically by the specified amount. The unit is undefined. A
2721positive value moves the camera up, a negative value down. A value of
2722zero does not cause motion. This is a write-only control.</entry>
2723 </row>
2724 <row><entry></entry></row>
2725
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,
2730the camera moves horizontally to the default position.</entry>
2731 </row>
2732 <row><entry></entry></row>
2733
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,
2738the camera moves vertically to the default position.</entry>
2739 </row>
2740 <row><entry></entry></row>
2741
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
2746turns the camera horizontally to the specified position. Positive
2747values move the camera to the right (clockwise when viewed from above),
2748negative values to the left. Drivers should interpret the values as arc
2749seconds, with valid values between -180 * 3600 and +180 * 3600
2750inclusive.</entry>
2751 </row>
2752 <row><entry></entry></row>
2753
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
2758turns the camera vertically to the specified position. Positive values
2759move the camera up, negative values down. Drivers should interpret the
2760values as arc seconds, with valid values between -180 * 3600 and +180
2761* 3600 inclusive.</entry>
2762 </row>
2763 <row><entry></entry></row>
2764
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
2769focal point of the camera to the specified position. The unit is
2770undefined. Positive values set the focus closer to the camera,
2771negative values towards infinity.</entry>
2772 </row>
2773 <row><entry></entry></row>
2774
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
2779focal point of the camera by the specified amount. The unit is
2780undefined. Positive values move the focus closer to the camera,
2781negative values towards infinity. This is a write-only control.</entry>
2782 </row>
2783 <row><entry></entry></row>
2784
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
2789adjustments. The effect of manual focus adjustments while this feature
2790is enabled is undefined, drivers should ignore such requests.</entry>
2791 </row>
2792 <row><entry></entry></row>
2793
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
2798focal length as an absolute value. The zoom unit is driver-specific and its
2799value should be a positive integer.</entry>
2800 </row>
2801 <row><entry></entry></row>
2802
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
2807focal length relatively to the current value. Positive values move the zoom
2808lens group towards the telephoto direction, negative values towards the
2809wide-angle direction. The zoom unit is driver-specific. This is a write-only control.</entry>
2810 </row>
2811 <row><entry></entry></row>
2812
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
2817at the specified speed until it reaches physical device limits or until an
2818explicit request to stop the movement. A positive value moves the zoom lens
2819group towards the telephoto direction. A value of zero stops the zoom lens
2820group movement. A negative value moves the zoom lens group towards the
2821wide-angle direction. The zoom speed unit is driver-specific.</entry>
2822 </row>
2823 <row><entry></entry></row>
2824
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
2829camera's aperture to the specified value. The unit is undefined.
2830Larger values open the iris wider, smaller values close it.</entry>
2831 </row>
2832 <row><entry></entry></row>
2833
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
2838camera's aperture by the specified amount. The unit is undefined.
2839Positive values open the iris one step further, negative values close
2840it one step further. This is a write-only control.</entry>
2841 </row>
2842 <row><entry></entry></row>
2843
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
2848by the camera. When this control is set to <constant>TRUE</constant> (1), no
2849image can be captured by the camera. Common means to enforce privacy are
2850mechanical obturation of the sensor and firmware image processing, but the
2851device is not restricted to these methods. Devices that implement the privacy
2852control must support read access and may support write access.</entry>
2853 </row>
2854
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
2859camera sensor on or off, or specify its strength. Such band-stop filters can
2860be 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>
2867
2868 <section id="fm-tx-controls">
2869 <title>FM Transmitter Control Reference</title>
2870
2871 <para>The FM Transmitter (FM_TX) class includes controls for common features of
2872FM transmissions capable devices. Currently this class includes parameters for audio
2873compression, pilot tone generation, audio deviation limiter, RDS transmission and
2874tuning power features.</para>
2875
2876 <table pgwide="1" frame="none" id="fm-tx-control-id">
2877 <title>FM_TX Control IDs</title>
2878
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
2899descriptor. Calling &VIDIOC-QUERYCTRL; for this control will return a
2900description 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.
2907The 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
2914for 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.
2921This 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.
2928It is intended for static display on a receiver. It is the primary aid to listeners in programme service
2929identification and selection. In Annex E of <xref linkend="en50067" />, the RDS specification,
2930there is a full description of the correct character encoding for Programme Service name strings.
2931Also from RDS specification, PS is usually a single eight character text. However, it is also possible
2932to find receivers which can scroll strings sized as 8 x N characters. So, this control must be configured
2933with 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
2940what is being broadcasted. RDS Radio Text can be applied when broadcaster wishes to transmit longer PS names,
2941programme-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
2943in Annex E of <xref linkend="en50067" />. The length of Radio Text strings depends on which RDS Block is being
2944used to transmit it, either 32 (2A block) or 64 (2B block). However, it is also possible
2945to find receivers which can scroll strings sized as 32 x N or 64 x N characters. So, this control must be configured
2946with 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.
2953The limiter is useful when trying to maximize the audio volume, minimize receiver-generated
2954distortion 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.
2962Unit 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.
2969The 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.
2976This feature amplifies signals below the threshold by a fixed gain and compresses audio
2977signals 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
2984a 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.
2991It 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.
2998It 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.
3005It 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
3018in 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
3025in 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.
3032A pre-emphasis filter is applied to the broadcast to accentuate the high audio frequencies.
3033Depending on the region, a time constant of either 50 or 75 useconds is used. The enum v4l2_preemphasis
3034defines 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>
3052
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.
3059Unit 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
3066manually 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>
3072
3073<para>For more details about RDS specification, refer to
3074<xref linkend="en50067" /> document, from CENELEC.</para>
3075 </section>
3076
3077 <section id="flash-controls">
3078 <title>Flash Control Reference</title>
3079
3080 <note>
3081 <title>Experimental</title>
3082
3083 <para>This is an <link linkend="experimental">experimental</link>
3084interface and may change in the future.</para>
3085 </note>
3086
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>
3092
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>
3098
3099 <section id="flash-controls-use-cases">
3100 <title>Supported use cases</title>
3101
3102 <section>
3103 <title>Unsynchronised LED flash (software strobe)</title>
3104
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>
3112
3113 <para>Example of such device: Nokia N900.</para>
3114 </section>
3115
3116 <section>
3117 <title>Synchronised LED flash (hardware strobe)</title>
3118
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>
3124
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>
3130
3131 </section>
3132
3133 <section>
3134 <title>LED flash as torch</title>
3135
3136 <para>
3137 LED flash may be used as torch in conjunction with another
3138 use case involving camera or individually.
3139 </para>
3140
3141 </section>
3142
3143 </section>
3144
3145 <table pgwide="1" frame="none" id="flash-control-id">
3146 <title>Flash Control IDs</title>
3147
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>
3357
3358 </section>
3359</section>
3360
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