diff options
| author | Mauro Carvalho Chehab <mchehab@redhat.com> | 2011-05-31 16:27:44 -0300 |
|---|---|---|
| committer | Mauro Carvalho Chehab <mchehab@redhat.com> | 2011-07-27 17:52:05 -0300 |
| commit | 4266129964b8238526936d723de65b419d8069c6 (patch) | |
| tree | 38c6b5cd3dc99b8599391ffad3b87e399bef56a2 /Documentation/DocBook/v4l/controls.xml | |
| parent | 04893043ae9ea8aa82b712491ed25ba6c4ffbca3 (diff) | |
[media] DocBook: Move all media docbook stuff into its own directory
This patch addresses several issues pointed by Randy Dunlap
<rdunlap@xenotime.net> at changeset ece722c:
- In the generated index.html file, "media" is listed first, but it
should be listed in alphabetical order, not first.
- The generated files are (hidden) in .tmpmedia/
- The link from the top-level index.html file to "media" is to
media/index.html, but the file is actually in .tmpmedia/media/index.html
- Please build docs with and without using "O=builddir" and test that.
- Would it be possible for media to have its own Makefile instead of
merging into this one?
Due to the way cleandocs target works, I had to rename the media DocBook
to media_api, otherwise cleandocs would remove the /media directory.
Thanks-to: Randy Dunlap <rdunlap@xenotime.net>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
Diffstat (limited to 'Documentation/DocBook/v4l/controls.xml')
| -rw-r--r-- | Documentation/DocBook/v4l/controls.xml | 2103 |
1 files changed, 0 insertions, 2103 deletions
diff --git a/Documentation/DocBook/v4l/controls.xml b/Documentation/DocBook/v4l/controls.xml deleted file mode 100644 index a920ee80f64..00000000000 --- a/Documentation/DocBook/v4l/controls.xml +++ /dev/null @@ -1,2103 +0,0 @@ - <section id="control"> - <title>User Controls</title> - - <para>Devices typically have a number of user-settable controls -such as brightness, saturation and so on, which would be presented to -the user on a graphical user interface. But, different devices -will have different controls available, and furthermore, the range of -possible values, and the default value will vary from device to -device. The control ioctls provide the information and a mechanism to -create a nice user interface for these controls that will work -correctly with any device.</para> - - <para>All controls are accessed using an ID value. V4L2 defines -several IDs for specific purposes. Drivers can also implement their -own custom controls using <constant>V4L2_CID_PRIVATE_BASE</constant> -and higher values. The pre-defined control IDs have the prefix -<constant>V4L2_CID_</constant>, and are listed in <xref -linkend="control-id" />. The ID is used when querying the attributes of -a control, and when getting or setting the current value.</para> - - <para>Generally applications should present controls to the user -without assumptions about their purpose. Each control comes with a -name string the user is supposed to understand. When the purpose is -non-intuitive the driver writer should provide a user manual, a user -interface plug-in or a driver specific panel application. Predefined -IDs were introduced to change a few controls programmatically, for -example to mute a device during a channel switch.</para> - - <para>Drivers may enumerate different controls after switching -the current video input or output, tuner or modulator, or audio input -or output. Different in the sense of other bounds, another default and -current value, step size or other menu items. A control with a certain -<emphasis>custom</emphasis> ID can also change name and -type.<footnote> - <para>It will be more convenient for applications if drivers -make use of the <constant>V4L2_CTRL_FLAG_DISABLED</constant> flag, but -that was never required.</para> - </footnote> Control values are stored globally, they do not -change when switching except to stay within the reported bounds. They -also do not change ⪚ when the device is opened or closed, when the -tuner radio frequency is changed or generally never without -application request. Since V4L2 specifies no event mechanism, panel -applications intended to cooperate with other panel applications (be -they built into a larger application, as a TV viewer) may need to -regularly poll control values to update their user -interface.<footnote> - <para>Applications could call an ioctl to request events. -After another process called &VIDIOC-S-CTRL; or another ioctl changing -shared properties the &func-select; function would indicate -readability until any ioctl (querying the properties) is -called.</para> - </footnote></para> - - <table pgwide="1" frame="none" id="control-id"> - <title>Control IDs</title> - <tgroup cols="3"> - &cs-def; - <thead> - <row> - <entry>ID</entry> - <entry>Type</entry> - <entry>Description</entry> - </row> - </thead> - <tbody valign="top"> - <row> - <entry><constant>V4L2_CID_BASE</constant></entry> - <entry></entry> - <entry>First predefined ID, equal to -<constant>V4L2_CID_BRIGHTNESS</constant>.</entry> - </row> - <row> - <entry><constant>V4L2_CID_USER_BASE</constant></entry> - <entry></entry> - <entry>Synonym of <constant>V4L2_CID_BASE</constant>.</entry> - </row> - <row> - <entry><constant>V4L2_CID_BRIGHTNESS</constant></entry> - <entry>integer</entry> - <entry>Picture brightness, or more precisely, the black -level.</entry> - </row> - <row> - <entry><constant>V4L2_CID_CONTRAST</constant></entry> - <entry>integer</entry> - <entry>Picture contrast or luma gain.</entry> - </row> - <row> - <entry><constant>V4L2_CID_SATURATION</constant></entry> - <entry>integer</entry> - <entry>Picture color saturation or chroma gain.</entry> - </row> - <row> - <entry><constant>V4L2_CID_HUE</constant></entry> - <entry>integer</entry> - <entry>Hue or color balance.</entry> - </row> - <row> - <entry><constant>V4L2_CID_AUDIO_VOLUME</constant></entry> - <entry>integer</entry> - <entry>Overall audio volume. Note some drivers also -provide an OSS or ALSA mixer interface.</entry> - </row> - <row> - <entry><constant>V4L2_CID_AUDIO_BALANCE</constant></entry> - <entry>integer</entry> - <entry>Audio stereo balance. Minimum corresponds to all -the way left, maximum to right.</entry> - </row> - <row> - <entry><constant>V4L2_CID_AUDIO_BASS</constant></entry> - <entry>integer</entry> - <entry>Audio bass adjustment.</entry> - </row> - <row> - <entry><constant>V4L2_CID_AUDIO_TREBLE</constant></entry> - <entry>integer</entry> - <entry>Audio treble adjustment.</entry> - </row> - <row> - <entry><constant>V4L2_CID_AUDIO_MUTE</constant></entry> - <entry>boolean</entry> - <entry>Mute audio, &ie; set the volume to zero, however -without affecting <constant>V4L2_CID_AUDIO_VOLUME</constant>. Like -ALSA drivers, V4L2 drivers must mute at load time to avoid excessive -noise. Actually the entire device should be reset to a low power -consumption state.</entry> - </row> - <row> - <entry><constant>V4L2_CID_AUDIO_LOUDNESS</constant></entry> - <entry>boolean</entry> - <entry>Loudness mode (bass boost).</entry> - </row> - <row> - <entry><constant>V4L2_CID_BLACK_LEVEL</constant></entry> - <entry>integer</entry> - <entry>Another name for brightness (not a synonym of -<constant>V4L2_CID_BRIGHTNESS</constant>). This control is deprecated -and should not be used in new drivers and applications.</entry> - </row> - <row> - <entry><constant>V4L2_CID_AUTO_WHITE_BALANCE</constant></entry> - <entry>boolean</entry> - <entry>Automatic white balance (cameras).</entry> - </row> - <row> - <entry><constant>V4L2_CID_DO_WHITE_BALANCE</constant></entry> - <entry>button</entry> - <entry>This is an action control. When set (the value is -ignored), the device will do a white balance and then hold the current -setting. Contrast this with the boolean -<constant>V4L2_CID_AUTO_WHITE_BALANCE</constant>, which, when -activated, keeps adjusting the white balance.</entry> - </row> - <row> - <entry><constant>V4L2_CID_RED_BALANCE</constant></entry> - <entry>integer</entry> - <entry>Red chroma balance.</entry> - </row> - <row> - <entry><constant>V4L2_CID_BLUE_BALANCE</constant></entry> - <entry>integer</entry> - <entry>Blue chroma balance.</entry> - </row> - <row> - <entry><constant>V4L2_CID_GAMMA</constant></entry> - <entry>integer</entry> - <entry>Gamma adjust.</entry> - </row> - <row> - <entry><constant>V4L2_CID_WHITENESS</constant></entry> - <entry>integer</entry> - <entry>Whiteness for grey-scale devices. This is a synonym -for <constant>V4L2_CID_GAMMA</constant>. This control is deprecated -and should not be used in new drivers and applications.</entry> - </row> - <row> - <entry><constant>V4L2_CID_EXPOSURE</constant></entry> - <entry>integer</entry> - <entry>Exposure (cameras). [Unit?]</entry> - </row> - <row> - <entry><constant>V4L2_CID_AUTOGAIN</constant></entry> - <entry>boolean</entry> - <entry>Automatic gain/exposure control.</entry> - </row> - <row> - <entry><constant>V4L2_CID_GAIN</constant></entry> - <entry>integer</entry> - <entry>Gain control.</entry> - </row> - <row> - <entry><constant>V4L2_CID_HFLIP</constant></entry> - <entry>boolean</entry> - <entry>Mirror the picture horizontally.</entry> - </row> - <row> - <entry><constant>V4L2_CID_VFLIP</constant></entry> - <entry>boolean</entry> - <entry>Mirror the picture vertically.</entry> - </row> - <row> - <entry><constant>V4L2_CID_HCENTER_DEPRECATED</constant> (formerly <constant>V4L2_CID_HCENTER</constant>)</entry> - <entry>integer</entry> - <entry>Horizontal image centering. This control is -deprecated. New drivers and applications should use the <link -linkend="camera-controls">Camera class controls</link> -<constant>V4L2_CID_PAN_ABSOLUTE</constant>, -<constant>V4L2_CID_PAN_RELATIVE</constant> and -<constant>V4L2_CID_PAN_RESET</constant> instead.</entry> - </row> - <row> - <entry><constant>V4L2_CID_VCENTER_DEPRECATED</constant> - (formerly <constant>V4L2_CID_VCENTER</constant>)</entry> - <entry>integer</entry> - <entry>Vertical image centering. Centering is intended to -<emphasis>physically</emphasis> adjust cameras. For image cropping see -<xref linkend="crop" />, for clipping <xref linkend="overlay" />. This -control is deprecated. New drivers and applications should use the -<link linkend="camera-controls">Camera class controls</link> -<constant>V4L2_CID_TILT_ABSOLUTE</constant>, -<constant>V4L2_CID_TILT_RELATIVE</constant> and -<constant>V4L2_CID_TILT_RESET</constant> instead.</entry> - </row> - <row id="v4l2-power-line-frequency"> - <entry><constant>V4L2_CID_POWER_LINE_FREQUENCY</constant></entry> - <entry>enum</entry> - <entry>Enables a power line frequency filter to avoid -flicker. Possible values for <constant>enum v4l2_power_line_frequency</constant> are: -<constant>V4L2_CID_POWER_LINE_FREQUENCY_DISABLED</constant> (0), -<constant>V4L2_CID_POWER_LINE_FREQUENCY_50HZ</constant> (1) and -<constant>V4L2_CID_POWER_LINE_FREQUENCY_60HZ</constant> (2).</entry> - </row> - <row> - <entry><constant>V4L2_CID_HUE_AUTO</constant></entry> - <entry>boolean</entry> - <entry>Enables automatic hue control by the device. The -effect of setting <constant>V4L2_CID_HUE</constant> while automatic -hue control is enabled is undefined, drivers should ignore such -request.</entry> - </row> - <row> - <entry><constant>V4L2_CID_WHITE_BALANCE_TEMPERATURE</constant></entry> - <entry>integer</entry> - <entry>This control specifies the white balance settings -as a color temperature in Kelvin. A driver should have a minimum of -2800 (incandescent) to 6500 (daylight). For more information about -color temperature see <ulink -url="http://en.wikipedia.org/wiki/Color_temperature">Wikipedia</ulink>.</entry> - </row> - <row> - <entry><constant>V4L2_CID_SHARPNESS</constant></entry> - <entry>integer</entry> - <entry>Adjusts the sharpness filters in a camera. The -minimum value disables the filters, higher values give a sharper -picture.</entry> - </row> - <row> - <entry><constant>V4L2_CID_BACKLIGHT_COMPENSATION</constant></entry> - <entry>integer</entry> - <entry>Adjusts the backlight compensation in a camera. The -minimum value disables backlight compensation.</entry> - </row> - <row> - <entry><constant>V4L2_CID_CHROMA_AGC</constant></entry> - <entry>boolean</entry> - <entry>Chroma automatic gain control.</entry> - </row> - <row> - <entry><constant>V4L2_CID_CHROMA_GAIN</constant></entry> - <entry>integer</entry> - <entry>Adjusts the Chroma gain control (for use when chroma AGC - is disabled).</entry> - </row> - <row> - <entry><constant>V4L2_CID_COLOR_KILLER</constant></entry> - <entry>boolean</entry> - <entry>Enable the color killer (&ie; force a black & white image in case of a weak video signal).</entry> - </row> - <row id="v4l2-colorfx"> - <entry><constant>V4L2_CID_COLORFX</constant></entry> - <entry>enum</entry> - <entry>Selects a color effect. Possible values for -<constant>enum v4l2_colorfx</constant> are: -<constant>V4L2_COLORFX_NONE</constant> (0), -<constant>V4L2_COLORFX_BW</constant> (1), -<constant>V4L2_COLORFX_SEPIA</constant> (2), -<constant>V4L2_COLORFX_NEGATIVE</constant> (3), -<constant>V4L2_COLORFX_EMBOSS</constant> (4), -<constant>V4L2_COLORFX_SKETCH</constant> (5), -<constant>V4L2_COLORFX_SKY_BLUE</constant> (6), -<constant>V4L2_COLORFX_GRASS_GREEN</constant> (7), -<constant>V4L2_COLORFX_SKIN_WHITEN</constant> (8) and -<constant>V4L2_COLORFX_VIVID</constant> (9).</entry> - </row> - <row> - <entry><constant>V4L2_CID_ROTATE</constant></entry> - <entry>integer</entry> - <entry>Rotates the image by specified angle. Common angles are 90, - 270 and 180. Rotating the image to 90 and 270 will reverse the height - and width of the display window. It is necessary to set the new height and - width of the picture using the &VIDIOC-S-FMT; ioctl according to - the rotation angle selected.</entry> - </row> - <row> - <entry><constant>V4L2_CID_BG_COLOR</constant></entry> - <entry>integer</entry> - <entry>Sets the background color on the current output device. - Background color needs to be specified in the RGB24 format. The - supplied 32 bit value is interpreted as bits 0-7 Red color information, - bits 8-15 Green color information, bits 16-23 Blue color - information and bits 24-31 must be zero.</entry> - </row> - <row> - <entry><constant>V4L2_CID_ILLUMINATORS_1</constant> - <constant>V4L2_CID_ILLUMINATORS_2</constant></entry> - <entry>boolean</entry> - <entry>Switch on or off the illuminator 1 or 2 of the device - (usually a microscope).</entry> - </row> - <row> - <entry><constant>V4L2_CID_LASTP1</constant></entry> - <entry></entry> - <entry>End of the predefined control IDs (currently -<constant>V4L2_CID_ILLUMINATORS_2</constant> + 1).</entry> - </row> - <row> - <entry><constant>V4L2_CID_PRIVATE_BASE</constant></entry> - <entry></entry> - <entry>ID of the first custom (driver specific) control. -Applications depending on particular custom controls should check the -driver name and version, see <xref linkend="querycap" />.</entry> - </row> - </tbody> - </tgroup> - </table> - - <para>Applications can enumerate the available controls with the -&VIDIOC-QUERYCTRL; and &VIDIOC-QUERYMENU; ioctls, get and set a -control value with the &VIDIOC-G-CTRL; and &VIDIOC-S-CTRL; ioctls. -Drivers must implement <constant>VIDIOC_QUERYCTRL</constant>, -<constant>VIDIOC_G_CTRL</constant> and -<constant>VIDIOC_S_CTRL</constant> when the device has one or more -controls, <constant>VIDIOC_QUERYMENU</constant> when it has one or -more menu type controls.</para> - - <example> - <title>Enumerating all controls</title> - - <programlisting> -&v4l2-queryctrl; queryctrl; -&v4l2-querymenu; querymenu; - -static void -enumerate_menu (void) -{ - printf (" Menu items:\n"); - - memset (&querymenu, 0, sizeof (querymenu)); - querymenu.id = queryctrl.id; - - for (querymenu.index = queryctrl.minimum; - querymenu.index <= queryctrl.maximum; - querymenu.index++) { - if (0 == ioctl (fd, &VIDIOC-QUERYMENU;, &querymenu)) { - printf (" %s\n", querymenu.name); - } - } -} - -memset (&queryctrl, 0, sizeof (queryctrl)); - -for (queryctrl.id = V4L2_CID_BASE; - queryctrl.id < V4L2_CID_LASTP1; - queryctrl.id++) { - if (0 == ioctl (fd, &VIDIOC-QUERYCTRL;, &queryctrl)) { - if (queryctrl.flags & V4L2_CTRL_FLAG_DISABLED) - continue; - - printf ("Control %s\n", queryctrl.name); - - if (queryctrl.type == V4L2_CTRL_TYPE_MENU) - enumerate_menu (); - } else { - if (errno == EINVAL) - continue; - - perror ("VIDIOC_QUERYCTRL"); - exit (EXIT_FAILURE); - } -} - -for (queryctrl.id = V4L2_CID_PRIVATE_BASE;; - queryctrl.id++) { - if (0 == ioctl (fd, &VIDIOC-QUERYCTRL;, &queryctrl)) { - if (queryctrl.flags & V4L2_CTRL_FLAG_DISABLED) - continue; - - printf ("Control %s\n", queryctrl.name); - - if (queryctrl.type == V4L2_CTRL_TYPE_MENU) - enumerate_menu (); - } else { - if (errno == EINVAL) - break; - - perror ("VIDIOC_QUERYCTRL"); - exit (EXIT_FAILURE); - } -} -</programlisting> - </example> - - <example> - <title>Changing controls</title> - - <programlisting> -&v4l2-queryctrl; queryctrl; -&v4l2-control; control; - -memset (&queryctrl, 0, sizeof (queryctrl)); -queryctrl.id = V4L2_CID_BRIGHTNESS; - -if (-1 == ioctl (fd, &VIDIOC-QUERYCTRL;, &queryctrl)) { - if (errno != EINVAL) { - perror ("VIDIOC_QUERYCTRL"); - exit (EXIT_FAILURE); - } else { - printf ("V4L2_CID_BRIGHTNESS is not supported\n"); - } -} else if (queryctrl.flags & V4L2_CTRL_FLAG_DISABLED) { - printf ("V4L2_CID_BRIGHTNESS is not supported\n"); -} else { - memset (&control, 0, sizeof (control)); - control.id = V4L2_CID_BRIGHTNESS; - control.value = queryctrl.default_value; - - if (-1 == ioctl (fd, &VIDIOC-S-CTRL;, &control)) { - perror ("VIDIOC_S_CTRL"); - exit (EXIT_FAILURE); - } -} - -memset (&control, 0, sizeof (control)); -control.id = V4L2_CID_CONTRAST; - -if (0 == ioctl (fd, &VIDIOC-G-CTRL;, &control)) { - control.value += 1; - - /* The driver may clamp the value or return ERANGE, ignored here */ - - if (-1 == ioctl (fd, &VIDIOC-S-CTRL;, &control) - && errno != ERANGE) { - perror ("VIDIOC_S_CTRL"); - exit (EXIT_FAILURE); - } -/* Ignore if V4L2_CID_CONTRAST is unsupported */ -} else if (errno != EINVAL) { - perror ("VIDIOC_G_CTRL"); - exit (EXIT_FAILURE); -} - -control.id = V4L2_CID_AUDIO_MUTE; -control.value = TRUE; /* silence */ - -/* Errors ignored */ -ioctl (fd, VIDIOC_S_CTRL, &control); -</programlisting> - </example> - </section> - - <section id="extended-controls"> - <title>Extended Controls</title> - - <section> - <title>Introduction</title> - - <para>The control mechanism as originally designed was meant -to be used for user settings (brightness, saturation, etc). However, -it turned out to be a very useful model for implementing more -complicated driver APIs where each driver implements only a subset of -a larger API.</para> - - <para>The MPEG encoding API was the driving force behind -designing and implementing this extended control mechanism: the MPEG -standard is quite large and the currently supported hardware MPEG -encoders each only implement a subset of this standard. Further more, -many parameters relating to how the video is encoded into an MPEG -stream are specific to the MPEG encoding chip since the MPEG standard -only defines the format of the resulting MPEG stream, not how the -video is actually encoded into that format.</para> - - <para>Unfortunately, the original control API lacked some -features needed for these new uses and so it was extended into the -(not terribly originally named) extended control API.</para> - - <para>Even though the MPEG encoding API was the first effort -to use the Extended Control API, nowadays there are also other classes -of Extended Controls, such as Camera Controls and FM Transmitter Controls. -The Extended Controls API as well as all Extended Controls classes are -described in the following text.</para> - </section> - - <section> - <title>The Extended Control API</title> - - <para>Three new ioctls are available: &VIDIOC-G-EXT-CTRLS;, -&VIDIOC-S-EXT-CTRLS; and &VIDIOC-TRY-EXT-CTRLS;. These ioctls act on -arrays of controls (as opposed to the &VIDIOC-G-CTRL; and -&VIDIOC-S-CTRL; ioctls that act on a single control). This is needed -since it is often required to atomically change several controls at -once.</para> - - <para>Each of the new ioctls expects a pointer to a -&v4l2-ext-controls;. This structure contains a pointer to the control -array, a count of the number of controls in that array and a control -class. Control classes are used to group similar controls into a -single class. For example, control class -<constant>V4L2_CTRL_CLASS_USER</constant> contains all user controls -(&ie; all controls that can also be set using the old -<constant>VIDIOC_S_CTRL</constant> ioctl). Control class -<constant>V4L2_CTRL_CLASS_MPEG</constant> contains all controls -relating to MPEG encoding, etc.</para> - - <para>All controls in the control array must belong to the -specified control class. An error is returned if this is not the -case.</para> - - <para>It is also possible to use an empty control array (count -== 0) to check whether the specified control class is -supported.</para> - - <para>The control array is a &v4l2-ext-control; array. The -<structname>v4l2_ext_control</structname> structure is very similar to -&v4l2-control;, except for the fact that it also allows for 64-bit -values and pointers to be passed.</para> - - <para>It is important to realize that due to the flexibility of -controls it is necessary to check whether the control you want to set -actually is supported in the driver and what the valid range of values -is. So use the &VIDIOC-QUERYCTRL; and &VIDIOC-QUERYMENU; ioctls to -check this. Also note that it is possible that some of the menu -indices in a control of type <constant>V4L2_CTRL_TYPE_MENU</constant> -may not be supported (<constant>VIDIOC_QUERYMENU</constant> will -return an error). A good example is the list of supported MPEG audio -bitrates. Some drivers only support one or two bitrates, others -support a wider range.</para> - </section> - - <section> - <title>Enumerating Extended Controls</title> - - <para>The recommended way to enumerate over the extended -controls is by using &VIDIOC-QUERYCTRL; in combination with the -<constant>V4L2_CTRL_FLAG_NEXT_CTRL</constant> flag:</para> - - <informalexample> - <programlisting> -&v4l2-queryctrl; qctrl; - -qctrl.id = V4L2_CTRL_FLAG_NEXT_CTRL; -while (0 == ioctl (fd, &VIDIOC-QUERYCTRL;, &qctrl)) { - /* ... */ - qctrl.id |= V4L2_CTRL_FLAG_NEXT_CTRL; -} -</programlisting> - </informalexample> - - <para>The initial control ID is set to 0 ORed with the -<constant>V4L2_CTRL_FLAG_NEXT_CTRL</constant> flag. The -<constant>VIDIOC_QUERYCTRL</constant> ioctl will return the first -control with a higher ID than the specified one. When no such controls -are found an error is returned.</para> - - <para>If you want to get all controls within a specific control -class, then you can set the initial -<structfield>qctrl.id</structfield> value to the control class and add -an extra check to break out of the loop when a control of another -control class is found:</para> - - <informalexample> - <programlisting> -qctrl.id = V4L2_CTRL_CLASS_MPEG | V4L2_CTRL_FLAG_NEXT_CTRL; -while (0 == ioctl (fd, &VIDIOC-QUERYCTRL;, &qctrl)) { - if (V4L2_CTRL_ID2CLASS (qctrl.id) != V4L2_CTRL_CLASS_MPEG) - break; - /* ... */ - qctrl.id |= V4L2_CTRL_FLAG_NEXT_CTRL; - } -</programlisting> - </informalexample> - - <para>The 32-bit <structfield>qctrl.id</structfield> value is -subdivided into three bit ranges: the top 4 bits are reserved for -flags (⪚ <constant>V4L2_CTRL_FLAG_NEXT_CTRL</constant>) and are not -actually part of the ID. The remaining 28 bits form the control ID, of -which the most significant 12 bits define the control class and the -least significant 16 bits identify the control within the control -class. It is guaranteed that these last 16 bits are always non-zero -for controls. The range of 0x1000 and up are reserved for -driver-specific controls. The macro -<constant>V4L2_CTRL_ID2CLASS(id)</constant> returns the control class -ID based on a control ID.</para> - - <para>If the driver does not support extended controls, then -<constant>VIDIOC_QUERYCTRL</constant> will fail when used in -combination with <constant>V4L2_CTRL_FLAG_NEXT_CTRL</constant>. In -that case the old method of enumerating control should be used (see -1.8). But if it is supported, then it is guaranteed to enumerate over -all controls, including driver-private controls.</para> - </section> - - <section> - <title>Creating Control Panels</title> - - <para>It is possible to create control panels for a graphical -user interface where the user can select the various controls. -Basically you will have to iterate over all controls using the method -described above. Each control class starts with a control of type -<constant>V4L2_CTRL_TYPE_CTRL_CLASS</constant>. -<constant>VIDIOC_QUERYCTRL</constant> will return the name of this -control class which can be used as the title of a tab page within a -control panel.</para> - - <para>The flags field of &v4l2-queryctrl; also contains hints on -the behavior of the control. See the &VIDIOC-QUERYCTRL; documentation -for more details.</para> - </section> - - <section id="mpeg-controls"> - <title>MPEG Control Reference</title> - - <para>Below all controls within the MPEG control class are -described. First the generic controls, then controls specific for -certain hardware.</para> - - <section> - <title>Generic MPEG Controls</title> - - <table pgwide="1" frame="none" id="mpeg-control-id"> - <title>MPEG Control IDs</title> - <tgroup cols="4"> - <colspec colname="c1" colwidth="1*" /> - <colspec colname="c2" colwidth="6*" /> - <colspec colname="c3" colwidth="2*" /> - <colspec colname="c4" colwidth="6*" /> - <spanspec namest="c1" nameend="c2" spanname="id" /> - <spanspec namest="c2" nameend="c4" spanname="descr" /> - <thead> - <row> - <entry spanname="id" align="left">ID</entry> - <entry align="left">Type</entry> - </row><row rowsep="1"><entry spanname="descr" align="left">Description</entry> - </row> - </thead> - <tbody valign="top"> - <row><entry></entry></row> - <row> - <entry spanname="id"><constant>V4L2_CID_MPEG_CLASS</constant> </entry> - <entry>class</entry> - </row><row><entry spanname="descr">The MPEG class -descriptor. Calling &VIDIOC-QUERYCTRL; for this control will return a -description of this control class. This description can be used as the -caption of a Tab page in a GUI, for example.</entry> - </row> - <row><entry></entry></row> - <row id="v4l2-mpeg-stream-type"> - <entry spanname="id"><constant>V4L2_CID_MPEG_STREAM_TYPE</constant> </entry> - <entry>enum v4l2_mpeg_stream_type</entry> - </row><row><entry spanname="descr">The MPEG-1, -2 or -4 -output stream type. One cannot assume anything here. Each hardware -MPEG encoder tends to support different subsets of the available MPEG -stream types. The currently defined stream types are:</entry> - </row> - <row> - <entrytbl spanname="descr" cols="2"> - <tbody valign="top"> - <row> - <entry><constant>V4L2_MPEG_STREAM_TYPE_MPEG2_PS</constant> </entry> - <entry>MPEG-2 program stream</entry> - </row> - <row> - <entry><constant>V4L2_MPEG_STREAM_TYPE_MPEG2_TS</constant> </entry> - <entry>MPEG-2 transport stream</entry> - </row> - <row> - <entry><constant>V4L2_MPEG_STREAM_TYPE_MPEG1_SS</constant> </entry> - <entry>MPEG-1 system stream</entry> - </row> - <row> - <entry><constant>V4L2_MPEG_STREAM_TYPE_MPEG2_DVD</constant> </entry> - <entry>MPEG-2 DVD-compatible stream</entry> - </row> - <row> - <entry><constant>V4L2_MPEG_STREAM_TYPE_MPEG1_VCD</constant> </entry> - <entry>MPEG-1 VCD-compatible stream</entry> - </row> - <row> - <entry><constant>V4L2_MPEG_STREAM_TYPE_MPEG2_SVCD</constant> </entry> - <entry>MPEG-2 SVCD-compatible stream</entry> - </row> - </tbody> - </entrytbl> - </row> - <row><entry></entry></row> - <row> - <entry spanname="id"><constant>V4L2_CID_MPEG_STREAM_PID_PMT</constant> </entry> - <entry>integer</entry> - </row><row><entry spanname="descr">Program Map Table -Packet ID for the MPEG transport stream (default 16)</entry> - </row> - <row><entry></entry></row> - <row> - <entry spanname="id"><constant>V4L2_CID_MPEG_STREAM_PID_AUDIO</constant> </entry> - <entry>integer</entry> - </row><row><entry spanname="descr">Audio Packet ID for -the MPEG transport stream (default 256)</entry> - </row> - <row><entry></entry></row> - <row> - <entry spanname="id"><constant>V4L2_CID_MPEG_STREAM_PID_VIDEO</constant> </entry> - <entry>integer</entry> - </row><row><entry spanname="descr">Video Packet ID for -the MPEG transport stream (default 260)</entry> - </row> - <row><entry></entry></row> - <row> - <entry spanname="id"><constant>V4L2_CID_MPEG_STREAM_PID_PCR</constant> </entry> - <entry>integer</entry> - </row><row><entry spanname="descr">Packet ID for the -MPEG transport stream carrying PCR fields (default 259)</entry> - </row> - <row><entry></entry></row> - <row> - <entry spanname="id"><constant>V4L2_CID_MPEG_STREAM_PES_ID_AUDIO</constant> </entry> - <entry>integer</entry> - </row><row><entry spanname="descr">Audio ID for MPEG -PES</entry> - </row> - <row><entry></entry></row> - <row> - <entry spanname="id"><constant>V4L2_CID_MPEG_STREAM_PES_ID_VIDEO</constant> </entry> - <entry>integer</entry> - </row><row><entry spanname="descr">Video ID for MPEG -PES</entry> - </row> - <row><entry></entry></row> - <row id="v4l2-mpeg-stream-vbi-fmt"> - <entry spanname="id"><constant>V4L2_CID_MPEG_STREAM_VBI_FMT</constant> </entry> - <entry>enum v4l2_mpeg_stream_vbi_fmt</entry> - </row><row><entry spanname="descr">Some cards can embed -VBI data (⪚ Closed Caption, Teletext) into the MPEG stream. This -control selects whether VBI data should be embedded, and if so, what -embedding method should be used. The list of possible VBI formats -depends on the driver. The currently defined VBI format types -are:</entry> - </row> - <row> - <entrytbl spanname="descr" cols="2"> - <tbody valign="top"> - <row> - <entry><constant>V4L2_MPEG_STREAM_VBI_FMT_NONE</constant> </entry> - <entry>No VBI in the MPEG stream</entry> - </row> - <row> - <entry><constant>V4L2_MPEG_STREAM_VBI_FMT_IVTV</constant> </entry> - <entry>VBI in private packets, IVTV format (documented -in the kernel sources in the file <filename>Documentation/video4linux/cx2341x/README.vbi</filename>)</entry> - </row> - </tbody> - </entrytbl> - </row> - <row><entry></entry></row> - <row id="v4l2-mpeg-audio-sampling-freq"> - <entry spanname="id"><constant>V4L2_CID_MPEG_AUDIO_SAMPLING_FREQ</constant> </entry> - <entry>enum v4l2_mpeg_audio_sampling_freq</entry> - </row><row><entry spanname="descr">MPEG Audio sampling -frequency. Possible values are:</entry> - </row> - <row> - <entrytbl spanname="descr" cols="2"> - <tbody valign="top"> - <row> - <entry><constant>V4L2_MPEG_AUDIO_SAMPLING_FREQ_44100</constant> </entry> - <entry>44.1 kHz</entry> - </row> - <row> - <entry><constant>V4L2_MPEG_AUDIO_SAMPLING_FREQ_48000</constant> </entry> - <entry>48 kHz</entry> - </row> - <row> - <entry><constant>V4L2_MPEG_AUDIO_SAMPLING_FREQ_32000</constant> </entry> - <entry>32 kHz</entry> - </row> - </tbody> - </entrytbl> - </row> - <row><entry></entry></row> - <row id="v4l2-mpeg-audio-encoding"> - <entry spanname="id"><constant>V4L2_CID_MPEG_AUDIO_ENCODING</constant> </entry> - <entry>enum v4l2_mpeg_audio_encoding</entry> - </row><row><entry spanname="descr">MPEG Audio encoding. -Possible values are:</entry> - </row> - <row> - <entrytbl spanname="descr" cols="2"> - <tbody valign="top"> - <row> - <entry><constant>V4L2_MPEG_AUDIO_ENCODING_LAYER_1</constant> </entry> - <entry>MPEG-1/2 Layer I encoding</entry> - </row> - <row> - <entry><constant>V4L2_MPEG_AUDIO_ENCODING_LAYER_2</constant> </entry> - <entry>MPEG-1/2 Layer II encoding</entry> - </row> - <row> - <entry><constant>V4L2_MPEG_AUDIO_ENCODING_LAYER_3</constant> </entry> - <entry>MPEG-1/2 Layer III encoding</entry> - </row> - <row> - <entry><constant>V4L2_MPEG_AUDIO_ENCODING_AAC</constant> </entry> - <entry>MPEG-2/4 AAC (Advanced Audio Coding)</entry> - </row> - <row> - <entry><constant>V4L2_MPEG_AUDIO_ENCODING_AC3</constant> </entry> - <entry>AC-3 aka ATSC A/52 encoding</entry> - </row> - </tbody> - </entrytbl> - </row> - <row><entry></entry></row> - <row id="v4l2-mpeg-audio-l1-bitrate"> - <entry spanname="id"><constant>V4L2_CID_MPEG_AUDIO_L1_BITRATE</constant> </entry> - <entry>enum v4l2_mpeg_audio_l1_bitrate</entry> - </row><row><entry spanname="descr">MPEG-1/2 Layer I bitrate. -Possible values are:</entry> - </row> - <row> - <entrytbl spanname="descr" cols="2"> - <tbody valign="top"> - <row> - <entry><constant>V4L2_MPEG_AUDIO_L1_BITRATE_32K</constant> </entry> - <entry>32 kbit/s</entry></row> - <row> - <entry><constant>V4L2_MPEG_AUDIO_L1_BITRATE_64K</constant> </entry> - <entry>64 kbit/s</entry> - </row> - <row> - <entry><constant>V4L2_MPEG_AUDIO_L1_BITRATE_96K</constant> </entry> - <entry>96 kbit/s</entry> - </row> - <row> - <entry><constant>V4L2_MPEG_AUDIO_L1_BITRATE_128K</constant> </entry> - <entry>128 kbit/s</entry> - </row> - <row> - <entry><constant>V4L2_MPEG_AUDIO_L1_BITRATE_160K</constant> </entry> - <entry>160 kbit/s</entry> - </row> - <row> - <entry><constant>V4L2_MPEG_AUDIO_L1_BITRATE_192K</constant> </entry> - <entry>192 kbit/s</entry> - </row> - <row> - <entry><constant>V4L2_MPEG_AUDIO_L1_BITRATE_224K</constant> </entry> - <entry>224 kbit/s</entry> - </row> - <row> - <entry><constant>V4L2_MPEG_AUDIO_L1_BITRATE_256K</constant> </entry> - <entry>256 kbit/s</entry> - </row> - <row> - <entry><constant>V4L2_MPEG_AUDIO_L1_BITRATE_288K</constant> </entry> - <entry>288 kbit/s</entry> - </row> - <row> - <entry><constant>V4L2_MPEG_AUDIO_L1_BITRATE_320K</constant> </entry> - <entry>320 kbit/s</entry> - </row> - <row> - <entry><constant>V4L2_MPEG_AUDIO_L1_BITRATE_352K</constant> </entry> - <entry>352 kbit/s</entry> - </row> - <row> - <entry><constant>V4L2_MPEG_AUDIO_L1_BITRATE_384K</constant> </entry> - <entry>384 kbit/s</entry> - </row> - <row> - <entry><constant>V4L2_MPEG_AUDIO_L1_BITRATE_416K</constant> </entry> - <entry>416 kbit/s</entry> - </row> - <row> - <entry><constant>V4L2_MPEG_AUDIO_L1_BITRATE_448K</constant> </entry> - <entry>448 kbit/s</entry> - </row> - </tbody> - </entrytbl> - </row> - <row><entry></entry></row> - <row id="v4l2-mpeg-audio-l2-bitrate"> - <entry spanname="id"><constant>V4L2_CID_MPEG_AUDIO_L2_BITRATE</constant> </entry> - <entry>enum v4l2_mpeg_audio_l2_bitrate</entry> - </row><row><entry spanname="descr">MPEG-1/2 Layer II bitrate. -Possible values are:</entry> - </row> - <row> - <entrytbl spanname="descr" cols="2"> - <tbody valign="top"> - <row> - <entry><constant>V4L2_MPEG_AUDIO_L2_BITRATE_32K</constant> </entry> - <entry>32 kbit/s</entry> - </row> - <row> - <entry><constant>V4L2_MPEG_AUDIO_L2_BITRATE_48K</constant> </entry> - <entry>48 kbit/s</entry> - </row> - <row> - <entry><constant>V4L2_MPEG_AUDIO_L2_BITRATE_56K</constant> </entry> - <entry>56 kbit/s</entry> - </row> - <row> - <entry><constant>V4L2_MPEG_AUDIO_L2_BITRATE_64K</constant> </entry> - <entry>64 kbit/s</entry> - </row> - <row> - <entry><constant>V4L2_MPEG_AUDIO_L2_BITRATE_80K</constant> </entry> - <entry>80 kbit/s</entry> - </row> - <row> - <entry><constant>V4L2_MPEG_AUDIO_L2_BITRATE_96K</constant> </entry> - <entry>96 kbit/s</entry> - </row> - <row> - <entry><constant>V4L2_MPEG_AUDIO_L2_BITRATE_112K</constant> </entry> - <entry>112 kbit/s</entry> - </row> - <row> - <entry><constant>V4L2_MPEG_AUDIO_L2_BITRATE_128K</constant> </entry> - <entry>128 kbit/s</entry> - </row> - <row> - <entry><constant>V4L2_MPEG_AUDIO_L2_BITRATE_160K</constant> </entry> - <entry>160 kbit/s</entry> - </row> - <row> - <entry><constant>V4L2_MPEG_AUDIO_L2_BITRATE_192K</constant> </entry> - <entry>192 kbit/s</entry> - </row> - <row> - <entry><constant>V4L2_MPEG_AUDIO_L2_BITRATE_224K</constant> </entry> - <entry>224 kbit/s</entry> - </row> - <row> - <entry><constant>V4L2_MPEG_AUDIO_L2_BITRATE_256K</constant> </entry> - <entry>256 kbit/s</entry> - </row> - <row> - <entry><constant>V4L2_MPEG_AUDIO_L2_BITRATE_320K</constant> </entry> - <entry>320 kbit/s</entry> - </row> - <row> - <entry><constant>V4L2_MPEG_AUDIO_L2_BITRATE_384K</constant> </entry> - <entry>384 kbit/s</entry> - </row> - </tbody> - </entrytbl> - </row> - <row><entry></entry></row> - <row id="v4l2-mpeg-audio-l3-bitrate"> - <entry spanname="id"><constant>V4L2_CID_MPEG_AUDIO_L3_BITRATE</constant> </entry> - <entry>enum v4l2_mpeg_audio_l3_bitrate</entry> - </row><row><entry spanname="descr">MPEG-1/2 Layer III bitrate. -Possible values are:</entry> - </row> - <row> - <entrytbl spanname="descr" cols="2"> - <tbody valign="top"> - <row> - <entry><constant>V4L2_MPEG_AUDIO_L3_BITRATE_32K</constant> </entry> - <entry>32 kbit/s</entry> - </row> - <row> - <entry><constant>V4L2_MPEG_AUDIO_L3_BITRATE_40K</constant> </entry> - <entry>40 kbit/s</entry> - </row> - <row> - <entry><constant>V4L2_MPEG_AUDIO_L3_BITRATE_48K</constant> </entry> - <entry>48 kbit/s</entry> - </row> - <row> - <entry><constant>V4L2_MPEG_AUDIO_L3_BITRATE_56K</constant> </entry> - <entry>56 kbit/s</entry> - </row> - <row> - <entry><constant>V4L2_MPEG_AUDIO_L3_BITRATE_64K</constant> </entry> - <entry>64 kbit/s</entry> - </row> - <row> - <entry><constant>V4L2_MPEG_AUDIO_L3_BITRATE_80K</constant> </entry> - <entry>80 kbit/s</entry> - </row> - <row> - <entry><constant>V4L2_MPEG_AUDIO_L3_BITRATE_96K</constant> </entry> - <entry>96 kbit/s</entry> - </row> - <row> - <entry><constant>V4L2_MPEG_AUDIO_L3_BITRATE_112K</constant> </entry> - <entry>112 kbit/s</entry> - </row> - <row> - <entry><constant>V4L2_MPEG_AUDIO_L3_BITRATE_128K</constant> </entry> - <entry>128 kbit/s</entry> - </row> - <row> - <entry><constant>V4L2_MPEG_AUDIO_L3_BITRATE_160K</constant> </entry> - <entry>160 kbit/s</entry> - </row> - <row> - <entry><constant>V4L2_MPEG_AUDIO_L3_BITRATE_192K</constant> </entry> - <entry>192 kbit/s</entry> - </row> - <row> - <entry><constant>V4L2_MPEG_AUDIO_L3_BITRATE_224K</constant> </entry> - <entry>224 kbit/s</entry> - </row> - <row> - <entry><constant>V4L2_MPEG_AUDIO_L3_BITRATE_256K</constant> </entry> - <entry>256 kbit/s</entry> - </row> - <row> - <entry><constant>V4L2_MPEG_AUDIO_L3_BITRATE_320K</constant> </entry> - <entry>320 kbit/s</entry> - </row> - </tbody> - </entrytbl> - </row> - <row><entry></entry></row> - <row> - <entry spanname="id"><constant>V4L2_CID_MPEG_AUDIO_AAC_BITRATE</constant> </entry> - <entry>integer</entry> - </row><row><entry spanname="descr">AAC bitrate in bits per second.</entry> - </row> - <row><entry></entry></row> - <row id="v4l2-mpeg-audio-ac3-bitrate"> - <entry spanname="id"><constant>V4L2_CID_MPEG_AUDIO_AC3_BITRATE</constant> </entry> - <entry>enum v4l2_mpeg_audio_ac3_bitrate</entry> - </row><row><entry spanname="descr">AC-3 bitrate. -Possible values are:</entry> - </row> - <row> - <entrytbl spanname="descr" cols="2"> - <tbody valign="top"> - <row> - <entry><constant>V4L2_MPEG_AUDIO_AC3_BITRATE_32K</constant> </entry> - <entry>32 kbit/s</entry> - </row> - <row> - <entry><constant>V4L2_MPEG_AUDIO_AC3_BITRATE_40K</constant> </entry> - <entry>40 kbit/s</entry> - </row> - <row> - <entry><constant>V4L2_MPEG_AUDIO_AC3_BITRATE_48K</constant> </entry> - <entry>48 kbit/s</entry> - </row> - <row> - <entry><constant>V4L2_MPEG_AUDIO_AC3_BITRATE_56K</constant> </entry> - <entry>56 kbit/s</entry> - </row> - <row> - <entry><constant>V4L2_MPEG_AUDIO_AC3_BITRATE_64K</constant> </entry> - <entry>64 kbit/s</entry> - </row> - <row> - <entry><constant>V4L2_MPEG_AUDIO_AC3_BITRATE_80K</constant> </entry> - <entry>80 kbit/s</entry> - </row> - <row> - <entry><constant>V4L2_MPEG_AUDIO_AC3_BITRATE_96K</constant> </entry> - <entry>96 kbit/s</entry> - </row> - <row> - <entry><constant>V4L2_MPEG_AUDIO_AC3_BITRATE_112K</constant> </entry> - <entry>112 kbit/s</entry> - </row> - <row> - <entry><constant>V4L2_MPEG_AUDIO_AC3_BITRATE_128K</constant> </entry> - <entry>128 kbit/s</entry> - </row> - <row> - <entry><constant>V4L2_MPEG_AUDIO_AC3_BITRATE_160K</constant> </entry> - <entry>160 kbit/s</entry> - </row> - <row> - <entry><constant>V4L2_MPEG_AUDIO_AC3_BITRATE_192K</constant> </entry> - <entry>192 kbit/s</entry> - </row> - <row> - <entry><constant>V4L2_MPEG_AUDIO_AC3_BITRATE_224K</constant> </entry> - <entry>224 kbit/s</entry> - </row> - <row> - <entry><constant>V4L2_MPEG_AUDIO_AC3_BITRATE_256K</constant> </entry> - <entry>256 kbit/s</entry> - </row> - <row> - <entry><constant>V4L2_MPEG_AUDIO_AC3_BITRATE_320K</constant> </entry> - <entry>320 kbit/s</entry> - </row> - <row> - <entry><constant>V4L2_MPEG_AUDIO_AC3_BITRATE_384K</constant> </entry> - <entry>384 kbit/s</entry> - </row> - <row> - <entry><constant>V4L2_MPEG_AUDIO_AC3_BITRATE_448K</constant> </entry> - <entry>448 kbit/s</entry> - </row> - <row> - <entry><constant>V4L2_MPEG_AUDIO_AC3_BITRATE_512K</constant> </entry> - <entry>512 kbit/s</entry> - </row> - <row> - <entry><constant>V4L2_MPEG_AUDIO_AC3_BITRATE_576K</constant> </entry> - <entry>576 kbit/s</entry> - </row> - <row> - <entry><constant>V4L2_MPEG_AUDIO_AC3_BITRATE_640K</constant> </entry> - <entry>640 kbit/s</entry> - </row> - </tbody> - </entrytbl> - </row> - <row><entry></entry></row> - <row id="v4l2-mpeg-audio-mode"> - <entry spanname="id"><constant>V4L2_CID_MPEG_AUDIO_MODE</constant> </entry> - <entry>enum v4l2_mpeg_audio_mode</entry> - </row><row><entry spanname="descr">MPEG Audio mode. -Possible values are:</entry> - </row> - <row> - <entrytbl spanname="descr" cols="2"> - <tbody valign="top"> - <row> - <entry><constant>V4L2_MPEG_AUDIO_MODE_STEREO</constant> </entry> - <entry>Stereo</entry> - </row> - <row> - <entry><constant>V4L2_MPEG_AUDIO_MODE_JOINT_STEREO</constant> </entry> - <entry>Joint Stereo</entry> - </row> - <row> - <entry><constant>V4L2_MPEG_AUDIO_MODE_DUAL</constant> </entry> - <entry>Bilingual</entry> - </row> - <row> - <entry><constant>V4L2_MPEG_AUDIO_MODE_MONO</constant> </entry> - <entry>Mono</entry> - </row> - </tbody> - </entrytbl> - </row> - <row><entry></entry></row> - <row id="v4l2-mpeg-audio-mode-extension"> - <entry spanname="id"><constant>V4L2_CID_MPEG_AUDIO_MODE_EXTENSION</constant> </entry> - <entry>enum v4l2_mpeg_audio_mode_extension</entry> - </row><row><entry spanname="descr">Joint Stereo -audio mode extension. In Layer I and II they indicate which subbands -are in intensity stereo. All other subbands are coded in stereo. Layer -III is not (yet) supported. Possible values -are:</entry> - </row> - <row> - <entrytbl spanname="descr" cols="2"> - <tbody valign="top"> - <row> - <entry><constant>V4L2_MPEG_AUDIO_MODE_EXTENSION_BOUND_4</constant> </entry> - <entry>Subbands 4-31 in intensity stereo</entry> - </row> - <row> - <entry><constant>V4L2_MPEG_AUDIO_MODE_EXTENSION_BOUND_8</constant> </entry> - <entry>Subbands 8-31 in intensity stereo</entry> - </row> - <row> - <entry><constant>V4L2_MPEG_AUDIO_MODE_EXTENSION_BOUND_12</constant> </entry> - <entry>Subbands 12-31 in intensity stereo</entry> - </row> - <row> - <entry><constant>V4L2_MPEG_AUDIO_MODE_EXTENSION_BOUND_16</constant> </entry> - <entry>Subbands 16-31 in intensity stereo</entry> - </row> - </tbody> - </entrytbl> - </row> - <row><entry></entry></row> - <row id="v4l2-mpeg-audio-emphasis"> - <entry spanname="id"><constant>V4L2_CID_MPEG_AUDIO_EMPHASIS</constant> </entry> - <entry>enum v4l2_mpeg_audio_emphasis</entry> - </row><row><entry spanname="descr">Audio Emphasis. -Possible values are:</entry> - </row> - <row> - <entrytbl spanname="descr" cols="2"> - <tbody valign="top"> - <row> - <entry><constant>V4L2_MPEG_AUDIO_EMPHASIS_NONE</constant> </entry> - <entry>None</entry> - </row> - <row> - <entry><constant>V4L2_MPEG_AUDIO_EMPHASIS_50_DIV_15_uS</constant> </entry> - <entry>50/15 microsecond emphasis</entry> - </row> - <row> - <entry><constant>V4L2_MPEG_AUDIO_EMPHASIS_CCITT_J17</constant> </entry> - <entry>CCITT J.17</entry> - </row> - </tbody> - </entrytbl> - </row> - <row><entry></entry></row> - <row id="v4l2-mpeg-audio-crc"> - <entry spanname="id"><constant>V4L2_CID_MPEG_AUDIO_CRC</constant> </entry> - <entry>enum v4l2_mpeg_audio_crc</entry> - </row><row><entry spanname="descr">CRC method. Possible -values are:</entry> - </row> - <row> - <entrytbl spanname="descr" cols="2"> - <tbody valign="top"> - <row> - <entry><constant>V4L2_MPEG_AUDIO_CRC_NONE</constant> </entry> - <entry>None</entry> - </row> - <row> - <entry><constant>V4L2_MPEG_AUDIO_CRC_CRC16</constant> </entry> - <entry>16 bit parity check</entry> - </row> - </tbody> - </entrytbl> - </row> - <row><entry></entry></row> - <row> - <entry spanname="id"><constant>V4L2_CID_MPEG_AUDIO_MUTE</constant> </entry> - <entry>boolean</entry> - </row><row><entry spanname="descr">Mutes the audio when -capturing. This is not done by muting audio hardware, which can still -produce a slight hiss, but in the encoder itself, guaranteeing a fixed -and reproducible audio bitstream. 0 = unmuted, 1 = muted.</entry> - </row> - <row><entry></entry></row> - <row id="v4l2-mpeg-video-encoding"> - <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_ENCODING</constant> </entry> - <entry>enum v4l2_mpeg_video_encoding</entry> - </row><row><entry spanname="descr">MPEG Video encoding -method. Possible values are:</entry> - </row> - <row> - <entrytbl spanname="descr" cols="2"> - <tbody valign="top"> - <row> - <entry><constant>V4L2_MPEG_VIDEO_ENCODING_MPEG_1</constant> </entry> - <entry>MPEG-1 Video encoding</entry> - </row> - <row> - <entry><constant>V4L2_MPEG_VIDEO_ENCODING_MPEG_2</constant> </entry> - <entry>MPEG-2 Video encoding</entry> - </row> - <row> - <entry><constant>V4L2_MPEG_VIDEO_ENCODING_MPEG_4_AVC</constant> </entry> - <entry>MPEG-4 AVC (H.264) Video encoding</entry> - </row> - </tbody> - </entrytbl> - </row> - <row><entry></entry></row> - <row id="v4l2-mpeg-video-aspect"> - <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_ASPECT</constant> </entry> - <entry>enum v4l2_mpeg_video_aspect</entry> - </row><row><entry spanname="descr">Video aspect. -Possible values are:</entry> - </row> - <row> - <entrytbl spanname="descr" cols="2"> - <tbody valign="top"> - <row> - <entry><constant>V4L2_MPEG_VIDEO_ASPECT_1x1</constant> </entry> - </row> - <row> - <entry><constant>V4L2_MPEG_VIDEO_ASPECT_4x3</constant> </entry> - </row> - <row> - <entry><constant>V4L2_MPEG_VIDEO_ASPECT_16x9</constant> </entry> - </row> - <row> - <entry><constant>V4L2_MPEG_VIDEO_ASPECT_221x100</constant> </entry> - </row> - </tbody> - </entrytbl> - </row> - <row><entry></entry></row> - <row> - <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_B_FRAMES</constant> </entry> - <entry>integer</entry> - </row><row><entry spanname="descr">Number of B-Frames -(default 2)</entry> - </row> - <row><entry></entry></row> - <row> - <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_GOP_SIZE</constant> </entry> - <entry>integer</entry> - </row><row><entry spanname="descr">GOP size (default -12)</entry> - </row> - <row><entry></entry></row> - <row> - <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_GOP_CLOSURE</constant> </entry> - <entry>boolean</entry> - </row><row><entry spanname="descr">GOP closure (default -1)</entry> - </row> - <row><entry></entry></row> - <row> - <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_PULLDOWN</constant> </entry> - <entry>boolean</entry> - </row><row><entry spanname="descr">Enable 3:2 pulldown -(default 0)</entry> - </row> - <row><entry></entry></row> - <row id="v4l2-mpeg-video-bitrate-mode"> - <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_BITRATE_MODE</constant> </entry> - <entry>enum v4l2_mpeg_video_bitrate_mode</entry> - </row><row><entry spanname="descr">Video bitrate mode. -Possible values are:</entry> - </row> - <row> - <entrytbl spanname="descr" cols="2"> - <tbody valign="top"> - <row> - <entry><constant>V4L2_MPEG_VIDEO_BITRATE_MODE_VBR</constant> </entry> - <entry>Variable bitrate</entry> - </row> - <row> - <entry><constant>V4L2_MPEG_VIDEO_BITRATE_MODE_CBR</constant> </entry> - <entry>Constant bitrate</entry> - </row> - </tbody> - </entrytbl> - </row> - <row><entry></entry></row> - <row> - <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_BITRATE</constant> </entry> - <entry>integer</entry> - </row><row><entry spanname="descr">Video bitrate in bits -per second.</entry> - </row> - <row><entry></entry></row> - <row> - <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_BITRATE_PEAK</constant> </entry> - <entry>integer</entry> - </row><row><entry spanname="descr">Peak video bitrate in -bits per second. Must be larger or equal to the average video bitrate. -It is ignored if the video bitrate mode is set to constant -bitrate.</entry> - </row> - <row><entry></entry></row> - <row> - <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_TEMPORAL_DECIMATION</constant> </entry> - <entry>integer</entry> - </row><row><entry spanname="descr">For every captured -frame, skip this many subsequent frames (default 0).</entry> - </row> - <row><entry></entry></row> - <row> - <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_MUTE</constant> </entry> - <entry>boolean</entry> - </row> - <row><entry spanname="descr">"Mutes" the video to a -fixed color when capturing. This is useful for testing, to produce a -fixed video bitstream. 0 = unmuted, 1 = muted.</entry> - </row> - <row><entry></entry></row> - <row> - <entry spanname="id"><constant>V4L2_CID_MPEG_VIDEO_MUTE_YUV</constant> </entry> - <entry>integer</entry> - </row><row><entry spanname="descr">Sets the "mute" color -of the video. The supplied 32-bit integer is interpreted as follows (bit -0 = least significant bit):</entry> - </row> - <row> - <entrytbl spanname="descr" cols="2"> - <tbody valign="top"> - <row> - <entry>Bit 0:7</entry> - <entry>V chrominance information</entry> - </row> - <row> - <entry>Bit 8:15</entry> - <entry>U chrominance information</entry> - </row> - <row> - <entry>Bit 16:23</entry> - <entry>Y luminance information</entry> - </row> - <row> - <entry>Bit 24:31</entry> - <entry>Must be zero.</entry> - </row> - </tbody> - </entrytbl> - </row> - </tbody> - </tgroup> - </table> - </section> - - <section> - <title>CX2341x MPEG Controls</title> - - <para>The following MPEG class controls deal with MPEG -encoding settings that are specific to the Conexant CX23415 and -CX23416 MPEG encoding chips.</para> - - <table pgwide="1" frame="none" id="cx2341x-control-id"> - <title>CX2341x Control IDs</title> - <tgroup cols="4"> - <colspec colname="c1" colwidth="1*" /> - <colspec colname="c2" colwidth="6*" /> - <colspec colname="c3" colwidth="2*" /> - <colspec colname="c4" colwidth="6*" /> - <spanspec namest="c1" nameend="c2" spanname="id" /> - <spanspec namest="c2" nameend="c4" spanname="descr" /> - <thead> - <row> - <entry spanname="id" align="left">ID</entry> - <entry align="left">Type</entry> - </row><row><entry spanname="descr" align="left">Description</entry> - </row> - </thead> - <tbody valign="top"> - <row><entry></entry></row> - <row id="v4l2-mpeg-cx2341x-video-spatial-filter-mode"> - <entry spanname="id"><constant>V4L2_CID_MPEG_CX2341X_VIDEO_SPATIAL_FILTER_MODE</constant> </entry> - <entry>enum v4l2_mpeg_cx2341x_video_spatial_filter_mode</entry> - </row><row><entry spanname="descr">Sets the Spatial -Filter mode (default <constant>MANUAL</constant>). Possible values -are:</entry> - </row> - <row> - <entrytbl spanname="descr" cols="2"> - <tbody valign="top"> - <row> - <entry><constant>V4L2_MPEG_CX2341X_VIDEO_SPATIAL_FILTER_MODE_MANUAL</constant> </entry> - <entry>Choose the filter manually</entry> - </row> - <row> - <entry><constant>V4L2_MPEG_CX2341X_VIDEO_SPATIAL_FILTER_MODE_AUTO</constant> </entry> - <entry>Choose the filter automatically</entry> - </row> - </tbody> - </entrytbl> - </row> - <row><entry></entry></row> - <row> - <entry spanname="id"><constant>V4L2_CID_MPEG_CX2341X_VIDEO_SPATIAL_FILTER</constant> </entry> - <entry>integer (0-15)</entry> - </row><row><entry spanname="descr">The setting for the -Spatial Filter. 0 = off, 15 = maximum. (Default is 0.)</entry> - </row> - <row><entry></entry></row> - <row id="luma-spatial-filter-type"> - <entry spanname="id"><constant>V4L2_CID_MPEG_CX2341X_VIDEO_LUMA_SPATIAL_FILTER_TYPE</constant> </entry> - <entry>enum v4l2_mpeg_cx2341x_video_luma_spatial_filter_type</entry> - </row><row><entry spanname="descr">Select the algorithm -to use for the Luma Spatial Filter (default -<constant>1D_HOR</constant>). Possible values:</entry> - </row> - <row> - <entrytbl spanname="descr" cols="2"> - <tbody valign="top"> - <row> - <entry><constant>V4L2_MPEG_CX2341X_VIDEO_LUMA_SPATIAL_FILTER_TYPE_OFF</constant> </entry> - <entry>No filter</entry> - </row> - <row> - <entry><constant>V4L2_MPEG_CX2341X_VIDEO_LUMA_SPATIAL_FILTER_TYPE_1D_HOR</constant> </entry> - <entry>One-dimensional horizontal</entry> - </row> - <row> - <entry><constant>V4L2_MPEG_CX2341X_VIDEO_LUMA_SPATIAL_FILTER_TYPE_1D_VERT</constant> </entry> - <entry>One-dimensional vertical</entry> - </row> - <row> - <entry><constant>V4L2_MPEG_CX2341X_VIDEO_LUMA_SPATIAL_FILTER_TYPE_2D_HV_SEPARABLE</constant> </entry> - <entry>Two-dimensional separable</entry> - </row> - <row> - <entry><constant>V4L2_MPEG_CX2341X_VIDEO_LUMA_SPATIAL_FILTER_TYPE_2D_SYM_NON_SEPARABLE</constant> </entry> - <entry>Two-dimensional symmetrical -non-separable</entry> - </row> - </tbody> - </entrytbl> - </row> - <row><entry></entry></row> - <row id="chroma-spatial-filter-type"> - <entry spanname="id"><constant>V4L2_CID_MPEG_CX2341X_VIDEO_CHROMA_SPATIAL_FILTER_TYPE</constant> </entry> - <entry>enum v4l2_mpeg_cx2341x_video_chroma_spatial_filter_type</entry> - </row><row><entry spanname="descr">Select the algorithm -for the Chroma Spatial Filter (default <constant>1D_HOR</constant>). -Possible values are:</entry> - </row> - <row> - <entrytbl spanname="descr" cols="2"> - <tbody valign="top"> - <row> - <entry><constant>V4L2_MPEG_CX2341X_VIDEO_CHROMA_SPATIAL_FILTER_TYPE_OFF</constant> </entry> - <entry>No filter</entry> - </row> - <row> - <entry><constant>V4L2_MPEG_CX2341X_VIDEO_CHROMA_SPATIAL_FILTER_TYPE_1D_HOR</constant> </entry> - <entry>One-dimensional horizontal</entry> - </row> - </tbody> - </entrytbl> - </row> - <row><entry></entry></row> - <row id="v4l2-mpeg-cx2341x-video-temporal-filter-mode"> - <entry spanname="id"><constant>V4L2_CID_MPEG_CX2341X_VIDEO_TEMPORAL_FILTER_MODE</constant> </entry> - <entry>enum v4l2_mpeg_cx2341x_video_temporal_filter_mode</entry> - </row><row><entry spanname="descr">Sets the Temporal -Filter mode (default <constant>MANUAL</constant>). Possible values -are:</entry> - </row> - <row> - <entrytbl spanname="descr" cols="2"> - <tbody valign="top"> - <row> - <entry><constant>V4L2_MPEG_CX2341X_VIDEO_TEMPORAL_FILTER_MODE_MANUAL</constant> </entry> - <entry>Choose the filter manually</entry> - </row> - <row> - <entry><constant>V4L2_MPEG_CX2341X_VIDEO_TEMPORAL_FILTER_MODE_AUTO</constant> </entry> - <entry>Choose the filter automatically</entry> - </row> - </tbody> - </entrytbl> - </row> - <row><entry></entry></row> - <row> - <entry spanname="id"><constant>V4L2_CID_MPEG_CX2341X_VIDEO_TEMPORAL_FILTER</constant> </entry> - <entry>integer (0-31)</entry> - </row><row><entry spanname="descr">The setting for the -Temporal Filter. 0 = off, 31 = maximum. (Default is 8 for full-scale -capturing and 0 for scaled capturing.)</entry> - </row> - <row><entry></entry></row> - <row id="v4l2-mpeg-cx2341x-video-median-filter-type"> - <entry spanname="id"><constant>V4L2_CID_MPEG_CX2341X_VIDEO_MEDIAN_FILTER_TYPE</constant> </entry> - <entry>enum v4l2_mpeg_cx2341x_video_median_filter_type</entry> - </row><row><entry spanname="descr">Median Filter Type -(default <constant>OFF</constant>). Possible values are:</entry> - </row> - <row> - <entrytbl spanname="descr" cols="2"> - <tbody valign="top"> - <row> - <entry><constant>V4L2_MPEG_CX2341X_VIDEO_MEDIAN_FILTER_TYPE_OFF</constant> </entry> - <entry>No filter</entry> - </row> - <row> - <entry><constant>V4L2_MPEG_CX2341X_VIDEO_MEDIAN_FILTER_TYPE_HOR</constant> </entry> - <entry>Horizontal filter</entry> - </row> - <row> - <entry><constant>V4L2_MPEG_CX2341X_VIDEO_MEDIAN_FILTER_TYPE_VERT</constant> </entry> - <entry>Vertical filter</entry> - </row> - <row> - <entry><constant>V4L2_MPEG_CX2341X_VIDEO_MEDIAN_FILTER_TYPE_HOR_VERT</constant> </entry> - <entry>Horizontal and vertical filter</entry> - </row> - <row> - <entry><constant>V4L2_MPEG_CX2341X_VIDEO_MEDIAN_FILTER_TYPE_DIAG</constant> </entry> - <entry>Diagonal filter</entry> - </row> - </tbody> - </entrytbl> - </row> - <row><entry></entry></row> - <row> - <entry spanname="id"><constant>V4L2_CID_MPEG_CX2341X_VIDEO_LUMA_MEDIAN_FILTER_BOTTOM</constant> </entry> - <entry>integer (0-255)</entry> - </row><row><entry spanname="descr">Threshold above which -the luminance median filter is enabled (default 0)</entry> - </row> - <row><entry></entry></row> - <row> - <entry spanname="id"><constant>V4L2_CID_MPEG_CX2341X_VIDEO_LUMA_MEDIAN_FILTER_TOP</constant> </entry> - <entry>integer (0-255)</entry> - </row><row><entry spanname="descr">Threshold below which -the luminance median filter is enabled (default 255)</entry> - </row> - <row><entry></entry></row> - <row> - <entry spanname="id"><constant>V4L2_CID_MPEG_CX2341X_VIDEO_CHROMA_MEDIAN_FILTER_BOTTOM</constant> </entry> - <entry>integer (0-255)</entry> - </row><row><entry spanname="descr">Threshold above which -the chroma median filter is enabled (default 0)</entry> - </row> - <row><entry></entry></row> - <row> - <entry spanname="id"><constant>V4L2_CID_MPEG_CX2341X_VIDEO_CHROMA_MEDIAN_FILTER_TOP</constant> </entry> - <entry>integer (0-255)</entry> - </row><row><entry spanname="descr">Threshold below which -the chroma median filter is enabled (default 255)</entry> - </row> - <row><entry></entry></row> - <row> - <entry spanname="id"><constant>V4L2_CID_MPEG_CX2341X_STREAM_INSERT_NAV_PACKETS</constant> </entry> - <entry>boolean</entry> - </row> - <row><entry spanname="descr">The CX2341X MPEG encoder -can insert one empty MPEG-2 PES packet into the stream between every -four video frames. The packet size is 2048 bytes, including the -packet_start_code_prefix and stream_id fields. The stream_id is 0xBF -(private stream 2). The payload consists of 0x00 bytes, to be filled -in by the application. 0 = do not insert, 1 = insert packets.</entry> - </row> - </tbody> - </tgroup> - </table> - </section> - </section> - - <section id="camera-controls"> - <title>Camera Control Reference</title> - - <para>The Camera class includes controls for mechanical (or -equivalent digital) features of a device such as controllable lenses -or sensors.</para> - - <table pgwide="1" frame="none" id="camera-control-id"> - <title>Camera Control IDs</title> - <tgroup cols="4"> - <colspec colname="c1" colwidth="1*" /> - <colspec colname="c2" colwidth="6*" /> - <colspec colname="c3" colwidth="2*" /> - <colspec colname="c4" colwidth="6*" /> - <spanspec namest="c1" nameend="c2" spanname="id" /> - <spanspec namest="c2" nameend="c4" spanname="descr" /> - <thead> - <row> - <entry spanname="id" align="left">ID</entry> - <entry align="left">Type</entry> - </row><row rowsep="1"><entry spanname="descr" align="left">Description</entry> - </row> - </thead> - <tbody valign="top"> - <row><entry></entry></row> - <row> - <entry spanname="id"><constant>V4L2_CID_CAMERA_CLASS</constant> </entry> - <entry>class</entry> - </row><row><entry spanname="descr">The Camera class -descriptor. Calling &VIDIOC-QUERYCTRL; for this control will return a -description of this control class.</entry> - </row> - <row><entry></entry></row> - - <row id="v4l2-exposure-auto-type"> - <entry spanname="id"><constant>V4L2_CID_EXPOSURE_AUTO</constant> </entry> - <entry>enum v4l2_exposure_auto_type</entry> - </row><row><entry spanname="descr">Enables automatic -adjustments of the exposure time and/or iris aperture. The effect of -manual changes of the exposure time or iris aperture while these -features are enabled is undefined, drivers should ignore such -requests. Possible values are:</entry> - </row> - <row> - <entrytbl spanname="descr" cols="2"> - <tbody valign="top"> - <row> - <entry><constant>V4L2_EXPOSURE_AUTO</constant> </entry> - <entry>Automatic exposure time, automatic iris -aperture.</entry> - </row> - <row> - <entry><constant>V4L2_EXPOSURE_MANUAL</constant> </entry> - <entry>Manual exposure time, manual iris.</entry> - </row> - <row> - <entry><constant>V4L2_EXPOSURE_SHUTTER_PRIORITY</constant> </entry> - <entry>Manual exposure time, auto iris.</entry> - </row> - <row> - <entry><constant>V4L2_EXPOSURE_APERTURE_PRIORITY</constant> </entry> - <entry>Auto exposure time, manual iris.</entry> - </row> - </tbody> - </entrytbl> - </row> - <row><entry></entry></row> - - <row> - <entry spanname="id"><constant>V4L2_CID_EXPOSURE_ABSOLUTE</constant> </entry> - <entry>integer</entry> - </row><row><entry spanname="descr">Determines the exposure -time of the camera sensor. The exposure time is limited by the frame -interval. Drivers should interpret the values as 100 µs units, -where the value 1 stands for 1/10000th of a second, 10000 for 1 second -and 100000 for 10 seconds.</entry> - </row> - <row><entry></entry></row> - - <row> - <entry spanname="id"><constant>V4L2_CID_EXPOSURE_AUTO_PRIORITY</constant> </entry> - <entry>boolean</entry> - </row><row><entry spanname="descr">When -<constant>V4L2_CID_EXPOSURE_AUTO</constant> is set to -<constant>AUTO</constant> or <constant>APERTURE_PRIORITY</constant>, -this control determines if the device may dynamically vary the frame -rate. By default this feature is disabled (0) and the frame rate must -remain constant.</entry> - </row> - <row><entry></entry></row> - - <row> - <entry spanname="id"><constant>V4L2_CID_PAN_RELATIVE</constant> </entry> - <entry>integer</entry> - </row><row><entry spanname="descr">This control turns the -camera horizontally by the specified amount. The unit is undefined. A -positive value moves the camera to the right (clockwise when viewed -from above), a negative value to the left. A value of zero does not -cause motion. This is a write-only control.</entry> - </row> - <row><entry></entry></row> - - <row> - <entry spanname="id"><constant>V4L2_CID_TILT_RELATIVE</constant> </entry> - <entry>integer</entry> - </row><row><entry spanname="descr">This control turns the -camera vertically by the specified amount. The unit is undefined. A -positive value moves the camera up, a negative value down. A value of -zero does not cause motion. This is a write-only control.</entry> - </row> - <row><entry></entry></row> - - <row> - <entry spanname="id"><constant>V4L2_CID_PAN_RESET</constant> </entry> - <entry>button</entry> - </row><row><entry spanname="descr">When this control is set, -the camera moves horizontally to the default position.</entry> - </row> - <row><entry></entry></row> - - <row> - <entry spanname="id"><constant>V4L2_CID_TILT_RESET</constant> </entry> - <entry>button</entry> - </row><row><entry spanname="descr">When this control is set, -the camera moves vertically to the default position.</entry> - </row> - <row><entry></entry></row> - - <row> - <entry spanname="id"><constant>V4L2_CID_PAN_ABSOLUTE</constant> </entry> - <entry>integer</entry> - </row><row><entry spanname="descr">This control -turns the camera horizontally to the specified position. Positive -values move the camera to the right (clockwise when viewed from above), -negative values to the left. Drivers should interpret the values as arc -seconds, with valid values between -180 * 3600 and +180 * 3600 -inclusive.</entry> - </row> - <row><entry></entry></row> - - <row> - <entry spanname="id"><constant>V4L2_CID_TILT_ABSOLUTE</constant> </entry> - <entry>integer</entry> - </row><row><entry spanname="descr">This control -turns the camera vertically to the specified position. Positive values -move the camera up, negative values down. Drivers should interpret the -values as arc seconds, with valid values between -180 * 3600 and +180 -* 3600 inclusive.</entry> - </row> - <row><entry></entry></row> - - <row> - <entry spanname="id"><constant>V4L2_CID_FOCUS_ABSOLUTE</constant> </entry> - <entry>integer</entry> - </row><row><entry spanname="descr">This control sets the -focal point of the camera to the specified position. The unit is -undefined. Positive values set the focus closer to the camera, -negative values towards infinity.</entry> - </row> - <row><entry></entry></row> - - <row> - <entry spanname="id"><constant>V4L2_CID_FOCUS_RELATIVE</constant> </entry> - <entry>integer</entry> - </row><row><entry spanname="descr">This control moves the -focal point of the camera by the specified amount. The unit is -undefined. Positive values move the focus closer to the camera, -negative values towards infinity. This is a write-only control.</entry> - </row> - <row><entry></entry></row> - - <row> - <entry spanname="id"><constant>V4L2_CID_FOCUS_AUTO</constant> </entry> - <entry>boolean</entry> - </row><row><entry spanname="descr">Enables automatic focus -adjustments. The effect of manual focus adjustments while this feature -is enabled is undefined, drivers should ignore such requests.</entry> - </row> - <row><entry></entry></row> - - <row> - <entry spanname="id"><constant>V4L2_CID_ZOOM_ABSOLUTE</constant> </entry> - <entry>integer</entry> - </row><row><entry spanname="descr">Specify the objective lens -focal length as an absolute value. The zoom unit is driver-specific and its -value should be a positive integer.</entry> - </row> - <row><entry></entry></row> - - <row> - <entry spanname="id"><constant>V4L2_CID_ZOOM_RELATIVE</constant> </entry> - <entry>integer</entry> - </row><row><entry spanname="descr">Specify the objective lens -focal length relatively to the current value. Positive values move the zoom -lens group towards the telephoto direction, negative values towards the -wide-angle direction. The zoom unit is driver-specific. This is a write-only control.</entry> - </row> - <row><entry></entry></row> - - <row> - <entry spanname="id"><constant>V4L2_CID_ZOOM_CONTINUOUS</constant> </entry> - <entry>integer</entry> - </row><row><entry spanname="descr">Move the objective lens group -at the specified speed until it reaches physical device limits or until an -explicit request to stop the movement. A positive value moves the zoom lens -group towards the telephoto direction. A value of zero stops the zoom lens -group movement. A negative value moves the zoom lens group towards the -wide-angle direction. The zoom speed unit is driver-specific.</entry> - </row> - <row><entry></entry></row> - - <row> - <entry spanname="id"><constant>V4L2_CID_IRIS_ABSOLUTE</constant> </entry> - <entry>integer</entry> - </row><row><entry spanname="descr">This control sets the -camera's aperture to the specified value. The unit is undefined. -Larger values open the iris wider, smaller values close it.</entry> - </row> - <row><entry></entry></row> - - <row> - <entry spanname="id"><constant>V4L2_CID_IRIS_RELATIVE</constant> </entry> - <entry>integer</entry> - </row><row><entry spanname="descr">This control modifies the -camera's aperture by the specified amount. The unit is undefined. -Positive values open the iris one step further, negative values close -it one step further. This is a write-only control.</entry> - </row> - <row><entry></entry></row> - - <row> - <entry spanname="id"><constant>V4L2_CID_PRIVACY</constant> </entry> - <entry>boolean</entry> - </row><row><entry spanname="descr">Prevent video from being acquired -by the camera. When this control is set to <constant>TRUE</constant> (1), no -image can be captured by the camera. Common means to enforce privacy are -mechanical obturation of the sensor and firmware image processing, but the -device is not restricted to these methods. Devices that implement the privacy -control must support read access and may support write access.</entry> - </row> - - <row> - <entry spanname="id"><constant>V4L2_CID_BAND_STOP_FILTER</constant> </entry> - <entry>integer</entry> - </row><row><entry spanname="descr">Switch the band-stop filter of a -camera sensor on or off, or specify its strength. Such band-stop filters can -be used, for example, to filter out the fluorescent light component.</entry> - </row> - <row><entry></entry></row> - </tbody> - </tgroup> - </table> - </section> - - <section id="fm-tx-controls"> - <title>FM Transmitter Control Reference</title> - - <para>The FM Transmitter (FM_TX) class includes controls for common features of -FM transmissions capable devices. Currently this class includes parameters for audio -compression, pilot tone generation, audio deviation limiter, RDS transmission and -tuning power features.</para> - - <table pgwide="1" frame="none" id="fm-tx-control-id"> - <title>FM_TX Control IDs</title> - - <tgroup cols="4"> - <colspec colname="c1" colwidth="1*" /> - <colspec colname="c2" colwidth="6*" /> - <colspec colname="c3" colwidth="2*" /> - <colspec colname="c4" colwidth="6*" /> - <spanspec namest="c1" nameend="c2" spanname="id" /> - <spanspec namest="c2" nameend="c4" spanname="descr" /> - <thead> - <row> - <entry spanname="id" align="left">ID</entry> - <entry align="left">Type</entry> - </row><row rowsep="1"><entry spanname="descr" align="left">Description</entry> - </row> - </thead> - <tbody valign="top"> - <row><entry></entry></row> - <row> - <entry spanname="id"><constant>V4L2_CID_FM_TX_CLASS</constant> </entry> - <entry>class</entry> - </row><row><entry spanname="descr">The FM_TX class -descriptor. Calling &VIDIOC-QUERYCTRL; for this control will return a -description of this control class.</entry> - </row> - <row> - <entry spanname="id"><constant>V4L2_CID_RDS_TX_DEVIATION</constant> </entry> - <entry>integer</entry> - </row> - <row><entry spanname="descr">Configures RDS signal frequency deviation level in Hz. -The range and step are driver-specific.</entry> - </row> - <row> - <entry spanname="id"><constant>V4L2_CID_RDS_TX_PI</constant> </entry> - <entry>integer</entry> - </row> - <row><entry spanname="descr">Sets the RDS Programme Identification field -for transmission.</entry> - </row> - <row> - <entry spanname="id"><constant>V4L2_CID_RDS_TX_PTY</constant> </entry> - <entry>integer</entry> - </row> - <row><entry spanname="descr">Sets the RDS Programme Type field for transmission. -This encodes up to 31 pre-defined programme types.</entry> - </row> - <row> - <entry spanname="id"><constant>V4L2_CID_RDS_TX_PS_NAME</constant> </entry> - <entry>string</entry> - </row> - <row><entry spanname="descr">Sets the Programme Service name (PS_NAME) for transmission. -It is intended for static display on a receiver. It is the primary aid to listeners in programme service -identification and selection. In Annex E of <xref linkend="en50067" />, the RDS specification, -there is a full description of the correct character encoding for Programme Service name strings. -Also from RDS specification, PS is usually a single eight character text. However, it is also possible -to find receivers which can scroll strings sized as 8 x N characters. So, this control must be configured -with steps of 8 characters. The result is it must always contain a string with size multiple of 8.</entry> - </row> - <row> - <entry spanname="id"><constant>V4L2_CID_RDS_TX_RADIO_TEXT</constant> </entry> - <entry>string</entry> - </row> - <row><entry spanname="descr">Sets the Radio Text info for transmission. It is a textual description of -what is being broadcasted. RDS Radio Text can be applied when broadcaster wishes to transmit longer PS names, -programme-related information or any other text. In these cases, RadioText should be used in addition to -<constant>V4L2_CID_RDS_TX_PS_NAME</constant>. The encoding for Radio Text strings is also fully described -in Annex E of <xref linkend="en50067" />. The length of Radio Text strings depends on which RDS Block is being -used to transmit it, either 32 (2A block) or 64 (2B block). However, it is also possible -to find receivers which can scroll strings sized as 32 x N or 64 x N characters. So, this control must be configured -with steps of 32 or 64 characters. The result is it must always contain a string with size multiple of 32 or 64. </entry> - </row> - <row> - <entry spanname="id"><constant>V4L2_CID_AUDIO_LIMITER_ENABLED</constant> </entry> - <entry>boolean</entry> - </row> - <row><entry spanname="descr">Enables or disables the audio deviation limiter feature. -The limiter is useful when trying to maximize the audio volume, minimize receiver-generated -distortion and prevent overmodulation. -</entry> - </row> - <row> - <entry spanname="id"><constant>V4L2_CID_AUDIO_LIMITER_RELEASE_TIME</constant> </entry> - <entry>integer</entry> - </row> - <row><entry spanname="descr">Sets the audio deviation limiter feature release time. -Unit is in useconds. Step and range are driver-specific.</entry> - </row> - <row> - <entry spanname="id"><constant>V4L2_CID_AUDIO_LIMITER_DEVIATION</constant> </entry> - <entry>integer</entry> - </row> - <row><entry spanname="descr">Configures audio frequency deviation level in Hz. -The range and step are driver-specific.</entry> - </row> - <row> - <entry spanname="id"><constant>V4L2_CID_AUDIO_COMPRESSION_ENABLED</constant> </entry> - <entry>boolean</entry> - </row> - <row><entry spanname="descr">Enables or disables the audio compression feature. -This feature amplifies signals below the threshold by a fixed gain and compresses audio -signals above the threshold by the ratio of Threshold/(Gain + Threshold).</entry> - </row> - <row> - <entry spanname="id"><constant>V4L2_CID_AUDIO_COMPRESSION_GAIN</constant> </entry> - <entry>integer</entry> - </row> - <row><entry spanname="descr">Sets the gain for audio compression feature. It is -a dB value. The range and step are driver-specific.</entry> - </row> - <row> - <entry spanname="id"><constant>V4L2_CID_AUDIO_COMPRESSION_THRESHOLD</constant> </entry> - <entry>integer</entry> - </row> - <row><entry spanname="descr">Sets the threshold level for audio compression freature. -It is a dB value. The range and step are driver-specific.</entry> - </row> - <row> - <entry spanname="id"><constant>V4L2_CID_AUDIO_COMPRESSION_ATTACK_TIME</constant> </entry> - <entry>integer</entry> - </row> - <row><entry spanname="descr">Sets the attack time for audio compression feature. -It is a useconds value. The range and step are driver-specific.</entry> - </row> - <row> - <entry spanname="id"><constant>V4L2_CID_AUDIO_COMPRESSION_RELEASE_TIME</constant> </entry> - <entry>integer</entry> - </row> - <row><entry spanname="descr">Sets the release time for audio compression feature. -It is a useconds value. The range and step are driver-specific.</entry> - </row> - <row> - <entry spanname="id"><constant>V4L2_CID_PILOT_TONE_ENABLED</constant> </entry> - <entry>boolean</entry> - </row> - <row><entry spanname="descr">Enables or disables the pilot tone generation feature.</entry> - </row> - <row> - <entry spanname="id"><constant>V4L2_CID_PILOT_TONE_DEVIATION</constant> </entry> - <entry>integer</entry> - </row> - <row><entry spanname="descr">Configures pilot tone frequency deviation level. Unit is -in Hz. The range and step are driver-specific.</entry> - </row> - <row> - <entry spanname="id"><constant>V4L2_CID_PILOT_TONE_FREQUENCY</constant> </entry> - <entry>integer</entry> - </row> - <row><entry spanname="descr">Configures pilot tone frequency value. Unit is -in Hz. The range and step are driver-specific.</entry> - </row> - <row> - <entry spanname="id"><constant>V4L2_CID_TUNE_PREEMPHASIS</constant> </entry> - <entry>integer</entry> - </row> - <row id="v4l2-preemphasis"><entry spanname="descr">Configures the pre-emphasis value for broadcasting. -A pre-emphasis filter is applied to the broadcast to accentuate the high audio frequencies. -Depending on the region, a time constant of either 50 or 75 useconds is used. The enum v4l2_preemphasis -defines possible values for pre-emphasis. Here they are:</entry> - </row><row> - <entrytbl spanname="descr" cols="2"> - <tbody valign="top"> - <row> - <entry><constant>V4L2_PREEMPHASIS_DISABLED</constant> </entry> - <entry>No pre-emphasis is applied.</entry> - </row> - <row> - <entry><constant>V4L2_PREEMPHASIS_50_uS</constant> </entry> - <entry>A pre-emphasis of 50 uS is used.</entry> - </row> - <row> - <entry><constant>V4L2_PREEMPHASIS_75_uS</constant> </entry> - <entry>A pre-emphasis of 75 uS is used.</entry> - </row> - </tbody> - </entrytbl> - - </row> - <row> - <entry spanname="id"><constant>V4L2_CID_TUNE_POWER_LEVEL</constant> </entry> - <entry>integer</entry> - </row> - <row><entry spanname="descr">Sets the output power level for signal transmission. -Unit is in dBuV. Range and step are driver-specific.</entry> - </row> - <row> - <entry spanname="id"><constant>V4L2_CID_TUNE_ANTENNA_CAPACITOR</constant> </entry> - <entry>integer</entry> - </row> - <row><entry spanname="descr">This selects the value of antenna tuning capacitor -manually or automatically if set to zero. Unit, range and step are driver-specific.</entry> - </row> - <row><entry></entry></row> - </tbody> - </tgroup> - </table> - -<para>For more details about RDS specification, refer to -<xref linkend="en50067" /> document, from CENELEC.</para> - </section> -</section> - - <!-- -Local Variables: -mode: sgml -sgml-parent-document: "common.sgml" -indent-tabs-mode: nil -End: - --> |