diff options
| author | Mauro Carvalho Chehab <mchehab@redhat.com> | 2009-09-13 22:16:04 -0300 |
|---|---|---|
| committer | Mauro Carvalho Chehab <mchehab@redhat.com> | 2009-09-18 23:47:55 -0300 |
| commit | 8e080c2e6cadada82a6b520e0c23a1cb974822d5 (patch) | |
| tree | 991450ff1abba98e5313906478c33816a202ccab /Documentation/DocBook/v4l/controls.xml | |
| parent | f4e96deb4513d044653027d4921fd7592195503a (diff) | |
| download | talos-op-linux-8e080c2e6cadada82a6b520e0c23a1cb974822d5.tar.gz talos-op-linux-8e080c2e6cadada82a6b520e0c23a1cb974822d5.zip | |
V4L/DVB (12761): DocBook: add media API specs
The V4L and DVB API's are there for a long time. however, up to now,
no efforts were done to merge them to kernel DocBook.
This patch adds the current versions of the specs as an unique compendium.
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 | 2049 |
1 files changed, 2049 insertions, 0 deletions
diff --git a/Documentation/DocBook/v4l/controls.xml b/Documentation/DocBook/v4l/controls.xml new file mode 100644 index 000000000000..f492accb691d --- /dev/null +++ b/Documentation/DocBook/v4l/controls.xml @@ -0,0 +1,2049 @@ + <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_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) and +<constant>V4L2_COLORFX_SEPIA</constant> (2).</entry> + </row> + <row> + <entry><constant>V4L2_CID_LASTP1</constant></entry> + <entry></entry> + <entry>End of the predefined control IDs (currently +<constant>V4L2_CID_COLORFX</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); + } else { + perror ("VIDIOC_QUERYMENU"); + exit (EXIT_FAILURE); + } + } +} + +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 reproducable 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_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: + --> |
