2050 lines
77 KiB
XML
2050 lines
77 KiB
XML
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<section id="control">
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<title>User Controls</title>
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<para>Devices typically have a number of user-settable controls
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such as brightness, saturation and so on, which would be presented to
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the user on a graphical user interface. But, different devices
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will have different controls available, and furthermore, the range of
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possible values, and the default value will vary from device to
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device. The control ioctls provide the information and a mechanism to
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create a nice user interface for these controls that will work
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correctly with any device.</para>
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<para>All controls are accessed using an ID value. V4L2 defines
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several IDs for specific purposes. Drivers can also implement their
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own custom controls using <constant>V4L2_CID_PRIVATE_BASE</constant>
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and higher values. The pre-defined control IDs have the prefix
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<constant>V4L2_CID_</constant>, and are listed in <xref
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linkend="control-id" />. The ID is used when querying the attributes of
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a control, and when getting or setting the current value.</para>
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<para>Generally applications should present controls to the user
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without assumptions about their purpose. Each control comes with a
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name string the user is supposed to understand. When the purpose is
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non-intuitive the driver writer should provide a user manual, a user
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interface plug-in or a driver specific panel application. Predefined
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IDs were introduced to change a few controls programmatically, for
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example to mute a device during a channel switch.</para>
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<para>Drivers may enumerate different controls after switching
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the current video input or output, tuner or modulator, or audio input
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or output. Different in the sense of other bounds, another default and
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current value, step size or other menu items. A control with a certain
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<emphasis>custom</emphasis> ID can also change name and
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type.<footnote>
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<para>It will be more convenient for applications if drivers
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make use of the <constant>V4L2_CTRL_FLAG_DISABLED</constant> flag, but
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that was never required.</para>
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</footnote> Control values are stored globally, they do not
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change when switching except to stay within the reported bounds. They
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also do not change ⪚ when the device is opened or closed, when the
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tuner radio frequency is changed or generally never without
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application request. Since V4L2 specifies no event mechanism, panel
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applications intended to cooperate with other panel applications (be
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they built into a larger application, as a TV viewer) may need to
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regularly poll control values to update their user
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interface.<footnote>
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<para>Applications could call an ioctl to request events.
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After another process called &VIDIOC-S-CTRL; or another ioctl changing
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shared properties the &func-select; function would indicate
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readability until any ioctl (querying the properties) is
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called.</para>
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</footnote></para>
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<table pgwide="1" frame="none" id="control-id">
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<title>Control IDs</title>
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<tgroup cols="3">
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&cs-def;
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<thead>
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<row>
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<entry>ID</entry>
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<entry>Type</entry>
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<entry>Description</entry>
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</row>
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</thead>
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<tbody valign="top">
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<row>
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<entry><constant>V4L2_CID_BASE</constant></entry>
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<entry></entry>
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<entry>First predefined ID, equal to
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<constant>V4L2_CID_BRIGHTNESS</constant>.</entry>
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</row>
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<row>
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<entry><constant>V4L2_CID_USER_BASE</constant></entry>
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<entry></entry>
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<entry>Synonym of <constant>V4L2_CID_BASE</constant>.</entry>
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</row>
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<row>
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<entry><constant>V4L2_CID_BRIGHTNESS</constant></entry>
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<entry>integer</entry>
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<entry>Picture brightness, or more precisely, the black
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level.</entry>
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</row>
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<row>
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<entry><constant>V4L2_CID_CONTRAST</constant></entry>
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<entry>integer</entry>
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<entry>Picture contrast or luma gain.</entry>
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</row>
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<row>
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<entry><constant>V4L2_CID_SATURATION</constant></entry>
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<entry>integer</entry>
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<entry>Picture color saturation or chroma gain.</entry>
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</row>
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<row>
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<entry><constant>V4L2_CID_HUE</constant></entry>
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<entry>integer</entry>
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<entry>Hue or color balance.</entry>
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</row>
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<row>
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<entry><constant>V4L2_CID_AUDIO_VOLUME</constant></entry>
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<entry>integer</entry>
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<entry>Overall audio volume. Note some drivers also
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provide an OSS or ALSA mixer interface.</entry>
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</row>
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<row>
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<entry><constant>V4L2_CID_AUDIO_BALANCE</constant></entry>
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<entry>integer</entry>
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<entry>Audio stereo balance. Minimum corresponds to all
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the way left, maximum to right.</entry>
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</row>
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<row>
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<entry><constant>V4L2_CID_AUDIO_BASS</constant></entry>
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<entry>integer</entry>
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<entry>Audio bass adjustment.</entry>
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</row>
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<row>
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<entry><constant>V4L2_CID_AUDIO_TREBLE</constant></entry>
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<entry>integer</entry>
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<entry>Audio treble adjustment.</entry>
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</row>
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<row>
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<entry><constant>V4L2_CID_AUDIO_MUTE</constant></entry>
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<entry>boolean</entry>
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<entry>Mute audio, &ie; set the volume to zero, however
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without affecting <constant>V4L2_CID_AUDIO_VOLUME</constant>. Like
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ALSA drivers, V4L2 drivers must mute at load time to avoid excessive
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noise. Actually the entire device should be reset to a low power
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consumption state.</entry>
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</row>
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<row>
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<entry><constant>V4L2_CID_AUDIO_LOUDNESS</constant></entry>
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<entry>boolean</entry>
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<entry>Loudness mode (bass boost).</entry>
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</row>
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<row>
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<entry><constant>V4L2_CID_BLACK_LEVEL</constant></entry>
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<entry>integer</entry>
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<entry>Another name for brightness (not a synonym of
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<constant>V4L2_CID_BRIGHTNESS</constant>). This control is deprecated
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and should not be used in new drivers and applications.</entry>
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</row>
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<row>
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<entry><constant>V4L2_CID_AUTO_WHITE_BALANCE</constant></entry>
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<entry>boolean</entry>
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<entry>Automatic white balance (cameras).</entry>
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</row>
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<row>
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<entry><constant>V4L2_CID_DO_WHITE_BALANCE</constant></entry>
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<entry>button</entry>
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<entry>This is an action control. When set (the value is
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ignored), the device will do a white balance and then hold the current
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setting. Contrast this with the boolean
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<constant>V4L2_CID_AUTO_WHITE_BALANCE</constant>, which, when
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activated, keeps adjusting the white balance.</entry>
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</row>
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<row>
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<entry><constant>V4L2_CID_RED_BALANCE</constant></entry>
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<entry>integer</entry>
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<entry>Red chroma balance.</entry>
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</row>
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<row>
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<entry><constant>V4L2_CID_BLUE_BALANCE</constant></entry>
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<entry>integer</entry>
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<entry>Blue chroma balance.</entry>
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</row>
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<row>
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<entry><constant>V4L2_CID_GAMMA</constant></entry>
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<entry>integer</entry>
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<entry>Gamma adjust.</entry>
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</row>
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<row>
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<entry><constant>V4L2_CID_WHITENESS</constant></entry>
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<entry>integer</entry>
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<entry>Whiteness for grey-scale devices. This is a synonym
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for <constant>V4L2_CID_GAMMA</constant>. This control is deprecated
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and should not be used in new drivers and applications.</entry>
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</row>
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<row>
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<entry><constant>V4L2_CID_EXPOSURE</constant></entry>
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<entry>integer</entry>
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<entry>Exposure (cameras). [Unit?]</entry>
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</row>
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<row>
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<entry><constant>V4L2_CID_AUTOGAIN</constant></entry>
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<entry>boolean</entry>
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<entry>Automatic gain/exposure control.</entry>
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</row>
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<row>
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<entry><constant>V4L2_CID_GAIN</constant></entry>
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<entry>integer</entry>
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<entry>Gain control.</entry>
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</row>
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<row>
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<entry><constant>V4L2_CID_HFLIP</constant></entry>
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<entry>boolean</entry>
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<entry>Mirror the picture horizontally.</entry>
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</row>
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<row>
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<entry><constant>V4L2_CID_VFLIP</constant></entry>
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<entry>boolean</entry>
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<entry>Mirror the picture vertically.</entry>
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</row>
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<row>
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<entry><constant>V4L2_CID_HCENTER_DEPRECATED</constant> (formerly <constant>V4L2_CID_HCENTER</constant>)</entry>
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<entry>integer</entry>
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<entry>Horizontal image centering. This control is
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deprecated. New drivers and applications should use the <link
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linkend="camera-controls">Camera class controls</link>
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<constant>V4L2_CID_PAN_ABSOLUTE</constant>,
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<constant>V4L2_CID_PAN_RELATIVE</constant> and
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<constant>V4L2_CID_PAN_RESET</constant> instead.</entry>
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</row>
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<row>
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<entry><constant>V4L2_CID_VCENTER_DEPRECATED</constant>
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(formerly <constant>V4L2_CID_VCENTER</constant>)</entry>
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<entry>integer</entry>
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<entry>Vertical image centering. Centering is intended to
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<emphasis>physically</emphasis> adjust cameras. For image cropping see
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<xref linkend="crop" />, for clipping <xref linkend="overlay" />. This
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control is deprecated. New drivers and applications should use the
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<link linkend="camera-controls">Camera class controls</link>
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<constant>V4L2_CID_TILT_ABSOLUTE</constant>,
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<constant>V4L2_CID_TILT_RELATIVE</constant> and
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<constant>V4L2_CID_TILT_RESET</constant> instead.</entry>
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</row>
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<row id="v4l2-power-line-frequency">
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<entry><constant>V4L2_CID_POWER_LINE_FREQUENCY</constant></entry>
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<entry>enum</entry>
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<entry>Enables a power line frequency filter to avoid
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flicker. Possible values for <constant>enum v4l2_power_line_frequency</constant> are:
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<constant>V4L2_CID_POWER_LINE_FREQUENCY_DISABLED</constant> (0),
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<constant>V4L2_CID_POWER_LINE_FREQUENCY_50HZ</constant> (1) and
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<constant>V4L2_CID_POWER_LINE_FREQUENCY_60HZ</constant> (2).</entry>
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</row>
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<row>
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<entry><constant>V4L2_CID_HUE_AUTO</constant></entry>
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<entry>boolean</entry>
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<entry>Enables automatic hue control by the device. The
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effect of setting <constant>V4L2_CID_HUE</constant> while automatic
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hue control is enabled is undefined, drivers should ignore such
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request.</entry>
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</row>
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<row>
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<entry><constant>V4L2_CID_WHITE_BALANCE_TEMPERATURE</constant></entry>
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<entry>integer</entry>
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<entry>This control specifies the white balance settings
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as a color temperature in Kelvin. A driver should have a minimum of
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2800 (incandescent) to 6500 (daylight). For more information about
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color temperature see <ulink
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url="http://en.wikipedia.org/wiki/Color_temperature">Wikipedia</ulink>.</entry>
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</row>
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<row>
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<entry><constant>V4L2_CID_SHARPNESS</constant></entry>
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<entry>integer</entry>
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<entry>Adjusts the sharpness filters in a camera. The
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minimum value disables the filters, higher values give a sharper
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picture.</entry>
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</row>
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<row>
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<entry><constant>V4L2_CID_BACKLIGHT_COMPENSATION</constant></entry>
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<entry>integer</entry>
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<entry>Adjusts the backlight compensation in a camera. The
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minimum value disables backlight compensation.</entry>
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</row>
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<row>
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<entry><constant>V4L2_CID_CHROMA_AGC</constant></entry>
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<entry>boolean</entry>
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<entry>Chroma automatic gain control.</entry>
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</row>
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<row>
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<entry><constant>V4L2_CID_COLOR_KILLER</constant></entry>
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<entry>boolean</entry>
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<entry>Enable the color killer (&ie; force a black & white image in case of a weak video signal).</entry>
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</row>
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<row id="v4l2-colorfx">
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<entry><constant>V4L2_CID_COLORFX</constant></entry>
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<entry>enum</entry>
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<entry>Selects a color effect. Possible values for
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<constant>enum v4l2_colorfx</constant> are:
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<constant>V4L2_COLORFX_NONE</constant> (0),
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<constant>V4L2_COLORFX_BW</constant> (1) and
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<constant>V4L2_COLORFX_SEPIA</constant> (2).</entry>
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</row>
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<row>
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<entry><constant>V4L2_CID_LASTP1</constant></entry>
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<entry></entry>
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<entry>End of the predefined control IDs (currently
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<constant>V4L2_CID_COLORFX</constant> + 1).</entry>
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</row>
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<row>
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<entry><constant>V4L2_CID_PRIVATE_BASE</constant></entry>
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<entry></entry>
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<entry>ID of the first custom (driver specific) control.
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Applications depending on particular custom controls should check the
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driver name and version, see <xref linkend="querycap" />.</entry>
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</row>
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</tbody>
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</tgroup>
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</table>
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<para>Applications can enumerate the available controls with the
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&VIDIOC-QUERYCTRL; and &VIDIOC-QUERYMENU; ioctls, get and set a
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control value with the &VIDIOC-G-CTRL; and &VIDIOC-S-CTRL; ioctls.
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Drivers must implement <constant>VIDIOC_QUERYCTRL</constant>,
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<constant>VIDIOC_G_CTRL</constant> and
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<constant>VIDIOC_S_CTRL</constant> when the device has one or more
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controls, <constant>VIDIOC_QUERYMENU</constant> when it has one or
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more menu type controls.</para>
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<example>
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<title>Enumerating all controls</title>
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<programlisting>
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&v4l2-queryctrl; queryctrl;
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&v4l2-querymenu; querymenu;
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static void
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enumerate_menu (void)
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{
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printf (" Menu items:\n");
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memset (&querymenu, 0, sizeof (querymenu));
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querymenu.id = queryctrl.id;
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for (querymenu.index = queryctrl.minimum;
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querymenu.index <= queryctrl.maximum;
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querymenu.index++) {
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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:
|
||
|
|
-->
|