media/v4l/selection-api.xml

84 areas that can be sampled is given by the <constant> V4L2_SEL_TGT_CROP_BOUNDS
85 </constant> target. It is recommended for the driver developers to put the
86 top/left corner at position <constant> (0,0) </constant>.  The rectangle's
90 the area actually sampled, is given by the <constant> V4L2_SEL_TGT_CROP_ACTIVE
91 </constant> target. It uses the same coordinate system as <constant>
92 V4L2_SEL_TGT_CROP_BOUNDS </constant>. The active cropping area must lie
97 <constant> V4L2_SEL_TGT_CROP_DEFAULT </constant> target. This rectangle shall
103 coordinates are obtained using <constant> V4L2_SEL_TGT_COMPOSE_BOUNDS
104 </constant>.  All coordinates are expressed in pixels. The rectangle's top/left
105 corner must be located at position <constant> (0,0) </constant>. The width and
106 height are equal to the image size set by <constant> VIDIOC_S_FMT </constant>.
110 controlled by the <constant> V4L2_SEL_TGT_COMPOSE_ACTIVE </constant> target.
119 <constant> V4L2_SEL_TGT_COMPOSE_DEFAULT </constant>. It is usually equal to the
123 <constant> V4L2_SEL_TGT_COMPOSE_PADDED </constant>. It contains all pixels
124 defined using <constant> V4L2_SEL_TGT_COMPOSE_ACTIVE </constant> plus all
145 coordinates are obtained using <constant> V4L2_SEL_TGT_CROP_BOUNDS </constant>.
147 <constant> (0,0) </constant>.  The width and height is equal to the image size
148 specified using <constant> VIDIOC_S_FMT </constant> ioctl.</para>
152 <constant> V4L2_SEL_TGT_CROP_ACTIVE </constant>. Its coordinates are expressed
159 <constant> V4L2_SEL_TGT_CROP_DEFAULT </constant>. It is usually equal to the
163 inserted by the hardware is controlled by <constant>
164 V4L2_SEL_TGT_COMPOSE_ACTIVE </constant> target.  The rectangle's coordinates
170 <para>The device has a default composing rectangle, given by the <constant>
171 V4L2_SEL_TGT_COMPOSE_DEFAULT </constant> target. This rectangle shall cover what
173 driver developers to put the top/left corner at position <constant> (0,0)
174 </constant>. Drivers shall set the active composing rectangle to the default
181 The padded target is accessed by the <constant> V4L2_SEL_TGT_COMPOSE_PADDED
182 </constant> identifier.  It must contain all pixels from the <constant>
183 V4L2_SEL_TGT_COMPOSE_ACTIVE </constant> target.</para>
192 and the height of rectangles obtained using <constant> V4L2_SEL_TGT_CROP_ACTIVE
193 </constant> and <constant> V4L2_SEL_TGT_COMPOSE_ACTIVE </constant> targets. If
218 </structfield> before calling <constant> VIDIOC_QBUF </constant>. Those
237 	<para>(A video capture device is assumed; change <constant>
238 V4L2_BUF_TYPE_VIDEO_CAPTURE </constant> for other devices; change target to
239 <constant> V4L2_SEL_TGT_COMPOSE_* </constant> family to configure composing
291 	<para>A video output device is assumed; change <constant>
292 V4L2_BUF_TYPE_VIDEO_OUTPUT </constant> for other devices</para>