media/v4l/crop.rst

1 .. SPDX-License-Identifier: GFDL-1.1-no-invariants-or-later
6 Image Cropping, Insertion and Scaling -- the CROP API
12    <selection-api>`. The new API should be preferred in most cases,
15    equivalent in the SELECTION API. See :ref:`selection-vs-crop` for a
25 signal, query the default area and the hardware limits.
62 .. _crop-scale:
64 .. kernel-figure:: crop.svg
81 :ref:`vbi-hsync`). Vertically ITU-R line numbers of the first field
82 (see ITU R-525 line numbering for :ref:`525 lines <vbi-525>` and for
83 :ref:`625 lines <vbi-625>`), multiplied by two if the driver
117 lower size limits. In particular the maximum ``width`` and ``height`` in
167 .. code-block:: c
175     if (-1 == ioctl (fd, VIDIOC_CROPCAP, &cropcap)) {
186     if (-1 == ioctl (fd, VIDIOC_S_CROP, &crop)
196 .. code-block:: c
209     format.fmt.pix.width = cropcap.defrect.width >> 1;
210     format.fmt.pix.height = cropcap.defrect.height >> 1;
211     format.fmt.pix.pixelformat = V4L2_PIX_FMT_YUYV;
213     if (-1 == ioctl (fd, VIDIOC_S_FMT, &format)) {
226 .. code-block:: c
234     if (-1 == ioctl (fd, VIDIOC_CROPCAP;, &cropcap)) {
254     if (-1 == ioctl (fd, VIDIOC_S_CROP, &crop)
265 .. code-block:: c
277     if (-1 == ioctl (fd, VIDIOC_CROPCAP, &cropcap)) {
285     if (-1 == ioctl (fd, VIDIOC_G_CROP, &crop)) {
298     if (-1 == ioctl (fd, VIDIOC_G_FMT, &format)) {
305     hscale = format.fmt.pix.width / (double) crop.c.width;
306     vscale = format.fmt.pix.height / (double) crop.c.height;
312     /* Devices following ITU-R BT.601 do not capture
316     dwidth = format.fmt.pix.width / aspect;
317     dheight = format.fmt.pix.height;