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Diffstat (limited to 'Documentation/media/uapi/v4l/selection-api-examples.rst')
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diff --git a/Documentation/media/uapi/v4l/selection-api-examples.rst b/Documentation/media/uapi/v4l/selection-api-examples.rst deleted file mode 100644 index bb288b06cc17..000000000000 --- a/Documentation/media/uapi/v4l/selection-api-examples.rst +++ /dev/null @@ -1,91 +0,0 @@ -.. Permission is granted to copy, distribute and/or modify this -.. document under the terms of the GNU Free Documentation License, -.. Version 1.1 or any later version published by the Free Software -.. Foundation, with no Invariant Sections, no Front-Cover Texts -.. and no Back-Cover Texts. A copy of the license is included at -.. Documentation/media/uapi/fdl-appendix.rst. -.. -.. TODO: replace it to GFDL-1.1-or-later WITH no-invariant-sections - -******** -Examples -******** - -(A video capture device is assumed; change -``V4L2_BUF_TYPE_VIDEO_CAPTURE`` for other devices; change target to -``V4L2_SEL_TGT_COMPOSE_*`` family to configure composing area) - -Example: Resetting the cropping parameters -========================================== - -.. code-block:: c - - struct v4l2_selection sel = { - .type = V4L2_BUF_TYPE_VIDEO_CAPTURE, - .target = V4L2_SEL_TGT_CROP_DEFAULT, - }; - ret = ioctl(fd, VIDIOC_G_SELECTION, &sel); - if (ret) - exit(-1); - sel.target = V4L2_SEL_TGT_CROP; - ret = ioctl(fd, VIDIOC_S_SELECTION, &sel); - if (ret) - exit(-1); - -Setting a composing area on output of size of *at most* half of limit -placed at a center of a display. - -Example: Simple downscaling -=========================== - -.. code-block:: c - - struct v4l2_selection sel = { - .type = V4L2_BUF_TYPE_VIDEO_OUTPUT, - .target = V4L2_SEL_TGT_COMPOSE_BOUNDS, - }; - struct v4l2_rect r; - - ret = ioctl(fd, VIDIOC_G_SELECTION, &sel); - if (ret) - exit(-1); - /* setting smaller compose rectangle */ - r.width = sel.r.width / 2; - r.height = sel.r.height / 2; - r.left = sel.r.width / 4; - r.top = sel.r.height / 4; - sel.r = r; - sel.target = V4L2_SEL_TGT_COMPOSE; - sel.flags = V4L2_SEL_FLAG_LE; - ret = ioctl(fd, VIDIOC_S_SELECTION, &sel); - if (ret) - exit(-1); - -A video output device is assumed; change ``V4L2_BUF_TYPE_VIDEO_OUTPUT`` -for other devices - -Example: Querying for scaling factors -===================================== - -.. code-block:: c - - struct v4l2_selection compose = { - .type = V4L2_BUF_TYPE_VIDEO_OUTPUT, - .target = V4L2_SEL_TGT_COMPOSE, - }; - struct v4l2_selection crop = { - .type = V4L2_BUF_TYPE_VIDEO_OUTPUT, - .target = V4L2_SEL_TGT_CROP, - }; - double hscale, vscale; - - ret = ioctl(fd, VIDIOC_G_SELECTION, &compose); - if (ret) - exit(-1); - ret = ioctl(fd, VIDIOC_G_SELECTION, &crop); - if (ret) - exit(-1); - - /* computing scaling factors */ - hscale = (double)compose.r.width / crop.r.width; - vscale = (double)compose.r.height / crop.r.height; |