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Diffstat (limited to 'Documentation/media/uapi/v4l/vidioc-cropcap.rst')
| -rw-r--r-- | Documentation/media/uapi/v4l/vidioc-cropcap.rst | 145 |
1 files changed, 55 insertions, 90 deletions
diff --git a/Documentation/media/uapi/v4l/vidioc-cropcap.rst b/Documentation/media/uapi/v4l/vidioc-cropcap.rst index 8dcbe6d26219..f21a69b554e1 100644 --- a/Documentation/media/uapi/v4l/vidioc-cropcap.rst +++ b/Documentation/media/uapi/v4l/vidioc-cropcap.rst @@ -15,7 +15,8 @@ VIDIOC_CROPCAP - Information about the video cropping and scaling abilities Synopsis ======== -.. cpp:function:: int ioctl( int fd, int request, struct v4l2_cropcap *argp ) +.. c:function:: int ioctl( int fd, VIDIOC_CROPCAP, struct v4l2_cropcap *argp ) + :name: VIDIOC_CROPCAP Arguments @@ -24,9 +25,6 @@ Arguments ``fd`` File descriptor returned by :ref:`open() <func-open>`. -``request`` - VIDIOC_CROPCAP - ``argp`` @@ -52,107 +50,71 @@ support cropping and/or scaling and/or have non-square pixels, and for overlay devices. -.. _v4l2-cropcap: +.. c:type:: v4l2_cropcap + +.. tabularcolumns:: |p{4.4cm}|p{4.4cm}|p{8.7cm}| .. flat-table:: struct v4l2_cropcap :header-rows: 0 :stub-columns: 0 :widths: 1 1 2 - - - .. row 1 - - - __u32 - - - ``type`` - - - Type of the data stream, set by the application. Only these types - are valid here: ``V4L2_BUF_TYPE_VIDEO_CAPTURE``, - ``V4L2_BUF_TYPE_VIDEO_OUTPUT`` and - ``V4L2_BUF_TYPE_VIDEO_OVERLAY``. See :ref:`v4l2-buf-type`. - - - .. row 2 - - - struct :ref:`v4l2_rect <v4l2-rect-crop>` - - - ``bounds`` - - - Defines the window within capturing or output is possible, this - may exclude for example the horizontal and vertical blanking - areas. The cropping rectangle cannot exceed these limits. Width - and height are defined in pixels, the driver writer is free to - choose origin and units of the coordinate system in the analog - domain. - - - .. row 3 - - - struct :ref:`v4l2_rect <v4l2-rect-crop>` - - - ``defrect`` - - - Default cropping rectangle, it shall cover the "whole picture". - Assuming pixel aspect 1/1 this could be for example a 640 × 480 - rectangle for NTSC, a 768 × 576 rectangle for PAL and SECAM - centered over the active picture area. The same co-ordinate system - as for ``bounds`` is used. - - - .. row 4 - - - struct :ref:`v4l2_fract <v4l2-fract>` - - - ``pixelaspect`` - - - This is the pixel aspect (y / x) when no scaling is applied, the - ratio of the actual sampling frequency and the frequency required - to get square pixels. - - When cropping coordinates refer to square pixels, the driver sets - ``pixelaspect`` to 1/1. Other common values are 54/59 for PAL and - SECAM, 11/10 for NTSC sampled according to [:ref:`itu601`]. + * - __u32 + - ``type`` + - Type of the data stream, set by the application. Only these types + are valid here: ``V4L2_BUF_TYPE_VIDEO_CAPTURE``, + ``V4L2_BUF_TYPE_VIDEO_OUTPUT`` and + ``V4L2_BUF_TYPE_VIDEO_OVERLAY``. See :c:type:`v4l2_buf_type`. + * - struct :ref:`v4l2_rect <v4l2-rect-crop>` + - ``bounds`` + - Defines the window within capturing or output is possible, this + may exclude for example the horizontal and vertical blanking + areas. The cropping rectangle cannot exceed these limits. Width + and height are defined in pixels, the driver writer is free to + choose origin and units of the coordinate system in the analog + domain. + * - struct :ref:`v4l2_rect <v4l2-rect-crop>` + - ``defrect`` + - Default cropping rectangle, it shall cover the "whole picture". + Assuming pixel aspect 1/1 this could be for example a 640 × 480 + rectangle for NTSC, a 768 × 576 rectangle for PAL and SECAM + centered over the active picture area. The same co-ordinate system + as for ``bounds`` is used. + * - struct :c:type:`v4l2_fract` + - ``pixelaspect`` + - This is the pixel aspect (y / x) when no scaling is applied, the + ratio of the actual sampling frequency and the frequency required + to get square pixels. + + When cropping coordinates refer to square pixels, the driver sets + ``pixelaspect`` to 1/1. Other common values are 54/59 for PAL and + SECAM, 11/10 for NTSC sampled according to [:ref:`itu601`]. .. _v4l2-rect-crop: +.. tabularcolumns:: |p{4.4cm}|p{4.4cm}|p{8.7cm}| + .. flat-table:: struct v4l2_rect :header-rows: 0 :stub-columns: 0 :widths: 1 1 2 - - - .. row 1 - - - __s32 - - - ``left`` - - - Horizontal offset of the top, left corner of the rectangle, in - pixels. - - - .. row 2 - - - __s32 - - - ``top`` - - - Vertical offset of the top, left corner of the rectangle, in - pixels. - - - .. row 3 - - - __u32 - - - ``width`` - - - Width of the rectangle, in pixels. - - - .. row 4 - - - __u32 - - - ``height`` - - - Height of the rectangle, in pixels. + * - __s32 + - ``left`` + - Horizontal offset of the top, left corner of the rectangle, in + pixels. + * - __s32 + - ``top`` + - Vertical offset of the top, left corner of the rectangle, in + pixels. + * - __u32 + - ``width`` + - Width of the rectangle, in pixels. + * - __u32 + - ``height`` + - Height of the rectangle, in pixels. Return Value @@ -163,5 +125,8 @@ appropriately. The generic error codes are described at the :ref:`Generic Error Codes <gen-errors>` chapter. EINVAL - The struct :ref:`v4l2_cropcap <v4l2-cropcap>` ``type`` is + The struct :c:type:`v4l2_cropcap` ``type`` is invalid. + +ENODATA + Cropping is not supported for this input or output. |