From 670027c507e99521d416994a18a498def9ef2ea3 Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Andr=C3=A9=20Fabian=20Silva=20Delgado?= Date: Sat, 22 Oct 2016 19:31:08 -0300 Subject: Linux-libre 4.8.3-gnu --- Documentation/DocBook/media/v4l/vidioc-g-fmt.xml | 204 ----------------------- 1 file changed, 204 deletions(-) delete mode 100644 Documentation/DocBook/media/v4l/vidioc-g-fmt.xml (limited to 'Documentation/DocBook/media/v4l/vidioc-g-fmt.xml') diff --git a/Documentation/DocBook/media/v4l/vidioc-g-fmt.xml b/Documentation/DocBook/media/v4l/vidioc-g-fmt.xml deleted file mode 100644 index ffcb44825..000000000 --- a/Documentation/DocBook/media/v4l/vidioc-g-fmt.xml +++ /dev/null @@ -1,204 +0,0 @@ - - - ioctl VIDIOC_G_FMT, VIDIOC_S_FMT, -VIDIOC_TRY_FMT - &manvol; - - - - VIDIOC_G_FMT - VIDIOC_S_FMT - VIDIOC_TRY_FMT - Get or set the data format, try a format - - - - - - int ioctl - int fd - int request - struct v4l2_format -*argp - - - - - - Arguments - - - - fd - - &fd; - - - - request - - VIDIOC_G_FMT, VIDIOC_S_FMT, VIDIOC_TRY_FMT - - - - argp - - - - - - - - - Description - - These ioctls are used to negotiate the format of data -(typically image format) exchanged between driver and -application. - - To query the current parameters applications set the -type field of a struct -v4l2_format to the respective buffer (stream) -type. For example video capture devices use -V4L2_BUF_TYPE_VIDEO_CAPTURE or -V4L2_BUF_TYPE_VIDEO_CAPTURE_MPLANE. When the application -calls the VIDIOC_G_FMT ioctl with a pointer to -this structure the driver fills the respective member of the -fmt union. In case of video capture devices -that is either the &v4l2-pix-format; pix or -the &v4l2-pix-format-mplane; pix_mp member. -When the requested buffer type is not supported drivers return an -&EINVAL;. - - To change the current format parameters applications -initialize the type field and all -fields of the respective fmt -union member. For details see the documentation of the various devices -types in . Good practice is to query the -current parameters first, and to -modify only those parameters not suitable for the application. When -the application calls the VIDIOC_S_FMT ioctl -with a pointer to a v4l2_format structure -the driver checks -and adjusts the parameters against hardware abilities. Drivers -should not return an error code unless the type field is invalid, this is -a mechanism to fathom device capabilities and to approach parameters -acceptable for both the application and driver. On success the driver -may program the hardware, allocate resources and generally prepare for -data exchange. -Finally the VIDIOC_S_FMT ioctl returns the -current format parameters as VIDIOC_G_FMT does. -Very simple, inflexible devices may even ignore all input and always -return the default parameters. However all V4L2 devices exchanging -data with the application must implement the -VIDIOC_G_FMT and -VIDIOC_S_FMT ioctl. When the requested buffer -type is not supported drivers return an &EINVAL; on a -VIDIOC_S_FMT attempt. When I/O is already in -progress or the resource is not available for other reasons drivers -return the &EBUSY;. - - The VIDIOC_TRY_FMT ioctl is equivalent -to VIDIOC_S_FMT with one exception: it does not -change driver state. It can also be called at any time, never -returning EBUSY. This function is provided to -negotiate parameters, to learn about hardware limitations, without -disabling I/O or possibly time consuming hardware preparations. -Although strongly recommended drivers are not required to implement -this ioctl. - - The format as returned by VIDIOC_TRY_FMT -must be identical to what VIDIOC_S_FMT returns for -the same input or output. - - - struct <structname>v4l2_format</structname> - - - - - - - - __u32 - type - - Type of the data stream, see . - - - union - fmt - - - - &v4l2-pix-format; - pix - Definition of an image format, see , used by video capture and output -devices. - - - - &v4l2-pix-format-mplane; - pix_mp - Definition of an image format, see , used by video capture and output -devices that support the multi-planar -version of the API. - - - - &v4l2-window; - win - Definition of an overlaid image, see , used by video overlay devices. - - - - &v4l2-vbi-format; - vbi - Raw VBI capture or output parameters. This is -discussed in more detail in . Used by raw VBI -capture and output devices. - - - - &v4l2-sliced-vbi-format; - sliced - Sliced VBI capture or output parameters. See - for details. Used by sliced VBI -capture and output devices. - - - - &v4l2-sdr-format; - sdr - Definition of a data format, see -, used by SDR capture and output devices. - - - - __u8 - raw_data[200] - Place holder for future extensions. - - - -
- - - - &return-value; - - - - EINVAL - - The &v4l2-format; type -field is invalid or the requested buffer type not supported. - - - - - -- cgit v1.2.3