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authorLinus Torvalds <torvalds@linux-foundation.org>2016-10-11 13:22:22 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2016-10-11 13:22:22 -0700
commitde34f4da7f62ff59ac6e1ef320b0fcfa3296fce3 (patch)
tree88b5db2fc7fbbb0353edd8447a832a5225a49d01 /Documentation/media/uapi/v4l/dev-overlay.rst
parent56e520c7a0a490b63b042b047ec9659fc08762a4 (diff)
parent9fce0c226536fc36c7fb0a80000ca38a995be43e (diff)
Merge tag 'media/v4.9-1' of git://git.kernel.org/pub/scm/linux/kernel/git/mchehab/linux-media
Pull media updates from Mauro Carvalho Chehab: - Documentation improvements: conversion of all non-DocBook documents to Sphinx and lots of fixes to the uAPI media book - New PCI driver for Techwell TW5864 media grabber boards - New SoC driver for ATMEL Image Sensor Controller - Removal of some obsolete SoC drivers (s5p-tv driver and soc_camera drivers) - Addition of ST CEC driver - Lots of drivers fixes, improvements and additions * tag 'media/v4.9-1' of git://git.kernel.org/pub/scm/linux/kernel/git/mchehab/linux-media: (464 commits) [media] ttusb_dec: avoid the risk of go past buffer [media] cx23885: Fix some smatch warnings [media] si2165: switch to regmap [media] si2165: use i2c_client->dev instead of i2c_adapter->dev for logging [media] si2165: Remove legacy attach [media] cx231xx: attach si2165 driver via i2c_client [media] cx231xx: Prepare for attaching new style i2c_client DVB demod drivers [media] cx23885: attach si2165 driver via i2c_client [media] si2165: support i2c_client attach [media] si2165: avoid division by zero [media] rcar-vin: add R-Car gen2 fallback compatibility string [media] lgdt3306a: remove 20*50 msec unnecessary timeout [media] cx25821: Remove deprecated create_singlethread_workqueue [media] cx25821: Drop Freeing of Workqueue [media] cxd2841er: force 8MHz bandwidth for DVB-C if specified bw not supported [media] redrat3: hardware-specific parameters [media] redrat3: remove hw_timeout member [media] cxd2841er: BER and SNR reading for ISDB-T [media] dvb-usb: avoid link error with dib3000m{b,c| [media] dvb-usb: split out common parts of dibusb ...
Diffstat (limited to 'Documentation/media/uapi/v4l/dev-overlay.rst')
-rw-r--r--Documentation/media/uapi/v4l/dev-overlay.rst34
1 files changed, 19 insertions, 15 deletions
diff --git a/Documentation/media/uapi/v4l/dev-overlay.rst b/Documentation/media/uapi/v4l/dev-overlay.rst
index 92b4471b0c6e..9be14b55e305 100644
--- a/Documentation/media/uapi/v4l/dev-overlay.rst
+++ b/Documentation/media/uapi/v4l/dev-overlay.rst
@@ -19,7 +19,9 @@ video into a window.
Video overlay devices are accessed through the same character special
files as :ref:`video capture <capture>` devices.
-.. note:: The default function of a ``/dev/video`` device is video
+.. note::
+
+ The default function of a ``/dev/video`` device is video
capturing. The overlay function is only available after calling
the :ref:`VIDIOC_S_FMT <VIDIOC_G_FMT>` ioctl.
@@ -41,7 +43,7 @@ Querying Capabilities
Devices supporting the video overlay interface set the
``V4L2_CAP_VIDEO_OVERLAY`` flag in the ``capabilities`` field of struct
-:ref:`v4l2_capability <v4l2-capability>` returned by the
+:c:type:`v4l2_capability` returned by the
:ref:`VIDIOC_QUERYCAP` ioctl. The overlay I/O
method specified below must be supported. Tuners and audio inputs are
optional.
@@ -117,17 +119,17 @@ at minimum requires to reset the parameters to defaults. An example is
given in :ref:`crop`.
The overlay window is described by a struct
-:ref:`v4l2_window <v4l2-window>`. It defines the size of the image,
+:c:type:`v4l2_window`. It defines the size of the image,
its position over the graphics surface and the clipping to be applied.
To get the current parameters applications set the ``type`` field of a
-struct :ref:`v4l2_format <v4l2-format>` to
+struct :c:type:`v4l2_format` to
``V4L2_BUF_TYPE_VIDEO_OVERLAY`` and call the
:ref:`VIDIOC_G_FMT <VIDIOC_G_FMT>` ioctl. The driver fills the
-:ref:`struct v4l2_window <v4l2-window>` substructure named ``win``. It is not
+struct :c:type:`v4l2_window` substructure named ``win``. It is not
possible to retrieve a previously programmed clipping list or bitmap.
To program the overlay window applications set the ``type`` field of a
-struct :ref:`v4l2_format <v4l2-format>` to
+struct :c:type:`v4l2_format` to
``V4L2_BUF_TYPE_VIDEO_OVERLAY``, initialize the ``win`` substructure and
call the :ref:`VIDIOC_S_FMT <VIDIOC_G_FMT>` ioctl. The driver
adjusts the parameters against hardware limits and returns the actual
@@ -137,7 +139,7 @@ about driver capabilities without actually changing driver state. Unlike
:ref:`VIDIOC_S_FMT <VIDIOC_G_FMT>` this also works after the overlay has been enabled.
The scaling factor of the overlaid image is implied by the width and
-height given in struct :ref:`v4l2_window <v4l2-window>` and the size
+height given in struct :c:type:`v4l2_window` and the size
of the cropping rectangle. For more information see :ref:`crop`.
When simultaneous capturing and overlay is supported and the hardware
@@ -147,7 +149,7 @@ takes precedence. The attempt to capture or overlay as well
code or return accordingly modified parameters.
-.. _v4l2-window:
+.. c:type:: v4l2_window
struct v4l2_window
------------------
@@ -173,7 +175,7 @@ struct v4l2_window
:ref:`VIDIOC_S_FBUF <VIDIOC_G_FBUF>` applications set this field
to the desired pixel value for the chroma key. The format is the
same as the pixel format of the framebuffer (struct
- :ref:`v4l2_framebuffer <v4l2-framebuffer>` ``fmt.pixelformat``
+ :c:type:`v4l2_framebuffer` ``fmt.pixelformat``
field), with bytes in host order. E. g. for
:ref:`V4L2_PIX_FMT_BGR24 <V4L2-PIX-FMT-BGR32>` the value should
be 0xRRGGBB on a little endian, 0xBBGGRR on a big endian host.
@@ -236,13 +238,15 @@ exceeded are undefined. [#f3]_
:ref:`VIDIOC_S_FBUF <VIDIOC_G_FBUF>`,
:ref:`framebuffer-flags`).
- .. note:: This field was added in Linux 2.6.23, extending the
- structure. However the :ref:`VIDIOC_[G|S|TRY]_FMT <VIDIOC_G_FMT>`
- ioctls, which take a pointer to a :ref:`v4l2_format <v4l2-format>`
- parent structure with padding bytes at the end, are not affected.
+.. note::
+
+ This field was added in Linux 2.6.23, extending the
+ structure. However the :ref:`VIDIOC_[G|S|TRY]_FMT <VIDIOC_G_FMT>`
+ ioctls, which take a pointer to a :c:type:`v4l2_format`
+ parent structure with padding bytes at the end, are not affected.
-.. _v4l2-clip:
+.. c:type:: v4l2_clip
struct v4l2_clip [#f4]_
-----------------------
@@ -258,7 +262,7 @@ struct v4l2_clip [#f4]_
linked list of clipping rectangles.
-.. _v4l2-rect:
+.. c:type:: v4l2_rect
struct v4l2_rect
----------------