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diff --git a/Documentation/media/uapi/v4l/dev-meta.rst b/Documentation/media/uapi/v4l/dev-meta.rst deleted file mode 100644 index c5dbe882be65..000000000000 --- a/Documentation/media/uapi/v4l/dev-meta.rst +++ /dev/null @@ -1,74 +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 - -.. _metadata: - -****************** -Metadata Interface -****************** - -Metadata refers to any non-image data that supplements video frames with -additional information. This may include statistics computed over the image, -frame capture parameters supplied by the image source or device specific -parameters for specifying how the device processes images. This interface is -intended for transfer of metadata between the userspace and the hardware and -control of that operation. - -The metadata interface is implemented on video device nodes. The device can be -dedicated to metadata or can support both video and metadata as specified in its -reported capabilities. - -Querying Capabilities -===================== - -Device nodes supporting the metadata capture interface set the -``V4L2_CAP_META_CAPTURE`` flag in the ``device_caps`` field of the -:c:type:`v4l2_capability` structure returned by the :c:func:`VIDIOC_QUERYCAP` -ioctl. That flag means the device can capture metadata to memory. Similarly, -device nodes supporting metadata output interface set the -``V4L2_CAP_META_OUTPUT`` flag in the ``device_caps`` field of -:c:type:`v4l2_capability` structure. That flag means the device can read -metadata from memory. - -At least one of the read/write or streaming I/O methods must be supported. - - -Data Format Negotiation -======================= - -The metadata device uses the :ref:`format` ioctls to select the capture format. -The metadata buffer content format is bound to that selected format. In addition -to the basic :ref:`format` ioctls, the :c:func:`VIDIOC_ENUM_FMT` ioctl must be -supported as well. - -To use the :ref:`format` ioctls applications set the ``type`` field of the -:c:type:`v4l2_format` structure to ``V4L2_BUF_TYPE_META_CAPTURE`` or to -``V4L2_BUF_TYPE_META_OUTPUT`` and use the :c:type:`v4l2_meta_format` ``meta`` -member of the ``fmt`` union as needed per the desired operation. Both drivers -and applications must set the remainder of the :c:type:`v4l2_format` structure -to 0. - -.. c:type:: v4l2_meta_format - -.. tabularcolumns:: |p{1.4cm}|p{2.2cm}|p{13.9cm}| - -.. flat-table:: struct v4l2_meta_format - :header-rows: 0 - :stub-columns: 0 - :widths: 1 1 2 - - * - __u32 - - ``dataformat`` - - The data format, set by the application. This is a little endian - :ref:`four character code <v4l2-fourcc>`. V4L2 defines metadata formats - in :ref:`meta-formats`. - * - __u32 - - ``buffersize`` - - Maximum buffer size in bytes required for data. The value is set by the - driver. |