From mboxrd@z Thu Jan 1 00:00:00 1970 From: Sakari Ailus Subject: [PATCH 2/2] docs-rst: v4l: Document V4L2_BUF_TYPE_META_OUTPUT interface Date: Sat, 19 Aug 2017 00:30:56 +0300 Message-ID: <1503091856-18294-3-git-send-email-sakari.ailus@linux.intel.com> References: <1503091856-18294-1-git-send-email-sakari.ailus@linux.intel.com> Return-path: In-Reply-To: <1503091856-18294-1-git-send-email-sakari.ailus@linux.intel.com> Sender: linux-media-owner@vger.kernel.org To: linux-media@vger.kernel.org Cc: linux-api@vger.kernel.org, tfiga@chromium.org, yong.zhi@intel.com List-Id: linux-api@vger.kernel.org Document the interface for metadata output, including V4L2_BUF_TYPE_META_OUTPUT buffer type and V4L2_CAP_META_OUTPUT capability bits. Signed-off-by: Sakari Ailus Acked-by: Hans Verkuil --- Documentation/media/uapi/v4l/buffer.rst | 3 +++ Documentation/media/uapi/v4l/dev-meta.rst | 33 ++++++++++++++---------- Documentation/media/uapi/v4l/vidioc-querycap.rst | 3 +++ Documentation/media/videodev2.h.rst.exceptions | 2 ++ 4 files changed, 28 insertions(+), 13 deletions(-) diff --git a/Documentation/media/uapi/v4l/buffer.rst b/Documentation/media/uapi/v4l/buffer.rst index ae6ee73..33b932e 100644 --- a/Documentation/media/uapi/v4l/buffer.rst +++ b/Documentation/media/uapi/v4l/buffer.rst @@ -452,6 +452,9 @@ enum v4l2_buf_type * - ``V4L2_BUF_TYPE_META_CAPTURE`` - 13 - Buffer for metadata capture, see :ref:`metadata`. + * - ``V4L2_BUF_TYPE_META_OUTPUT`` + - 14 + - Buffer for metadata output, see :ref:`metadata`. diff --git a/Documentation/media/uapi/v4l/dev-meta.rst b/Documentation/media/uapi/v4l/dev-meta.rst index 62518ad..a1e54bc 100644 --- a/Documentation/media/uapi/v4l/dev-meta.rst +++ b/Documentation/media/uapi/v4l/dev-meta.rst @@ -7,21 +7,27 @@ Metadata Interface ****************** Metadata refers to any non-image data that supplements video frames with -additional information. This may include statistics computed over the image -or frame capture parameters supplied by the image source. This interface is -intended for transfer of metadata to userspace and control of that operation. +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 capture device nodes. The device -can be dedicated to metadata or can implement both video and metadata capture -as specified in its reported capabilities. +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 interface set the ``V4L2_CAP_META_CAPTURE`` -flag in the ``device_caps`` field of the +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. +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. @@ -35,10 +41,11 @@ 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`` 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_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. .. _v4l2-meta-format: diff --git a/Documentation/media/uapi/v4l/vidioc-querycap.rst b/Documentation/media/uapi/v4l/vidioc-querycap.rst index 12e0d9a..36bf879 100644 --- a/Documentation/media/uapi/v4l/vidioc-querycap.rst +++ b/Documentation/media/uapi/v4l/vidioc-querycap.rst @@ -249,6 +249,9 @@ specification the ioctl returns an ``EINVAL`` error code. * - ``V4L2_CAP_STREAMING`` - 0x04000000 - The device supports the :ref:`streaming ` I/O method. + * - ``V4L2_CAP_META_OUTPUT`` + - 0x08000000 + - The device supports the :ref:`metadata` output interface. * - ``V4L2_CAP_TOUCH`` - 0x10000000 - This is a touch device. diff --git a/Documentation/media/videodev2.h.rst.exceptions b/Documentation/media/videodev2.h.rst.exceptions index a5cb0a8..32172db 100644 --- a/Documentation/media/videodev2.h.rst.exceptions +++ b/Documentation/media/videodev2.h.rst.exceptions @@ -28,6 +28,7 @@ replace symbol V4L2_FIELD_TOP :c:type:`v4l2_field` # Documented enum v4l2_buf_type replace symbol V4L2_BUF_TYPE_META_CAPTURE :c:type:`v4l2_buf_type` +replace symbol V4L2_BUF_TYPE_META_OUTPUT :c:type:`v4l2_buf_type` replace symbol V4L2_BUF_TYPE_SDR_CAPTURE :c:type:`v4l2_buf_type` replace symbol V4L2_BUF_TYPE_SDR_OUTPUT :c:type:`v4l2_buf_type` replace symbol V4L2_BUF_TYPE_SLICED_VBI_CAPTURE :c:type:`v4l2_buf_type` @@ -157,6 +158,7 @@ replace define V4L2_CAP_META_CAPTURE device-capabilities replace define V4L2_CAP_READWRITE device-capabilities replace define V4L2_CAP_ASYNCIO device-capabilities replace define V4L2_CAP_STREAMING device-capabilities +replace define V4L2_CAP_META_OUTPUT device-capabilities replace define V4L2_CAP_DEVICE_CAPS device-capabilities replace define V4L2_CAP_TOUCH device-capabilities -- 2.7.4