From: Hans Verkuil <hverkuil-cisco@xxxxxxxxx>
Document V4L2_BUF_FLAG_TAG.
Signed-off-by: Hans Verkuil <hverkuil-cisco@xxxxxxxxx>
Reviewed-by: Paul Kocialkowski <paul.kocialkowski@xxxxxxxxxxx>
Reviewed-by: Alexandre Courbot <acourbot@xxxxxxxxxxxx>
---
Documentation/media/uapi/v4l/buffer.rst | 17 ++++++++++++++---
Documentation/media/uapi/v4l/vidioc-reqbufs.rst | 4 ++++
2 files changed, 18 insertions(+), 3 deletions(-)
diff --git a/Documentation/media/uapi/v4l/buffer.rst b/Documentation/media/uapi/v4l/buffer.rst
index 2e266d32470a..f83ee00cb30b 100644
--- a/Documentation/media/uapi/v4l/buffer.rst
+++ b/Documentation/media/uapi/v4l/buffer.rst
@@ -301,10 +301,13 @@ struct v4l2_buffer
elements in the ``planes`` array. The driver will fill in the
actual number of valid elements in that array.
* - __u32
- - ``reserved2``
+ - ``tag``
-
- - A place holder for future extensions. Drivers and applications
- must set this to 0.
+ - When the ``V4L2_BUF_FLAG_TAG`` flag is set in ``flags``, this
+ field contains a user-specified tag value.
+
+ It is used by stateless codecs where this tag can be used to
+ refer to buffers that contain reference frames.
* - __u32
- ``request_fd``
-
@@ -567,6 +570,14 @@ Buffer Flags
when the ``VIDIOC_DQBUF`` ioctl is called. Applications can set
this bit and the corresponding ``timecode`` structure when
``type`` refers to an output stream.
+ * .. _`V4L2-BUF-FLAG-TAG`:
+
+ - ``V4L2_BUF_FLAG_TAG``
+ - 0x00000200
+ - The ``tag`` field is valid. Applications can set
+ this bit and the corresponding ``tag`` field. If tags are
+ supported then the ``V4L2_BUF_CAP_SUPPORTS_TAGS`` capability
+ is also set.
* .. _`V4L2-BUF-FLAG-PREPARED`:
- ``V4L2_BUF_FLAG_PREPARED``
diff --git a/Documentation/media/uapi/v4l/vidioc-reqbufs.rst b/Documentation/media/uapi/v4l/vidioc-reqbufs.rst
index e62a15782790..38a7d0aee483 100644
--- a/Documentation/media/uapi/v4l/vidioc-reqbufs.rst
+++ b/Documentation/media/uapi/v4l/vidioc-reqbufs.rst
@@ -118,6 +118,7 @@ aborting or finishing any DMA in progress, an implicit
.. _V4L2-BUF-CAP-SUPPORTS-DMABUF:
.. _V4L2-BUF-CAP-SUPPORTS-REQUESTS:
.. _V4L2-BUF-CAP-SUPPORTS-ORPHANED-BUFS:
+.. _V4L2-BUF-CAP-SUPPORTS-TAGS:
.. cssclass:: longtable
@@ -143,6 +144,9 @@ aborting or finishing any DMA in progress, an implicit
- The kernel allows calling :ref:`VIDIOC_REQBUFS` while buffers are still
mapped or exported via DMABUF. These orphaned buffers will be freed
when they are unmapped or when the exported DMABUF fds are closed.
+ * - ``V4L2_BUF_CAP_SUPPORTS_TAGS``
+ - 0x00000020
+ - This buffer type supports ``V4L2_BUF_FLAG_TAG``.
Return Value
============
--
2.19.1
