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authorHans Verkuil <hans.verkuil@cisco.com>2017-05-08 11:35:06 -0300
committerMauro Carvalho Chehab <mchehab@s-opensource.com>2017-06-23 09:22:17 -0300
commit8780f1d9d696c7f466a0ff2a2016476a7ebf42b6 (patch)
tree2ee66411a8c138081ae0103705b0ab265419a3ec
parenteaec420f530d376d6bb6e547a741203344619f47 (diff)
[media] media/uapi/v4l: clarify cropcap/crop/selection behavior
Unfortunately the use of 'type' was inconsistent for multiplanar buffer types. Starting with 4.13 both the normal and _MPLANE variants are allowed, thus making it possible to write sensible code. Yes, we messed up :-( Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com> Reviewed-by: Sylwester Nawrocki <s.nawrocki@samsung.com> Acked-by: Sakari Ailus <sakari.ailus@linux.intel.com> [hans.verkuil@cisco.com: 4.14 -> 4.13 since this would go in for 4.13 after all] Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
-rw-r--r--Documentation/media/uapi/v4l/vidioc-cropcap.rst23
-rw-r--r--Documentation/media/uapi/v4l/vidioc-g-crop.rst22
-rw-r--r--Documentation/media/uapi/v4l/vidioc-g-selection.rst22
3 files changed, 38 insertions, 29 deletions
diff --git a/Documentation/media/uapi/v4l/vidioc-cropcap.rst b/Documentation/media/uapi/v4l/vidioc-cropcap.rst
index f21a69b554e1..0f80d5ca2643 100644
--- a/Documentation/media/uapi/v4l/vidioc-cropcap.rst
+++ b/Documentation/media/uapi/v4l/vidioc-cropcap.rst
@@ -39,17 +39,10 @@ structure. Drivers fill the rest of the structure. The results are
constant except when switching the video standard. Remember this switch
can occur implicit when switching the video input or output.
-Do not use the multiplanar buffer types. Use
-``V4L2_BUF_TYPE_VIDEO_CAPTURE`` instead of
-``V4L2_BUF_TYPE_VIDEO_CAPTURE_MPLANE`` and use
-``V4L2_BUF_TYPE_VIDEO_OUTPUT`` instead of
-``V4L2_BUF_TYPE_VIDEO_OUTPUT_MPLANE``.
-
This ioctl must be implemented for video capture or output devices that
support cropping and/or scaling and/or have non-square pixels, and for
overlay devices.
-
.. c:type:: v4l2_cropcap
.. tabularcolumns:: |p{4.4cm}|p{4.4cm}|p{8.7cm}|
@@ -62,9 +55,9 @@ overlay devices.
* - __u32
- ``type``
- Type of the data stream, set by the application. Only these types
- are valid here: ``V4L2_BUF_TYPE_VIDEO_CAPTURE``,
- ``V4L2_BUF_TYPE_VIDEO_OUTPUT`` and
- ``V4L2_BUF_TYPE_VIDEO_OVERLAY``. See :c:type:`v4l2_buf_type`.
+ are valid here: ``V4L2_BUF_TYPE_VIDEO_CAPTURE``, ``V4L2_BUF_TYPE_VIDEO_CAPTURE_MPLANE``,
+ ``V4L2_BUF_TYPE_VIDEO_OUTPUT``, ``V4L2_BUF_TYPE_VIDEO_OUTPUT_MPLANE`` and
+ ``V4L2_BUF_TYPE_VIDEO_OVERLAY``. See :c:type:`v4l2_buf_type` and the note above.
* - struct :ref:`v4l2_rect <v4l2-rect-crop>`
- ``bounds``
- Defines the window within capturing or output is possible, this
@@ -90,6 +83,16 @@ overlay devices.
``pixelaspect`` to 1/1. Other common values are 54/59 for PAL and
SECAM, 11/10 for NTSC sampled according to [:ref:`itu601`].
+.. note::
+ Unfortunately in the case of multiplanar buffer types
+ (``V4L2_BUF_TYPE_VIDEO_CAPTURE_MPLANE`` and ``V4L2_BUF_TYPE_VIDEO_OUTPUT_MPLANE``)
+ this API was messed up with regards to how the :c:type:`v4l2_cropcap` ``type`` field
+ should be filled in. Some drivers only accepted the ``_MPLANE`` buffer type while
+ other drivers only accepted a non-multiplanar buffer type (i.e. without the
+ ``_MPLANE`` at the end).
+
+ Starting with kernel 4.13 both variations are allowed.
+
.. _v4l2-rect-crop:
diff --git a/Documentation/media/uapi/v4l/vidioc-g-crop.rst b/Documentation/media/uapi/v4l/vidioc-g-crop.rst
index 56a36340f565..13771ee3e94a 100644
--- a/Documentation/media/uapi/v4l/vidioc-g-crop.rst
+++ b/Documentation/media/uapi/v4l/vidioc-g-crop.rst
@@ -45,12 +45,6 @@ and struct :c:type:`v4l2_rect` substructure named ``c`` of a
v4l2_crop structure and call the :ref:`VIDIOC_S_CROP <VIDIOC_G_CROP>` ioctl with a pointer
to this structure.
-Do not use the multiplanar buffer types. Use
-``V4L2_BUF_TYPE_VIDEO_CAPTURE`` instead of
-``V4L2_BUF_TYPE_VIDEO_CAPTURE_MPLANE`` and use
-``V4L2_BUF_TYPE_VIDEO_OUTPUT`` instead of
-``V4L2_BUF_TYPE_VIDEO_OUTPUT_MPLANE``.
-
The driver first adjusts the requested dimensions against hardware
limits, i. e. the bounds given by the capture/output window, and it
rounds to the closest possible values of horizontal and vertical offset,
@@ -87,14 +81,24 @@ When cropping is not supported then no parameters are changed and
* - __u32
- ``type``
- Type of the data stream, set by the application. Only these types
- are valid here: ``V4L2_BUF_TYPE_VIDEO_CAPTURE``,
- ``V4L2_BUF_TYPE_VIDEO_OUTPUT`` and
- ``V4L2_BUF_TYPE_VIDEO_OVERLAY``. See :c:type:`v4l2_buf_type`.
+ are valid here: ``V4L2_BUF_TYPE_VIDEO_CAPTURE``, ``V4L2_BUF_TYPE_VIDEO_CAPTURE_MPLANE``,
+ ``V4L2_BUF_TYPE_VIDEO_OUTPUT``, ``V4L2_BUF_TYPE_VIDEO_OUTPUT_MPLANE`` and
+ ``V4L2_BUF_TYPE_VIDEO_OVERLAY``. See :c:type:`v4l2_buf_type` and the note above.
* - struct :c:type:`v4l2_rect`
- ``c``
- Cropping rectangle. The same co-ordinate system as for struct
:c:type:`v4l2_cropcap` ``bounds`` is used.
+.. note::
+ Unfortunately in the case of multiplanar buffer types
+ (``V4L2_BUF_TYPE_VIDEO_CAPTURE_MPLANE`` and ``V4L2_BUF_TYPE_VIDEO_OUTPUT_MPLANE``)
+ this API was messed up with regards to how the :c:type:`v4l2_crop` ``type`` field
+ should be filled in. Some drivers only accepted the ``_MPLANE`` buffer type while
+ other drivers only accepted a non-multiplanar buffer type (i.e. without the
+ ``_MPLANE`` at the end).
+
+ Starting with kernel 4.13 both variations are allowed.
+
Return Value
============
diff --git a/Documentation/media/uapi/v4l/vidioc-g-selection.rst b/Documentation/media/uapi/v4l/vidioc-g-selection.rst
index deb1f6fb473b..09923b86ec5d 100644
--- a/Documentation/media/uapi/v4l/vidioc-g-selection.rst
+++ b/Documentation/media/uapi/v4l/vidioc-g-selection.rst
@@ -42,11 +42,7 @@ The ioctls are used to query and configure selection rectangles.
To query the cropping (composing) rectangle set struct
:c:type:`v4l2_selection` ``type`` field to the
-respective buffer type. Do not use the multiplanar buffer types. Use
-``V4L2_BUF_TYPE_VIDEO_CAPTURE`` instead of
-``V4L2_BUF_TYPE_VIDEO_CAPTURE_MPLANE`` and use
-``V4L2_BUF_TYPE_VIDEO_OUTPUT`` instead of
-``V4L2_BUF_TYPE_VIDEO_OUTPUT_MPLANE``. The next step is setting the
+respective buffer type. The next step is setting the
value of struct :c:type:`v4l2_selection` ``target``
field to ``V4L2_SEL_TGT_CROP`` (``V4L2_SEL_TGT_COMPOSE``). Please refer
to table :ref:`v4l2-selections-common` or :ref:`selection-api` for
@@ -64,11 +60,7 @@ pixels.
To change the cropping (composing) rectangle set the struct
:c:type:`v4l2_selection` ``type`` field to the
-respective buffer type. Do not use multiplanar buffers. Use
-``V4L2_BUF_TYPE_VIDEO_CAPTURE`` instead of
-``V4L2_BUF_TYPE_VIDEO_CAPTURE_MPLANE``. Use
-``V4L2_BUF_TYPE_VIDEO_OUTPUT`` instead of
-``V4L2_BUF_TYPE_VIDEO_OUTPUT_MPLANE``. The next step is setting the
+respective buffer type. The next step is setting the
value of struct :c:type:`v4l2_selection` ``target`` to
``V4L2_SEL_TGT_CROP`` (``V4L2_SEL_TGT_COMPOSE``). Please refer to table
:ref:`v4l2-selections-common` or :ref:`selection-api` for additional
@@ -169,6 +161,16 @@ Selection targets and flags are documented in
- Reserved fields for future use. Drivers and applications must zero
this array.
+.. note::
+ Unfortunately in the case of multiplanar buffer types
+ (``V4L2_BUF_TYPE_VIDEO_CAPTURE_MPLANE`` and ``V4L2_BUF_TYPE_VIDEO_OUTPUT_MPLANE``)
+ this API was messed up with regards to how the :c:type:`v4l2_selection` ``type`` field
+ should be filled in. Some drivers only accepted the ``_MPLANE`` buffer type while
+ other drivers only accepted a non-multiplanar buffer type (i.e. without the
+ ``_MPLANE`` at the end).
+
+ Starting with kernel 4.13 both variations are allowed.
+
Return Value
============

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