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| author | Hans Verkuil <hans.verkuil@cisco.com> | 2017-05-08 17:35:06 +0300 |
|---|---|---|
| committer | Mauro Carvalho Chehab <mchehab@s-opensource.com> | 2017-06-23 15:22:17 +0300 |
| commit | 8780f1d9d696c7f466a0ff2a2016476a7ebf42b6 (patch) | |
| tree | 2ee66411a8c138081ae0103705b0ab265419a3ec /Documentation/media/uapi/v4l/vidioc-cropcap.rst | |
| parent | eaec420f530d376d6bb6e547a741203344619f47 (diff) | |
| download | linux-8780f1d9d696c7f466a0ff2a2016476a7ebf42b6.tar.xz | |
[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>
Diffstat (limited to 'Documentation/media/uapi/v4l/vidioc-cropcap.rst')
| -rw-r--r-- | Documentation/media/uapi/v4l/vidioc-cropcap.rst | 23 |
1 files changed, 13 insertions, 10 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: |