Am 22.07.20 um 14:53 schrieb Tomasz Figa:
Hi Dafna,
On Fri, Jul 03, 2020 at 07:10:16PM +0200, Dafna Hirschfeld wrote:
This patch extends the CSC API in video devices to be supported
also on sub-devices. The flag V4L2_MBUS_FRAMEFMT_SET_CSC set by
the application when calling VIDIOC_SUBDEV_S_FMT ioctl.
The flags:
V4L2_SUBDEV_MBUS_CODE_CSC_COLORSPACE, V4L2_SUBDEV_MBUS_CODE_CSC_YCBCR_ENC,
V4L2_SUBDEV_MBUS_CODE_CSC_QUANTIZATION V4L2_SUBDEV_MBUS_CODE_CSC_XFER_FUNC,
are set by the driver in the VIDIOC_SUBDEV_ENUM_MBUS_CODE ioctl.
New 'flags' fields were added to the structs
v4l2_subdev_mbus_code_enum, v4l2_mbus_framefmt which are borrowed
from the 'reserved' field
Signed-off-by: Dafna Hirschfeld <dafna.hirschfeld@xxxxxxxxxxxxx>
---
.../media/v4l/subdev-formats.rst | 78 +++++++++++++++++--
.../v4l/vidioc-subdev-enum-mbus-code.rst | 44 ++++++++++-
include/uapi/linux/v4l2-mediabus.h | 9 ++-
include/uapi/linux/v4l2-subdev.h | 8 +-
4 files changed, 129 insertions(+), 10 deletions(-)
Thank you for the patch. Please see my comments inline.
diff --git a/Documentation/userspace-api/media/v4l/subdev-formats.rst b/Documentation/userspace-api/media/v4l/subdev-formats.rst
index 9a4d61b0d76f..7362ee0b1e96 100644
--- a/Documentation/userspace-api/media/v4l/subdev-formats.rst
+++ b/Documentation/userspace-api/media/v4l/subdev-formats.rst
@@ -41,32 +41,96 @@ Media Bus Formats
:ref:`field-order` for details.
* - __u32
- ``colorspace``
- - Image colorspace, from enum
- :c:type:`v4l2_colorspace`. See
- :ref:`colorspaces` for details.
+ - Image colorspace, from enum :c:type:`v4l2_colorspace`.
+ Must be set by the driver for capture streams and by the application
+ for output streams, see :ref:`colorspaces`. If the application sets the
+ flag ``V4L2_MBUS_FRAMEFMT_SET_CSC`` then the application can set
+ this field for a capture stream to request a specific colorspace
What is a "capture stream" in terms of the subdev API? Should this
perhaps refer to "source pads" instead?
Hi, yes, I should change it to 'source pad'. I see that for the other colorimetry fields,
the docs for v4l2_mbus_framefmt already writes
"This information supplements the colorspace and must be set by the driver for capture streams and by the application for output streams,"
I guess this should also change,
Thanks,
Dafna
[snip]
+.. _v4l2-mbus-framefmt-flags:
+
+.. flat-table:: v4l2_mbus_framefmt Flags
+ :header-rows: 0
+ :stub-columns: 0
+ :widths: 3 1 4
+
+ * .. _`mbus-framefmt-set-csc`:
+
+ - ``V4L2_MBUS_FRAMEFMT_SET_CSC``
+ - 0x00000001
+ - Set by the application. It is only used for capture and is
+ ignored for output streams. If set, then request the subdevice to do
Ditto.
+ colorspace conversion from the received colorspace to the requested
+ colorspace values. If colorimetry field (``colorspace``, ``ycbcr_enc``,
nit: a colorimetry field
+ ``quantization`` or ``xfer_func``) is set to 0, then that colorimetry
Is it okay to explicitly mention 0 here, rather than the defined
"_DEFAULT" values?
Best regards,
Tomasz
