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* [PATCH 1/1] v4l: uAPI doc: Changing frame interval won't change format
@ 2018-11-21 17:33 Sakari Ailus
  2018-11-22  9:08 ` Hans Verkuil
  0 siblings, 1 reply; 2+ messages in thread
From: Sakari Ailus @ 2018-11-21 17:33 UTC (permalink / raw)
  To: linux-media; +Cc: hverkuil

Document that changing the frame interval has no effect on frame size.
While this was the assumption in the API, it was not documented as such.

Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
---
 Documentation/media/uapi/v4l/vidioc-g-parm.rst                  | 3 +++
 Documentation/media/uapi/v4l/vidioc-subdev-g-frame-interval.rst | 3 +++
 2 files changed, 6 insertions(+)

diff --git a/Documentation/media/uapi/v4l/vidioc-g-parm.rst b/Documentation/media/uapi/v4l/vidioc-g-parm.rst
index e831fa5512f0..c31585a7701b 100644
--- a/Documentation/media/uapi/v4l/vidioc-g-parm.rst
+++ b/Documentation/media/uapi/v4l/vidioc-g-parm.rst
@@ -42,6 +42,9 @@ side. This is especially useful when using the :ref:`read() <func-read>` or
 :ref:`write() <func-write>`, which are not augmented by timestamps or sequence
 counters, and to avoid unnecessary data copying.
 
+Changing the frame interval shall never change the format. Changing the
+format, on the other hand, may change the frame interval.
+
 Further these ioctls can be used to determine the number of buffers used
 internally by a driver in read/write mode. For implications see the
 section discussing the :ref:`read() <func-read>` function.
diff --git a/Documentation/media/uapi/v4l/vidioc-subdev-g-frame-interval.rst b/Documentation/media/uapi/v4l/vidioc-subdev-g-frame-interval.rst
index 5af0a7179941..f889c20f231c 100644
--- a/Documentation/media/uapi/v4l/vidioc-subdev-g-frame-interval.rst
+++ b/Documentation/media/uapi/v4l/vidioc-subdev-g-frame-interval.rst
@@ -63,6 +63,9 @@ doesn't match the device capabilities. They must instead modify the
 interval to match what the hardware can provide. The modified interval
 should be as close as possible to the original request.
 
+Changing the frame interval shall never change the format. Changing the
+format, on the other hand, may change the frame interval.
+
 Sub-devices that support the frame interval ioctls should implement them
 on a single pad only. Their behaviour when supported on multiple pads of
 the same sub-device is not defined.
-- 
2.11.0

^ permalink raw reply related	[flat|nested] 2+ messages in thread

* Re: [PATCH 1/1] v4l: uAPI doc: Changing frame interval won't change format
  2018-11-21 17:33 [PATCH 1/1] v4l: uAPI doc: Changing frame interval won't change format Sakari Ailus
@ 2018-11-22  9:08 ` Hans Verkuil
  0 siblings, 0 replies; 2+ messages in thread
From: Hans Verkuil @ 2018-11-22  9:08 UTC (permalink / raw)
  To: Sakari Ailus, linux-media

On 11/21/2018 06:33 PM, Sakari Ailus wrote:
> Document that changing the frame interval has no effect on frame size.
> While this was the assumption in the API, it was not documented as such.
> 
> Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>

Acked-by: Hans Verkuil <hans.verkuil@cisco.com>

Thanks!

	Hans

> ---
>  Documentation/media/uapi/v4l/vidioc-g-parm.rst                  | 3 +++
>  Documentation/media/uapi/v4l/vidioc-subdev-g-frame-interval.rst | 3 +++
>  2 files changed, 6 insertions(+)
> 
> diff --git a/Documentation/media/uapi/v4l/vidioc-g-parm.rst b/Documentation/media/uapi/v4l/vidioc-g-parm.rst
> index e831fa5512f0..c31585a7701b 100644
> --- a/Documentation/media/uapi/v4l/vidioc-g-parm.rst
> +++ b/Documentation/media/uapi/v4l/vidioc-g-parm.rst
> @@ -42,6 +42,9 @@ side. This is especially useful when using the :ref:`read() <func-read>` or
>  :ref:`write() <func-write>`, which are not augmented by timestamps or sequence
>  counters, and to avoid unnecessary data copying.
>  
> +Changing the frame interval shall never change the format. Changing the
> +format, on the other hand, may change the frame interval.
> +
>  Further these ioctls can be used to determine the number of buffers used
>  internally by a driver in read/write mode. For implications see the
>  section discussing the :ref:`read() <func-read>` function.
> diff --git a/Documentation/media/uapi/v4l/vidioc-subdev-g-frame-interval.rst b/Documentation/media/uapi/v4l/vidioc-subdev-g-frame-interval.rst
> index 5af0a7179941..f889c20f231c 100644
> --- a/Documentation/media/uapi/v4l/vidioc-subdev-g-frame-interval.rst
> +++ b/Documentation/media/uapi/v4l/vidioc-subdev-g-frame-interval.rst
> @@ -63,6 +63,9 @@ doesn't match the device capabilities. They must instead modify the
>  interval to match what the hardware can provide. The modified interval
>  should be as close as possible to the original request.
>  
> +Changing the frame interval shall never change the format. Changing the
> +format, on the other hand, may change the frame interval.
> +
>  Sub-devices that support the frame interval ioctls should implement them
>  on a single pad only. Their behaviour when supported on multiple pads of
>  the same sub-device is not defined.
> 

^ permalink raw reply	[flat|nested] 2+ messages in thread

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