From 5f229dcabc4acfb4e233e7678569f0fb9ab9c469 Mon Sep 17 00:00:00 2001 From: Sakari Ailus Date: Wed, 21 Nov 2018 12:29:35 -0500 Subject: media: v4l: uAPI doc: Changing frame interval won't change format 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 Acked-by: Hans Verkuil Signed-off-by: Mauro Carvalho Chehab --- 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(+) (limited to 'Documentation/media') 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() ` or :ref:`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() ` 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. -- cgit