Re: [PATCH v2] v4l: doc: Clarify v4l2_mbus_fmt height definition
From: Niklas Söderlund
Date: Mon Jan 08 2018 - 17:38:11 EST
Hi Kieran,
Thanks for your patch.
On 2018-01-08 17:55:24 +0000, Kieran Bingham wrote:
> The v4l2_mbus_fmt width and height corresponds directly with the
> v4l2_pix_format definitions, yet the differences in documentation make
> it ambiguous what to do in the event of field heights.
>
> Clarify this using the same text as is provided for the v4l2_pix_format
> which is explicit on the matter, and by matching the terminology of
> 'image height' rather than the misleading 'frame height'.
>
> Signed-off-by: Kieran Bingham <kieran.bingham+renesas@xxxxxxxxxxxxxxxx>
Reviewed-by: Niklas Söderlund <niklas.soderlund+renesas@xxxxxxxxxxxx>
> ---
> v2:
> - Duplicated explicit text from v4l2_pix_format rather than
> referencing it.
>
> Documentation/media/uapi/v4l/subdev-formats.rst | 8 ++++++--
> include/uapi/linux/v4l2-mediabus.h | 4 ++--
> 2 files changed, 8 insertions(+), 4 deletions(-)
>
> diff --git a/Documentation/media/uapi/v4l/subdev-formats.rst b/Documentation/media/uapi/v4l/subdev-formats.rst
> index b1eea44550e1..9fcabe7f9367 100644
> --- a/Documentation/media/uapi/v4l/subdev-formats.rst
> +++ b/Documentation/media/uapi/v4l/subdev-formats.rst
> @@ -16,10 +16,14 @@ Media Bus Formats
>
> * - __u32
> - ``width``
> - - Image width, in pixels.
> + - Image width in pixels.
> * - __u32
> - ``height``
> - - Image height, in pixels.
> + - Image height in pixels. If ``field`` is one of ``V4L2_FIELD_TOP``,
> + ``V4L2_FIELD_BOTTOM`` or ``V4L2_FIELD_ALTERNATE`` then height
> + refers to the number of lines in the field, otherwise it refers to
> + the number of lines in the frame (which is twice the field height
> + for interlaced formats).
> * - __u32
> - ``code``
> - Format code, from enum
> diff --git a/include/uapi/linux/v4l2-mediabus.h b/include/uapi/linux/v4l2-mediabus.h
> index 6e20de63ec59..123a231001a8 100644
> --- a/include/uapi/linux/v4l2-mediabus.h
> +++ b/include/uapi/linux/v4l2-mediabus.h
> @@ -18,8 +18,8 @@
>
> /**
> * struct v4l2_mbus_framefmt - frame format on the media bus
> - * @width: frame width
> - * @height: frame height
> + * @width: image width
> + * @height: image height
> * @code: data format code (from enum v4l2_mbus_pixelcode)
> * @field: used interlacing type (from enum v4l2_field)
> * @colorspace: colorspace of the data (from enum v4l2_colorspace)
> --
> 2.7.4
>
--
Regards,
Niklas Söderlund