Re: [PATCH] Documentation: media: improve V4L2_CID_MIN_BUFFERS_FOR_*, doc

[Laurent Pinchart <laurent.pinchart@ideasonboard.com>]

Hi Hans,

Thank you for the patch.

On Thu, Oct 31, 2024 at 08:50:04AM +0100, Hans Verkuil wrote:
> Clearly state that the V4L2_CID_MIN_BUFFERS_FOR_OUTPUT and
> V4L2_CID_MIN_BUFFERS_FOR_CAPTURE controls are required for
> stateful codecs.

Wouldn't it be better for this kind of information to be centralized in
a stateful decoder document ? That would make it easier for developers
to see all they need to implement. Otherwise they would need to read
through the whole documentation to pick the parts of the API they need
to support in their drivers.

> Signed-off-by: Hans Verkuil <hverkuil@xs4all.nl>
> ---
>  Documentation/userspace-api/media/v4l/control.rst | 6 ++++--
>  1 file changed, 4 insertions(+), 2 deletions(-)
> 
> diff --git a/Documentation/userspace-api/media/v4l/control.rst b/Documentation/userspace-api/media/v4l/control.rst
> index 57893814a1e5..9253cc946f02 100644
> --- a/Documentation/userspace-api/media/v4l/control.rst
> +++ b/Documentation/userspace-api/media/v4l/control.rst
> @@ -290,13 +290,15 @@ Control IDs
>      This is a read-only control that can be read by the application and
>      used as a hint to determine the number of CAPTURE buffers to pass to
>      REQBUFS. The value is the minimum number of CAPTURE buffers that is
> -    necessary for hardware to work.
> +    necessary for hardware to work. This control is required for stateful
> +    decoders.
> 
>  ``V4L2_CID_MIN_BUFFERS_FOR_OUTPUT`` ``(integer)``
>      This is a read-only control that can be read by the application and
>      used as a hint to determine the number of OUTPUT buffers to pass to
>      REQBUFS. The value is the minimum number of OUTPUT buffers that is
> -    necessary for hardware to work.
> +    necessary for hardware to work. This control is required for stateful
> +    encoders.
> 
>  .. _v4l2-alpha-component:
> 

-- 
Regards,

Laurent Pinchart