From: Laurent Pinchart Date: Wed, 21 May 2014 22:16:01 +0000 (+0200) Subject: DocBook: media: Document ALPHA_COMPONENT control usage on output devices X-Git-Tag: v3.14.28+ltsi~297 X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=f97fb6d6ac94793e28e182707299be1aaafbb612;p=platform%2Fkernel%2Flinux-stable.git DocBook: media: Document ALPHA_COMPONENT control usage on output devices Extend the V4L2_CID_ALPHA_COMPONENT control for use on output devices, to set the alpha component value when the output format doesn't have an alpha channel. Signed-off-by: Laurent Pinchart (cherry picked from commit e632d2f4e25c574a29b269f9f4b0cef2995e402d) Signed-off-by: Simon Horman --- diff --git a/Documentation/DocBook/media/v4l/controls.xml b/Documentation/DocBook/media/v4l/controls.xml index a5a3188e5af7..066800dcb123 100644 --- a/Documentation/DocBook/media/v4l/controls.xml +++ b/Documentation/DocBook/media/v4l/controls.xml @@ -398,14 +398,17 @@ to work. V4L2_CID_ALPHA_COMPONENT integer - Sets the alpha color component on the capture device or on - the capture buffer queue of a mem-to-mem device. When a mem-to-mem - device produces frame format that includes an alpha component + Sets the alpha color component. When a capture device (or + capture queue of a mem-to-mem device) produces a frame format that + includes an alpha component (e.g. packed RGB image formats) - and the alpha value is not defined by the mem-to-mem input data - this control lets you select the alpha component value of all - pixels. It is applicable to any pixel format that contains an alpha - component. + and the alpha value is not defined by the device or the mem-to-mem + input data this control lets you select the alpha component value of + all pixels. When an output device (or output queue of a mem-to-mem + device) consumes a frame format that doesn't include an alpha + component and the device supports alpha channel processing this + control lets you set the alpha component value of all pixels for + further processing in the device.