From mboxrd@z Thu Jan 1 00:00:00 1970 Return-path: Received: from smtp-vbr11.xs4all.nl ([194.109.24.31]:3213 "EHLO smtp-vbr11.xs4all.nl" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932375AbaE3M20 (ORCPT ); Fri, 30 May 2014 08:28:26 -0400 Message-ID: <53887960.3050003@xs4all.nl> Date: Fri, 30 May 2014 14:28:16 +0200 From: Hans Verkuil MIME-Version: 1.0 To: Laurent Pinchart , Sakari Ailus CC: linux-media@vger.kernel.org Subject: Re: [PATCH v3 1/3] v4l: Add test pattern colour component controls References: <1401374448-30411-1-git-send-email-sakari.ailus@linux.intel.com> <48325310.Ydj7bxFi9C@avalon> <53874B33.5050109@linux.intel.com> <1559123.5XHCoOtRWQ@avalon> In-Reply-To: <1559123.5XHCoOtRWQ@avalon> Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Sender: linux-media-owner@vger.kernel.org List-ID: On 05/29/2014 05:01 PM, Laurent Pinchart wrote: > On Thursday 29 May 2014 17:58:59 Sakari Ailus wrote: >> Laurent Pinchart wrote: >>> On Thursday 29 May 2014 17:40:46 Sakari Ailus wrote: >>>> In many cases the test pattern has selectable values for each colour >>>> component. Implement controls for raw bayer components. Additional >>>> controls >>>> should be defined for colour components that are not covered by these >>>> controls. >>>> >>>> Signed-off-by: Sakari Ailus >>>> --- >>>> >>>> Documentation/DocBook/media/v4l/controls.xml | 34 +++++++++++++++++++++ >>>> drivers/media/v4l2-core/v4l2-ctrls.c | 4 ++++ >>>> include/uapi/linux/v4l2-controls.h | 4 ++++ >>>> 3 files changed, 42 insertions(+) >>>> >>>> diff --git a/Documentation/DocBook/media/v4l/controls.xml >>>> b/Documentation/DocBook/media/v4l/controls.xml index 47198ee..bf23994 >>>> 100644 >>>> --- a/Documentation/DocBook/media/v4l/controls.xml >>>> +++ b/Documentation/DocBook/media/v4l/controls.xml >>>> @@ -4677,6 +4677,40 @@ interface and may change in the future. >>>> conversion. >>>> >>>> >>>> + >>>> + >>> spanname="id">V4L2_CID_TEST_PATTERN_RED >>>> + integer >>>> + >>>> + >>>> + Test pattern red colour component. >>>> + >>>> + >>>> + >>>> + >>> spanname="id">V4L2_CID_TEST_PATTERN_GREENR >>>> + integer >>>> + >>>> + >>>> + Test pattern green (next to red) >>>> + colour component. >>> >>> What about non-Bayer RGB sensors ? Should they use the GREENR or the >>> GREENB control for the green component ? Or a different control ? >> >> A different one. It should be simply green. I could add it to the same >> patch if you wish. >> >>> I'm wondering whether we shouldn't have a single test pattern color >>> control and create a color type using Hans' complex controls API. >> >> A raw bayer four-pixel value, you mean? > > Yes. I'll let Hans comment on that. > Why would you need the complex control API for that? It would fit in a s32, and certainly in a s64. We have done something similar to this in the past (V4L2_CID_BG_COLOR). The main problem is that the interpretation of the s32 value has to be clearly defined. And if different sensors might have different min/max values for each component, then it becomes messy to use a single control. My feeling is that it is better to go with separate controls, one for each component. Regards, Hans