From mboxrd@z Thu Jan 1 00:00:00 1970 Return-path: Received: from mx1.redhat.com ([209.132.183.28]:19030 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751821Ab0BVN7C (ORCPT ); Mon, 22 Feb 2010 08:59:02 -0500 Message-ID: <4B828D9C.50303@redhat.com> Date: Mon, 22 Feb 2010 10:58:52 -0300 From: Mauro Carvalho Chehab MIME-Version: 1.0 To: Devin Heitmueller CC: Andy Walls , Sakari Ailus , hverkuil@xs4all.nl, Linux Media Mailing List Subject: Re: Chroma gain configuration References: <829197381002212007q342fc01bm1c528a2f15027a1e@mail.gmail.com> <1266838852.3095.20.camel@palomino.walls.org> <4B827548.10005@redhat.com> <829197381002220510v64f6e948pfb73ebe4fcc180af@mail.gmail.com> <4B828939.4040708@redhat.com> <829197381002220547n3468019bmdb17f401f7c5b6e1@mail.gmail.com> In-Reply-To: <829197381002220547n3468019bmdb17f401f7c5b6e1@mail.gmail.com> Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Sender: linux-media-owner@vger.kernel.org List-ID: Devin Heitmueller wrote: > On Mon, Feb 22, 2010 at 8:40 AM, Mauro Carvalho Chehab > wrote: >> I think that the control you want is V4L2_CID_GAIN. > > I would have guessed the CID_GAIN control would have been responsible > for *luma* gain. I could be wrong about that of course (but that is > what I believe people typically think of when they think of "gain" in > general). Maybe it is for luma, but I bet that this is also is used for more than one different kind of control. We should revisit those controls and properly specify what they should do. > >>> I believe there probably are cases where extended controls are required, >>> but I believe just a general user control based on >>> V4L2_CID_PRIVATE_BASE should probably be able to work even with the >>> generic VIDIOC_S_CTRL >>> >>> I'm just asking because it would mean in order for v4l2-dbg to work >>> with my solution i would have to add support for extended controls in >>> general to the saa7115 driver, which shouldn't be necessary. >> The end objective is to have everybody implementing extended controls and >> removing the old controls, letting the V4L2 ioctl2 to convert a call to a >> simple control into an extended control callback. So, I think it would >> be worthy to implement extended control on saa7115. > > Ok then. I'll add the 15-20 lines of code which add the extended > controls mechanism to the 7115, which just operates as a passthrough > for the older control interface. The better is to do the opposite: extended being the control interface and the old calls as a passthrough, since the idea is to remove the old interface after having all drivers converted. -- Cheers, Mauro