From mboxrd@z Thu Jan 1 00:00:00 1970 Return-path: Received: from smtp.nokia.com ([147.243.128.26]:44630 "EHLO mgw-da02.nokia.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751143Ab2EGEze (ORCPT ); Mon, 7 May 2012 00:55:34 -0400 Message-ID: <4FA6BF6A.4030902@iki.fi> Date: Sun, 06 May 2012 21:14:02 +0300 From: Sakari Ailus MIME-Version: 1.0 To: Laurent Pinchart CC: linux-media@vger.kernel.org Subject: Re: [media-ctl PATCH 2/3] New, more flexible syntax for media-ctl References: <1336119883-14978-1-git-send-email-sakari.ailus@iki.fi> <14849350.mp0nWfDsvJ@avalon> <20120505130933.GI852@valkosipuli.localdomain> <2542901.vLyHxKHSqR@avalon> In-Reply-To: <2542901.vLyHxKHSqR@avalon> Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Sender: linux-media-owner@vger.kernel.org List-ID: Hi Laurent, Laurent Pinchart wrote: > On Saturday 05 May 2012 16:09:33 Sakari Ailus wrote: ... >> The pixel format and the image size at the pad are clearly format >> (VIDIOC_SUBDEV_S_FMT) but the other things are related to pads but not >> format. >> >> I see them different kinds of properties of pads. That suggests we might be >> better renaming the option (-f) to something else as well. > > You like breaking interfaces, don't you ? :-D I thought you said we have no stable release yet. :-D The selection interface on subdevs is currently used to change format related things (cropping and scaling, for example) but it was one of Sylwester's patches ("V4L: Add auto focus targets to the selections API") that adds a focus window target to the V4L2 selection interface. I don't see why it couldn't be present on subdevs, too. That's got nothing to do with the image format. I've been pondering a bit using another option to configure things related to selections. Conveniently "-s" is free. We could leave the crop things to -f but remove the documentation related to them. I'm fine with keeping the things as they are for now, too, but in that case we should recognise that -f will not be for formats only. Or we split handling selections into separate options, but I don't like that idea either. >>> I find the '/' a bit confusing compared to the ' ' (but I think you find >>> the space confusing compared to '/' :-)). I also wonder whether we >>> shouldn't just drop 'fmt:', as there can be a single format only. >> >> You can set it multiple times, or you may not set it at all. That's why I >> think we should explicitly say it's the format. > > Not at all makes sense, but why would you set it multiple times ? I guess that's not a very practical use case, albeit there may be dependencies between the two: Guennadi had a piece of hardware where the hardware cropping or scaling capabilities depended on the format. But not setting it at all definitely is a valid use case. Kind regards, -- Sakari Ailus sakari.ailus@iki.fi