From mboxrd@z Thu Jan 1 00:00:00 1970 Return-path: Received: from smtp.nokia.com ([147.243.128.24]:25658 "EHLO mgw-da01.nokia.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751937Ab1I1KD4 (ORCPT ); Wed, 28 Sep 2011 06:03:56 -0400 Message-ID: <4E82F106.6040407@maxwell.research.nokia.com> Date: Wed, 28 Sep 2011 13:03:50 +0300 From: Sakari Ailus MIME-Version: 1.0 To: Mauro Carvalho Chehab CC: Laurent Pinchart , "Hiremath, Vaibhav" , "Ravi, Deepthy" , "linux-media@vger.kernel.org" , "g.liakhovetski@gmx.de" Subject: Re: [PATCH 4/8] ispvideo: Add support for G/S/ENUM_STD ioctl References: <1315488922-16152-1-git-send-email-deepthy.ravi@ti.com> <19F8576C6E063C45BE387C64729E739404EC8113E2@dbde02.ent.ti.com> <4E824EC4.20305@infradead.org> <201109280041.29952.laurent.pinchart@ideasonboard.com> <4E82F002.4040401@infradead.org> In-Reply-To: <4E82F002.4040401@infradead.org> Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Sender: linux-media-owner@vger.kernel.org List-ID: Mauro Carvalho Chehab wrote: > Em 27-09-2011 19:41, Laurent Pinchart escreveu: >> Hi Mauro, >> >> On Wednesday 28 September 2011 00:31:32 Mauro Carvalho Chehab wrote: >>> Em 19-09-2011 12:31, Hiremath, Vaibhav escreveu: >>>> On Friday, September 16, 2011 6:36 PM Laurent Pinchart wrote: > >> On >> Friday 16 September 2011 15:00:53 Ravi, Deepthy wrote: >>>>>> On Thursday, September 08, 2011 10:51 PM Laurent Pinchart wrote: >>>>>>> On Thursday 08 September 2011 15:35:22 Deepthy Ravi wrote: >>>>>>>> From: Vaibhav Hiremath >>>>>>>> >>>>>>>> In order to support TVP5146 (for that matter any video decoder), >>>>>>>> it is important to support G/S/ENUM_STD ioctl on /dev/videoX >>>>>>>> device node. >>>>>>> >>>>>>> Why so ? Shouldn't it be queried on the subdev output pad directly ? >>>>>> >>>>>> Because standard v4l2 application for analog devices will call these >>>>>> std ioctls on the streaming device node. So it's done on /dev/video to >>>>>> make the existing apllication work. >>>>> >>>>> Existing applications can't work with the OMAP3 ISP (and similar complex >>>>> embedded devices) without userspace support anyway, either in the form >>>>> of a GStreamer element or a libv4l plugin. I still believe that analog >>>>> video standard operations should be added to the subdev pad operations >>>>> and exposed through subdev device nodes, exactly as done with formats. >>>> >>>> I completely agree with your point that, existing application will not >>>> work without setting links properly. But I believe the assumption here >>>> is, media-controller should set the links (along with pad formants) and >>>> all existing application should work as is. Isn't it? >>> >>> Yes. >>> >>>> The way it is being done currently is, set the format at the pad level >>>> which is same as analog standard resolution and use existing application >>>> for streaming... >>> >>> Yes. >>> >>>> I am ok, if we add s/g/enum_std api support at sub-dev level but this >>>> should also be supported on streaming device node. >>> >>> Agreed. Standards selection should be done at device node, just like any >>> other device. >> >> No. Please see my reply to Vaibhav's e-mail. Standard selection should be done >> on the subdev pads, for the exact same reason why formats and selection >> rectangles are configured on subdev pads. > > NACK. Let's not reinvent the wheel. the MC should not replace the V4L2 API. That has never been the intention. My proposal is that the {G,S,ENUM}_STD is implemented in the V4L2 subdev user space interface and then the libv4l plugin redirects the call to the right subdev, in a similar fashion which is planned for V4L2 controls. Kind regards, -- Sakari Ailus sakari.ailus@maxwell.research.nokia.com