Messages in this thread | | | Date | Tue, 27 Sep 2011 16:49:21 -0600 | From | Gary Thomas <> | Subject | Re: [PATCH 4/8] ispvideo: Add support for G/S/ENUM_STD ioctl |
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On 2011-09-27 16:31, Mauro Carvalho Chehab wrote: > Em 19-09-2011 12:31, Hiremath, Vaibhav escreveu: >> >>> -----Original Message----- >>> From: Laurent Pinchart [mailto:laurent.pinchart@ideasonboard.com] >>> Sent: Friday, September 16, 2011 6:36 PM >>> To: Ravi, Deepthy >>> Cc: linux-media@vger.kernel.org; tony@atomide.com; linux@arm.linux.org.uk; >>> linux-omap@vger.kernel.org; linux-arm-kernel@lists.infradead.org; linux- >>> kernel@vger.kernel.org; mchehab@infradead.org; g.liakhovetski@gmx.de; >>> Hiremath, Vaibhav >>> Subject: Re: [PATCH 4/8] ispvideo: Add support for G/S/ENUM_STD ioctl >>> >>> Hi Deepthy, >>> >>> 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<hvaibhav@ti.com> >>>>>> >>>>>> 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. >>> >> [Hiremath, Vaibhav] Laurent, >> >> 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.
So how do you handle a part like the TVP5150 that is standard agnostic? That device can sense the standard from the input signal and sets the result appropriately.
-- ------------------------------------------------------------ Gary Thomas | Consulting for the MLB Associates | Embedded world ------------------------------------------------------------
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