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Date: Thu, 24 Mar 2011 08:28:31 +0100
From: Michael Jones <michael.jones@matrix-vision.de>
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To: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
CC: Sakari Ailus <sakari.ailus@maxwell.research.nokia.com>,
	Linux Media Mailing List <linux-media@vger.kernel.org>,
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Subject: Re: [PATCH] omap3isp: implement ENUM_FMT
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Hi Laurent,

On 03/23/2011 01:16 PM, Laurent Pinchart wrote:
> Hi Michael,
> 
[snip]
>>
>> Is there a policy decision that in the future, apps will be required to
>> use libv4l to get images from the ISP?  Are we not intending to support
>> using e.g. media-ctl + some v4l2 app, as I'm currently doing during
>> development?
> 
> Apps should be able to use the V4L2 API directly. However, we can't implement 
> all that API, as most calls don't make sense for the OMA3 ISP driver. Which 
> calls need to be implemented is a grey area at the moment, as there's no 
> detailed semantics on how subdev-level configuration and video device 
> configuration should interact.
> 
> Your implementation of ENUM_FMT looks correct to me, but the question is 
> whether ENUM_FMT should be implemented. I don't think ENUM_FMT is a required 
> ioctl, so maybe v4l2src shouldn't depend on it. I'm interesting in getting 
> Hans' opinion on this.
> 

I only implemented it after I saw that ENUM_FMT _was_ required by V4L2.
 From http://v4l2spec.bytesex.org/spec/x1859.htm#AEN1894 :
"The VIDIOC_ENUM_FMT ioctl must be supported by all drivers exchanging
image data with applications."

-Michael

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