Re: [PATCH v4 2/9] [media] v4l2-core: Add VFL_TYPE_TOUCH_SENSOR

From: Florian Echtler
Date: Wed Jun 22 2016 - 16:38:17 EST


On Wed, 22 Jun 2016, Nick Dyer wrote:

On 22/06/2016 12:48, Florian Echtler wrote:
On 20.06.2016 14:00, Hans Verkuil wrote:
On 06/17/2016 04:16 PM, Nick Dyer wrote:

Use a new device prefix v4l-touch for these devices, to stop generic
capture software from treating them as webcams.

Come to think of it, wouldn't it make sense to expose the other touch
devices as generic frame grabbers, too, so you can easily view the debug
output with any generic tool like cheese?

While I like the idea of being able to use the generic tools, I think we
needed to do something to stop these devices turning up in e.g. video
conferencing software - it would cause a lot of confusion. There's nothing
stopping particular tools adding the necessary code to handle touch devices
if they feel their users want it.

Just to clarify: from the userspace point-of-view, would this change simply modify the prefix of the device node (i.e. /dev/video1 -> /dev/v4l-touch1), or would it somehow affect the API? If it's just the device node name, then that shouldn't be a problem after all, because e.g. reacTIVision requires you to specify the exact camera to be used anyway.

Florian
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