Re: [PATCH 4/8] ispvideo: Add support for G/S/ENUM_STD ioctl

Laurent Pinchart
2011-09-16T13:06:16Z

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.

--
Regards,

Laurent Pinchart