From: Sergey Senozhatsky <sergey.senozhatsky.work@gmail.com>
To: Ricardo Ribalda Delgado <ricardo.ribalda@gmail.com>
Cc: Sergey Senozhatsky <sergey.senozhatsky.work@gmail.com>,
Laurent Pinchart <laurent.pinchart@ideasonboard.com>,
Tomasz Figa <tfiga@chromium.org>,
Mauro Carvalho Chehab <mchehab@kernel.org>,
linux-media <linux-media@vger.kernel.org>,
LKML <linux-kernel@vger.kernel.org>,
Sergey Senozhatsky <senozhatsky@chromium.org>,
Ricardo Ribalda <ribalda@chromium.org>
Subject: Re: [PATCHv2 3/3] media: uvcvideo: add UVC 1.5 ROI control
Date: Thu, 18 Mar 2021 13:47:30 +0900 [thread overview]
Message-ID: <YFLbYjm0VyzaEMkr@google.com> (raw)
In-Reply-To: <CAPybu_0ruoc-w3402j-vVNs2-xq8=-_XzVKSxiG+iuyB=eNimA@mail.gmail.com>
On (21/03/17 08:58), Ricardo Ribalda Delgado wrote:
[..]
> >
> > GET_CUR?
> yep
>
> >
> > > https://www.kernel.org/doc/html/v4.13/media/uapi/v4l/vidioc-g-selection.html?highlight=vidioc_s_selection
> > > On success the struct v4l2_rect r field contains the adjusted
> > > rectangle.
> >
> > What is the adjusted rectangle here? Does this mean that firmware can
> > successfully apply SET_CUR and return 0, but in reality it was not happy
> > with the rectangle dimensions so it modified it behind the scenes?
>
> I can imagine that some hw might have spooky requirements for the roi
> rectangle (multiple of 4, not crossing the bayer filter, odd/even
> line...) so they might be able to go the closest valid config.
Hmm. Honestly, I'm very unsure about it. ROI::SET_CUR can be a very
hot path, depending on what user-space considers to be of interest
and how frequently that object of interest changes its position/shape/etc.
Doing GET_CUR after every SET_CUR doubles the number of firmware calls
we issue, that's for sure; is it worth it - that's something that I'm
not sure of.
May I please ask for more opinions on this?
-ss
next prev parent reply other threads:[~2021-03-18 4:48 UTC|newest]
Thread overview: 23+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-02-08 5:17 [PATCHv2 0/3] Add UVC 1.5 Region Of Interest control to uvcvideo Sergey Senozhatsky
2021-02-08 5:17 ` [PATCHv2 1/3] media: v4l UAPI docs: document ROI selection targets Sergey Senozhatsky
2021-03-16 18:19 ` Ricardo Ribalda Delgado
2021-03-17 1:31 ` Sergey Senozhatsky
2021-03-17 8:04 ` Ricardo Ribalda Delgado
2021-03-17 8:08 ` Sergey Senozhatsky
2021-02-08 5:17 ` [PATCHv2 2/3] media: uvcvideo: add ROI auto controls Sergey Senozhatsky
2021-03-16 18:29 ` Ricardo Ribalda Delgado
2021-03-17 1:34 ` Sergey Senozhatsky
2021-03-17 8:08 ` Ricardo Ribalda Delgado
2021-03-17 8:12 ` Sergey Senozhatsky
2021-03-17 9:18 ` Sergey Senozhatsky
2021-03-17 9:27 ` Sergey Senozhatsky
2021-02-08 5:17 ` [PATCHv2 3/3] media: uvcvideo: add UVC 1.5 ROI control Sergey Senozhatsky
2021-03-16 18:46 ` Ricardo Ribalda Delgado
2021-03-17 1:59 ` Sergey Senozhatsky
2021-03-17 7:58 ` Ricardo Ribalda Delgado
2021-03-18 4:47 ` Sergey Senozhatsky [this message]
2021-03-18 21:19 ` Ricardo Ribalda
2021-03-18 21:20 ` Ricardo Ribalda
2021-03-19 5:35 ` Sergey Senozhatsky
2021-03-19 16:40 ` Ricardo Ribalda
2021-03-16 5:25 ` [PATCHv2 0/3] Add UVC 1.5 Region Of Interest control to uvcvideo Sergey Senozhatsky
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