From: ivo.g.dimitrov.75@gmail•com (Ivaylo Dimitrov)
To: linux-arm-kernel@lists•infradead.org
Subject: [patch] autogain support for bayer10 format (was Re: [patch] propagating controls in libv4l2)
Date: Thu, 27 Apr 2017 08:52:21 +0300 [thread overview]
Message-ID: <8a129dca-69c2-366f-1a81-c64dbabc1983@gmail.com> (raw)
In-Reply-To: <20170426225150.GA4188@amd>
On 27.04.2017 01:51, Pavel Machek wrote:
> Hi!
>
>>>> There are two separate things here:
>>>>
>>>> 1) Autofoucs for a device that doesn't use subdev API
>>>> 2) libv4l2 support for devices that require MC and subdev API
>>>
>>> Actually there are three: 0) autogain. Unfortunately, I need autogain
>>> first before autofocus has a chance...
>>>
>>> And that means... bayer10 support for autogain.
>>>
>>> Plus, I changed avg_lum to long long. Quick calculation tells me int
>>> could overflow with few megapixel sensor.
>>>
>>> Oh, btw http://ytse.tricolour.net/docs/LowLightOptimization.html no
>>> longer works.
>>>
>>> Regards,
>>> Pavel
>>>
>>> diff --git a/lib/libv4lconvert/processing/autogain.c b/lib/libv4lconvert/processing/autogain.c
>>> index c6866d6..0b52d0f 100644
>>> --- a/lib/libv4lconvert/processing/autogain.c
>>> +++ b/lib/libv4lconvert/processing/autogain.c
>>> @@ -68,6 +71,41 @@ static void autogain_adjust(struct v4l2_queryctrl *ctrl, int *value,
>>> }
>>> }
>>>
>>> +static int get_luminosity_bayer10(uint16_t *buf, const struct v4l2_format *fmt)
>>> +{
>>> + long long avg_lum = 0;
>>> + int x, y;
>>> +
>>> + buf += fmt->fmt.pix.height * fmt->fmt.pix.bytesperline / 4 +
>>> + fmt->fmt.pix.width / 4;
>>> +
>>> + for (y = 0; y < fmt->fmt.pix.height / 2; y++) {
>>> + for (x = 0; x < fmt->fmt.pix.width / 2; x++)
>>
>> That would take some time :). AIUI, we have NEON support in ARM kernels
>> (CONFIG_KERNEL_MODE_NEON), I wonder if it makes sense (me) to convert the
>> above loop to NEON-optimized when it comes to it? Are there any drawbacks in
>> using NEON code in kernel?
>
> Well, thanks for offer. This is actualy libv4l2.
>
Oh, somehow I got confused that this is kernel code :)
> But I'd say NEON conversion is not neccessary anytime soon. First,
> this is just trying to get average luminosity. We can easily skip
> quite a lot of pixels, and still get reasonable answer.
>
> Second, omap3isp actually has a hardware block computing statistics
> for us. We just don't use it for simplicity.
>
Right, I forgot about that.
> (But if you want to play with camera, I'll get you patches; there's
> ton of work to be done, both kernel and userspace :-).
Well, I saw a low hanging fruit I thought I can convert to NEON in a day
or two, while having some rest from the huge "project" I am devoting all
my spare time recently (rebasing hildon/maemo 5 on top of devuan
Jessie). Still, if there is something relatively small to be done, just
email me and I'll have a look.
Regards,
Ivo
next prev parent reply other threads:[~2017-04-27 5:52 UTC|newest]
Thread overview: 38+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <1487074823-28274-1-git-send-email-sakari.ailus@linux.intel.com>
[not found] ` <1487074823-28274-2-git-send-email-sakari.ailus@linux.intel.com>
[not found] ` <20170414232332.63850d7b@vento.lan>
[not found] ` <20170416091209.GB7456@valkosipuli.retiisi.org.uk>
[not found] ` <20170419105118.72b8e284@vento.lan>
[not found] ` <20170424093059.GA20427@amd>
2017-04-24 13:38 ` support autofocus / autogain in libv4l2 Mauro Carvalho Chehab
2017-04-24 21:29 ` Pavel Machek
2017-04-25 1:47 ` Mauro Carvalho Chehab
2017-04-25 8:05 ` Pavel Machek
2017-04-25 8:08 ` Pali Rohár
2017-04-25 11:23 ` Pavel Machek
2017-04-25 11:30 ` Pali Rohár
2017-04-25 12:28 ` Pavel Machek
2017-04-25 12:51 ` Pali Rohár
2017-04-25 16:55 ` Nicolas Dufresne
2017-04-25 16:51 ` Nicolas Dufresne
2017-04-25 16:53 ` Nicolas Dufresne
2017-04-26 10:53 ` Pavel Machek
2017-04-26 10:53 ` [patch] propagating controls in libv4l2 was " Pavel Machek
2017-04-26 11:13 ` Mauro Carvalho Chehab
2017-04-26 13:23 ` [patch] autogain support for bayer10 format (was Re: [patch] propagating controls in libv4l2) Pavel Machek
2017-04-26 15:43 ` Ivaylo Dimitrov
2017-04-26 22:51 ` Pavel Machek
2017-04-27 5:52 ` Ivaylo Dimitrov [this message]
2017-07-13 7:57 ` Pavel Machek
2017-05-03 19:05 ` Russell King - ARM Linux
2017-05-03 19:58 ` Pavel Machek
2017-04-30 22:48 ` Pavel Machek
2017-07-13 9:49 ` [patch] propagating controls in libv4l2 was Re: support autofocus / autogain in libv4l2 Pavel Machek
2017-04-26 11:26 ` Mauro Carvalho Chehab
2017-04-29 9:19 ` Pavel Machek
[not found] ` <20171021220026.GA26881@amd>
2017-10-22 7:36 ` Camera support, Prague next week, sdlcam Hans Verkuil
2017-10-22 8:31 ` Pavel Machek
2017-10-23 18:54 ` Pavel Machek
2017-10-23 19:24 ` Hans Verkuil
2017-10-23 20:15 ` Sakari Ailus
2017-10-23 21:02 ` Mauro Carvalho Chehab
[not found] ` <20171031212812.GA11148@amd>
2017-11-01 6:36 ` Nokia N9: fun with camera Pavel Machek
2017-11-01 15:32 ` Pavel Machek
2017-04-24 22:07 ` support autofocus / autogain in libv4l2 Pavel Machek
2017-04-25 1:57 ` Mauro Carvalho Chehab
2017-04-25 8:20 ` Pavel Machek
2017-04-25 11:23 ` Pavel Machek
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