[libcamera-devel] [PATCH v3 3/3] libcamera: ipa: raspberrypi: Add support for ov9281 sensor

David Plowman david.plowman at raspberrypi.com
Mon Jun 28 08:47:39 CEST 2021


Hi Laurent

Thanks for the comments.

On Mon, 28 Jun 2021 at 07:17, Laurent Pinchart
<laurent.pinchart at ideasonboard.com> wrote:
>
> Hi David,
>
> Thank you for the patch.
>
> On Fri, Jun 18, 2021 at 11:04:30PM +0100, David Plowman wrote:
> > The necessary tuning file and CamHelper is added for the ov9281 sensor
> > (which the driver names as the "mov9281").
>
> This bothers me a little bit, as it will likely need to be renamed to
> ov9281 when upstreaming. Why is there an "m" prefix, and could it be
> dropped ?

Yes, I'm suspicious that the "m" is actually a reference to "mono",
thereby opening the way for colour versions of this sensor. In fact it
would be helpful for the driver to advertise a different name in such
cases so that a more appropriate tuning file can be identified (though
as we know, that still isn't really good enough...!) But maybe
something a little less cryptic than just "m" would help?

Best regards
David

>
> > The ov9281 is a 1280x800 monochrome global shutter sensor. To enable
> > it, please add
> >
> > dtoverlay=ov9281
> >
> > to the /boot/config.txt file and reboot the Pi.
> >
> > Signed-off-by: David Plowman <david.plowman at raspberrypi.com>
> > Reviewed-by: Naushir Patuck <naush at raspberrypi.com>
> > ---
> >  src/ipa/raspberrypi/cam_helper_mov9281.cpp | 65 +++++++++++++++
> >  src/ipa/raspberrypi/data/meson.build       |  1 +
> >  src/ipa/raspberrypi/data/mov9281.json      | 92 ++++++++++++++++++++++
> >  src/ipa/raspberrypi/meson.build            |  1 +
> >  4 files changed, 159 insertions(+)
> >  create mode 100644 src/ipa/raspberrypi/cam_helper_mov9281.cpp
> >  create mode 100644 src/ipa/raspberrypi/data/mov9281.json
> >
> > diff --git a/src/ipa/raspberrypi/cam_helper_mov9281.cpp b/src/ipa/raspberrypi/cam_helper_mov9281.cpp
> > new file mode 100644
> > index 00000000..29519cb0
> > --- /dev/null
> > +++ b/src/ipa/raspberrypi/cam_helper_mov9281.cpp
> > @@ -0,0 +1,65 @@
> > +/* SPDX-License-Identifier: BSD-2-Clause */
> > +/*
> > + * Copyright (C) 2021, Raspberry Pi (Trading) Limited
> > + *
> > + * cam_helper_mov9281.cpp - camera information for ov9281 sensor
> > + */
> > +
> > +#include <assert.h>
> > +
> > +#include "cam_helper.hpp"
> > +
> > +using namespace RPiController;
> > +
> > +class CamHelperOv9281 : public CamHelper
> > +{
> > +public:
> > +     CamHelperOv9281();
> > +     uint32_t GainCode(double gain) const override;
> > +     double Gain(uint32_t gain_code) const override;
> > +     void GetDelays(int &exposure_delay, int &gain_delay,
> > +                    int &vblank_delay) const override;
> > +
> > +private:
> > +     /*
> > +      * Smallest difference between the frame length and integration time,
> > +      * in units of lines.
> > +      */
> > +     static constexpr int frameIntegrationDiff = 4;
> > +};
> > +
> > +/*
> > + * OV9281 doesn't output metadata, so we have to use the "unicam parser" which
> > + * works by counting frames.
> > + */
> > +
> > +CamHelperOv9281::CamHelperOv9281()
> > +     : CamHelper(nullptr, frameIntegrationDiff)
> > +{
> > +}
> > +
> > +uint32_t CamHelperOv9281::GainCode(double gain) const
> > +{
> > +     return static_cast<uint32_t>(gain * 16.0);
> > +}
> > +
> > +double CamHelperOv9281::Gain(uint32_t gain_code) const
> > +{
> > +     return static_cast<double>(gain_code) / 16.0;
> > +}
> > +
> > +void CamHelperOv9281::GetDelays(int &exposure_delay, int &gain_delay,
> > +                             int &vblank_delay) const
> > +{
> > +     /* The driver appears to behave as follows: */
> > +     exposure_delay = 2;
> > +     gain_delay = 2;
> > +     vblank_delay = 2;
> > +}
> > +
> > +static CamHelper *Create()
> > +{
> > +     return new CamHelperOv9281();
> > +}
> > +
> > +static RegisterCamHelper reg("mov9281", &Create);
> > diff --git a/src/ipa/raspberrypi/data/meson.build b/src/ipa/raspberrypi/data/meson.build
> > index 92ad3272..f8baab6d 100644
> > --- a/src/ipa/raspberrypi/data/meson.build
> > +++ b/src/ipa/raspberrypi/data/meson.build
> > @@ -4,6 +4,7 @@ conf_files = files([
> >      'imx219.json',
> >      'imx290.json',
> >      'imx477.json',
> > +    'mov9281.json',
> >      'ov5647.json',
> >      'se327m12.json',
> >      'uncalibrated.json',
> > diff --git a/src/ipa/raspberrypi/data/mov9281.json b/src/ipa/raspberrypi/data/mov9281.json
> > new file mode 100644
> > index 00000000..ecd262be
> > --- /dev/null
> > +++ b/src/ipa/raspberrypi/data/mov9281.json
> > @@ -0,0 +1,92 @@
> > +{
> > +    "rpi.black_level":
> > +    {
> > +        "black_level": 4096
> > +    },
> > +    "rpi.lux":
> > +    {
> > +        "reference_shutter_speed": 2000,
> > +        "reference_gain": 1.0,
> > +        "reference_aperture": 1.0,
> > +        "reference_lux": 800,
> > +        "reference_Y": 20000
> > +    },
> > +    "rpi.noise":
> > +    {
> > +        "reference_constant": 0,
> > +        "reference_slope": 2.5
> > +    },
> > +    "rpi.sdn":
> > +    {
> > +    },
> > +    "rpi.agc":
> > +    {
> > +        "metering_modes":
> > +        {
> > +            "centre-weighted": {
> > +                "weights": [4, 4, 4, 2, 2, 2, 2, 1, 1, 1, 1, 0, 0, 0, 0]
> > +            }
> > +        },
> > +        "exposure_modes":
> > +        {
> > +            "normal":
> > +            {
> > +                "shutter": [ 100, 15000, 30000, 60000, 120000 ],
> > +                "gain":    [ 1.0, 2.0,   3.0,   4.0,   6.0    ]
> > +            }
> > +        },
> > +        "constraint_modes":
> > +        {
> > +            "normal":
> > +            [
> > +                { "bound": "LOWER", "q_lo": 0.98, "q_hi": 1.0, "y_target": [ 0, 0.4, 1000, 0.4 ] }
> > +            ]
> > +        },
> > +        "y_target": [ 0, 0.16, 1000, 0.165, 10000, 0.17 ]
> > +    },
> > +    "rpi.alsc":
> > +    {
> > +        "n_iter": 0,
> > +        "luminance_strength": 1.0,
> > +        "corner_strength": 1.5
> > +    },
> > +    "rpi.contrast":
> > +    {
> > +        "ce_enable": 0,
> > +        "gamma_curve": [
> > +            0,     0,
> > +            1024,  5040,
> > +            2048,  9338,
> > +            3072,  12356,
> > +            4096,  15312,
> > +            5120,  18051,
> > +            6144,  20790,
> > +            7168,  23193,
> > +            8192,  25744,
> > +            9216,  27942,
> > +            10240, 30035,
> > +            11264, 32005,
> > +            12288, 33975,
> > +            13312, 35815,
> > +            14336, 37600,
> > +            15360, 39168,
> > +            16384, 40642,
> > +            18432, 43379,
> > +            20480, 45749,
> > +            22528, 47753,
> > +            24576, 49621,
> > +            26624, 51253,
> > +            28672, 52698,
> > +            30720, 53796,
> > +            32768, 54876,
> > +            36864, 57012,
> > +            40960, 58656,
> > +            45056, 59954,
> > +            49152, 61183,
> > +            53248, 62355,
> > +            57344, 63419,
> > +            61440, 64476,
> > +            65535, 65535
> > +        ]
> > +    }
> > +}
> > diff --git a/src/ipa/raspberrypi/meson.build b/src/ipa/raspberrypi/meson.build
> > index 230356d3..93f04e9e 100644
> > --- a/src/ipa/raspberrypi/meson.build
> > +++ b/src/ipa/raspberrypi/meson.build
> > @@ -22,6 +22,7 @@ rpi_ipa_sources = files([
> >      'cam_helper_imx219.cpp',
> >      'cam_helper_imx290.cpp',
> >      'cam_helper_imx477.cpp',
> > +    'cam_helper_mov9281.cpp',
> >      'controller/controller.cpp',
> >      'controller/histogram.cpp',
> >      'controller/algorithm.cpp',
>
> --
> Regards,
>
> Laurent Pinchart


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