[v2,2/2] ipa: rpi: Add cam_helper for Sony IMX678

26994 diff mbox series

From: will whang <will@willwhang.com>

This adds a basic cam helper for Sony IMX678, modelling the gain curve
and the sensor limits for the maximum exposure time.

Link: https://github.com/will127534/libcamera/commit/619459e7c70306ba18476
Signed-off-by: will whang <will@willwhang.com>
Co-developed-by: Jai Luthra <jai.luthra@ideasonboard.com>
Signed-off-by: Jai Luthra <jai.luthra@ideasonboard.com>
---
Changes in v2:
- Drop hideFramesStartup() and hideFramesModeSwitch()
- Use std::pow() instead of pow()
- Drop unnecessary includes, and include <algorithm> and <cmath> for
  std::pow and std::min/max
- Reword comment for embedded data, as the sensor supports it but the
  driver currently does not
- Cleanup more issues with whitespace
- Add a Co-developed-by tag now that it's not a complete copy-paste
- Update commit message
---
 src/ipa/rpi/cam_helper/cam_helper_imx678.cpp | 56 ++++++++++++++++++++++++++++
 src/ipa/rpi/cam_helper/meson.build           |  1 +
 2 files changed, 57 insertions(+)

Quoting Jai Luthra (2026-06-18 15:56:42)
> From: will whang <will@willwhang.com>
> 
> This adds a basic cam helper for Sony IMX678, modelling the gain curve
> and the sensor limits for the maximum exposure time.
> 
> Link: https://github.com/will127534/libcamera/commit/619459e7c70306ba18476
> Signed-off-by: will whang <will@willwhang.com>
> Co-developed-by: Jai Luthra <jai.luthra@ideasonboard.com>
> Signed-off-by: Jai Luthra <jai.luthra@ideasonboard.com>

We're in RPi IPA space here, so I've added Naush for consideration, but
you've tackled my concerns, Thanks.

Reviewed-by: Kieran Bingham <kieran.bingham@ideasonboard.com>

> ---
> Changes in v2:
> - Drop hideFramesStartup() and hideFramesModeSwitch()
> - Use std::pow() instead of pow()
> - Drop unnecessary includes, and include <algorithm> and <cmath> for
>   std::pow and std::min/max
> - Reword comment for embedded data, as the sensor supports it but the
>   driver currently does not
> - Cleanup more issues with whitespace
> - Add a Co-developed-by tag now that it's not a complete copy-paste
> - Update commit message
> ---
>  src/ipa/rpi/cam_helper/cam_helper_imx678.cpp | 56 ++++++++++++++++++++++++++++
>  src/ipa/rpi/cam_helper/meson.build           |  1 +
>  2 files changed, 57 insertions(+)
> 
> diff --git a/src/ipa/rpi/cam_helper/cam_helper_imx678.cpp b/src/ipa/rpi/cam_helper/cam_helper_imx678.cpp
> new file mode 100644
> index 000000000..916433bf6
> --- /dev/null
> +++ b/src/ipa/rpi/cam_helper/cam_helper_imx678.cpp
> @@ -0,0 +1,56 @@
> +/* SPDX-License-Identifier: BSD-2-Clause */
> +/*
> + * Copyright (C) 2026, Will Whang
> + *
> + * cam_helper_imx678.cpp - camera information for Sony IMX678 sensor
> + */
> +
> +#include <algorithm>
> +#include <cmath>
> +
> +#include "cam_helper.h"
> +
> +using namespace RPiController;
> +
> +class CamHelperImx678 : public CamHelper
> +{
> +public:
> +       CamHelperImx678();
> +       uint32_t gainCode(double gain) const override;
> +       double gain(uint32_t gainCode) const override;
> +
> +private:
> +       /*
> +        * Smallest difference between the frame length and integration time,
> +        * in units of lines.
> +        */
> +       static constexpr int frameIntegrationDiff = 4;
> +};
> +
> +/*
> + * IMX678 driver currently doesn't expose a metadata stream, so we have to use
> + * the "unicam parser" which works by counting frames.
> + */
> +
> +CamHelperImx678::CamHelperImx678()
> +       : CamHelper({}, frameIntegrationDiff)
> +{
> +}
> +
> +uint32_t CamHelperImx678::gainCode(double gain) const
> +{
> +       int code = 66.6667 * log10(gain);
> +       return std::max(0, std::min(code, 0xf0));
> +}
> +
> +double CamHelperImx678::gain(uint32_t gainCode) const
> +{
> +       return std::pow(10, 0.015 * gainCode);
> +}
> +
> +static CamHelper *create()
> +{
> +       return new CamHelperImx678();
> +}
> +
> +static RegisterCamHelper reg("imx678", &create);
> diff --git a/src/ipa/rpi/cam_helper/meson.build b/src/ipa/rpi/cam_helper/meson.build
> index 87b6a3600..eabd55dce 100644
> --- a/src/ipa/rpi/cam_helper/meson.build
> +++ b/src/ipa/rpi/cam_helper/meson.build
> @@ -10,6 +10,7 @@ rpi_ipa_cam_helper_sources = files([
>      'cam_helper_imx415.cpp',
>      'cam_helper_imx477.cpp',
>      'cam_helper_imx519.cpp',
> +    'cam_helper_imx678.cpp',
>      'cam_helper_imx708.cpp',
>      'cam_helper_ov64a40.cpp',
>      'cam_helper_ov7251.cpp',
> 
> -- 
> 2.54.0
>

On Thu, Jun 18, 2026 at 08:26:42PM +0530, Jai Luthra wrote:
> From: will whang <will@willwhang.com>
> 
> This adds a basic cam helper for Sony IMX678, modelling the gain curve
> and the sensor limits for the maximum exposure time.
> 
> Link: https://github.com/will127534/libcamera/commit/619459e7c70306ba18476
> Signed-off-by: will whang <will@willwhang.com>
> Co-developed-by: Jai Luthra <jai.luthra@ideasonboard.com>
> Signed-off-by: Jai Luthra <jai.luthra@ideasonboard.com>

Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>

> ---
> Changes in v2:
> - Drop hideFramesStartup() and hideFramesModeSwitch()
> - Use std::pow() instead of pow()
> - Drop unnecessary includes, and include <algorithm> and <cmath> for
>   std::pow and std::min/max
> - Reword comment for embedded data, as the sensor supports it but the
>   driver currently does not
> - Cleanup more issues with whitespace
> - Add a Co-developed-by tag now that it's not a complete copy-paste
> - Update commit message
> ---
>  src/ipa/rpi/cam_helper/cam_helper_imx678.cpp | 56 ++++++++++++++++++++++++++++
>  src/ipa/rpi/cam_helper/meson.build           |  1 +
>  2 files changed, 57 insertions(+)
> 
> diff --git a/src/ipa/rpi/cam_helper/cam_helper_imx678.cpp b/src/ipa/rpi/cam_helper/cam_helper_imx678.cpp
> new file mode 100644
> index 000000000..916433bf6
> --- /dev/null
> +++ b/src/ipa/rpi/cam_helper/cam_helper_imx678.cpp
> @@ -0,0 +1,56 @@
> +/* SPDX-License-Identifier: BSD-2-Clause */
> +/*
> + * Copyright (C) 2026, Will Whang
> + *
> + * cam_helper_imx678.cpp - camera information for Sony IMX678 sensor
> + */
> +
> +#include <algorithm>
> +#include <cmath>
> +
> +#include "cam_helper.h"
> +
> +using namespace RPiController;
> +
> +class CamHelperImx678 : public CamHelper
> +{
> +public:
> +	CamHelperImx678();
> +	uint32_t gainCode(double gain) const override;
> +	double gain(uint32_t gainCode) const override;
> +
> +private:
> +	/*
> +	 * Smallest difference between the frame length and integration time,
> +	 * in units of lines.
> +	 */
> +	static constexpr int frameIntegrationDiff = 4;
> +};
> +
> +/*
> + * IMX678 driver currently doesn't expose a metadata stream, so we have to use
> + * the "unicam parser" which works by counting frames.
> + */
> +
> +CamHelperImx678::CamHelperImx678()
> +	: CamHelper({}, frameIntegrationDiff)
> +{
> +}
> +
> +uint32_t CamHelperImx678::gainCode(double gain) const
> +{
> +	int code = 66.6667 * log10(gain);
> +	return std::max(0, std::min(code, 0xf0));
> +}
> +
> +double CamHelperImx678::gain(uint32_t gainCode) const
> +{
> +	return std::pow(10, 0.015 * gainCode);
> +}
> +
> +static CamHelper *create()
> +{
> +	return new CamHelperImx678();
> +}
> +
> +static RegisterCamHelper reg("imx678", &create);
> diff --git a/src/ipa/rpi/cam_helper/meson.build b/src/ipa/rpi/cam_helper/meson.build
> index 87b6a3600..eabd55dce 100644
> --- a/src/ipa/rpi/cam_helper/meson.build
> +++ b/src/ipa/rpi/cam_helper/meson.build
> @@ -10,6 +10,7 @@ rpi_ipa_cam_helper_sources = files([
>      'cam_helper_imx415.cpp',
>      'cam_helper_imx477.cpp',
>      'cam_helper_imx519.cpp',
> +    'cam_helper_imx678.cpp',
>      'cam_helper_imx708.cpp',
>      'cam_helper_ov64a40.cpp',
>      'cam_helper_ov7251.cpp',