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authorNaushir Patuck <naush@raspberrypi.com>2020-11-26 10:49:49 +0000
committerLaurent Pinchart <laurent.pinchart@ideasonboard.com>2022-03-23 01:50:14 +0200
commitf687116904001cf9189bdf878d7c1e60b209c26a (patch)
treea54b24a1cd139ce4c8b4fb92c6a7fd913b08f2eb /src/ipa/raspberrypi/cam_helper_imx296.cpp
parent3dc81300c73be0e406ce702811ba2b5dc5b516e2 (diff)
ipa: raspberrypi: Add camera helper for Sony IMX296 sensor
The Sony IMX296 sensor has an exponential gain model, and adds a fixed 14.26µs offset to the exposure time expressed in line units. Signed-off-by: Naushir Patuck <naush@raspberrypi.com> Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com> Reviewed-by: Naushir Patuck <naush@raspberrypi.com> Reviewed-by: Kieran Bingham <kieran.bingham@ideasonboard.com>
Diffstat (limited to 'src/ipa/raspberrypi/cam_helper_imx296.cpp')
-rw-r--r--src/ipa/raspberrypi/cam_helper_imx296.cpp69
1 files changed, 69 insertions, 0 deletions
diff --git a/src/ipa/raspberrypi/cam_helper_imx296.cpp b/src/ipa/raspberrypi/cam_helper_imx296.cpp
new file mode 100644
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+++ b/src/ipa/raspberrypi/cam_helper_imx296.cpp
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+/* SPDX-License-Identifier: BSD-2-Clause */
+/*
+ * Copyright (C) 2020, Raspberry Pi (Trading) Limited
+ *
+ * cam_helper_imx296.cpp - Camera helper for IMX296 sensor
+ */
+
+#include <algorithm>
+#include <cmath>
+#include <stddef.h>
+
+#include "cam_helper.hpp"
+
+using namespace RPiController;
+using libcamera::utils::Duration;
+using namespace std::literals::chrono_literals;
+
+class CamHelperImx296 : public CamHelper
+{
+public:
+ CamHelperImx296();
+ uint32_t GainCode(double gain) const override;
+ double Gain(uint32_t gain_code) const override;
+ uint32_t ExposureLines(Duration exposure) const override;
+ Duration Exposure(uint32_t exposure_lines) const override;
+
+private:
+ static constexpr uint32_t maxGainCode = 239;
+ static constexpr Duration timePerLine = 550.0 / 37.125e6 * 1.0s;
+
+ /*
+ * Smallest difference between the frame length and integration time,
+ * in units of lines.
+ */
+ static constexpr int frameIntegrationDiff = 4;
+};
+
+CamHelperImx296::CamHelperImx296()
+ : CamHelper(nullptr, frameIntegrationDiff)
+{
+}
+
+uint32_t CamHelperImx296::GainCode(double gain) const
+{
+ uint32_t code = 20 * std::log10(gain) * 10;
+ return std::min(code, maxGainCode);
+}
+
+double CamHelperImx296::Gain(uint32_t gain_code) const
+{
+ return std::pow(10.0, gain_code / 200.0);
+}
+
+uint32_t CamHelperImx296::ExposureLines(Duration exposure) const
+{
+ return (exposure - 14.26us) / timePerLine;
+}
+
+Duration CamHelperImx296::Exposure(uint32_t exposure_lines) const
+{
+ return exposure_lines * timePerLine + 14.26us;
+}
+
+static CamHelper *Create()
+{
+ return new CamHelperImx296();
+}
+
+static RegisterCamHelper reg("imx296", &Create);