libcamera: ipa: Raspberry Pi IPA

Initial implementation of the Raspberry Pi (BCM2835) libcamera IPA and
associated libraries.

All code is licensed under the BSD-2-Clause terms.
Copyright (c) 2019-2020 Raspberry Pi Trading Ltd.

Signed-off-by: Naushir Patuck <naush@raspberrypi.com>
Acked-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>

1 files changed, 89 insertions, 0 deletions

diff --git a/src/ipa/raspberrypi/cam_helper_ov5647.cpp b/src/ipa/raspberrypi/cam_helper_ov5647.cpp
new file mode 100644
index 00000000..3dbcb164
--- /dev/null
+++ b/src/ipa/raspberrypi/cam_helper_ov5647.cpp
@@ -0,0 +1,89 @@
+/* SPDX-License-Identifier: BSD-2-Clause */
+/*
+ * Copyright (C) 2019, Raspberry Pi (Trading) Limited
+ *
+ * cam_helper_ov5647.cpp - camera information for ov5647 sensor
+ */
+
+#include <assert.h>
+
+#include "cam_helper.hpp"
+#include "md_parser_rpi.hpp"
+
+using namespace RPi;
+
+class CamHelperOv5647 : public CamHelper
+{
+public:
+	CamHelperOv5647();
+	uint32_t GainCode(double gain) const override;
+	double Gain(uint32_t gain_code) const override;
+	void GetDelays(int &exposure_delay, int &gain_delay) const override;
+	unsigned int HideFramesModeSwitch() const override;
+	unsigned int MistrustFramesStartup() const override;
+	unsigned int MistrustFramesModeSwitch() const override;
+};
+
+/*
+ * OV5647 doesn't output metadata, so we have to use the "unicam parser" which
+ * works by counting frames.
+ */
+
+CamHelperOv5647::CamHelperOv5647()
+	: CamHelper(new MdParserRPi())
+{
+}
+
+uint32_t CamHelperOv5647::GainCode(double gain) const
+{
+	return static_cast<uint32_t>(gain * 16.0);
+}
+
+double CamHelperOv5647::Gain(uint32_t gain_code) const
+{
+	return static_cast<double>(gain_code) / 16.0;
+}
+
+void CamHelperOv5647::GetDelays(int &exposure_delay, int &gain_delay) const
+{
+	/*
+	 * We run this sensor in a mode where the gain delay is bumped up to
+	 * 2. It seems to be the only way to make the delays "predictable".
+	 */
+	exposure_delay = 2;
+	gain_delay = 2;
+}
+
+unsigned int CamHelperOv5647::HideFramesModeSwitch() const
+{
+	/*
+	 * After a mode switch, we get a couple of under-exposed frames which
+	 * we don't want shown.
+	 */
+	return 2;
+}
+
+unsigned int CamHelperOv5647::MistrustFramesStartup() const
+{
+	/*
+	 * First couple of frames are under-exposed and are no good for control
+	 * algos.
+	 */
+	return 2;
+}
+
+unsigned int CamHelperOv5647::MistrustFramesModeSwitch() const
+{
+	/*
+	 * First couple of frames are under-exposed even after a simple
+	 * mode switch, and are no good for control algos.
+	 */
+	return 2;
+}
+
+static CamHelper *Create()
+{
+	return new CamHelperOv5647();
+}
+
+static RegisterCamHelper reg("ov5647", &Create);