pipeline: ipa: raspberrypi: Refactor and move the Raspberry Pi code

Split the Raspberry Pi pipeline handler and IPA source code into common
and VC4/BCM2835 specific file structures.

For the pipeline handler, the common code files now live in
src/libcamera/pipeline/rpi/common/
and the VC4-specific files in src/libcamera/pipeline/rpi/vc4/.

For the IPA, the common code files now live in
src/ipa/rpi/{cam_helper,controller}/
and the vc4 specific files in src/ipa/rpi/vc4/. With this change, the
camera tuning files are now installed under share/libcamera/ipa/rpi/vc4/.

To build the pipeline and IPA, the meson configuration options have now
changed from "raspberrypi" to "rpi/vc4":

meson setup build -Dipas=rpi/vc4 -Dpipelines=rpi/vc4

Signed-off-by: Naushir Patuck <naush@raspberrypi.com>
Reviewed-by: Jacopo Mondi <jacopo.mondi@ideasonboard.com>
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>

1 files changed, 53 insertions, 0 deletions

diff --git a/src/ipa/rpi/controller/histogram.h b/src/ipa/rpi/controller/histogram.h
new file mode 100644
index 00000000..6b3e3a9e
--- /dev/null
+++ b/src/ipa/rpi/controller/histogram.h
@@ -0,0 +1,53 @@
+/* SPDX-License-Identifier: BSD-2-Clause */
+/*
+ * Copyright (C) 2019, Raspberry Pi Ltd
+ *
+ * histogram.h - histogram calculation interface
+ */
+#pragma once
+
+#include <stdint.h>
+#include <vector>
+#include <cassert>
+
+/*
+ * A simple histogram class, for use in particular to find "quantiles" and
+ * averages between "quantiles".
+ */
+
+namespace RPiController {
+
+class Histogram
+{
+public:
+	Histogram()
+	{
+		cumulative_.push_back(0);
+	}
+
+	template<typename T> Histogram(T *histogram, int num)
+	{
+		assert(num);
+		cumulative_.reserve(num + 1);
+		cumulative_.push_back(0);
+		for (int i = 0; i < num; i++)
+			cumulative_.push_back(cumulative_.back() +
+					      histogram[i]);
+	}
+	uint32_t bins() const { return cumulative_.size() - 1; }
+	uint64_t total() const { return cumulative_[cumulative_.size() - 1]; }
+	/* Cumulative frequency up to a (fractional) point in a bin. */
+	uint64_t cumulativeFreq(double bin) const;
+	/*
+	 * Return the (fractional) bin of the point q (0 <= q <= 1) through the
+	 * histogram. Optionally provide limits to help.
+	 */
+	double quantile(double q, int first = -1, int last = -1) const;
+	/* Return the average histogram bin value between the two quantiles. */
+	double interQuantileMean(double qLo, double qHi) const;
+
+private:
+	std::vector<uint64_t> cumulative_;
+};
+
+} /* namespace RPiController */