libcamera: software_isp: Move benchmark code to its own class

Move the code for the builtin benchmark to its own small
Benchmark class.

Reviewed-by: Kieran Bingham <kieran.bingham@ideasonboard.com>
Reviewed-by: Milan Zamazal <mzamazal@redhat.com>
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
[bod: Fixed up some drift in this patch since initial propostion]
Signed-off-by: Bryan O'Donoghue <bryan.odonoghue@linaro.org>
Signed-off-by: Kieran Bingham <kieran.bingham@ideasonboard.com>

include/libcamera/internal/software_isp/benchmark.h

@@ -0,0 +1,39 @@
+/* SPDX-License-Identifier: LGPL-2.1-or-later */
+/*
+ * Copyright (C) 2024, Red Hat Inc.
+ *
+ * Authors:
+ * Hans de Goede <hdegoede@redhat.com>
+ *
+ * Simple builtin benchmark to measure software ISP processing times
+ */
+
+#pragma once
+
+#include <stdint.h>
+#include <time.h>
+#include <libcamera/base/log.h>
+#include "libcamera/internal/global_configuration.h"
+
+namespace libcamera {
+
+class Benchmark
+{
+public:
+	Benchmark(const GlobalConfiguration &configuration);
+	~Benchmark();
+
+	void startFrame(void);
+	void finishFrame(void);
+
+private:
+	timespec frameStartTime_;
+	bool measure;
+	/* Skip 30 frames for things to stabilize then measure 30 frames */
+	unsigned int encounteredFrames_ = 0;
+	int64_t frameProcessTime_ = 0;
+	unsigned int skipBeforeMeasure_ = 30;
+	unsigned int framesToMeasure_ = 30;
+};
+
+} /* namespace libcamera */

include/libcamera/internal/software_isp/meson.build

@@ -1,6 +1,7 @@
 # SPDX-License-Identifier: CC0-1.0
 
 libcamera_internal_headers += files([
+    'benchmark.h',
     'debayer_params.h',
     'software_isp.h',
     'swisp_stats.h',