summaryrefslogtreecommitdiff
path: root/test/shared-fd.cpp
blob: 997d7be18c47d2930e08ce5046b1d66367ce126f (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
/* SPDX-License-Identifier: GPL-2.0-or-later */
/*
 * Copyright (C) 2019, Google Inc.
 *
 * shared_fd.cpp - SharedFD test
 */

#include <fcntl.h>
#include <iostream>
#include <sys/stat.h>
#include <sys/types.h>
#include <unistd.h>

#include <libcamera/base/shared_fd.h>
#include <libcamera/base/utils.h>

#include "test.h"

using namespace libcamera;
using namespace std;

class SharedFDTest : public Test
{
protected:
	int init()
	{
		desc1_ = nullptr;
		desc2_ = nullptr;

		fd_ = open("/tmp", O_TMPFILE | O_RDWR, S_IRUSR | S_IWUSR);
		if (fd_ < 0)
			return TestFail;

		/* Cache inode number of temp file. */
		struct stat s;
		if (fstat(fd_, &s))
			return TestFail;

		inodeNr_ = s.st_ino;

		return 0;
	}

	int run()
	{
		/* Test creating empty SharedFD. */
		desc1_ = new SharedFD();

		if (desc1_->get() != -1) {
			std::cout << "Failed fd numerical check (default constructor)"
				  << std::endl;
			return TestFail;
		}

		delete desc1_;
		desc1_ = nullptr;

		/*
		 * Test creating SharedFD by copying numerical file
		 * descriptor.
		 */
		desc1_ = new SharedFD(fd_);
		if (desc1_->get() == fd_) {
			std::cout << "Failed fd numerical check (lvalue ref constructor)"
				  << std::endl;
			return TestFail;
		}

		if (!isValidFd(fd_) || !isValidFd(desc1_->get())) {
			std::cout << "Failed fd validity after construction (lvalue ref constructor)"
				  << std::endl;
			return TestFail;
		}

		int fd = desc1_->get();

		delete desc1_;
		desc1_ = nullptr;

		if (!isValidFd(fd_) || isValidFd(fd)) {
			std::cout << "Failed fd validity after destruction (lvalue ref constructor)"
				  << std::endl;
			return TestFail;
		}

		/*
		 * Test creating SharedFD by taking ownership of
		 * numerical file descriptor.
		 */
		int dupFd = dup(fd_);
		int dupFdCopy = dupFd;

		desc1_ = new SharedFD(std::move(dupFd));
		if (desc1_->get() != dupFdCopy) {
			std::cout << "Failed fd numerical check (rvalue ref constructor)"
				  << std::endl;
			return TestFail;
		}

		if (dupFd != -1 || !isValidFd(fd_) || !isValidFd(desc1_->get())) {
			std::cout << "Failed fd validity after construction (rvalue ref constructor)"
				  << std::endl;
			return TestFail;
		}

		fd = desc1_->get();

		delete desc1_;
		desc1_ = nullptr;

		if (!isValidFd(fd_) || isValidFd(fd)) {
			std::cout << "Failed fd validity after destruction (rvalue ref constructor)"
				  << std::endl;
			return TestFail;
		}

		/* Test creating SharedFD from other SharedFD. */
		desc1_ = new SharedFD(fd_);
		desc2_ = new SharedFD(*desc1_);

		if (desc1_->get() == fd_ || desc2_->get() == fd_ ||
		    desc1_->get() != desc2_->get()) {
			std::cout << "Failed fd numerical check (copy constructor)"
				  << std::endl;
			return TestFail;
		}

		if (!isValidFd(desc1_->get()) || !isValidFd(desc2_->get())) {
			std::cout << "Failed fd validity after construction (copy constructor)"
				  << std::endl;
			return TestFail;
		}

		delete desc1_;
		desc1_ = nullptr;

		if (!isValidFd(desc2_->get())) {
			std::cout << "Failed fd validity after destruction (copy constructor)"
				  << std::endl;
			return TestFail;
		}

		delete desc2_;
		desc2_ = nullptr;

		/* Test creating SharedFD by taking over other SharedFD. */
		desc1_ = new SharedFD(fd_);
		fd = desc1_->get();
		desc2_ = new SharedFD(std::move(*desc1_));

		if (desc1_->get() != -1 || desc2_->get() != fd) {
			std::cout << "Failed fd numerical check (move constructor)"
				  << std::endl;
			return TestFail;
		}

		if (!isValidFd(desc2_->get())) {
			std::cout << "Failed fd validity after construction (move constructor)"
				  << std::endl;
			return TestFail;
		}

		delete desc1_;
		desc1_ = nullptr;
		delete desc2_;
		desc2_ = nullptr;

		/* Test creating SharedFD by copy assignment. */
		desc1_ = new SharedFD();
		desc2_ = new SharedFD(fd_);

		fd = desc2_->get();
		*desc1_ = *desc2_;

		if (desc1_->get() != fd || desc2_->get() != fd) {
			std::cout << "Failed fd numerical check (copy assignment)"
				  << std::endl;
			return TestFail;
		}

		if (!isValidFd(desc1_->get()) || !isValidFd(desc2_->get())) {
			std::cout << "Failed fd validity after construction (copy assignment)"
				  << std::endl;
			return TestFail;
		}

		delete desc1_;
		desc1_ = nullptr;
		delete desc2_;
		desc2_ = nullptr;

		/* Test creating SharedFD by move assignment. */
		desc1_ = new SharedFD();
		desc2_ = new SharedFD(fd_);

		fd = desc2_->get();
		*desc1_ = std::move(*desc2_);

		if (desc1_->get() != fd || desc2_->get() != -1) {
			std::cout << "Failed fd numerical check (move assignment)"
				  << std::endl;
			return TestFail;
		}

		if (!isValidFd(desc1_->get())) {
			std::cout << "Failed fd validity after construction (move assignment)"
				  << std::endl;
			return TestFail;
		}

		delete desc1_;
		desc1_ = nullptr;
		delete desc2_;
		desc2_ = nullptr;

		return TestPass;
	}

	void cleanup()
	{
		delete desc2_;
		delete desc1_;

		if (fd_ > 0)
			close(fd_);
	}

private:
	bool isValidFd(int fd)
	{
		struct stat s;
		if (fstat(fd, &s))
			return false;

		/* Check that inode number matches cached temp file. */
		return s.st_ino == inodeNr_;
	}

	int fd_;
	ino_t inodeNr_;
	SharedFD *desc1_, *desc2_;
};

TEST_REGISTER(SharedFDTest)
9 860 861 862 863 864 865 866 867 868 869 870 871 872 873 874 875 876 877 878 879 880 881 882 883 884 885 886 887 888 889 890 891 892 893 894 895 896 897 898 899 900 901 902 903 904 905 906 907 908 909 910 911 912 913 914 915 916 917 918 919 920 921 922 923 924 925 926 927 928 929 930 931 932 933 934 935 936 937 938 939 940 941 942 943 944 945 946 947 948 949 950 951 952 953 954 955 956 957 958 959 960 961 962 963 964 965 966 967 968 969 970 971 972 973 974 975 976 977 978 979 980 981 982 983 984 985 986 987 988 989 990 991 992 993 994 995 996 997 998 999 1000 1001 1002 1003 1004 1005 1006 1007 1008 1009 1010 1011 1012 1013 1014 1015 1016 1017 1018 1019 1020 1021 1022 1023 1024 1025 1026 1027 1028 1029 1030 1031 1032 1033 1034 1035 1036 1037 1038 1039 1040 1041 1042 1043 1044 1045 1046 1047 1048 1049 1050 1051 1052 1053 1054 1055 1056 1057 1058 1059 1060 1061 1062 1063 1064 1065 1066 1067 1068 1069 1070 1071 1072 1073 1074 1075 1076 1077 1078 1079 1080 1081 1082 1083 1084 1085 1086 1087 1088
/* SPDX-License-Identifier: BSD-2-Clause */
/*
 * Copyright (C) 2019-2020, Raspberry Pi (Trading) Ltd.
 *
 * rpi.cpp - Raspberry Pi Image Processing Algorithms
 */

#include <algorithm>
#include <fcntl.h>
#include <math.h>
#include <stdint.h>
#include <string.h>
#include <sys/mman.h>

#include <ipa/ipa_interface.h>
#include <ipa/ipa_module_info.h>
#include <ipa/raspberrypi.h>
#include <libcamera/buffer.h>
#include <libcamera/control_ids.h>
#include <libcamera/controls.h>
#include <libcamera/request.h>
#include <libcamera/span.h>
#include <libipa/ipa_interface_wrapper.h>

#include <linux/bcm2835-isp.h>

#include "agc_algorithm.hpp"
#include "agc_status.h"
#include "alsc_status.h"
#include "awb_algorithm.hpp"
#include "awb_status.h"
#include "black_level_status.h"
#include "cam_helper.hpp"
#include "ccm_algorithm.hpp"
#include "ccm_status.h"
#include "contrast_algorithm.hpp"
#include "contrast_status.h"
#include "controller.hpp"
#include "dpc_status.h"
#include "geq_status.h"
#include "lux_status.h"
#include "metadata.hpp"
#include "noise_status.h"
#include "sdn_status.h"
#include "sharpen_status.h"

#include "camera_sensor.h"
#include "log.h"
#include "utils.h"

namespace libcamera {

/* Configure the sensor with these values initially. */
#define DEFAULT_ANALOGUE_GAIN 1.0
#define DEFAULT_EXPOSURE_TIME 20000

LOG_DEFINE_CATEGORY(IPARPI)

class IPARPi : public IPAInterface
{
public:
	IPARPi()
		: lastMode_({}), controller_(), controllerInit_(false),
		  frame_count_(0), check_count_(0), hide_count_(0),
		  mistrust_count_(0), lsTableHandle_(0), lsTable_(nullptr)
	{
	}

	~IPARPi()
	{
	}

	int init(const IPASettings &settings) override;
	int start() override { return 0; }
	void stop() override {}

	void configure(const CameraSensorInfo &sensorInfo,
		       const std::map<unsigned int, IPAStream> &streamConfig,
		       const std::map<unsigned int, const ControlInfoMap &> &entityControls) override;
	void mapBuffers(const std::vector<IPABuffer> &buffers) override;
	void unmapBuffers(const std::vector<unsigned int> &ids) override;
	void processEvent(const IPAOperationData &event) override;

private:
	void setMode(const CameraSensorInfo &sensorInfo);
	void queueRequest(const ControlList &controls);
	void returnEmbeddedBuffer(unsigned int bufferId);
	void prepareISP(unsigned int bufferId);
	void reportMetadata();
	bool parseEmbeddedData(unsigned int bufferId, struct DeviceStatus &deviceStatus);
	void processStats(unsigned int bufferId);
	void applyAGC(const struct AgcStatus *agcStatus);
	void applyAWB(const struct AwbStatus *awbStatus, ControlList &ctrls);
	void applyDG(const struct AgcStatus *dgStatus, ControlList &ctrls);
	void applyCCM(const struct CcmStatus *ccmStatus, ControlList &ctrls);
	void applyBlackLevel(const struct BlackLevelStatus *blackLevelStatus, ControlList &ctrls);
	void applyGamma(const struct ContrastStatus *contrastStatus, ControlList &ctrls);
	void applyGEQ(const struct GeqStatus *geqStatus, ControlList &ctrls);
	void applyDenoise(const struct SdnStatus *denoiseStatus, ControlList &ctrls);
	void applySharpen(const struct SharpenStatus *sharpenStatus, ControlList &ctrls);
	void applyDPC(const struct DpcStatus *dpcStatus, ControlList &ctrls);
	void applyLS(const struct AlscStatus *lsStatus, ControlList &ctrls);
	void resampleTable(uint16_t dest[], double const src[12][16], int dest_w, int dest_h);

	std::map<unsigned int, FrameBuffer> buffers_;
	std::map<unsigned int, void *> buffersMemory_;

	ControlInfoMap unicam_ctrls_;
	ControlInfoMap isp_ctrls_;
	ControlList libcameraMetadata_;

	/* IPA configuration. */
	std::string tuningFile_;

	/* Camera sensor params. */
	CameraMode mode_;
	CameraMode lastMode_;

	/* Raspberry Pi controller specific defines. */
	std::unique_ptr<RPi::CamHelper> helper_;
	RPi::Controller controller_;
	bool controllerInit_;
	RPi::Metadata rpiMetadata_;

	/*
	 * We count frames to decide if the frame must be hidden (e.g. from
	 * display) or mistrusted (i.e. not given to the control algos).
	 */
	uint64_t frame_count_;
	/* For checking the sequencing of Prepare/Process calls. */
	uint64_t check_count_;
	/* How many frames the pipeline handler should hide, or "drop". */
	unsigned int hide_count_;
	/* How many frames we should avoid running control algos on. */
	unsigned int mistrust_count_;
	/* LS table allocation passed in from the pipeline handler. */
	uint32_t lsTableHandle_;
	void *lsTable_;
};

int IPARPi::init(const IPASettings &settings)
{
	tuningFile_ = settings.configurationFile;
	return 0;
}

void IPARPi::setMode(const CameraSensorInfo &sensorInfo)
{
	mode_.bitdepth = sensorInfo.bitsPerPixel;
	mode_.width = sensorInfo.outputSize.width;
	mode_.height = sensorInfo.outputSize.height;
	mode_.sensor_width = sensorInfo.activeAreaSize.width;
	mode_.sensor_height = sensorInfo.activeAreaSize.height;
	mode_.crop_x = sensorInfo.analogCrop.x;
	mode_.crop_y = sensorInfo.analogCrop.y;

	/*
	 * Calculate scaling parameters. The scale_[xy] factors are determined
	 * by the ratio between the crop rectangle size and the output size.
	 */
	mode_.scale_x = sensorInfo.analogCrop.width / sensorInfo.outputSize.width;
	mode_.scale_y = sensorInfo.analogCrop.height / sensorInfo.outputSize.height;

	/*
	 * We're not told by the pipeline handler how scaling is split between
	 * binning and digital scaling. For now, as a heuristic, assume that
	 * downscaling up to 2 is achieved through binning, and that any
	 * additional scaling is achieved through digital scaling.
	 *
	 * \todo Get the pipeline handle to provide the full data
	 */
	mode_.bin_y = std::min(2, static_cast<int>(mode_.scale_x));
	mode_.bin_y = std::min(2, static_cast<int>(mode_.scale_y));

	/* The noise factor is the square root of the total binning factor. */
	mode_.noise_factor = sqrt(mode_.bin_x * mode_.bin_y);

	/*
	 * Calculate the line length in nanoseconds as the ratio between
	 * the line length in pixels and the pixel rate.
	 */
	mode_.line_length = 1e9 * sensorInfo.lineLength / sensorInfo.pixelRate;
}

void IPARPi::configure(const CameraSensorInfo &sensorInfo,
		       const std::map<unsigned int, IPAStream> &streamConfig,
		       const std::map<unsigned int, const ControlInfoMap &> &entityControls)
{
	if (entityControls.empty())
		return;

	unicam_ctrls_ = entityControls.at(0);
	isp_ctrls_ = entityControls.at(1);
	/* Setup a metadata ControlList to output metadata. */
	libcameraMetadata_ = ControlList(controls::controls);

	/*
	 * Load the "helper" for this sensor. This tells us all the device specific stuff
	 * that the kernel driver doesn't. We only do this the first time; we don't need
	 * to re-parse the metadata after a simple mode-switch for no reason.
	 */
	std::string cameraName(sensorInfo.model);
	if (!helper_) {
		helper_ = std::unique_ptr<RPi::CamHelper>(RPi::CamHelper::Create(cameraName));
		/*
		 * Pass out the sensor config to the pipeline handler in order
		 * to setup the staggered writer class.
		 */
		int gainDelay, exposureDelay, sensorMetadata;
		helper_->GetDelays(exposureDelay, gainDelay);
		sensorMetadata = helper_->SensorEmbeddedDataPresent();
		RPi::CamTransform orientation = helper_->GetOrientation();

		IPAOperationData op;
		op.operation = RPI_IPA_ACTION_SET_SENSOR_CONFIG;
		op.data.push_back(gainDelay);
		op.data.push_back(exposureDelay);
		op.data.push_back(sensorMetadata);

		ControlList ctrls(unicam_ctrls_);
		ctrls.set(V4L2_CID_HFLIP, (int32_t) !!(orientation & RPi::CamTransform_HFLIP));
		ctrls.set(V4L2_CID_VFLIP, (int32_t) !!(orientation & RPi::CamTransform_VFLIP));
		op.controls.push_back(ctrls);

		queueFrameAction.emit(0, op);
	}

	/* Re-assemble camera mode using the sensor info. */
	setMode(sensorInfo);

	/* Pass the camera mode to the CamHelper to setup algorithms. */
	helper_->SetCameraMode(mode_);

	/*
	 * Initialise frame counts, and decide how many frames must be hidden or
	 *"mistrusted", which depends on whether this is a startup from cold,
	 * or merely a mode switch in a running system.
	 */
	frame_count_ = 0;
	check_count_ = 0;
	if (controllerInit_) {
		hide_count_ = helper_->HideFramesModeSwitch();
		mistrust_count_ = helper_->MistrustFramesModeSwitch();
	} else {
		hide_count_ = helper_->HideFramesStartup();
		mistrust_count_ = helper_->MistrustFramesStartup();
	}

	if (!controllerInit_) {
		/* Load the tuning file for this sensor. */
		controller_.Read(tuningFile_.c_str());
		controller_.Initialise();
		controllerInit_ = true;

		/* Calculate initial values for gain and exposure. */
		int32_t gain_code = helper_->GainCode(DEFAULT_ANALOGUE_GAIN);
		int32_t exposure_lines = helper_->ExposureLines(DEFAULT_EXPOSURE_TIME);

		ControlList ctrls(unicam_ctrls_);
		ctrls.set(V4L2_CID_ANALOGUE_GAIN, gain_code);
		ctrls.set(V4L2_CID_EXPOSURE, exposure_lines);

		IPAOperationData op;
		op.operation = RPI_IPA_ACTION_V4L2_SET_STAGGERED;
		op.controls.push_back(ctrls);
		queueFrameAction.emit(0, op);
	}

	controller_.SwitchMode(mode_);

	lastMode_ = mode_;
}

void IPARPi::mapBuffers(const std::vector<IPABuffer> &buffers)
{
	for (const IPABuffer &buffer : buffers) {
		auto elem = buffers_.emplace(std::piecewise_construct,
					     std::forward_as_tuple(buffer.id),
					     std::forward_as_tuple(buffer.planes));
		const FrameBuffer &fb = elem.first->second;

		buffersMemory_[buffer.id] = mmap(nullptr, fb.planes()[0].length,
						 PROT_READ | PROT_WRITE, MAP_SHARED,
						 fb.planes()[0].fd.fd(), 0);

		if (buffersMemory_[buffer.id] == MAP_FAILED) {
			int ret = -errno;
			LOG(IPARPI, Fatal) << "Failed to mmap buffer: " << strerror(-ret);
		}
	}
}

void IPARPi::unmapBuffers(const std::vector<unsigned int> &ids)
{
	for (unsigned int id : ids) {
		const auto fb = buffers_.find(id);
		if (fb == buffers_.end())
			continue;

		munmap(buffersMemory_[id], fb->second.planes()[0].length);
		buffersMemory_.erase(id);
		buffers_.erase(id);
	}
}

void IPARPi::processEvent(const IPAOperationData &event)
{
	switch (event.operation) {
	case RPI_IPA_EVENT_SIGNAL_STAT_READY: {
		unsigned int bufferId = event.data[0];

		if (++check_count_ != frame_count_) /* assert here? */
			LOG(IPARPI, Error) << "WARNING: Prepare/Process mismatch!!!";
		if (frame_count_ > mistrust_count_)
			processStats(bufferId);

		IPAOperationData op;
		op.operation = RPI_IPA_ACTION_STATS_METADATA_COMPLETE;
		op.data = { bufferId & RPiIpaMask::ID };
		op.controls = { libcameraMetadata_ };
		queueFrameAction.emit(0, op);
		break;
	}

	case RPI_IPA_EVENT_SIGNAL_ISP_PREPARE: {
		unsigned int embeddedbufferId = event.data[0];
		unsigned int bayerbufferId = event.data[1];

		/*
		 * At start-up, or after a mode-switch, we may want to
		 * avoid running the control algos for a few frames in case
		 * they are "unreliable".
		 */
		prepareISP(embeddedbufferId);
		reportMetadata();

		/* Ready to push the input buffer into the ISP. */
		IPAOperationData op;
		if (++frame_count_ > hide_count_)
			op.operation = RPI_IPA_ACTION_RUN_ISP;
		else
			op.operation = RPI_IPA_ACTION_RUN_ISP_AND_DROP_FRAME;
		op.data = { bayerbufferId & RPiIpaMask::ID };
		queueFrameAction.emit(0, op);
		break;
	}

	case RPI_IPA_EVENT_QUEUE_REQUEST: {
		queueRequest(event.controls[0]);
		break;
	}

	case RPI_IPA_EVENT_LS_TABLE_ALLOCATION: {
		lsTable_ = reinterpret_cast<void *>(event.data[0]);
		lsTableHandle_ = event.data[1];
		break;
	}

	default:
		LOG(IPARPI, Error) << "Unknown event " << event.operation;
		break;
	}
}

void IPARPi::reportMetadata()
{
	std::unique_lock<RPi::Metadata> lock(rpiMetadata_);

	/*
	 * Certain information about the current frame and how it will be
	 * processed can be extracted and placed into the libcamera metadata
	 * buffer, where an application could query it.
	 */

	DeviceStatus *deviceStatus = rpiMetadata_.GetLocked<DeviceStatus>("device.status");
	if (deviceStatus) {
		libcameraMetadata_.set(controls::ExposureTime, deviceStatus->shutter_speed);
		libcameraMetadata_.set(controls::AnalogueGain, deviceStatus->analogue_gain);
	}

	AgcStatus *agcStatus = rpiMetadata_.GetLocked<AgcStatus>("agc.status");
	if (agcStatus)
		libcameraMetadata_.set(controls::AeLocked, agcStatus->locked);

	LuxStatus *luxStatus = rpiMetadata_.GetLocked<LuxStatus>("lux.status");
	if (luxStatus)
		libcameraMetadata_.set(controls::Lux, luxStatus->lux);

	AwbStatus *awbStatus = rpiMetadata_.GetLocked<AwbStatus>("awb.status");
	if (awbStatus) {
		libcameraMetadata_.set(controls::ColourGains, { static_cast<float>(awbStatus->gain_r),
								static_cast<float>(awbStatus->gain_b) });
		libcameraMetadata_.set(controls::ColourTemperature, awbStatus->temperature_K);
	}

	BlackLevelStatus *blackLevelStatus = rpiMetadata_.GetLocked<BlackLevelStatus>("black_level.status");
	if (blackLevelStatus)
		libcameraMetadata_.set(controls::SensorBlackLevels,
				       { static_cast<int32_t>(blackLevelStatus->black_level_r),
					 static_cast<int32_t>(blackLevelStatus->black_level_g),
					 static_cast<int32_t>(blackLevelStatus->black_level_g),
					 static_cast<int32_t>(blackLevelStatus->black_level_b) });
}

/*
 * Converting between enums (used in the libcamera API) and the names that
 * we use to identify different modes. Unfortunately, the conversion tables
 * must be kept up-to-date by hand.
 */

static const std::map<int32_t, std::string> MeteringModeTable = {
	{ controls::MeteringCentreWeighted, "centre-weighted" },
	{ controls::MeteringSpot, "spot" },
	{ controls::MeteringMatrix, "matrix" },
	{ controls::MeteringCustom, "custom" },
};

static const std::map<int32_t, std::string> ConstraintModeTable = {
	{ controls::ConstraintNormal, "normal" },
	{ controls::ConstraintHighlight, "highlight" },
	{ controls::ConstraintCustom, "custom" },
};

static const std::map<int32_t, std::string> ExposureModeTable = {
	{ controls::ExposureNormal, "normal" },
	{ controls::ExposureShort, "short" },
	{ controls::ExposureLong, "long" },
	{ controls::ExposureCustom, "custom" },
};

static const std::map<int32_t, std::string> AwbModeTable = {
	{ controls::AwbAuto, "normal" },
	{ controls::AwbIncandescent, "incandescent" },
	{ controls::AwbTungsten, "tungsten" },
	{ controls::AwbFluorescent, "fluorescent" },
	{ controls::AwbIndoor, "indoor" },
	{ controls::AwbDaylight, "daylight" },
	{ controls::AwbCustom, "custom" },
};

void IPARPi::queueRequest(const ControlList &controls)
{
	/* Clear the return metadata buffer. */
	libcameraMetadata_.clear();

	for (auto const &ctrl : controls) {
		LOG(IPARPI, Info) << "Request ctrl: "
				  << controls::controls.at(ctrl.first)->name()
				  << " = " << ctrl.second.toString();

		switch (ctrl.first) {
		case controls::AE_ENABLE: {
			RPi::Algorithm *agc = controller_.GetAlgorithm("agc");
			ASSERT(agc);
			if (ctrl.second.get<bool>() == false)
				agc->Pause();
			else
				agc->Resume();

			libcameraMetadata_.set(controls::AeEnable, ctrl.second.get<bool>());
			break;
		}

		case controls::EXPOSURE_TIME: {
			RPi::AgcAlgorithm *agc = dynamic_cast<RPi::AgcAlgorithm *>(
				controller_.GetAlgorithm("agc"));
			ASSERT(agc);
			/* This expects units of micro-seconds. */
			agc->SetFixedShutter(ctrl.second.get<int32_t>());
			/* For the manual values to take effect, AGC must be unpaused. */
			if (agc->IsPaused())
				agc->Resume();

			libcameraMetadata_.set(controls::ExposureTime, ctrl.second.get<int32_t>());
			break;
		}

		case controls::ANALOGUE_GAIN: {
			RPi::AgcAlgorithm *agc = dynamic_cast<RPi::AgcAlgorithm *>(
				controller_.GetAlgorithm("agc"));
			ASSERT(agc);
			agc->SetFixedAnalogueGain(ctrl.second.get<float>());
			/* For the manual values to take effect, AGC must be unpaused. */
			if (agc->IsPaused())
				agc->Resume();

			libcameraMetadata_.set(controls::AnalogueGain,
					       ctrl.second.get<float>());
			break;
		}

		case controls::AE_METERING_MODE: {
			RPi::AgcAlgorithm *agc = dynamic_cast<RPi::AgcAlgorithm *>(
				controller_.GetAlgorithm("agc"));
			ASSERT(agc);

			int32_t idx = ctrl.second.get<int32_t>();
			if (MeteringModeTable.count(idx)) {
				agc->SetMeteringMode(MeteringModeTable.at(idx));
				libcameraMetadata_.set(controls::AeMeteringMode, idx);
			} else {
				LOG(IPARPI, Error) << "Metering mode " << idx
						   << " not recognised";
			}
			break;
		}

		case controls::AE_CONSTRAINT_MODE: {
			RPi::AgcAlgorithm *agc = dynamic_cast<RPi::AgcAlgorithm *>(
				controller_.GetAlgorithm("agc"));
			ASSERT(agc);

			int32_t idx = ctrl.second.get<int32_t>();
			if (ConstraintModeTable.count(idx)) {
				agc->SetConstraintMode(ConstraintModeTable.at(idx));
				libcameraMetadata_.set(controls::AeConstraintMode, idx);
			} else {
				LOG(IPARPI, Error) << "Constraint mode " << idx
						   << " not recognised";
			}
			break;
		}

		case controls::AE_EXPOSURE_MODE: {
			RPi::AgcAlgorithm *agc = dynamic_cast<RPi::AgcAlgorithm *>(
				controller_.GetAlgorithm("agc"));
			ASSERT(agc);

			int32_t idx = ctrl.second.get<int32_t>();
			if (ExposureModeTable.count(idx)) {
				agc->SetExposureMode(ExposureModeTable.at(idx));
				libcameraMetadata_.set(controls::AeExposureMode, idx);
			} else {
				LOG(IPARPI, Error) << "Exposure mode " << idx
						   << " not recognised";
			}
			break;
		}

		case controls::EXPOSURE_VALUE: {
			RPi::AgcAlgorithm *agc = dynamic_cast<RPi::AgcAlgorithm *>(
				controller_.GetAlgorithm("agc"));
			ASSERT(agc);

			/*
			 * The SetEv() method takes in a direct exposure multiplier.
			 * So convert to 2^EV
			 */
			double ev = pow(2.0, ctrl.second.get<float>());
			agc->SetEv(ev);
			libcameraMetadata_.set(controls::ExposureValue,
					       ctrl.second.get<float>());
			break;
		}

		case controls::AWB_ENABLE: {
			RPi::Algorithm *awb = controller_.GetAlgorithm("awb");
			ASSERT(awb);

			if (ctrl.second.get<bool>() == false)
				awb->Pause();
			else
				awb->Resume();

			libcameraMetadata_.set(controls::AwbEnable,
					       ctrl.second.get<bool>());
			break;
		}

		case controls::AWB_MODE: {
			RPi::AwbAlgorithm *awb = dynamic_cast<RPi::AwbAlgorithm *>(
				controller_.GetAlgorithm("awb"));
			ASSERT(awb);

			int32_t idx = ctrl.second.get<int32_t>();
			if (AwbModeTable.count(idx)) {
				awb->SetMode(AwbModeTable.at(idx));
				libcameraMetadata_.set(controls::AwbMode, idx);
			} else {
				LOG(IPARPI, Error) << "AWB mode " << idx
						   << " not recognised";
			}
			break;
		}

		case controls::COLOUR_GAINS: {
			auto gains = ctrl.second.get<Span<const float>>();
			RPi::AwbAlgorithm *awb = dynamic_cast<RPi::AwbAlgorithm *>(
				controller_.GetAlgorithm("awb"));
			ASSERT(awb);

			awb->SetManualGains(gains[0], gains[1]);
			if (gains[0] != 0.0f && gains[1] != 0.0f)
				/* A gain of 0.0f will switch back to auto mode. */
				libcameraMetadata_.set(controls::ColourGains,
						       { gains[0], gains[1] });
			break;
		}

		case controls::BRIGHTNESS: {
			RPi::ContrastAlgorithm *contrast = dynamic_cast<RPi::ContrastAlgorithm *>(
				controller_.GetAlgorithm("contrast"));
			ASSERT(contrast);

			contrast->SetBrightness(ctrl.second.get<float>() * 65536);
			libcameraMetadata_.set(controls::Brightness,
					       ctrl.second.get<float>());
			break;
		}

		case controls::CONTRAST: {
			RPi::ContrastAlgorithm *contrast = dynamic_cast<RPi::ContrastAlgorithm *>(
				controller_.GetAlgorithm("contrast"));
			ASSERT(contrast);

			contrast->SetContrast(ctrl.second.get<float>());
			libcameraMetadata_.set(controls::Contrast,
					       ctrl.second.get<float>());
			break;
		}

		case controls::SATURATION: {
			RPi::CcmAlgorithm *ccm = dynamic_cast<RPi::CcmAlgorithm *>(
				controller_.GetAlgorithm("ccm"));
			ASSERT(ccm);

			ccm->SetSaturation(ctrl.second.get<float>());
			libcameraMetadata_.set(controls::Saturation,
					       ctrl.second.get<float>());
			break;
		}

		default:
			LOG(IPARPI, Warning)
				<< "Ctrl " << controls::controls.at(ctrl.first)->name()
				<< " is not handled.";
			break;
		}
	}
}

void IPARPi::returnEmbeddedBuffer(unsigned int bufferId)
{
	IPAOperationData op;
	op.operation = RPI_IPA_ACTION_EMBEDDED_COMPLETE;
	op.data = { bufferId & RPiIpaMask::ID };
	queueFrameAction.emit(0, op);
}

void IPARPi::prepareISP(unsigned int bufferId)
{
	struct DeviceStatus deviceStatus = {};
	bool success = parseEmbeddedData(bufferId, deviceStatus);

	/* Done with embedded data now, return to pipeline handler asap. */
	returnEmbeddedBuffer(bufferId);

	if (success) {
		ControlList ctrls(isp_ctrls_);

		rpiMetadata_.Clear();
		rpiMetadata_.Set("device.status", deviceStatus);
		controller_.Prepare(&rpiMetadata_);

		/* Lock the metadata buffer to avoid constant locks/unlocks. */
		std::unique_lock<RPi::Metadata> lock(rpiMetadata_);

		AwbStatus *awbStatus = rpiMetadata_.GetLocked<AwbStatus>("awb.status");
		if (awbStatus)
			applyAWB(awbStatus, ctrls);

		CcmStatus *ccmStatus = rpiMetadata_.GetLocked<CcmStatus>("ccm.status");
		if (ccmStatus)
			applyCCM(ccmStatus, ctrls);

		AgcStatus *dgStatus = rpiMetadata_.GetLocked<AgcStatus>("agc.status");
		if (dgStatus)
			applyDG(dgStatus, ctrls);

		AlscStatus *lsStatus = rpiMetadata_.GetLocked<AlscStatus>("alsc.status");
		if (lsStatus)
			applyLS(lsStatus, ctrls);

		ContrastStatus *contrastStatus = rpiMetadata_.GetLocked<ContrastStatus>("contrast.status");
		if (contrastStatus)
			applyGamma(contrastStatus, ctrls);

		BlackLevelStatus *blackLevelStatus = rpiMetadata_.GetLocked<BlackLevelStatus>("black_level.status");
		if (blackLevelStatus)
			applyBlackLevel(blackLevelStatus, ctrls);

		GeqStatus *geqStatus = rpiMetadata_.GetLocked<GeqStatus>("geq.status");
		if (geqStatus)
			applyGEQ(geqStatus, ctrls);

		SdnStatus *denoiseStatus = rpiMetadata_.GetLocked<SdnStatus>("sdn.status");
		if (denoiseStatus)
			applyDenoise(denoiseStatus, ctrls);

		SharpenStatus *sharpenStatus = rpiMetadata_.GetLocked<SharpenStatus>("sharpen.status");
		if (sharpenStatus)
			applySharpen(sharpenStatus, ctrls);

		DpcStatus *dpcStatus = rpiMetadata_.GetLocked<DpcStatus>("dpc.status");
		if (dpcStatus)
			applyDPC(dpcStatus, ctrls);

		if (!ctrls.empty()) {
			IPAOperationData op;
			op.operation = RPI_IPA_ACTION_V4L2_SET_ISP;
			op.controls.push_back(ctrls);
			queueFrameAction.emit(0, op);
		}
	}
}

bool IPARPi::parseEmbeddedData(unsigned int bufferId, struct DeviceStatus &deviceStatus)
{
	auto it = buffersMemory_.find(bufferId);
	if (it == buffersMemory_.end()) {
		LOG(IPARPI, Error) << "Could not find embedded buffer!";
		return false;
	}

	int size = buffers_.find(bufferId)->second.planes()[0].length;
	helper_->Parser().SetBufferSize(size);
	RPi::MdParser::Status status = helper_->Parser().Parse(it->second);
	if (status != RPi::MdParser::Status::OK) {
		LOG(IPARPI, Error) << "Embedded Buffer parsing failed, error " << status;
	} else {
		uint32_t exposure_lines, gain_code;
		if (helper_->Parser().GetExposureLines(exposure_lines) != RPi::MdParser::Status::OK) {
			LOG(IPARPI, Error) << "Exposure time failed";
			return false;
		}

		deviceStatus.shutter_speed = helper_->Exposure(exposure_lines);
		if (helper_->Parser().GetGainCode(gain_code) != RPi::MdParser::Status::OK) {
			LOG(IPARPI, Error) << "Gain failed";
			return false;
		}

		deviceStatus.analogue_gain = helper_->Gain(gain_code);
		LOG(IPARPI, Debug) << "Metadata - Exposure : "
				   << deviceStatus.shutter_speed << " Gain : "
				   << deviceStatus.analogue_gain;
	}

	return true;
}

void IPARPi::processStats(unsigned int bufferId)
{
	auto it = buffersMemory_.find(bufferId);
	if (it == buffersMemory_.end()) {
		LOG(IPARPI, Error) << "Could not find stats buffer!";
		return;
	}

	bcm2835_isp_stats *stats = static_cast<bcm2835_isp_stats *>(it->second);
	RPi::StatisticsPtr statistics = std::make_shared<bcm2835_isp_stats>(*stats);
	controller_.Process(statistics, &rpiMetadata_);

	struct AgcStatus agcStatus;
	if (rpiMetadata_.Get("agc.status", agcStatus) == 0)
		applyAGC(&agcStatus);
}

void IPARPi::applyAWB(const struct AwbStatus *awbStatus, ControlList &ctrls)
{
	const auto gainR = isp_ctrls_.find(V4L2_CID_RED_BALANCE);
	if (gainR == isp_ctrls_.end()) {
		LOG(IPARPI, Error) << "Can't find red gain control";
		return;
	}

	const auto gainB = isp_ctrls_.find(V4L2_CID_BLUE_BALANCE);
	if (gainB == isp_ctrls_.end()) {
		LOG(IPARPI, Error) << "Can't find blue gain control";
		return;
	}

	LOG(IPARPI, Debug) << "Applying WB R: " << awbStatus->gain_r << " B: "
			   << awbStatus->gain_b;

	ctrls.set(V4L2_CID_RED_BALANCE,
		  static_cast<int32_t>(awbStatus->gain_r * 1000));
	ctrls.set(V4L2_CID_BLUE_BALANCE,
		  static_cast<int32_t>(awbStatus->gain_b * 1000));
}

void IPARPi::applyAGC(const struct AgcStatus *agcStatus)
{
	IPAOperationData op;
	op.operation = RPI_IPA_ACTION_V4L2_SET_STAGGERED;

	int32_t gain_code = helper_->GainCode(agcStatus->analogue_gain);
	int32_t exposure_lines = helper_->ExposureLines(agcStatus->shutter_time);

	if (unicam_ctrls_.find(V4L2_CID_ANALOGUE_GAIN) == unicam_ctrls_.end()) {
		LOG(IPARPI, Error) << "Can't find analogue gain control";
		return;
	}

	if (unicam_ctrls_.find(V4L2_CID_EXPOSURE) == unicam_ctrls_.end()) {
		LOG(IPARPI, Error) << "Can't find exposure control";
		return;
	}

	LOG(IPARPI, Debug) << "Applying AGC Exposure: " << agcStatus->shutter_time
			   << " (Shutter lines: " << exposure_lines << ") Gain: "
			   << agcStatus->analogue_gain << " (Gain Code: "
			   << gain_code << ")";

	ControlList ctrls(unicam_ctrls_);
	ctrls.set(V4L2_CID_ANALOGUE_GAIN, gain_code);
	ctrls.set(V4L2_CID_EXPOSURE, exposure_lines);
	op.controls.push_back(ctrls);
	queueFrameAction.emit(0, op);
}

void IPARPi::applyDG(const struct AgcStatus *dgStatus, ControlList &ctrls)
{
	if (isp_ctrls_.find(V4L2_CID_DIGITAL_GAIN) == isp_ctrls_.end()) {
		LOG(IPARPI, Error) << "Can't find digital gain control";
		return;
	}

	ctrls.set(V4L2_CID_DIGITAL_GAIN,
		  static_cast<int32_t>(dgStatus->digital_gain * 1000));
}

void IPARPi::applyCCM(const struct CcmStatus *ccmStatus, ControlList &ctrls)
{
	if (isp_ctrls_.find(V4L2_CID_USER_BCM2835_ISP_CC_MATRIX) == isp_ctrls_.end()) {
		LOG(IPARPI, Error) << "Can't find CCM control";
		return;
	}

	bcm2835_isp_custom_ccm ccm;
	for (int i = 0; i < 9; i++) {
		ccm.ccm.ccm[i / 3][i % 3].den = 1000;
		ccm.ccm.ccm[i / 3][i % 3].num = 1000 * ccmStatus->matrix[i];
	}

	ccm.enabled = 1;
	ccm.ccm.offsets[0] = ccm.ccm.offsets[1] = ccm.ccm.offsets[2] = 0;

	ControlValue c(Span<const uint8_t>{ reinterpret_cast<uint8_t *>(&ccm),
					    sizeof(ccm) });
	ctrls.set(V4L2_CID_USER_BCM2835_ISP_CC_MATRIX, c);
}

void IPARPi::applyGamma(const struct ContrastStatus *contrastStatus, ControlList &ctrls)
{
	if (isp_ctrls_.find(V4L2_CID_USER_BCM2835_ISP_GAMMA) == isp_ctrls_.end()) {
		LOG(IPARPI, Error) << "Can't find Gamma control";
		return;
	}

	struct bcm2835_isp_gamma gamma;
	gamma.enabled = 1;
	for (int i = 0; i < CONTRAST_NUM_POINTS; i++) {
		gamma.x[i] = contrastStatus->points[i].x;
		gamma.y[i] = contrastStatus->points[i].y;
	}

	ControlValue c(Span<const uint8_t>{ reinterpret_cast<uint8_t *>(&gamma),
					    sizeof(gamma) });
	ctrls.set(V4L2_CID_USER_BCM2835_ISP_GAMMA, c);
}

void IPARPi::applyBlackLevel(const struct BlackLevelStatus *blackLevelStatus, ControlList &ctrls)
{
	if (isp_ctrls_.find(V4L2_CID_USER_BCM2835_ISP_BLACK_LEVEL) == isp_ctrls_.end()) {
		LOG(IPARPI, Error) << "Can't find black level control";
		return;
	}

	bcm2835_isp_black_level blackLevel;
	blackLevel.enabled = 1;
	blackLevel.black_level_r = blackLevelStatus->black_level_r;
	blackLevel.black_level_g = blackLevelStatus->black_level_g;
	blackLevel.black_level_b = blackLevelStatus->black_level_b;

	ControlValue c(Span<const uint8_t>{ reinterpret_cast<uint8_t *>(&blackLevel),
					    sizeof(blackLevel) });
	ctrls.set(V4L2_CID_USER_BCM2835_ISP_BLACK_LEVEL, c);
}

void IPARPi::applyGEQ(const struct GeqStatus *geqStatus, ControlList &ctrls)
{
	if (isp_ctrls_.find(V4L2_CID_USER_BCM2835_ISP_GEQ) == isp_ctrls_.end()) {
		LOG(IPARPI, Error) << "Can't find geq control";
		return;
	}

	bcm2835_isp_geq geq;
	geq.enabled = 1;
	geq.offset = geqStatus->offset;
	geq.slope.den = 1000;
	geq.slope.num = 1000 * geqStatus->slope;

	ControlValue c(Span<const uint8_t>{ reinterpret_cast<uint8_t *>(&geq),
					    sizeof(geq) });
	ctrls.set(V4L2_CID_USER_BCM2835_ISP_GEQ, c);
}

void IPARPi::applyDenoise(const struct SdnStatus *denoiseStatus, ControlList &ctrls)
{
	if (isp_ctrls_.find(V4L2_CID_USER_BCM2835_ISP_DENOISE) == isp_ctrls_.end()) {
		LOG(IPARPI, Error) << "Can't find denoise control";
		return;
	}

	bcm2835_isp_denoise denoise;
	denoise.enabled = 1;
	denoise.constant = denoiseStatus->noise_constant;
	denoise.slope.num = 1000 * denoiseStatus->noise_slope;
	denoise.slope.den = 1000;
	denoise.strength.num = 1000 * denoiseStatus->strength;
	denoise.strength.den = 1000;

	ControlValue c(Span<const uint8_t>{ reinterpret_cast<uint8_t *>(&denoise),
					    sizeof(denoise) });
	ctrls.set(V4L2_CID_USER_BCM2835_ISP_DENOISE, c);
}

void IPARPi::applySharpen(const struct SharpenStatus *sharpenStatus, ControlList &ctrls)
{
	if (isp_ctrls_.find(V4L2_CID_USER_BCM2835_ISP_SHARPEN) == isp_ctrls_.end()) {
		LOG(IPARPI, Error) << "Can't find sharpen control";
		return;
	}

	bcm2835_isp_sharpen sharpen;
	sharpen.enabled = 1;
	sharpen.threshold.num = 1000 * sharpenStatus->threshold;
	sharpen.threshold.den = 1000;
	sharpen.strength.num = 1000 * sharpenStatus->strength;
	sharpen.strength.den = 1000;
	sharpen.limit.num = 1000 * sharpenStatus->limit;
	sharpen.limit.den = 1000;

	ControlValue c(Span<const uint8_t>{ reinterpret_cast<uint8_t *>(&sharpen),
					    sizeof(sharpen) });
	ctrls.set(V4L2_CID_USER_BCM2835_ISP_SHARPEN, c);
}

void IPARPi::applyDPC(const struct DpcStatus *dpcStatus, ControlList &ctrls)
{
	if (isp_ctrls_.find(V4L2_CID_USER_BCM2835_ISP_DPC) == isp_ctrls_.end()) {
		LOG(IPARPI, Error) << "Can't find DPC control";
		return;
	}

	bcm2835_isp_dpc dpc;
	dpc.enabled = 1;
	dpc.strength = dpcStatus->strength;

	ControlValue c(Span<const uint8_t>{ reinterpret_cast<uint8_t *>(&dpc),
					    sizeof(dpc) });
	ctrls.set(V4L2_CID_USER_BCM2835_ISP_DPC, c);
}

void IPARPi::applyLS(const struct AlscStatus *lsStatus, ControlList &ctrls)
{
	if (isp_ctrls_.find(V4L2_CID_USER_BCM2835_ISP_LENS_SHADING) == isp_ctrls_.end()) {
		LOG(IPARPI, Error) << "Can't find LS control";
		return;
	}

	/*
	 * Program lens shading tables into pipeline.
	 * Choose smallest cell size that won't exceed 63x48 cells.
	 */
	const int cell_sizes[] = { 16, 32, 64, 128, 256 };
	unsigned int num_cells = ARRAY_SIZE(cell_sizes);
	unsigned int i, w, h, cell_size;
	for (i = 0; i < num_cells; i++) {
		cell_size = cell_sizes[i];
		w = (mode_.width + cell_size - 1) / cell_size;
		h = (mode_.height + cell_size - 1) / cell_size;
		if (w < 64 && h <= 48)
			break;
	}

	if (i == num_cells) {
		LOG(IPARPI, Error) << "Cannot find cell size";
		return;
	}

	/* We're going to supply corner sampled tables, 16 bit samples. */
	w++, h++;
	bcm2835_isp_lens_shading ls = {
		.enabled = 1,
		.grid_cell_size = cell_size,
		.grid_width = w,
		.grid_stride = w,
		.grid_height = h,
		.mem_handle_table = lsTableHandle_,
		.ref_transform = 0,
		.corner_sampled = 1,
		.gain_format = GAIN_FORMAT_U4P10
	};

	if (!lsTable_ || w * h * 4 * sizeof(uint16_t) > MAX_LS_GRID_SIZE) {
		LOG(IPARPI, Error) << "Do not have a correctly allocate lens shading table!";
		return;
	}

	if (lsStatus) {
		/* Format will be u4.10 */
		uint16_t *grid = static_cast<uint16_t *>(lsTable_);

		resampleTable(grid, lsStatus->r, w, h);
		resampleTable(grid + w * h, lsStatus->g, w, h);
		std::memcpy(grid + 2 * w * h, grid + w * h, w * h * sizeof(uint16_t));
		resampleTable(grid + 3 * w * h, lsStatus->b, w, h);
	}

	ControlValue c(Span<const uint8_t>{ reinterpret_cast<uint8_t *>(&ls),
					    sizeof(ls) });
	ctrls.set(V4L2_CID_USER_BCM2835_ISP_LENS_SHADING, c);
}

/*
 * Resamples a 16x12 table with central sampling to dest_w x dest_h with corner
 * sampling.
 */
void IPARPi::resampleTable(uint16_t dest[], double const src[12][16],
			   int dest_w, int dest_h)
{
	/*
	 * Precalculate and cache the x sampling locations and phases to
	 * save recomputing them on every row.
	 */
	assert(dest_w > 1 && dest_h > 1 && dest_w <= 64);
	int x_lo[64], x_hi[64];
	double xf[64];
	double x = -0.5, x_inc = 16.0 / (dest_w - 1);
	for (int i = 0; i < dest_w; i++, x += x_inc) {
		x_lo[i] = floor(x);
		xf[i] = x - x_lo[i];
		x_hi[i] = x_lo[i] < 15 ? x_lo[i] + 1 : 15;
		x_lo[i] = x_lo[i] > 0 ? x_lo[i] : 0;
	}

	/* Now march over the output table generating the new values. */
	double y = -0.5, y_inc = 12.0 / (dest_h - 1);
	for (int j = 0; j < dest_h; j++, y += y_inc) {
		int y_lo = floor(y);
		double yf = y - y_lo;
		int y_hi = y_lo < 11 ? y_lo + 1 : 11;
		y_lo = y_lo > 0 ? y_lo : 0;
		double const *row_above = src[y_lo];
		double const *row_below = src[y_hi];
		for (int i = 0; i < dest_w; i++) {
			double above = row_above[x_lo[i]] * (1 - xf[i])
				     + row_above[x_hi[i]] * xf[i];
			double below = row_below[x_lo[i]] * (1 - xf[i])