Move test applications to src/apps/

The cam and qcam test application share code, currently through a crude
hack that references the cam source files directly from the qcam
meson.build file. To prepare for the introduction of hosting that code
in a static library, move all applications to src/apps/.

Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Reviewed-by: Paul Elder <paul.elder@ideasonboard.com>
Reviewed-by: Kieran Bingham <kieran.bingham@ideasonboard.com>

1 files changed, 653 insertions, 0 deletions

diff --git a/src/apps/cam/dng_writer.cpp b/src/apps/cam/dng_writer.cpp
new file mode 100644
index 00000000..c945edce
--- /dev/null
+++ b/src/apps/cam/dng_writer.cpp
@@ -0,0 +1,653 @@
+/* SPDX-License-Identifier: LGPL-2.1-or-later */
+/*
+ * Copyright (C) 2020, Raspberry Pi Ltd
+ *
+ * dng_writer.cpp - DNG writer
+ */
+
+#include "dng_writer.h"
+
+#include <algorithm>
+#include <iostream>
+#include <map>
+
+#include <tiffio.h>
+
+#include <libcamera/control_ids.h>
+#include <libcamera/formats.h>
+#include <libcamera/property_ids.h>
+
+using namespace libcamera;
+
+enum CFAPatternColour : uint8_t {
+	CFAPatternRed = 0,
+	CFAPatternGreen = 1,
+	CFAPatternBlue = 2,
+};
+
+struct FormatInfo {
+	uint8_t bitsPerSample;
+	CFAPatternColour pattern[4];
+	void (*packScanline)(void *output, const void *input,
+			     unsigned int width);
+	void (*thumbScanline)(const FormatInfo &info, void *output,
+			      const void *input, unsigned int width,
+			      unsigned int stride);
+};
+
+struct Matrix3d {
+	Matrix3d()
+	{
+	}
+
+	Matrix3d(float m0, float m1, float m2,
+		 float m3, float m4, float m5,
+		 float m6, float m7, float m8)
+	{
+		m[0] = m0, m[1] = m1, m[2] = m2;
+		m[3] = m3, m[4] = m4, m[5] = m5;
+		m[6] = m6, m[7] = m7, m[8] = m8;
+	}
+
+	Matrix3d(const Span<const float> &span)
+		: Matrix3d(span[0], span[1], span[2],
+			   span[3], span[4], span[5],
+			   span[6], span[7], span[8])
+	{
+	}
+
+	static Matrix3d diag(float diag0, float diag1, float diag2)
+	{
+		return Matrix3d(diag0, 0, 0, 0, diag1, 0, 0, 0, diag2);
+	}
+
+	static Matrix3d identity()
+	{
+		return Matrix3d(1, 0, 0, 0, 1, 0, 0, 0, 1);
+	}
+
+	Matrix3d transpose() const
+	{
+		return { m[0], m[3], m[6], m[1], m[4], m[7], m[2], m[5], m[8] };
+	}
+
+	Matrix3d cofactors() const
+	{
+		return { m[4] * m[8] - m[5] * m[7],
+			 -(m[3] * m[8] - m[5] * m[6]),
+			 m[3] * m[7] - m[4] * m[6],
+			 -(m[1] * m[8] - m[2] * m[7]),
+			 m[0] * m[8] - m[2] * m[6],
+			 -(m[0] * m[7] - m[1] * m[6]),
+			 m[1] * m[5] - m[2] * m[4],
+			 -(m[0] * m[5] - m[2] * m[3]),
+			 m[0] * m[4] - m[1] * m[3] };
+	}
+
+	Matrix3d adjugate() const
+	{
+		return cofactors().transpose();
+	}
+
+	float determinant() const
+	{
+		return m[0] * (m[4] * m[8] - m[5] * m[7]) -
+		       m[1] * (m[3] * m[8] - m[5] * m[6]) +
+		       m[2] * (m[3] * m[7] - m[4] * m[6]);
+	}
+
+	Matrix3d inverse() const
+	{
+		return adjugate() * (1.0 / determinant());
+	}
+
+	Matrix3d operator*(const Matrix3d &other) const
+	{
+		Matrix3d result;
+		for (unsigned int i = 0; i < 3; i++) {
+			for (unsigned int j = 0; j < 3; j++) {
+				result.m[i * 3 + j] =
+					m[i * 3 + 0] * other.m[0 + j] +
+					m[i * 3 + 1] * other.m[3 + j] +
+					m[i * 3 + 2] * other.m[6 + j];
+			}
+		}
+		return result;
+	}
+
+	Matrix3d operator*(float f) const
+	{
+		Matrix3d result;
+		for (unsigned int i = 0; i < 9; i++)
+			result.m[i] = m[i] * f;
+		return result;
+	}
+
+	float m[9];
+};
+
+void packScanlineSBGGR8(void *output, const void *input, unsigned int width)
+{
+	const uint8_t *in = static_cast<const uint8_t *>(input);
+	uint8_t *out = static_cast<uint8_t *>(output);
+
+	std::copy(in, in + width, out);
+}
+
+void packScanlineSBGGR10P(void *output, const void *input, unsigned int width)
+{
+	const uint8_t *in = static_cast<const uint8_t *>(input);
+	uint8_t *out = static_cast<uint8_t *>(output);
+
+	/* \todo Can this be made more efficient? */
+	for (unsigned int x = 0; x < width; x += 4) {
+		*out++ = in[0];
+		*out++ = (in[4] & 0x03) << 6 | in[1] >> 2;
+		*out++ = (in[1] & 0x03) << 6 | (in[4] & 0x0c) << 2 | in[2] >> 4;
+		*out++ = (in[2] & 0x0f) << 4 | (in[4] & 0x30) >> 2 | in[3] >> 6;
+		*out++ = (in[3] & 0x3f) << 2 | (in[4] & 0xc0) >> 6;
+		in += 5;
+	}
+}
+
+void packScanlineSBGGR12P(void *output, const void *input, unsigned int width)
+{
+	const uint8_t *in = static_cast<const uint8_t *>(input);
+	uint8_t *out = static_cast<uint8_t *>(output);
+
+	/* \todo Can this be made more efficient? */
+	for (unsigned int i = 0; i < width; i += 2) {
+		*out++ = in[0];
+		*out++ = (in[2] & 0x0f) << 4 | in[1] >> 4;
+		*out++ = (in[1] & 0x0f) << 4 | in[2] >> 4;
+		in += 3;
+	}
+}
+
+void thumbScanlineSBGGRxxP(const FormatInfo &info, void *output,
+			   const void *input, unsigned int width,
+			   unsigned int stride)
+{
+	const uint8_t *in = static_cast<const uint8_t *>(input);
+	uint8_t *out = static_cast<uint8_t *>(output);
+
+	/* Number of bytes corresponding to 16 pixels. */
+	unsigned int skip = info.bitsPerSample * 16 / 8;
+
+	for (unsigned int x = 0; x < width; x++) {
+		uint8_t value = (in[0] + in[1] + in[stride] + in[stride + 1]) >> 2;
+		*out++ = value;
+		*out++ = value;
+		*out++ = value;
+		in += skip;
+	}
+}
+
+void packScanlineIPU3(void *output, const void *input, unsigned int width)
+{
+	const uint8_t *in = static_cast<const uint8_t *>(input);
+	uint16_t *out = static_cast<uint16_t *>(output);
+
+	/*
+	 * Upscale the 10-bit format to 16-bit as it's not trivial to pack it
+	 * as 10-bit without gaps.
+	 *
+	 * \todo Improve packing to keep the 10-bit sample size.
+	 */
+	unsigned int x = 0;
+	while (true) {
+		for (unsigned int i = 0; i < 6; i++) {
+			*out++ = (in[1] & 0x03) << 14 | (in[0] & 0xff) << 6;
+			if (++x >= width)
+				return;
+
+			*out++ = (in[2] & 0x0f) << 12 | (in[1] & 0xfc) << 4;
+			if (++x >= width)
+				return;
+
+			*out++ = (in[3] & 0x3f) << 10 | (in[2] & 0xf0) << 2;
+			if (++x >= width)
+				return;
+
+			*out++ = (in[4] & 0xff) <<  8 | (in[3] & 0xc0) << 0;
+			if (++x >= width)
+				return;
+
+			in += 5;
+		}
+
+		*out++ = (in[1] & 0x03) << 14 | (in[0] & 0xff) << 6;
+		if (++x >= width)
+			return;
+
+		in += 2;
+	}
+}
+
+void thumbScanlineIPU3([[maybe_unused]] const FormatInfo &info, void *output,
+		       const void *input, unsigned int width,
+		       unsigned int stride)
+{
+	uint8_t *out = static_cast<uint8_t *>(output);
+
+	for (unsigned int x = 0; x < width; x++) {
+		unsigned int pixel = x * 16;
+		unsigned int block = pixel / 25;
+		unsigned int pixelInBlock = pixel - block * 25;
+
+		/*
+		 * If the pixel is the last in the block cheat a little and
+		 * move one pixel backward to avoid reading between two blocks
+		 * and having to deal with the padding bits.
+		 */
+		if (pixelInBlock == 24)
+			pixelInBlock--;
+
+		const uint8_t *in = static_cast<const uint8_t *>(input)
+				  + block * 32 + (pixelInBlock / 4) * 5;
+
+		uint16_t val1, val2, val3, val4;
+		switch (pixelInBlock % 4) {
+		case 0:
+			val1 = (in[1] & 0x03) << 14 | (in[0] & 0xff) << 6;
+			val2 = (in[2] & 0x0f) << 12 | (in[1] & 0xfc) << 4;
+			val3 = (in[stride + 1] & 0x03) << 14 | (in[stride + 0] & 0xff) << 6;
+			val4 = (in[stride + 2] & 0x0f) << 12 | (in[stride + 1] & 0xfc) << 4;
+			break;
+		case 1:
+			val1 = (in[2] & 0x0f) << 12 | (in[1] & 0xfc) << 4;
+			val2 = (in[3] & 0x3f) << 10 | (in[2] & 0xf0) << 2;
+			val3 = (in[stride + 2] & 0x0f) << 12 | (in[stride + 1] & 0xfc) << 4;
+			val4 = (in[stride + 3] & 0x3f) << 10 | (in[stride + 2] & 0xf0) << 2;
+			break;
+		case 2:
+			val1 = (in[3] & 0x3f) << 10 | (in[2] & 0xf0) << 2;
+			val2 = (in[4] & 0xff) <<  8 | (in[3] & 0xc0) << 0;
+			val3 = (in[stride + 3] & 0x3f) << 10 | (in[stride + 2] & 0xf0) << 2;
+			val4 = (in[stride + 4] & 0xff) <<  8 | (in[stride + 3] & 0xc0) << 0;
+			break;
+		case 3:
+			val1 = (in[4] & 0xff) <<  8 | (in[3] & 0xc0) << 0;
+			val2 = (in[6] & 0x03) << 14 | (in[5] & 0xff) << 6;
+			val3 = (in[stride + 4] & 0xff) <<  8 | (in[stride + 3] & 0xc0) << 0;
+			val4 = (in[stride + 6] & 0x03) << 14 | (in[stride + 5] & 0xff) << 6;
+			break;
+		}
+
+		uint8_t value = (val1 + val2 + val3 + val4) >> 10;
+		*out++ = value;
+		*out++ = value;
+		*out++ = value;
+	}
+}
+
+static const std::map<PixelFormat, FormatInfo> formatInfo = {
+	{ formats::SBGGR8, {
+		.bitsPerSample = 8,
+		.pattern = { CFAPatternBlue, CFAPatternGreen, CFAPatternGreen, CFAPatternRed },
+		.packScanline = packScanlineSBGGR8,
+		.thumbScanline = thumbScanlineSBGGRxxP,
+	} },
+	{ formats::SGBRG8, {
+		.bitsPerSample = 8,
+		.pattern = { CFAPatternGreen, CFAPatternBlue, CFAPatternRed, CFAPatternGreen },
+		.packScanline = packScanlineSBGGR8,
+		.thumbScanline = thumbScanlineSBGGRxxP,
+	} },
+	{ formats::SGRBG8, {
+		.bitsPerSample = 8,
+		.pattern = { CFAPatternGreen, CFAPatternRed, CFAPatternBlue, CFAPatternGreen },
+		.packScanline = packScanlineSBGGR8,
+		.thumbScanline = thumbScanlineSBGGRxxP,
+	} },
+	{ formats::SRGGB8, {
+		.bitsPerSample = 8,
+		.pattern = { CFAPatternRed, CFAPatternGreen, CFAPatternGreen, CFAPatternBlue },
+		.packScanline = packScanlineSBGGR8,
+		.thumbScanline = thumbScanlineSBGGRxxP,
+	} },
+	{ formats::SBGGR10_CSI2P, {
+		.bitsPerSample = 10,
+		.pattern = { CFAPatternBlue, CFAPatternGreen, CFAPatternGreen, CFAPatternRed },
+		.packScanline = packScanlineSBGGR10P,
+		.thumbScanline = thumbScanlineSBGGRxxP,
+	} },
+	{ formats::SGBRG10_CSI2P, {
+		.bitsPerSample = 10,
+		.pattern = { CFAPatternGreen, CFAPatternBlue, CFAPatternRed, CFAPatternGreen },
+		.packScanline = packScanlineSBGGR10P,
+		.thumbScanline = thumbScanlineSBGGRxxP,
+	} },
+	{ formats::SGRBG10_CSI2P, {
+		.bitsPerSample = 10,
+		.pattern = { CFAPatternGreen, CFAPatternRed, CFAPatternBlue, CFAPatternGreen },
+		.packScanline = packScanlineSBGGR10P,
+		.thumbScanline = thumbScanlineSBGGRxxP,
+	} },
+	{ formats::SRGGB10_CSI2P, {
+		.bitsPerSample = 10,
+		.pattern = { CFAPatternRed, CFAPatternGreen, CFAPatternGreen, CFAPatternBlue },
+		.packScanline = packScanlineSBGGR10P,
+		.thumbScanline = thumbScanlineSBGGRxxP,
+	} },
+	{ formats::SBGGR12_CSI2P, {
+		.bitsPerSample = 12,
+		.pattern = { CFAPatternBlue, CFAPatternGreen, CFAPatternGreen, CFAPatternRed },
+		.packScanline = packScanlineSBGGR12P,
+		.thumbScanline = thumbScanlineSBGGRxxP,
+	} },
+	{ formats::SGBRG12_CSI2P, {
+		.bitsPerSample = 12,
+		.pattern = { CFAPatternGreen, CFAPatternBlue, CFAPatternRed, CFAPatternGreen },
+		.packScanline = packScanlineSBGGR12P,
+		.thumbScanline = thumbScanlineSBGGRxxP,
+	} },
+	{ formats::SGRBG12_CSI2P, {
+		.bitsPerSample = 12,
+		.pattern = { CFAPatternGreen, CFAPatternRed, CFAPatternBlue, CFAPatternGreen },
+		.packScanline = packScanlineSBGGR12P,
+		.thumbScanline = thumbScanlineSBGGRxxP,
+	} },
+	{ formats::SRGGB12_CSI2P, {
+		.bitsPerSample = 12,
+		.pattern = { CFAPatternRed, CFAPatternGreen, CFAPatternGreen, CFAPatternBlue },
+		.packScanline = packScanlineSBGGR12P,
+		.thumbScanline = thumbScanlineSBGGRxxP,
+	} },
+	{ formats::SBGGR10_IPU3, {
+		.bitsPerSample = 16,
+		.pattern = { CFAPatternBlue, CFAPatternGreen, CFAPatternGreen, CFAPatternRed },
+		.packScanline = packScanlineIPU3,
+		.thumbScanline = thumbScanlineIPU3,
+	} },
+	{ formats::SGBRG10_IPU3, {
+		.bitsPerSample = 16,
+		.pattern = { CFAPatternGreen, CFAPatternBlue, CFAPatternRed, CFAPatternGreen },
+		.packScanline = packScanlineIPU3,
+		.thumbScanline = thumbScanlineIPU3,
+	} },
+	{ formats::SGRBG10_IPU3, {
+		.bitsPerSample = 16,
+		.pattern = { CFAPatternGreen, CFAPatternRed, CFAPatternBlue, CFAPatternGreen },
+		.packScanline = packScanlineIPU3,
+		.thumbScanline = thumbScanlineIPU3,
+	} },
+	{ formats::SRGGB10_IPU3, {
+		.bitsPerSample = 16,
+		.pattern = { CFAPatternRed, CFAPatternGreen, CFAPatternGreen, CFAPatternBlue },
+		.packScanline = packScanlineIPU3,
+		.thumbScanline = thumbScanlineIPU3,
+	} },
+};
+
+int DNGWriter::write(const char *filename, const Camera *camera,
+		     const StreamConfiguration &config,
+		     const ControlList &metadata,
+		     [[maybe_unused]] const FrameBuffer *buffer,
+		     const void *data)
+{
+	const ControlList &cameraProperties = camera->properties();
+
+	const auto it = formatInfo.find(config.pixelFormat);
+	if (it == formatInfo.cend()) {
+		std::cerr << "Unsupported pixel format" << std::endl;
+		return -EINVAL;
+	}
+	const FormatInfo *info = &it->second;
+
+	TIFF *tif = TIFFOpen(filename, "w");
+	if (!tif) {
+		std::cerr << "Failed to open tiff file" << std::endl;
+		return -EINVAL;
+	}
+
+	/*
+	 * Scanline buffer, has to be large enough to store both a RAW scanline
+	 * or a thumbnail scanline. The latter will always be much smaller than
+	 * the former as we downscale by 16 in both directions.
+	 */
+	uint8_t scanline[(config.size.width * info->bitsPerSample + 7) / 8];
+
+	toff_t rawIFDOffset = 0;
+	toff_t exifIFDOffset = 0;
+
+	/*
+	 * Start with a thumbnail in IFD 0 for compatibility with TIFF baseline
+	 * readers, as required by the TIFF/EP specification. Tags that apply to
+	 * the whole file are stored here.
+	 */
+	const uint8_t version[] = { 1, 2, 0, 0 };
+
+	TIFFSetField(tif, TIFFTAG_DNGVERSION, version);
+	TIFFSetField(tif, TIFFTAG_DNGBACKWARDVERSION, version);
+	TIFFSetField(tif, TIFFTAG_FILLORDER, FILLORDER_MSB2LSB);
+	TIFFSetField(tif, TIFFTAG_MAKE, "libcamera");
+
+	const auto &model = cameraProperties.get(properties::Model);
+	if (model) {
+		TIFFSetField(tif, TIFFTAG_MODEL, model->c_str());
+		/* \todo set TIFFTAG_UNIQUECAMERAMODEL. */
+	}
+
+	TIFFSetField(tif, TIFFTAG_SOFTWARE, "qcam");
+	TIFFSetField(tif, TIFFTAG_ORIENTATION, ORIENTATION_TOPLEFT);
+
+	/*
+	 * Thumbnail-specific tags. The thumbnail is stored as an RGB image
+	 * with 1/16 of the raw image resolution. Greyscale would save space,
+	 * but doesn't seem well supported by RawTherapee.
+	 */
+	TIFFSetField(tif, TIFFTAG_SUBFILETYPE, FILETYPE_REDUCEDIMAGE);
+	TIFFSetField(tif, TIFFTAG_IMAGEWIDTH, config.size.width / 16);
+	TIFFSetField(tif, TIFFTAG_IMAGELENGTH, config.size.height / 16);
+	TIFFSetField(tif, TIFFTAG_BITSPERSAMPLE, 8);
+	TIFFSetField(tif, TIFFTAG_COMPRESSION, COMPRESSION_NONE);
+	TIFFSetField(tif, TIFFTAG_PHOTOMETRIC, PHOTOMETRIC_RGB);
+	TIFFSetField(tif, TIFFTAG_SAMPLESPERPIXEL, 3);
+	TIFFSetField(tif, TIFFTAG_PLANARCONFIG, PLANARCONFIG_CONTIG);
+	TIFFSetField(tif, TIFFTAG_SAMPLEFORMAT, SAMPLEFORMAT_UINT);
+
+	/*
+	 * Fill in some reasonable colour information in the DNG. We supply
+	 * the "neutral" colour values which determine the white balance, and the
+	 * "ColorMatrix1" which converts XYZ to (un-white-balanced) camera RGB.
+	 * Note that this is not a "proper" colour calibration for the DNG,
+	 * nonetheless, many tools should be able to render the colours better.
+	 */
+	float neutral[3] = { 1, 1, 1 };
+	Matrix3d wbGain = Matrix3d::identity();
+	/* From http://www.brucelindbloom.com/index.html?Eqn_RGB_XYZ_Matrix.html */
+	const Matrix3d rgb2xyz(0.4124564, 0.3575761, 0.1804375,
+			       0.2126729, 0.7151522, 0.0721750,
+			       0.0193339, 0.1191920, 0.9503041);
+	Matrix3d ccm = Matrix3d::identity();
+	/*
+	 * Pick a reasonable number eps to protect against singularities. It
+	 * should be comfortably larger than the point at which we run into
+	 * numerical trouble, yet smaller than any plausible gain that we might
+	 * apply to a colour, either explicitly or as part of the colour matrix.
+	 */
+	const double eps = 1e-2;
+
+	const auto &colourGains = metadata.get(controls::ColourGains);
+	if (colourGains) {
+		if ((*colourGains)[0] > eps && (*colourGains)[1] > eps) {
+			wbGain = Matrix3d::diag((*colourGains)[0], 1, (*colourGains)[1]);
+			neutral[0] = 1.0 / (*colourGains)[0]; /* red */
+			neutral[2] = 1.0 / (*colourGains)[1]; /* blue */
+		}
+	}
+
+	const auto &ccmControl = metadata.get(controls::ColourCorrectionMatrix);
+	if (ccmControl) {
+		Matrix3d ccmSupplied(*ccmControl);
+		if (ccmSupplied.determinant() > eps)
+			ccm = ccmSupplied;
+	}
+
+	/*
+	 * rgb2xyz is known to be invertible, and we've ensured above that both
+	 * the ccm and wbGain matrices are non-singular, so the product of all
+	 * three is guaranteed to be invertible too.
+	 */
+	Matrix3d colorMatrix1 = (rgb2xyz * ccm * wbGain).inverse();
+
+	TIFFSetField(tif, TIFFTAG_COLORMATRIX1, 9, colorMatrix1.m);
+	TIFFSetField(tif, TIFFTAG_ASSHOTNEUTRAL, 3, neutral);
+
+	/*
+	 * Reserve space for the SubIFD and ExifIFD tags, pointing to the IFD
+	 * for the raw image and EXIF data respectively. The real offsets will
+	 * be set later.
+	 */
+	TIFFSetField(tif, TIFFTAG_SUBIFD, 1, &rawIFDOffset);
+	TIFFSetField(tif, TIFFTAG_EXIFIFD, exifIFDOffset);
+
+	/* Write the thumbnail. */
+	const uint8_t *row = static_cast<const uint8_t *>(data);
+	for (unsigned int y = 0; y < config.size.height / 16; y++) {
+		info->thumbScanline(*info, &scanline, row,
+				    config.size.width / 16, config.stride);
+
+		if (TIFFWriteScanline(tif, &scanline, y, 0) != 1) {
+			std::cerr << "Failed to write thumbnail scanline"
+				  << std::endl;
+			TIFFClose(tif);
+			return -EINVAL;
+		}
+
+		row += config.stride * 16;
+	}
+
+	TIFFWriteDirectory(tif);
+
+	/* Create a new IFD for the RAW image. */
+	const uint16_t cfaRepeatPatternDim[] = { 2, 2 };
+	const uint8_t cfaPlaneColor[] = {
+		CFAPatternRed,
+		CFAPatternGreen,
+		CFAPatternBlue
+	};
+
+	TIFFSetField(tif, TIFFTAG_SUBFILETYPE, 0);
+	TIFFSetField(tif, TIFFTAG_IMAGEWIDTH, config.size.width);
+	TIFFSetField(tif, TIFFTAG_IMAGELENGTH, config.size.height);
+	TIFFSetField(tif, TIFFTAG_BITSPERSAMPLE, info->bitsPerSample);
+	TIFFSetField(tif, TIFFTAG_COMPRESSION, COMPRESSION_NONE);
+	TIFFSetField(tif, TIFFTAG_PHOTOMETRIC, PHOTOMETRIC_CFA);
+	TIFFSetField(tif, TIFFTAG_SAMPLESPERPIXEL, 1);
+	TIFFSetField(tif, TIFFTAG_PLANARCONFIG, PLANARCONFIG_CONTIG);
+	TIFFSetField(tif, TIFFTAG_SAMPLEFORMAT, SAMPLEFORMAT_UINT);
+	TIFFSetField(tif, TIFFTAG_CFAREPEATPATTERNDIM, cfaRepeatPatternDim);
+	if (TIFFLIB_VERSION < 20201219)
+		TIFFSetField(tif, TIFFTAG_CFAPATTERN, info->pattern);
+	else
+		TIFFSetField(tif, TIFFTAG_CFAPATTERN, 4, info->pattern);
+	TIFFSetField(tif, TIFFTAG_CFAPLANECOLOR, 3, cfaPlaneColor);
+	TIFFSetField(tif, TIFFTAG_CFALAYOUT, 1);
+
+	const uint16_t blackLevelRepeatDim[] = { 2, 2 };
+	float blackLevel[] = { 0.0f, 0.0f, 0.0f, 0.0f };
+	uint32_t whiteLevel = (1 << info->bitsPerSample) - 1;
+
+	const auto &blackLevels = metadata.get(controls::SensorBlackLevels);
+	if (blackLevels) {
+		Span<const int32_t, 4> levels = *blackLevels;
+
+		/*
+		 * The black levels control is specified in R, Gr, Gb, B order.
+		 * Map it to the TIFF tag that is specified in CFA pattern
+		 * order.
+		 */
+		unsigned int green = (info->pattern[0] == CFAPatternRed ||
+				      info->pattern[1] == CFAPatternRed)
+				   ? 0 : 1;
+
+		for (unsigned int i = 0; i < 4; ++i) {
+			unsigned int level;
+
+			switch (info->pattern[i]) {
+			case CFAPatternRed:
+				level = levels[0];
+				break;
+			case CFAPatternGreen:
+				level = levels[green + 1];
+				green = (green + 1) % 2;
+				break;
+			case CFAPatternBlue:
+			default:
+				level = levels[3];
+				break;
+			}
+
+			/* Map the 16-bit value to the bits per sample range. */
+			blackLevel[i] = level >> (16 - info->bitsPerSample);
+		}
+	}
+
+	TIFFSetField(tif, TIFFTAG_BLACKLEVELREPEATDIM, &blackLevelRepeatDim);
+	TIFFSetField(tif, TIFFTAG_BLACKLEVEL, 4, &blackLevel);
+	TIFFSetField(tif, TIFFTAG_WHITELEVEL, 1, &whiteLevel);
+
+	/* Write RAW content. */
+	row = static_cast<const uint8_t *>(data);
+	for (unsigned int y = 0; y < config.size.height; y++) {
+		info->packScanline(&scanline, row, config.size.width);
+
+		if (TIFFWriteScanline(tif, &scanline, y, 0) != 1) {
+			std::cerr << "Failed to write RAW scanline"
+				  << std::endl;
+			TIFFClose(tif);
+			return -EINVAL;
+		}
+
+		row += config.stride;
+	}
+
+	/* Checkpoint the IFD to retrieve its offset, and write it out. */
+	TIFFCheckpointDirectory(tif);
+	rawIFDOffset = TIFFCurrentDirOffset(tif);
+	TIFFWriteDirectory(tif);
+
+	/* Create a new IFD for the EXIF data and fill it. */
+	TIFFCreateEXIFDirectory(tif);
+
+	/* Store creation time. */
+	time_t rawtime;
+	struct tm *timeinfo;
+	char strTime[20];
+
+	time(&rawtime);
+	timeinfo = localtime(&rawtime);
+	strftime(strTime, 20, "%Y:%m:%d %H:%M:%S", timeinfo);
+
+	/*
+	 * \todo Handle timezone information by setting OffsetTimeOriginal and
+	 * OffsetTimeDigitized once libtiff catches up to the specification and
+	 * has EXIFTAG_ defines to handle them.
+	 */
+	TIFFSetField(tif, EXIFTAG_DATETIMEORIGINAL, strTime);
+	TIFFSetField(tif, EXIFTAG_DATETIMEDIGITIZED, strTime);
+
+	const auto &analogGain = metadata.get(controls::AnalogueGain);
+	if (analogGain) {
+		uint16_t iso = std::min(std::max(*analogGain * 100, 0.0f), 65535.0f);
+		TIFFSetField(tif, EXIFTAG_ISOSPEEDRATINGS, 1, &iso);
+	}
+
+	const auto &exposureTime = metadata.get(controls::ExposureTime);
+	if (exposureTime)
+		TIFFSetField(tif, EXIFTAG_EXPOSURETIME, *exposureTime / 1e6);
+
+	TIFFWriteCustomDirectory(tif, &exifIFDOffset);
+
+	/* Update the IFD offsets and close the file. */
+	TIFFSetDirectory(tif, 0);
+	TIFFSetField(tif, TIFFTAG_SUBIFD, 1, &rawIFDOffset);
+	TIFFSetField(tif, TIFFTAG_EXIFIFD, exifIFDOffset);
+	TIFFWriteDirectory(tif);
+
+	TIFFClose(tif);
+
+	return 0;
+}