qcam: Add DNGWriter

Add an initial DNG file writer. The writer can only deal with a small
set of pixel formats. The generated file is consumable by standard
tools. The writer needs to be extended to write more metadata to the
generated file.

Signed-off-by: Niklas Söderlund <niklas.soderlund@ragnatech.se>
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>

src/qcam/dng_writer.cpp

@@ -0,0 +1,165 @@
+/* SPDX-License-Identifier: LGPL-2.1-or-later */
+/*
+ * Copyright (C) 2020, Raspberry Pi (Trading) Ltd.
+ *
+ * dng_writer.cpp - DNG writer
+ */
+
+#include "dng_writer.h"
+
+#include <iostream>
+#include <map>
+
+#include <tiffio.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 *, const void *, unsigned int);
+};
+
+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;
+	}
+}
+
+static const std::map<PixelFormat, FormatInfo> formatInfo = {
+	{ PixelFormat(DRM_FORMAT_SBGGR10, MIPI_FORMAT_MOD_CSI2_PACKED), {
+		.bitsPerSample = 10,
+		.pattern = { CFAPatternBlue, CFAPatternGreen, CFAPatternGreen, CFAPatternRed },
+		.packScanline = packScanlineSBGGR10P,
+	} },
+	{ PixelFormat(DRM_FORMAT_SGBRG10, MIPI_FORMAT_MOD_CSI2_PACKED), {
+		.bitsPerSample = 10,
+		.pattern = { CFAPatternGreen, CFAPatternBlue, CFAPatternRed, CFAPatternGreen },
+		packScanlineSBGGR10P,
+	} },
+	{ PixelFormat(DRM_FORMAT_SGRBG10, MIPI_FORMAT_MOD_CSI2_PACKED), {
+		.bitsPerSample = 10,
+		.pattern = { CFAPatternGreen, CFAPatternRed, CFAPatternBlue, CFAPatternGreen },
+		.packScanline = packScanlineSBGGR10P,
+	} },
+	{ PixelFormat(DRM_FORMAT_SRGGB10, MIPI_FORMAT_MOD_CSI2_PACKED), {
+		.bitsPerSample = 10,
+		.pattern = { CFAPatternRed, CFAPatternGreen, CFAPatternGreen, CFAPatternBlue },
+		.packScanline = packScanlineSBGGR10P,
+	} },
+	{ PixelFormat(DRM_FORMAT_SBGGR12, MIPI_FORMAT_MOD_CSI2_PACKED), {
+		.bitsPerSample = 12,
+		.pattern = { CFAPatternBlue, CFAPatternGreen, CFAPatternGreen, CFAPatternRed },
+		.packScanline = packScanlineSBGGR12P,
+	} },
+	{ PixelFormat(DRM_FORMAT_SGBRG12, MIPI_FORMAT_MOD_CSI2_PACKED), {
+		.bitsPerSample = 12,
+		.pattern = { CFAPatternGreen, CFAPatternBlue, CFAPatternRed, CFAPatternGreen },
+		.packScanline = packScanlineSBGGR12P,
+	} },
+	{ PixelFormat(DRM_FORMAT_SGRBG12, MIPI_FORMAT_MOD_CSI2_PACKED), {
+		.bitsPerSample = 12,
+		.pattern = { CFAPatternGreen, CFAPatternRed, CFAPatternBlue, CFAPatternGreen },
+		.packScanline = packScanlineSBGGR12P,
+	} },
+	{ PixelFormat(DRM_FORMAT_SRGGB12, MIPI_FORMAT_MOD_CSI2_PACKED), {
+		.bitsPerSample = 12,
+		.pattern = { CFAPatternRed, CFAPatternGreen, CFAPatternGreen, CFAPatternBlue },
+		.packScanline = packScanlineSBGGR12P,
+	} },
+};
+
+int DNGWriter::write(const char *filename, const Camera *camera,
+		     const StreamConfiguration &config,
+		     const FrameBuffer *buffer, const void *data)
+{
+	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;
+	}
+
+	const uint8_t version[] = { 1, 2, 0, 0 };
+	const uint16_t cfa_repeatpatterndim[] = { 2, 2 };
+	TIFFSetField(tif, TIFFTAG_DNGVERSION, version);
+	TIFFSetField(tif, TIFFTAG_DNGBACKWARDVERSION, version);
+	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_FILLORDER, FILLORDER_MSB2LSB);
+	TIFFSetField(tif, TIFFTAG_MAKE, "libcamera");
+	TIFFSetField(tif, TIFFTAG_MODEL, camera->name().c_str());
+	TIFFSetField(tif, TIFFTAG_UNIQUECAMERAMODEL, camera->name().c_str());
+	TIFFSetField(tif, TIFFTAG_ORIENTATION, ORIENTATION_TOPLEFT);
+	TIFFSetField(tif, TIFFTAG_SAMPLESPERPIXEL, 1);
+	TIFFSetField(tif, TIFFTAG_PLANARCONFIG, PLANARCONFIG_CONTIG);
+	TIFFSetField(tif, TIFFTAG_SOFTWARE, "qcam");
+	TIFFSetField(tif, TIFFTAG_SAMPLEFORMAT, SAMPLEFORMAT_UINT);
+	TIFFSetField(tif, TIFFTAG_CFAREPEATPATTERNDIM, cfa_repeatpatterndim);
+	TIFFSetField(tif, TIFFTAG_CFAPATTERN, info->pattern);
+	TIFFSetField(tif, TIFFTAG_CFAPLANECOLOR, 3, "\00\01\02");
+	TIFFSetField(tif, TIFFTAG_CFALAYOUT, 1);
+
+	/* \todo Add more EXIF fields to output. */
+
+	/* Write RAW content. */
+	const uint8_t *row = static_cast<const uint8_t *>(data);
+	uint8_t scanline[(config.size.width * info->bitsPerSample + 7) / 8];
+	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 scanline" << std::endl;
+			TIFFClose(tif);
+			return -EINVAL;
+		}
+
+		row += config.stride;
+	}
+
+	TIFFWriteDirectory(tif);
+
+	TIFFClose(tif);
+
+	return 0;
+}

src/qcam/dng_writer.h

@@ -0,0 +1,29 @@
+/* SPDX-License-Identifier: LGPL-2.1-or-later */
+/*
+ * Copyright (C) 2020, Raspberry Pi (Trading) Ltd.
+ *
+ * dng_writer.h - DNG writer
+ */
+#ifndef __LIBCAMERA_DNG_WRITER_H__
+#define __LIBCAMERA_DNG_WRITER_H__
+
+#ifdef HAVE_TIFF
+#define HAVE_DNG
+
+#include <libcamera/buffer.h>
+#include <libcamera/camera.h>
+#include <libcamera/stream.h>
+
+using namespace libcamera;
+
+class DNGWriter
+{
+public:
+	static int write(const char *filename, const Camera *camera,
+			 const StreamConfiguration &config,
+			 const FrameBuffer *buffer, const void *data);
+};
+
+#endif /* HAVE_TIFF */
+
+#endif /* __LIBCAMERA_DNG_WRITER_H__ */

src/qcam/meson.build

@@ -1,9 +1,9 @@
 qcam_sources = files([
+    '../cam/options.cpp',
+    '../cam/stream_options.cpp',
     'format_converter.cpp',
     'main.cpp',
     'main_window.cpp',
-    '../cam/options.cpp',
-    '../cam/stream_options.cpp',
     'viewfinder.cpp',
 ])
 
@@ -23,8 +23,22 @@ qt5_dep = dependency('qt5',
                      required : false)
 
 if qt5_dep.found()
+    qcam_deps = [
+        libcamera_dep,
+        qt5_dep,
+    ]
+
     qt5_cpp_args = [ '-DQT_NO_KEYWORDS' ]
 
+    tiff_dep = dependency('libtiff-4', required : false)
+    if tiff_dep.found()
+        qt5_cpp_args += [ '-DHAVE_TIFF' ]
+        qcam_deps += [ tiff_dep ]
+        qcam_sources += files([
+            'dng_writer.cpp',
+        ])
+    endif
+
     # gcc 9 introduced a deprecated-copy warning that is triggered by Qt until
     # Qt 5.13. clang 10 introduced the same warning, but detects more issues
     # that are not fixed in Qt yet. Disable the warning manually in both cases.
@@ -40,6 +54,6 @@ if qt5_dep.found()
 
     qcam  = executable('qcam', qcam_sources, resources,
                        install : true,
-                       dependencies : [libcamera_dep, qt5_dep],
+                       dependencies : qcam_deps,
                        cpp_args : qt5_cpp_args)
 endif