DNG SDK CMake Build System

CMake build system for Adobe DNG SDK 1.7.1 with support for system libraries and cross-platform compilation.

Overview

This CMake build system allows building Adobe DNG SDK 1.7.1 using system-provided libraries instead of the bundled sources that may be obsolete or inefficient. It prioritizes using modern system libraries for ZIP, JPEGXL, JPEG, and optionally Boost (uuid) and XMP.

Prerequisites

Adobe DNG SDK

Download Adobe DNG SDK 1.7.1 from Adobe: Digital Negative (DNG)

Extract the SDK to the same folder as DNG-Cmake.

System Libraries

The build system uses the following system libraries by default:

• zlib (ZIP compression) zlib or zlib-ng in zlib compatible mode
• libjpeg (JPEG support) jpeg or turbo-jpeg
• libjxl (JPEGXL support)
• lcms2 (required by libjxl_cms for color transforms)
• libexpat (XML parsing)
• libbrotli (Brotli compression for JPEGXL)
• libhwy (Google Highway SIMD library for JPEGXL)
• Boost (uuid) - bundled in XMP SDK or optionally can use system Boost library
• XMP SDK (can use system library /not tested/ - note that official XMP SDK differs from the XMP SDK included in DNG SDK archive)

Bundled Library Options

By default, the build system prioritizes system libraries for better performance and security. However, you can optionally use bundled versions:

• DNG_BUNDLED_JPEG=OFF (default) - Use system libjpeg
• DNG_BUNDLED_JXL=OFF (default) - Use system libjxl
• XMP_USE_SYSTEM_ZLIB=ON (default) - Use system zlib
• XMP_USE_SYSTEM_BOOST=OFF (default) - Use bundled Boost UUID headers

To use bundled libraries instead of system libraries:

cmake -DDNG_BUNDLED_JPEG=ON -DDNG_BUNDLED_JXL=ON -DXMP_USE_SYSTEM_ZLIB=OFF -DXMP_USE_SYSTEM_BOOST=ON ..

Cache Variable Management

The build system preserves important CMake cache variables across reconfigurations:

• CMAKE_MSVC_RUNTIME_LIBRARY - Set to MultiThreaded$<$<CONFIG:Debug>:Debug> for static runtime linking
• CMAKE_DEBUG_POSTFIX - Set to "d" for debug library naming (e.g., dng_sdkd.lib)
• CMAKE_PREFIX_PATH - Preserved for system library search paths
• CMAKE_INSTALL_PREFIX - Defaults to ${CMAKE_SOURCE_DIR}/install

These variables are cached and persist across cmake reconfigurations, ensuring consistent builds.

Debug/Release Library Linking

The build system properly handles debug and release library linking using CMake generator expressions and imported targets with config-specific properties. This ensures that:

• Debug builds link only debug libraries (e.g., libjpegd.lib, jxld.lib)
• Release builds link only release libraries (e.g., libjpeg.lib, jxl.lib)
• No mixing of debug and release libraries in the same build
• No duplicate linking - libraries are linked only once through transitive dependencies

This prevents linker errors, runtime library mismatches, and ensures optimal performance for each build configuration.

How It Works

1. dng_sdk library links dependencies with PUBLIC linkage, making them available to consumers
2. dng_validate links only dng_sdk and gets all dependencies transitively
3. Imported targets use IMPORTED_LOCATION_RELEASE and IMPORTED_LOCATION_DEBUG properties
4. CMake automatically selects the correct library variant based on build configuration

Platform Requirements

Windows (MSVC)

• Visual Studio 2017 or later
• CMake 3.16 or later
• Ninja build system (optional)

Supported configurations:

• CMake + MSVC
• CMake + Visual Studio 2017 Generator
• Ninja + MSVC

Linux

• CMake 3.16 or later
• Clang 20 or GCC (GCC not tested)
• Ninja build system (optional)

Supported configurations:

• Ninja + Clang
• Ninja + GCC (not tested)

Installation of Dependencies

Ubuntu/Debian

sudo apt update
sudo apt install -y \
    clang-20 \
    cmake \
    ninja-build \
    build-essential \
    libjpeg-dev \
    libjxl-dev \
    liblcms2-dev \
    libexpat1-dev \
    zlib1g-dev \
    libbrotli-dev \
    libhwy-dev \
    libboost-dev \
    pkg-config

Windows

Use vcpkg or manually install the required libraries:

vcpkg install zlib:x64-windows libjpeg-turbo:x64-windows libjxl:x64-windows lcms2:x64-windows expat:x64-windows boost-uuid:x64-windows

Building

Linux with Clang + Ninja

1. Create a build directory:

mkdir build
cd build

2. Configure with Clang:

cmake -G Ninja \
      -DCMAKE_C_COMPILER=clang-20 \
      -DCMAKE_CXX_COMPILER=clang++-20 \
      -DCMAKE_BUILD_TYPE=Release \
      -DDNG_CLANG_STDLIB=default \
      -DCMAKE_PREFIX_PATH=/path/to/deps \
      ..

ABI note (Clang on Linux): pick DNG_CLANG_STDLIB to match your dependency ABI:

• default (recommended): use Clang toolchain default (typically libstdc++ on Linux)
• libstdc++: force GNU C++ standard library
• libc++: force LLVM C++ standard library

Examples:

• -DDNG_CLANG_STDLIB=libstdc++ -DCMAKE_PREFIX_PATH=/mnt/e/UBSTD/Release
• -DDNG_CLANG_STDLIB=libc++ -DCMAKE_PREFIX_PATH=/mnt/e/UBc/Release

3. Build:

ninja

Windows with Visual Studio 2022

1. Create a build directory:

mkdir build
cd build

2. Configure:

cmake -G "Visual Studio 17 2022" -A x64 -DCMAKE_BUILD_TYPE=Release ..

3. Build:

cmake --build . --config Release

Windows with Ninja + MSVC

1. Open Visual Studio Developer Command Prompt
2. Create a build directory:

mkdir build
cd build

3. Configure:

cmake -G Ninja -DCMAKE_BUILD_TYPE=Release ..

4. Build:

ninja

Building Documentation

To generate API documentation with Doxygen:

Prerequisites

Install Doxygen:

• Ubuntu/Debian: sudo apt install doxygen graphviz
• Windows: Download from doxygen.nl/download.html
• macOS: brew install doxygen graphviz

Note: Graphviz (dot) is optional but recommended for generating class diagrams.

Generate Documentation

1. Configure with documentation enabled:

cmake -DBUILD_DOCUMENTATION=ON ..

2. Build (documentation is built automatically):

# Standard build - documentation is generated automatically
cmake --build .

# Or explicitly build just documentation
cmake --build . --target docs

3. Install (documentation is installed automatically):

# Standard install - documentation is included
cmake --install .

The generated HTML documentation will be located in:

• Build directory: build/docs/dng_sdk/html/ and build/docs/xmp/html/
• After installation (Unix): <install-prefix>/share/doc/dng_sdk/ and <install-prefix>/share/doc/xmp/
• After installation (Windows): <install-prefix>/doc/dng_sdk/ and <install-prefix>/doc/xmp/

Note: When BUILD_DOCUMENTATION=ON, documentation is generated during the normal build process and installed with the standard install target. You don't need to use separate commands or components.

CMake Options

Core Build Options

• -DBUILD_DNG_VALIDATE=ON/OFF - Build dng_validate tool (default: ON)
• -DDNG_THREAD_SAFE=ON/OFF - Enable thread-safe DNG SDK (default: ON)
• -DDNG_WITH_JPEG=ON/OFF - Enable JPEG support via libjpeg (default: ON)
• -DDNG_WITH_JXL=ON/OFF - Enable JPEG-XL support via libjxl (default: ON)
• -DDNG_WITH_XMP=ON/OFF - Enable XMP metadata support (default: ON)

Debug and Diagnostic Options

• -DDNG_REPORT_ERRORS=ON/OFF - Enable error reporting (default: ON)
• -DDNG_VALIDATE=ON/OFF - Enable validation checks (default: OFF)
• -DDNG_DEBUG_PIXEL_TYPE=ON/OFF - Enable pixel type debugging (default: OFF)
• -DDNG_LOG_UPDATE_METADATA=ON/OFF - Log metadata updates (default: OFF)
• -DDNG_OPT_GETBITS_MATH=ON/OFF - Use optimized bit extraction (default: OFF)

Documentation Generation

• -DBUILD_DOCUMENTATION=ON/OFF - Build API documentation with Doxygen (default: OFF)

When enabled, requires Doxygen to be installed on your system. Generates HTML documentation for both DNG SDK and XMP Toolkit APIs.

Advanced Options

• -DXMP_USE_SYSTEM_BOOST=ON/OFF - Use system Boost UUID instead of vendored (default: OFF)
• -DXMP_ROOT=<path> - Path to XMP toolkit root if not in repo
• -DCMAKE_PREFIX_PATH=<paths> - Semicolon-separated library search paths
• -DDNG_CLANG_STDLIB=default|libstdc++|libc++ - Clang C++ standard library selection on non-MSVC Clang builds (default: default)
• -DDNG_TARGET_PLATFORM=auto|windows|macos|ios|linux|android|web - Resolved platform macros exported to consumers (default: auto)

Output

The build produces static libraries (tested):

• libdng_sdk.a / dng_sdk.lib - Static DNG SDK library
• libXMPCoreStatic.a / XMPCoreStatic.lib - XMP Core static library
• libXMPFilesStatic.a / XMPFilesStatic.lib - XMP Files static library
• dng_validate / dng_validate.exe - Command-line DNG validation tool

Note: Only static builds have been tested on Windows and Linux. Shared library builds are not currently supported.

Project Structure

• CMakeLists.txt - Root CMake configuration
• cmake/ - CMake patches and helper files
  • dng_jxl.patch - JPEGXL integration patch
• dng_sdk/ - Adobe DNG SDK source (user-provided)
• xmp/ - XMP SDK source (from DNG SDK archive)

Notes

• This build system prioritizes system libraries over bundled SDK sources for better performance and security
• All necessary preprocessor definitions and include paths from original Visual Studio projects are preserved
• JPEGXL and JPEG support are enabled by default
• XMP metadata support is fully integrated using the XMP SDK from DNG SDK archive
• System XMP SDK support is available but not tested (official XMP SDK has differences)
• System Boost library (uuid) can be used instead of bundled sources

Testing Status

• Tested platforms: Windows (MSVC), Linux (Clang)
• Tested build types: Static libraries only
• Tested features: XMP, JPEGXL, JPEG, dng_validate
• Not tested: GCC compilation, dynamic libraries, system XMP SDK or Boost

Troubleshooting

Missing Dependencies

Ensure all required development packages are installed. The build system will attempt to find system libraries automatically.

WSL2 Users

Make sure you have the latest distribution and all packages are up to date:

sudo apt update && sudo apt upgrade

vcpkg Integration

If using vcpkg on Windows, specify the toolchain file:

cmake -DCMAKE_TOOLCHAIN_FILE=path/to/vcpkg/scripts/buildsystems/vcpkg.cmake ..