# BUILDING

rsgain builds natively on Unix and Windows, and features a cross-platform CMake build system. The following external dependencies are required:

- [libebur128](https://github.com/jiixyj/libebur128) or [ebur128](https://github.com/sdroege/ebur128)
- TagLib
- FFmpeg, specifically the libraries:
    + libavformat
    + libavcodec
    + libswresample
    + libavutil
- inih
- Unix only: fmt (see [below](#fmt-library))

The Windows version uses C++23, and the Unix versions use either C++20 or C++23 depending on the compiler. As such, it requires a relatively modern compiler to build:

- On Windows, Visual Studio 2022 17.7 or later is required
- On Linux, use GCC 10 or later
- On macOS, the latest available Xcode for your machine should work

### fmt library

The features that rsgain uses from the fmt library have been integrated into the C++20 and C++23 standards, specifically the `<format>` and `<print>` headers. The standard library implementations are planned to completely replace rsgain's fmt dependency in the future. To support the transition, rsgain can use either the fmt library or standard library, depending on platform:
- MSVC has full support in the standard library since version 19.37. The fmt library has been dropped from the Windows version in favor of the standard library implementation
- GCC (libstdc++) has full support in the standard library since version 14. Pass `-DUSE_STD_FORMAT=ON` to `cmake` to use the standard library instead of the fmt library
- Clang (libc++) has full support in the standard library since version 18. Enable it using the configuration switch described above for GCC

### Matroska/WebM Support
Matroska/WebM support requires TagLib ≥2.2.

## Unix

Before starting, make sure you have the development tools Git, CMake and pkg-config installed.

Install the required dependencies:

### APT-based Linux (Debian, Ubuntu, Mint etc.)

```bash
sudo apt install libebur128-dev libtag1-dev libavformat-dev libavcodec-dev libswresample-dev libavutil-dev libfmt-dev libinih-dev
```

### Pacman-based Linux (Arch, Manjaro, etc.)

```bash
sudo pacman -S libebur128 taglib ffmpeg fmt libinih
```

### DNF-based Linux (Fedora)

FFmpeg is in the official repos in Fedora 36 and later only. If you're on an earlier version you will need to find an alternative source.

```bash
sudo dnf install libebur128-devel taglib-devel libavformat-free-devel libavcodec-free-devel libswresample-free-devel libavutil-free-devel fmt-devel inih-devel
```

### Portage-based Linux (Gentoo, LiGurOS, Xenia)

```bash
sudo emerge --ask --noreplace --tree media-libs/libebur128 media-libs/taglib media-video/ffmpeg dev-libs/inih dev-libs/libfmt
```

### macOS (Homebrew)

```bash
brew install libebur128 taglib ffmpeg fmt inih 
```

### FreeBSD (Packages)

```bash
pkg install ebur128 taglib libfmt inih ffmpeg
```

### Building

Clone the repo and create a build directory:

```bash
git clone https://github.com/complexlogic/rsgain.git
cd rsgain
mkdir build && cd build
```

Generate the Makefile:

```bash
cmake .. -DCMAKE_BUILD_TYPE=Release
```

Build and test the program:

```bash
make
./rsgain
```

Optionally, install to your system directories:

```bash
sudo make install
```

By default, this will install rsgain with a prefix of `/usr/local`. If you want a different prefix, re-run the CMake generation step with `-DCMAKE_INSTALL_PREFIX=prefix`.

#### Deb Packages

The build system includes support for .deb packages via CPack. Pass `-DPACKAGE=DEB` and `-DCMAKE_INSTALL_PREFIX=/usr` to cmake. Then, build the package with:

```bash
make package
```

By default, this will build a package for the amd64 architechture. To build the package for a different architecture, pass `-DCPACK_DEBIAN_PACKAGE_ARCHITECTURE=architecture` to cmake.

## Windows

The Windows toolchain consists of Visual Studio and vcpkg in addition to Git and CMake. Before starting, make sure that Visual Studio is installed with C++ core desktop features and C++ CMake tools. The free Community Edition is sufficient.

Clone the repo and create a build directory:

```bash
git clone https://github.com/complexlogic/rsgain.git
cd rsgain
mkdir build
cd build
```

Build the dependencies and generate the Visual Studio project files:

```bash
cmake .. -DVCPKG=ON
```

Build and test the program:

```bash
cmake --build . --config Release
.\Release\rsgain.exe
```

Optionally, generate a zipped install package:

```bash
cmake --build . --config Release --target package
```
