# Getting libaec
The source code of libaec is hosted at DKRZ GitLab.
## Source code and binary releases
The latest releases of libaec can be downloaded at the following
locations:
https://gitlab.dkrz.de/k202009/libaec/-/releases
or
https://github.com/MathisRosenhauer/libaec/releases
## Developer snapshot
```shell
git clone https://gitlab.dkrz.de/k202009/libaec.git
```
# Installation
## General considerations
Libaec achieves the best performance on 64 bit systems. The library
will work correctly on 32 bit systems but encoding and decoding
performance will be much lower.
## Installation from source code release with configure
The most common installation procedure on Unix-like systems looks as
follows:
Unpack the tar archive and change into the unpacked directory.
```shell
mkdir build
cd build
../configure
make check install
```
## Installation from source code release with CMake
As an alternative, you can use CMake to install libaec.
Unpack the tar archive and change into the unpacked directory.
```shell
mkdir build
cd build
cmake ..
make install
```
You can set options for compiling using the CMake GUI by replacing the cmake
command with
```shell
cmake-gui ..
```
or by setting the options manually, e.g.
```shell
cmake -DCMAKE_BUILD_TYPE=Release -DCMAKE_INSTALL_PREFIX=~/local ..
```
CMake can also generate project files for Microsoft Visual Studio when
used in Windows.
## Installation from cloned repository
The configure script is not included in the repository. You can
generate it with autotools and gnulib:
```shell
cd libaec
gnulib-tool --import lib-symbol-visibility
autoreconf -iv
mkdir build
cd build
../configure
make check install
```
# Intel compiler settings
The Intel compiler can improve performance by vectorizing certain
parts of the code on x86 architectures. Assuming your CPU supports
AVX2, the following options will increase encoding speed.
```shell
../configure CC=icc
make CFLAGS="-O3 -xCORE-AVX2" bench
```
On a 3.4 GHz E3-1240 v3 we see more than 400 MiB/s for encoding
typical data.
Using other SIMD instruction sets on older CPUs may also help.