| # libavif [](https://ci.appveyor.com/project/louquillio/libavif) [](https://travis-ci.com/AOMediaCodec/libavif) | |
| This library aims to be a friendly, portable C implementation of the AV1 Image File Format, as described here: | |
| <https://aomediacodec.github.io/av1-avif/> | |
| It is a work-in-progress, but can already encode and decode all AOM supported YUV formats and bit depths (with alpha). | |
| For now, it is recommended that you checkout/use [tagged releases](https://github.com/AOMediaCodec/libavif/releases) instead of just using the master branch. I will regularly create new versions as bugfixes and features are added. | |
| ## Usage | |
| Please see the examples in the examples directory. If you're already building `libavif`, enable the CMake option `AVIF_BUILD_EXAMPLES` in order to build and run the examples too. | |
| ## Build Notes | |
| Building libavif requires [CMake](https://cmake.org/). | |
| No AV1 codecs are enabled by default. Enable them by enabling any of the | |
| following CMake options: | |
| * `AVIF_CODEC_AOM` - requires CMake, NASM | |
| * `AVIF_CODEC_DAV1D` - requires Meson, Ninja, NASM | |
| * `AVIF_CODEC_LIBGAV1` - requires CMake, Ninja | |
| * `AVIF_CODEC_RAV1E` - requires cargo (Rust), NASM | |
| These libraries (in their C API form) must be externally available | |
| (discoverable via CMake's `FIND_LIBRARY`) to use them, or if libavif is | |
| a child CMake project, the appropriate CMake target must already exist | |
| by the time libavif's CMake scripts are executed. | |
| ## Local / Static Builds | |
| The `ext/` subdirectory contains a handful of basic scripts which each pull | |
| down a known-good copy of an AV1 codec and make a local static library build. | |
| If you want to statically link any codec into your local (static) build of | |
| libavif, building using one of these scripts and then enabling the associated | |
| `AVIF_LOCAL_*` is a convenient method, but you must make sure to disable | |
| `BUILD_SHARED_LIBS` in CMake to instruct it to make a static libavif library. | |
| If you want to build/install shared libraries for AV1 codecs, you can still | |
| peek inside of each script to see where the current known-good SHA is for each | |
| codec. | |
| ## Prebuilt Library (Windows) | |
| If you're building on Windows with Visual Studio 2019 and want to try out libavif without going through the build process, static library builds for both Debug and Release are available on [AppVeyor](https://ci.appveyor.com/project/louquillio/libavif). | |
| --- | |
| ## License | |
| Released under the BSD License. | |
| ```markdown | |
| Copyright 2019 Joe Drago. All rights reserved. | |
| Redistribution and use in source and binary forms, with or without | |
| modification, are permitted provided that the following conditions are met: | |
| 1. Redistributions of source code must retain the above copyright notice, this | |
| list of conditions and the following disclaimer. | |
| 2. Redistributions in binary form must reproduce the above copyright notice, | |
| this list of conditions and the following disclaimer in the documentation | |
| and/or other materials provided with the distribution. | |
| THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" | |
| AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE | |
| IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE | |
| DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE | |
| FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL | |
| DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR | |
| SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER | |
| CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, | |
| OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE | |
| OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. | |
| ``` |