# 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 check out/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. ### Tests A few tests written in C can be built by enabling the `AVIF_BUILD_TESTS` CMake option. The remaining tests can be built by enabling the `AVIF_BUILD_TESTS` and `AVIF_ENABLE_GTEST` CMake options. They require GoogleTest to be built locally with ext/googletest.cmd or installed on the system. ## Prebuilt Library (Windows) If you're building on Windows with Visual Studio 2022 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). ## Development Notes libavif is written in C99. ### Formatting Use [clang-format](https://clang.llvm.org/docs/ClangFormat.html) to format the C sources from the top-level folder: ```sh clang-format -style=file -i \ apps/*.c apps/shared/avifjpeg.* apps/shared/avifpng.* \ apps/shared/avifutil.* apps/shared/y4m.* examples/*.c \ include/avif/*.h src/*.c tests/*.c \ tests/gtest/*.h tests/gtest/*.cc tests/oss-fuzz/*.cc ``` Use [cmake-format](https://github.com/cheshirekow/cmake_format) to format the CMakeLists.txt files from the top-level folder: ```sh cmake-format -i \ CMakeLists.txt \ tests/CMakeLists.txt \ cmake/Modules/Find*.cmake \ contrib/CMakeLists.txt \ contrib/gdk-pixbuf/CMakeLists.txt \ android_jni/avifandroidjni/src/main/jni/CMakeLists.txt ``` --- ## 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. ```
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