README.md - libavif - Git at Google

 # libavif [![AppVeyor Build Status](https://ci.appveyor.com/api/projects/status/github/louquillio/libavif?branch=master&svg=true)](https://ci.appveyor.com/project/louquillio/libavif) [![Travis Build Status](https://travis-ci.com/AOMediaCodec/libavif.svg?branch=master)](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 can encode and decode all AV1 supported YUV formats and bit depths (with
 alpha).

 It is recommended that you check out/use
 [tagged releases](https://github.com/AOMediaCodec/libavif/releases) instead of
 just using the main branch. We will regularly create new versions as bug fixes
 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.

 ## Installation

 `libavif` is a package in most major OSs.

 ### Windows

 ```sh
 vcpkg install libavif
 ```
 You can also download the official windows binaries on the
 [release](https://github.com/AOMediaCodec/libavif/releases) page.

 ### macOS

 Homebrew:
 ```sh
 brew install libavif
 ```
 MacPorts:
 ```sh
 sudo port install libavif
 ```

 ### Linux

 Debian-based distributions:
 ```sh
 sudo apt install libavif-dev
 ```
 Red Hat-based distributions:
 ```sh
 sudo yum -y install libavif
 ```

 ### MinGW

 For the "default" MSYS2 UCRT64 environment:
 ```sh
 pacman -S mingw-w64-ucrt-x86_64-libavif
 ```

 ## Build Notes

 Building libavif requires [CMake](https://cmake.org/).

 No AV1 codecs are enabled by default. Enable them by setting any of the
 following CMake options to `LOCAL` or `SYSTEM` whether you want to use a
 locally built or a system installed version (e.g. `-DAVIF_CODEC_AOM=LOCAL`):

 * `AVIF_CODEC_AOM` for [libaom](https://aomedia.googlesource.com/aom/) (encoder
   and decoder)
 * `AVIF_CODEC_DAV1D` for [dav1d](https://code.videolan.org/videolan/dav1d)
   (decoder)
 * `AVIF_CODEC_LIBGAV1` for
   [libgav1](https://chromium.googlesource.com/codecs/libgav1/) (decoder)
 * `AVIF_CODEC_RAV1E` for [rav1e](https://github.com/xiph/rav1e) (encoder)
 * `AVIF_CODEC_SVT` for [SVT-AV1](https://gitlab.com/AOMediaCodec/SVT-AV1)
   (encoder)

 When set to `SYSTEM`, 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.
 Most scripts require CMake, Ninja and NASM. dav1d uses Meson instead of CMake,
 and rav1e uses cargo (Rust). Check each library's documentation for an exact
 list of requirements.

 If you want to statically link any codec into your local (static) build of
 libavif, building using one of these scripts and then setting the associated
 `AVIF_CODEC_*` to `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.

 ### Command Lines

 The following instructions can be used to build the libavif library and the
 `avifenc` and `avifdec` tools.

 #### Build using installed dependencies

 To link against the already installed `aom`, `libjpeg` and `libpng` dependency
 libraries (recommended):

 ```sh
 git clone -b v1.0.3 https://github.com/AOMediaCodec/libavif.git
 cd libavif
 cmake -S . -B build -DAVIF_CODEC_AOM=SYSTEM -DAVIF_BUILD_APPS=ON
 cmake --build build --parallel
 ```

 #### Build everything from scratch

 For development and debugging purposes, or to generate fully static binaries:

 ```sh
 git clone -b v1.0.3 https://github.com/AOMediaCodec/libavif.git
 cd libavif/ext
 ./aom.cmd
 ./libyuv.cmd
 ./libsharpyuv.cmd
 ./libjpeg.cmd
 ./zlibpng.cmd
 cd ..
 cmake -S . -B build -DBUILD_SHARED_LIBS=OFF -DAVIF_CODEC_AOM=LOCAL -DAVIF_LIBYUV=LOCAL -DAVIF_LIBSHARPYUV=LOCAL -DAVIF_JPEG=LOCAL -DAVIF_ZLIBPNG=LOCAL -DAVIF_BUILD_APPS=ON
 cmake --build build --parallel
 ```

 ## 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

 Please check the [wiki](https://github.com/AOMediaCodec/libavif/wiki) for extra
 resources on libavif, such as the Release Checklist.

 The libavif library is written in C99. Most of the tests are written in C++14.

 ### Formatting

 Use [clang-format](https://clang.llvm.org/docs/ClangFormat.html) to format the C
 sources from the top-level folder (`clang-format-16` preferred):

 ```sh
 clang-format -style=file -i \
   apps/*.c apps/*/*.c apps/*/*.cc apps/*/*.h examples/*.c \
   include/avif/*.h src/*.c src/*.cc \
   tests/*.c tests/*/*.cc tests/*/*.h
 ```

 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.
 ```
	# libavif [![AppVeyor Build Status](https://ci.appveyor.com/api/projects/status/github/louquillio/libavif?branch=master&svg=true)](https://ci.appveyor.com/project/louquillio/libavif) [![Travis Build Status](https://travis-ci.com/AOMediaCodec/libavif.svg?branch=master)](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 can encode and decode all AV1 supported YUV formats and bit depths (with
	alpha).

	It is recommended that you check out/use
	[tagged releases](https://github.com/AOMediaCodec/libavif/releases) instead of
	just using the main branch. We will regularly create new versions as bug fixes
	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.

	## Installation

	`libavif` is a package in most major OSs.

	### Windows

	```sh
	vcpkg install libavif
	```
	You can also download the official windows binaries on the
	[release](https://github.com/AOMediaCodec/libavif/releases) page.

	### macOS

	Homebrew:
	```sh
	brew install libavif
	```
	MacPorts:
	```sh
	sudo port install libavif
	```

	### Linux

	Debian-based distributions:
	```sh
	sudo apt install libavif-dev
	```
	Red Hat-based distributions:
	```sh
	sudo yum -y install libavif
	```

	### MinGW

	For the "default" MSYS2 UCRT64 environment:
	```sh
	pacman -S mingw-w64-ucrt-x86_64-libavif
	```

	## Build Notes

	Building libavif requires [CMake](https://cmake.org/).

	No AV1 codecs are enabled by default. Enable them by setting any of the
	following CMake options to `LOCAL` or `SYSTEM` whether you want to use a
	locally built or a system installed version (e.g. `-DAVIF_CODEC_AOM=LOCAL`):

	* `AVIF_CODEC_AOM` for [libaom](https://aomedia.googlesource.com/aom/) (encoder
	and decoder)
	* `AVIF_CODEC_DAV1D` for [dav1d](https://code.videolan.org/videolan/dav1d)
	(decoder)
	* `AVIF_CODEC_LIBGAV1` for
	[libgav1](https://chromium.googlesource.com/codecs/libgav1/) (decoder)
	* `AVIF_CODEC_RAV1E` for [rav1e](https://github.com/xiph/rav1e) (encoder)
	* `AVIF_CODEC_SVT` for [SVT-AV1](https://gitlab.com/AOMediaCodec/SVT-AV1)
	(encoder)

	When set to `SYSTEM`, 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.
	Most scripts require CMake, Ninja and NASM. dav1d uses Meson instead of CMake,
	and rav1e uses cargo (Rust). Check each library's documentation for an exact
	list of requirements.

	If you want to statically link any codec into your local (static) build of
	libavif, building using one of these scripts and then setting the associated
	`AVIF_CODEC_*` to `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.

	### Command Lines

	The following instructions can be used to build the libavif library and the
	`avifenc` and `avifdec` tools.

	#### Build using installed dependencies

	To link against the already installed `aom`, `libjpeg` and `libpng` dependency
	libraries (recommended):

	```sh
	git clone -b v1.0.3 https://github.com/AOMediaCodec/libavif.git
	cd libavif
	cmake -S . -B build -DAVIF_CODEC_AOM=SYSTEM -DAVIF_BUILD_APPS=ON
	cmake --build build --parallel
	```

	#### Build everything from scratch

	For development and debugging purposes, or to generate fully static binaries:

	```sh
	git clone -b v1.0.3 https://github.com/AOMediaCodec/libavif.git
	cd libavif/ext
	./aom.cmd
	./libyuv.cmd
	./libsharpyuv.cmd
	./libjpeg.cmd
	./zlibpng.cmd
	cd ..
	cmake -S . -B build -DBUILD_SHARED_LIBS=OFF -DAVIF_CODEC_AOM=LOCAL -DAVIF_LIBYUV=LOCAL -DAVIF_LIBSHARPYUV=LOCAL -DAVIF_JPEG=LOCAL -DAVIF_ZLIBPNG=LOCAL -DAVIF_BUILD_APPS=ON
	cmake --build build --parallel
	```

	## 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

	Please check the [wiki](https://github.com/AOMediaCodec/libavif/wiki) for extra
	resources on libavif, such as the Release Checklist.

	The libavif library is written in C99. Most of the tests are written in C++14.

	### Formatting

	Use [clang-format](https://clang.llvm.org/docs/ClangFormat.html) to format the C
	sources from the top-level folder (`clang-format-16` preferred):

	```sh
	clang-format -style=file -i \
	apps/.c apps//.c apps//.cc apps//.h examples/.c \
	include/avif/.h src/.c src/*.cc \
	tests/.c tests//.cc tests//*.h
	```

	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.
	```