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libheif is an ISO/IEC 23008-12:2017 HEIF and AVIF (AV1 Image File Format) file format decoder and encoder. There is partial support for ISO/IEC 23008-12:2022 (2nd Edition) capabilities.

HEIF and AVIF are new image file formats employing HEVC (H.265) or AV1 image coding, respectively, for the best compression ratios currently possible.

libheif makes use of libde265 for HEIF image decoding and x265 for encoding. For AVIF, libaom, dav1d, svt-av1, or rav1e are used as codecs.

Supported features

libheif has support for:

Supported codecs:

FormatDecodersEncoders
HEIClibde265, ffmpegx265, kvazaar
AVIFAOM, dav1dAOM, rav1e, svt-av1
VVCvvdecvvenc, uvg266
AVCopenh264-
JPEGlibjpeg(-turbo)libjpeg(-turbo)
JPEG2000OpenJPEGOpenJPEG
uncompressedbuilt-inbuilt-in

API

The library has a C API for easy integration and wide language support.

The decoder automatically supports both HEIF and AVIF (and the other compression formats) through the same API. The same code decoding code can be used to decode any of them. The encoder can be switched between HEIF and AVIF simply by setting heif_compression_HEVC or heif_compression_AV1 to heif_context_get_encoder_for_format(), or using any of the other compression formats.

Loading the primary image in an HEIF file is as easy as this:

heif_context* ctx = heif_context_alloc();
heif_context_read_from_file(ctx, input_filename, nullptr);

// get a handle to the primary image
heif_image_handle* handle;
heif_context_get_primary_image_handle(ctx, &handle);

// decode the image and convert colorspace to RGB, saved as 24bit interleaved
heif_image* img;
heif_decode_image(handle, &img, heif_colorspace_RGB, heif_chroma_interleaved_RGB, nullptr);

int stride;
const uint8_t* data = heif_image_get_plane_readonly(img, heif_channel_interleaved, &stride);

// ... process data as needed ...

// clean up resources
heif_image_release(img);
heif_image_handle_release(handle);
heif_context_free(ctx);

Writing an HEIF file can be done like this:

heif_context* ctx = heif_context_alloc();

// get the default encoder
heif_encoder* encoder;
heif_context_get_encoder_for_format(ctx, heif_compression_HEVC, &encoder);

// set the encoder parameters
heif_encoder_set_lossy_quality(encoder, 50);

// encode the image
heif_image* image; // code to fill in the image omitted in this example
heif_context_encode_image(ctx, image, encoder, nullptr, nullptr);

heif_encoder_release(encoder);

heif_context_write_to_file(ctx, "output.heic");

heif_context_free(ctx);

Get the EXIF data from an HEIF file:

heif_item_id exif_id;

int n = heif_image_handle_get_list_of_metadata_block_IDs(image_handle, "Exif", &exif_id, 1);
if (n==1) {
  size_t exifSize = heif_image_handle_get_metadata_size(image_handle, exif_id);
  uint8_t* exifData = malloc(exifSize);
  struct heif_error error = heif_image_handle_get_metadata(image_handle, exif_id, exifData);
}

See the header file heif.h for the complete C API.

There is also a C++ API which is a header-only wrapper to the C API. Hence, you can use the C++ API and still be binary compatible. Code using the C++ API is much less verbose than using the C API directly.

There is also an experimental Go API, but this is not stable yet.

Reading and Writing Tiled Images

For very large resolution images, it is not always feasible to process the whole image. In this case, libheif can process the image tile by tile. See this tutorial on how to use the API for this.

Compiling

This library uses the CMake build system (the earlier autotools build files have been removed in v1.16.0).

For a minimal configuration, we recommend to use the codecs libde265 and x265 for HEIC and AOM for AVIF. Make sure that you compile and install libde265 first, so that the configuration script will find this. Also install x265 and its development files if you want to use HEIF encoding, but note that x265 is GPL. An alternative to x265 is kvazaar (BSD).

The basic build steps are as follows (--preset argument needs CMake >= 3.21):

mkdir build
cd build
cmake --preset=release ..
make

There are CMake presets to cover the most frequent use cases.

You can optionally adapt these standard configurations to your needs. This can be done, for example, by calling ccmake . from within the build directory.

CMake configuration variables

Libheif supports many different codecs. In order to reduce the number of dependencies and the library size, you can choose which of these codecs to include. Each codec can be compiled either as built-in to the library with a hard dependency, or as a separate plugin file that is loaded dynamically.

For each codec, there are two configuration variables:

In order to use dynamic plugins, also make sure that ENABLE_PLUGIN_LOADING is enabled. The placeholder {codec} can have these values: LIBDE265, X265, AOM_DECODER, AOM_ENCODER, SvtEnc, DAV1D, FFMPEG_DECODER, JPEG_DECODER, JPEG_ENCODER, KVAZAAR, OpenJPEG_DECODER, OpenJPEG_ENCODER, OPENJPH_ENCODER, VVDEC, VVENC, UVG266.

Further options are:

macOS

  1. Install dependencies with Homebrew

    brew install cmake make pkg-config x265 libde265 libjpeg libtool

  2. Configure and build project (--preset argument needs CMake >= 3.21):

    mkdir build
cd build
cmake --preset=release ..
./configure
make

Windows

You can build and install libheif using the vcpkg dependency manager:

git clone https://github.com/Microsoft/vcpkg.git
cd vcpkg
./bootstrap-vcpkg.bat
./vcpkg integrate install
./vcpkg install libheif

The libheif port in vcpkg is kept up to date by Microsoft team members and community contributors. If the version is out of date, please create an issue or pull request on the vcpkg repository.

Adding libaom encoder/decoder for AVIF

When running cmake or configure, make sure that the environment variable PKG_CONFIG_PATH includes the absolute path to third-party/aom/dist/lib/pkgconfig.

Adding rav1e encoder for AVIF

cargo install --force cargo-c

When running cmake, make sure that the environment variable PKG_CONFIG_PATH includes the absolute path to third-party/rav1e/dist/lib/pkgconfig.

Adding dav1d decoder for AVIF

When running cmake, make sure that the environment variable PKG_CONFIG_PATH includes the absolute path to third-party/dav1d/dist/lib/x86_64-linux-gnu/pkgconfig.

Adding SVT-AV1 encoder for AVIF

You can either use the SVT-AV1 encoder libraries installed in the system or use a self-compiled current version. If you want to compile SVT-AV1 yourself,

When running cmake or configure, make sure that the environment variable PKG_CONFIG_PATH includes the absolute path to third-party/SVT-AV1/Build/linux/install/lib/pkgconfig. You may have to replace linux in this path with your system's identifier.

You have to enable SVT-AV1 with CMake.

Codec plugins

Starting with v1.14.0, each codec backend can be compiled statically into libheif or as a dynamically loaded plugin (currently Linux only). You can choose this individually for each codec backend in the CMake settings. Compiling a codec backend as dynamic plugin will generate a shared library that is installed in the system together with libheif. The advantage is that only the required plugins have to be installed and libheif has fewer dependencies.

The plugins are loaded from the colon-separated (semicolon-separated on Windows) list of directories stored in the environment variable LIBHEIF_PLUGIN_PATH. If this variable is empty, they are loaded from a directory specified in the CMake configuration. You can also add plugin directories programmatically.

Codec specific notes

Encoder benchmark

A current benchmark of the AVIF encoders (as of 14 Oct 2022) can be found on the Wiki page AVIF encoding benchmark.

Language bindings

Languages that can directly interface with C libraries (e.g., Swift, C#) should work out of the box.

Compiling to JavaScript / WASM

libheif can also be compiled to JavaScript using emscripten. It can be built like this (in the libheif directory):

mkdir buildjs
cd buildjs
USE_WASM=0 ../build-emscripten.sh ..

Set USE_WASM=1 to build with WASM output. See the build-emscripten.sh script for further options.

Online demo

Check out this online demo. This is libheif running in JavaScript in your browser.

Example programs

Some example programs are provided in the examples directory. The program heif-dec converts all images stored in an HEIF/AVIF file to JPEG or PNG. heif-enc lets you convert JPEG files to HEIF/AVIF. The program heif-info is a simple, minimal decoder that dumps the file structure to the console.

For example convert example.heic to JPEGs and one of the JPEGs back to HEIF:

cd examples/
./heif-dec example.heic example.jpeg
./heif-enc example-1.jpeg -o example.heif

In order to convert example-1.jpeg to AVIF use:

./heif-enc example-1.jpeg -A -o example.avif

There is also a GIMP plugin using libheif here.

HEIF/AVIF thumbnails for the Gnome desktop

The program heif-thumbnailer can be used as an HEIF/AVIF thumbnailer for the Gnome desktop. The matching Gnome configuration files are in the gnome directory. Place the files heif.xml and avif.xml into /usr/share/mime/packages and heif.thumbnailer into /usr/share/thumbnailers. You may have to run update-mime-database /usr/share/mime to update the list of known MIME types.

gdk-pixbuf loader

libheif also includes a gdk-pixbuf loader for HEIF/AVIF images. 'make install' will copy the plugin into the system directories. However, you will still have to run gdk-pixbuf-query-loaders --update-cache to update the gdk-pixbuf loader database.

Software using libheif

Packaging status

libheif packaging status

Sponsors

Since I work as an independent developer, I need your support to be able to allocate time for libheif. You can sponsor the development using the link in the right hand column.

A big thank you goes to these major sponsors for supporting the development of libheif:

License

The libheif is distributed under the terms of the GNU Lesser General Public License. The sample applications are distributed under the terms of the MIT License.

See COPYING for more details.

Copyright (c) 2017-2020 Struktur AG</br> Copyright (c) 2017-2024 Dirk Farin</br> Contact: Dirk Farin dirk.farin@gmail.com