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aomedia / libavif / fb17c6a283e41f1c6b1008398ebac616661d67c6
commitfb17c6a283e41f1c6b1008398ebac616661d67c6[log] [tgz]
authorVignesh Venkatasubramanian <vigneshv@google.com>Tue Jan 18 18:13:50 2022 -0800
committerWan-Teh Chang <wtc@google.com>Fri Jan 21 13:30:49 2022 -0800
treea1dc6f6614984f7621090e7ed48e4611346a8a5a
parent8fa6439f6215d6b60e28fd9d37a8a8683c795335 [diff]
reformat: Support F16 Half Float conversion in avifRGBImage

Some platforms (Android for example [1]) support only the F16 Half
Float format for images with bits-per-pixel == 16. This PR adds
support for converting the RGBA pixels into half float format.

It does so by adding a setting variable to avifRGBImage and then
doing the conversion at the end of avifImageYUVToRGB. It also
invokes libyuv if available to do the conversion with SIMD
optimizations.

While there is potential to make this even faster (instead of
doing this conversion in the end, we could potentially do it while
we do the YUV -> RGB conversion), that is a much larger change and
the performance gain from that may or may not be worth the trade
off in complicating the code paths.

[1] https://developer.android.com/reference/android/graphics/Bitmap.Config#RGBA_F16
5 files changed
tree: a1dc6f6614984f7621090e7ed48e4611346a8a5a
  1. .github/
  2. android_jni/
  3. apps/
  4. cmake/
  5. contrib/
  6. examples/
  7. ext/
  8. include/
  9. src/
  10. tests/
  11. .clang-format
  12. .gitattributes
  13. .gitignore
  14. .gitmodules
  15. .travis.yml
  16. appveyor.yml
  17. CHANGELOG.md
  18. CMakeLists.txt
  19. libavif.pc.cmake
  20. LICENSE
  21. README.md
README.md

libavif AppVeyor Build Status Travis Build Status

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 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.

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.

License

Released under the BSD License.

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.