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dav1d is anAV1 cross-platformdecoder, open-source, and focused on speed and correctness.

It is now battle-tested and production-ready and can be used everywhere.

The canonical repository URL for this repo ishttps://code.videolan.org/videolan/dav1d

This project was partially funded by theAlliance for Open Media/AOM.

The goal of this project is to provide a decoder formost platforms, and achieve thehighest speed possible to overcome the temporary lack of AV1 hardware decoder.

It supports all features from AV1, including all subsampling and bit-depth parameters.

In the future, this project will host simple tools or simple wrappings(like, for example, an MFT transform).

dav1d is released under a very liberal license, a contrario from the other VideoLAN projects, so that it can be embedded anywhere, including non-open-source software; or even drivers, to allow the creation of hybrid decoders.

The reasoning behind this decision is the same as for libvorbis, seeRMS on vorbis.

The plan is the following:

1. Complete C implementation of the decoder,
2. Provide a usable API,
3. Port to most platforms,
4. Make it fast on desktop, by writing asm for AVX2 chips.
5. Make it fast on mobile, by writing asm for ARMv8 chips,
6. Make it fast on older desktop, by writing asm for SSSE3+ chips,
7. Make high bit-depth fast on mobile, by writing asm for ARMv8 chips.
8. Make it fast on older mobile, by writing asm for ARMv7 chips,
9. Make high bit-depth fast on older mobile, by writing asm for ARMv7 chips,
10. Make high bit-depth fast on desktop, by writing asm for AVX2 chips,
11. Make high bit-depth fast on older desktop, by writing asm for SSSE3+ chips,
12. Improve threading.

13. Improve C code base withvarious tweaks,
14. Accelerate for less common architectures, like PPC, SSE2, RISC-V or AVX-512.

15. Use more GPU decoding, when possible.

Currently, we are looking for help from:

• C developers,
• asm developers,
• platform-specific developers,
• GPGPU developers,
• testers.

Our contributions guidelines are quite strict. We want to build a coherent codebase to simplify maintenance and achieve the highest possible speed.

Notably, the codebase is in pure C and asm.

We are on IRC, on the#dav1d channel onLibera.chat. If you do not have an IRC Client at hand, useIRC Web Interface.

See thecontributions document.

There is no CLA.

People will keep their copyright and their authorship rights, while adhering to the BSD 2-clause license.

VideoLAN will only have the collective work rights.

TheVideoLAN Code of Conduct applies to this project.

1. InstallMeson (0.49 or higher),Ninja, and, for x86* targets,nasm (2.14 or higher)
2. Runmkdir build && cd build to create a build directory and enter it
3. Runmeson setup .. to configure meson, add--default-library=static if static linking is desired
4. Runninja to compile

If you're on a linux build machine trying to compile .exe for a Windows target/host machine, run

meson setup build --cross-file=package/crossfiles/x86_64-w64-mingw32.meson

or, for 32-bit:

meson setup build --cross-file=package/crossfiles/i686-w64-mingw32.meson

mingw-w64 is a pre-requisite and should be installed on your linux machine via your preferred method or package manager. Note the binary name formats may differ between distributions. Verify the names, and usealias if certain binaries cannot be found.

For 32-bit linux, run

meson setup build --cross-file=package/crossfiles/i686-linux32.meson

1. Installdoxygen andgraphviz
2. Runmeson setup build -Denable_docs=true to create the build directory
3. Runninja -C build doc/html to build the docs

The result can be found inbuild/doc/html/. An online version built from master can be foundhere.

1. In the root directory, rungit clone https://code.videolan.org/videolan/dav1d-test-data.git tests/dav1d-test-data to fetch the test data repository
2. During meson configuration, specify-Dtestdata_tests=true
3. Runmeson test -v after compiling

This project is partially funded by theAlliance for Open Media/AOM and is supported by TwoOrioles and VideoLabs.

These companies can provide support and integration help, should you need it.

• We believe that libaom is a very good library. It was however developed for research purposes during AV1 design.We think that an implementation written from scratch can achieve faster decoding, in the same way thatffvp9 was faster thanlibvpx.

• Yes.

• Yes. See thecontributions document.

• Yes. We need testers, bug reporters and documentation writers.

• This project is an implementation of a decoder. It gives you no special rights on the AV1 patents.

Please read theAV1 patent license that applies to the AV1 specification and codec.

• We do, but we don't have either the time or the knowledge. Therefore, patches and contributions welcome.