1 ![dav1d logo](dav1d_logo.png)
5 **dav1d** is a new **AV1** cross-platform **d**ecoder, open-source, and focused on speed and correctness.
7 The canonical repository URL for this repo is https://code.videolan.org/videolan/dav1d
9 This project is partially funded by the *Alliance for Open Media*/**AOM**.
13 The goal of this project is to provide a decoder for **most platforms**, and achieve the **highest speed** possible to overcome the temporary lack of AV1 hardware decoder.
15 It supports all features from AV1, including all subsampling and bit-depth parameters.
17 In the future, this project will host simple tools or simple wrappings *(like, for example, an MFT transform)*.
21 **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.
23 The reasoning behind this decision is the same as for libvorbis, see [RMS on vorbis](https://lwn.net/2001/0301/a/rms-ov-license.php3).
27 The plan is the folllowing:
30 1. Complete C implementation of the decoder,
31 2. Provide a usable API,
32 3. Port to most platforms,
33 4. Make it fast on desktop, by writing asm for AVX-2 chips.
36 5. Make it fast on mobile, by writing asm for ARMv8 chips,
37 6. Make it fast on older desktop, by writing asm for SSE chips.
40 7. Improve C code base with [various tweaks](https://code.videolan.org/videolan/dav1d/wikis/task-list),
41 8. Accelerate for less common architectures,
42 9. Use more GPU, when possible.
46 Currently, we are looking for help from:
49 - platform-specific developers,
53 Our contributions guidelines are quite strict. We want to build a coherent codebase to simplify maintenance and achieve the highest possible speed.
55 Notably, the codebase is in pure C and asm.
57 We are on IRC, on the **#dav1d** channel on *Freenode*.
59 See the [contributions document](CONTRIBUTING.md).
65 People will keep their copyright and their authorship rights, while adhering to the BSD 2-clause license.
67 VideoLAN will only have the collective work rights.
71 The [VideoLAN Code of Conduct](https://wiki.videolan.org/CoC) applies to this project.
75 1. Install [Meson](https://mesonbuild.com/) (0.47 or higher), [Ninja](https://ninja-build.org/), and, for x86\* targets, [nasm](https://nasm.us/) (2.13.02 or higher)
76 2. Run `mkdir build && cd build` to create a build directory and enter it
77 3. Run `meson ..` to configure meson, add `--default-library=static` if static linking is desired
78 4. Run `ninja` to compile
82 1. In the root directory, run `git clone https://code.videolan.org/videolan/dav1d-test-data.git tests/dav1d-test-data` to fetch the test data repository
83 2. During meson configuration, specify `-Dtestdata_tests=true`
84 3. Run `meson test -v` after compiling
88 This project is partially funded by the *Alliance for Open Media*/**AOM** and is supported by TwoOrioles and VideoLabs.
90 These companies can provide support and integration help, should you need it.
95 ## Why do you not improve libaom rather than starting a new project?
97 - We believe that libaom is a very good library. It was however developed for research purposes during AV1 design.
98 We think that an implementation written from scratch can achieve faster decoding, in the same way that *ffvp9* was faster than *libvpx*.
100 ## Is dav1d a recursive acronym?
106 - Yes. See the [contributions document](CONTRIBUTING.md).
108 ## I am not a developer. Can I help?
110 - Yes. We need testers, bug reporters, and documentation writers.
112 ## What about the AV1 patent license?
114 - This project is an implementation of a decoder. It gives you no special rights on the AV1 patents.
116 Please read the [AV1 patent license](doc/PATENTS) that applies to the AV1 specification and codec.
118 ## Will you care about <my_arch>? <my_os>?
120 - We do, but we don't have either the time or the knowledge. Therefore, patches and contributions welcome.