Commit c001c4b0 authored by Jean-Baptiste Kempf's avatar Jean-Baptiste Kempf

Initial commit for dav1d

dav1d is an AV1 Decoder
parents
# Dav1d contribution guide
## CoC
The [VideoLAN Code of Conduct](https://wiki.videolan.org/CoC) applies to this project.
## Codebase language
The codebase is developed with the following assumptions:
For the library:
- C language with C99 version, without the VLA or the Complex (*\_\_STDC_NO_COMPLEX__*) features, and without compiler extension,
- asm in .asm files, using the NASM syntax,
- no C++ is allowed, whatever the version.
For the tools and utils:
- C *(see above for restrictions)*
- Rust
- C++ only for the MFT.
If you want to use *Threads* or *Atomic* features, please conform to the **C11**/**POSIX** semantic and use a wrapper for older compilers/platforms *(like done in VLC)*.
Please use modern standard POSIX functions *(strscpy, asprintf, tdestroy)*, and provide a compatibility fallback *(like done in VLC)*.
We will make reasonable efforts for compilers that are a bit older, but we won't support gcc 3 or MSVC 2012.
## Authorship
Please provide a correct authorship for your commit logs, with a name and a valid email.
We will reject anonymous contributions for now. As an exception, known pseudonyms from the multimedia community are accepted.
This project is respecting **Copyright** and **Droit d'auteur**. There is no copyright attribution or CLA.
## Commit logs
Please read [How to Write a Git Commit Message](https://chris.beams.io/posts/git-commit/).
## Submit requests (WIP)
- Code
- Test
- Try
- Submit patches
## Patent license
You need to read and understand the [AV1 patents license](doc/PATENTS), before committing.
Copyright © 2018, VideoLAN and dav1d authors
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 OWNER 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.
Changes for 0.0.1:
------------------
Initial release
# dav1d
**dav1d** is a new **AV1** cross-platform **D**ecoder, open-source, and focused on speed and correctness.
The canonical repository URL for this repo is https://code.videolan.org/videolan/dav1d
## Goal and Features
The goal of this project is to provide a decoder for **most platforms**, and achieve the **highest speed** possible to overcome the lack of AV1 hardware decoder.
It aims to support 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)*.
## License
**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, for hybrid decoders.
The reasoning behind this decision is the same as for libvorbis, [RMS on vorbis](https://lwn.net/2001/0301/a/rms-ov-license.php3).
# Roadmap
The plan is the folllowing:
1. Complete C implementation of the decoder,
2. Provide a usable API,
3. Port to most platforms,
4. Make it fast, by writing asm.
By the end of 2018, we hope to have a completely usable version that will be faster than any other software open source implementation.
# Contribute
Currently, we are looking for help from:
- C developers,
- asm developers,
- platform-specific developers.
Our contributions guidelines are 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 on *Freenode*.
See the [contributions document](CONTRIBUTING.md).
## CLA
There is no CLA.
People will keep their copyright and their authorship rights.
VideoLAN will only have the collective work rights.
## CoC
The [VideoLAN Code of Conduct](https://wiki.videolan.org/CoC) applies to this project.
# Compile
1. Install [Meson](https://mesonbuild.com/)
2. Run `meson build`
# Support
This project is partially funded by the *Alliance for Open Media*/**AOM** and is supported by TwoOrioles and VideoLabs.
These 2 companies can provide support and integration help, should you need it.
# FAQ
## Why do you not improve libaom rather than starting a new project?
- 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 that *ffvp9* was faster than *libvpx*.
## Is dav1d a recursive acronym?
- Yes.
## Can I help?
- Yes. See the [contributions document](CONTRIBUTING.md).
## I am not a developer. Can I help?
- Yes. We need testers, bug reporters, and documentation writers.
## What about the AV1 patent license?
This project is an implementation of a decoder. It gives you no special rights on the AV1 patents.
Please read the [AV1 patent license](doc/PATENTS) that applies to the AV1 specification and codec.
Alliance for Open Media Patent License 1.0
1. License Terms.
1.1. Patent License. Subject to the terms and conditions of this License, each
Licensor, on behalf of itself and successors in interest and assigns,
grants Licensee a non-sublicensable, perpetual, worldwide, non-exclusive,
no-charge, royalty-free, irrevocable (except as expressly stated in this
License) patent license to its Necessary Claims to make, use, sell, offer
for sale, import or distribute any Implementation.
1.2. Conditions.
1.2.1. Availability. As a condition to the grant of rights to Licensee to make,
sell, offer for sale, import or distribute an Implementation under
Section 1.1, Licensee must make its Necessary Claims available under
this License, and must reproduce this License with any Implementation
as follows:
a. For distribution in source code, by including this License in the
root directory of the source code with its Implementation.
b. For distribution in any other form (including binary, object form,
and/or hardware description code (e.g., HDL, RTL, Gate Level Netlist,
GDSII, etc.)), by including this License in the documentation, legal
notices, and/or other written materials provided with the
Implementation.
1.2.2. Additional Conditions. This license is directly from Licensor to
Licensee. Licensee acknowledges as a condition of benefiting from it
that no rights from Licensor are received from suppliers, distributors,
or otherwise in connection with this License.
1.3. Defensive Termination. If any Licensee, its Affiliates, or its agents
initiates patent litigation or files, maintains, or voluntarily
participates in a lawsuit against another entity or any person asserting
that any Implementation infringes Necessary Claims, any patent licenses
granted under this License directly to the Licensee are immediately
terminated as of the date of the initiation of action unless 1) that suit
was in response to a corresponding suit regarding an Implementation first
brought against an initiating entity, or 2) that suit was brought to
enforce the terms of this License (including intervention in a third-party
action by a Licensee).
1.4. Disclaimers. The Reference Implementation and Specification are provided
"AS IS" and without warranty. The entire risk as to implementing or
otherwise using the Reference Implementation or Specification is assumed
by the implementer and user. Licensor expressly disclaims any warranties
(express, implied, or otherwise), including implied warranties of
merchantability, non-infringement, fitness for a particular purpose, or
title, related to the material. IN NO EVENT WILL LICENSOR BE LIABLE TO
ANY OTHER PARTY FOR LOST PROFITS OR ANY FORM OF INDIRECT, SPECIAL,
INCIDENTAL, OR CONSEQUENTIAL DAMAGES OF ANY CHARACTER FROM ANY CAUSES OF
ACTION OF ANY KIND WITH RESPECT TO THIS LICENSE, WHETHER BASED ON BREACH
OF CONTRACT, TORT (INCLUDING NEGLIGENCE), OR OTHERWISE, AND WHETHER OR
NOT THE OTHER PARTRY HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
2. Definitions.
2.1. Affiliate. “Affiliate” means an entity that directly or indirectly
Controls, is Controlled by, or is under common Control of that party.
2.2. Control. “Control” means direct or indirect control of more than 50% of
the voting power to elect directors of that corporation, or for any other
entity, the power to direct management of such entity.
2.3. Decoder. "Decoder" means any decoder that conforms fully with all
non-optional portions of the Specification.
2.4. Encoder. "Encoder" means any encoder that produces a bitstream that can
be decoded by a Decoder only to the extent it produces such a bitstream.
2.5. Final Deliverable. “Final Deliverable” means the final version of a
deliverable approved by the Alliance for Open Media as a Final
Deliverable.
2.6. Implementation. "Implementation" means any implementation, including the
Reference Implementation, that is an Encoder and/or a Decoder. An
Implementation also includes components of an Implementation only to the
extent they are used as part of an Implementation.
2.7. License. “License” means this license.
2.8. Licensee. “Licensee” means any person or entity who exercises patent
rights granted under this License.
2.9. Licensor. "Licensor" means (i) any Licensee that makes, sells, offers
for sale, imports or distributes any Implementation, or (ii) a person
or entity that has a licensing obligation to the Implementation as a
result of its membership and/or participation in the Alliance for Open
Media working group that developed the Specification.
2.10. Necessary Claims. "Necessary Claims" means all claims of patents or
patent applications, (a) that currently or at any time in the future,
are owned or controlled by the Licensor, and (b) (i) would be an
Essential Claim as defined by the W3C Policy as of February 5, 2004
(https://www.w3.org/Consortium/Patent-Policy-20040205/#def-essential)
as if the Specification was a W3C Recommendation; or (ii) are infringed
by the Reference Implementation.
2.11. Reference Implementation. “Reference Implementation” means an Encoder
and/or Decoder released by the Alliance for Open Media as a Final
Deliverable.
2.12. Specification. “Specification” means the specification designated by
the Alliance for Open Media as a Final Deliverable for which this
License was issued.
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