commit | 3e7886db54d0cb3ce32909c71ad2a8c9d9eab223 | [log] [tgz] |
---|---|---|
author | Victorien Le Couviour--Tuffet <victorien@videolan.org> | Thu Oct 06 11:14:06 2022 +0200 |
committer | Victorien Le Couviour--Tuffet <victorien@videolan.org> | Thu Oct 20 14:23:30 2022 +0200 |
tree | 0bf03411882df77cb438f340a46479620fed6b5f | |
parent | 5b07b4256617913ec81277f07af592ebd62b11a3 [diff] |
threading: Fix a race around frame completion (frame-mt) The completion of the first frame to decode while an async reset request on that same frame is pending will render it stale. The processing of such a stale request is likely to result in a hang. One reason this happens is the skip condition at the beginning of reset_task_cur(). => Consume the async request before that check. Another reason is several threads producing async reset requests in parallel: an async request for the first frame could cascade through the other threads (other frames) during completion of that frame, meaning not being caught by the last synchronous reset_task_cur() after signaling the main thread and before releasing the lock. => To solve this we need to add protections at the racy locations. That means after we increase first, before returning from reset_task_cur_async(), and after consuming the async request.
dav1d is an AV1 cross-platform decoder, 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 is https://code.videolan.org/videolan/dav1d
This project was partially funded by the Alliance for Open Media/AOM.
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.
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, see RMS on vorbis.
The plan is the following:
Currently, we are looking for help from:
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 on Libera.chat. If you do not have an IRC Client at hand, use IRC Web Interface.
See the contributions 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.
The VideoLAN Code of Conduct applies to this project.
mkdir build && cd build
to create a build directory and enter itmeson ..
to configure meson, add --default-library=static
if static linking is desiredninja
to compileIf you're on a linux build machine trying to compile .exe for a Windows target/host machine, run
meson build --cross-file=package/crossfiles/x86_64-w64-mingw32.meson
or, for 32-bit:
meson 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 use alias
if certain binaries cannot be found.
For 32-bit linux, run
meson build --cross-file=package/crossfiles/i686-linux32.meson
meson build -Denable_docs=true
to create the build directoryninja -C build doc/html
to build the docsThe result can be found in build/doc/html/
. An online version built from master can be found here.
git clone https://code.videolan.org/videolan/dav1d-test-data.git tests/dav1d-test-data
to fetch the test data repository-Dtestdata_tests=true
meson test -v
after compilingThis project is partially funded by the Alliance for Open Media/AOM and is supported by TwoOrioles and VideoLabs.
These companies can provide support and integration help, should you need it.
Please read the AV1 patent license that applies to the AV1 specification and codec.