Versatile Video Coding (VVC) is the most recent international video coding standard, developed by the Joint Video Experts Team (JVET) of the ITU-T Video Coding Experts Group (VCEG) and the ISO/IEC Moving Picture Experts Group (MPEG). VVC is the successor of the High Efficiency Video Coding (HEVC) standard and is published by ITU-T as H.266 and by ISO/IEC as MPEG-I Part 3 (ISO/IEC 23090-3). The new standard targets a 50% bit-rate reduction over HEVC at the same visual quality. In addition, VVC proves to be truly versatile by including tools for efficient coding of video content in emerging applications, e.g. high dynamic range (HDR), adaptive streaming, computer generated content as well as immersive applications like 360-degree video and augmented reality (AR).
The Fraunhofer Versatile Video Encoder (VVenC) is a fast and efficient "real-world" VVC encoder implementation with the following main features:
- Easy to use encoder implementation with five predefined quality/speed presets;
- Perceptual optimization to improve subjective video quality, based on the XPSNR visual model;
- Frame-level single-pass and two-pass rate control supporting variable bit-rate (VBR) encoding;
- Expert mode encoder interface available, allowing fine-grained control of the encoding process.
The software uses CMake to create platform specific build files. A working CMake installation is required for building the software. Download CMake from http://www.cmake.org/ and install it. The following targets are supported: Windows (Visual Studio), Linux (gcc) and MacOS (clang).
In order to compile the software for Windows, Visual Studio 15 2017 or higher and cmake version 3.12 or higher are required. Install gnuwin32 that provides make for Windows. To build the software open a command prompt window, change into the project directory and use:
make install-release
This will create the statically linked release version of the encoder applications in the install/bin/release-static/ subdirectory.
In order to compile the software for Linux, gcc version 7.0 or higher and cmake version 3.12 or higher are required. For MacOS, Xcode and cmake version 3.12 or higher are required. To simplify the build process a Makefile with predefined targets is available. To build the VVenC encoder applications open a terminal, change into the project directory and use:
make install-release
This will create the statically linked release version of the encoder applications in the install/bin/release-static/ subdirectory.
The encoder project includes two encoder executables, a standard encoder (vvencapp) and a full featured expert encoder (vvencFFapp).
The standard encoder (vvencapp) can be used in one of five predefined presets. Each preset represents a different tradeoff between encoder runtime and video quality. In the slowest preset, the encoder reaches the highest compression gain, whilst in the fastest preset the runtime is significantly decreased. A list of the main encoder command line parameters is shown in the following table.
| OPTION | DEFAULT | DESCRIPTION |
|---|---|---|
| --help,-h | - | Show basic help |
| --input,-i | - | Raw yuv input file |
| --size,-s | 1920x1080 | Input file resolution (width x height) |
| --framerate,-r | 60 | Temporal rate of input file. Required for VBR encoding and calculation of output bit-rate. Also recommended with perceptual QP adaptation (see --qpa option below). |
| --format,-c | yuv420 | Set input format to YUV 4:2:0 8bit (yuv420) or YUV 4:2:0 10bit (yuv420_10) |
| --output,-o | not set | Bit-stream output file |
| --preset | medium | Preset for specific encoding setting (faster, fast, medium, slow, slower) |
| --qp,-q | 32 | Quantization parameter (0..63) |
| --bitrate | 0 | Bitrate for rate control (0: constant-QP encoding without rate control, otherwise bits per second). Rate control requires correct --framerate (see option above). |
| --passes,-p | 2 | Number of rate control passes (1: single-pass rate control, 2: two-pass rate control) |
| --qpa | 1 | Perceptual QP adaptation (QPA) to improve subjective video quality (0: off, 1: on) |
| --refreshsec,-rs | 1 | Intra period/refresh in seconds |
| --threads,-t | size > 832x480: 8, else: 4 |
Number of threads (1-N) |
| --hdr | off | HDR mode (+ SEI messages) + BT.709 or BT.2020 color space (off, pq, pq_2020, hlg, hlg_2020) |
Example usage: Given a YUV 4:2:0 input file with a bit-depth of 8bit and a resolution of 176x144 pixels, the following call will encode the input file with the medium speedup preset:
vvencapp --preset medium -i [email protected] -s 176x144 -o str.266
The expert mode encoder (vvencFFapp) is based on the VVC test model (VTM) reference software configuration scheme. Most of the parameters have been kept similar to VTM, but for some parameters, additional modes are available. Furthermore, not supported options have been removed. The following example configuration files for the expert mode encoder can be found in the cfg sub-directory:
| CONFIGURATION FILE | DESCRIPTION |
|---|---|
| sequence.cfg | Sequence specific configuration parameters. Must be always adapted to the input sequence. |
| randomaccess_faster.cfg randomaccess_fast.cfg randomaccess_medium.cfg randomaccess_slow.cfg randomaccess_slower.cfg |
Random access configuration for different presets. Each configuration file corresponds to one of the 5 preset modes. |
| qpa.cfg | Perceptually optimized QPA configuration file. |
| rc1p.cfg | Single pass rate control configuration, overriding default fix QP setup. |
| rc2p.cfg | Two pass rate control configuration, overriding default fix QP setup. |
Example usage: In order to start your first experiments with the expert mode encoder, adapt the sequence.cfg configuration file to your input YUV source file and use the following command:
vvencFFapp -c randomaccess_medium.cfg -c sequence.cfg
Feel free to contribute. To do so:
- Fork the current-most state of the master branch
- Apply the desired changes
- Create a pull-request to the upstream repository
Please see LICENSE.txt file for the terms of use of the contents of this repository.
For more information, please contact: [email protected]
Copyright (c) 2019-2021 Fraunhofer-Gesellschaft zur Förderung der angewandten Forschung e.V.
All rights reserved.