uavs3e

uavs3/uavs3e

No commits since Aug 2023

AVS3 encoder which supports AVS3-P2 baseline profile.

Latest release

v1.1Oct 12, 2022

Last commit

Aug 3, 2023

Stars

162

uavs3e is an open-source encoder for AVS3, the Chinese video standard, supporting the AVS3-P2 baseline profile. It was developed by Peking University Shenzhen Graduate School, Peng Cheng Laboratory and Guangdong Bohua UHD Innovation, and is licensed under the BSD 4-clause license. It is optimized for SSE4/AVX2 and also builds for ARM and LoongArch.

Development has stopped: the last commit on master is from August 2023, and the only tags, v1.3 and v1.1, date from 2022. It is slow by default and awkward to build today.

Build

There are no binaries. On Linux:

git clone https://github.com/uavs3/uavs3e.git
cd uavs3e
mkdir -p build/linux && cd build/linux
cmake ../.. -DCOMPILE_10BIT=0 -DCMAKE_POLICY_VERSION_MINIMUM=3.5 \
  -DCMAKE_C_FLAGS="-Wno-incompatible-pointer-types -D_LARGEFILE64_SOURCE -include unistd.h"
make -j8

The extra flags work around three problems with current toolchains: CMake 4 rejects the project’s old minimum version, GCC 14+ and recent Clang treat an incompatible-pointer warning in the AVX2 code as an error, and test/utest.c (where the encoder’s main lives) uses lseek64/read/write without including <unistd.h>. The result is a uavs3enc binary in the build directory. On Windows, run version.bat and build build/x86_windows/uavs3e.sln in Visual Studio.

Caution

-DCOMPILE_10BIT=1 enables 10-bit encoding, but without SIMD, and builds with it crash on AVX2 Linux (reported, unfixed). Stay with the 8-bit build unless you need 10-bit.

Encode

uavs3enc reads raw planar YUV only, from a seekable file: no Y4M, and -i - (stdin) does not work. Convert first, and give it the size and frame rate yourself:

ffmpeg -i input.mkv -pix_fmt yuv420p -f rawvideo input.yuv
uavs3enc -i input.yuv -w 1920 -h 1080 -d 8 --fps_num 24000 --fps_den 1001 -q 30 -o output.avs3

Note that -h is the height, not help. For rate-controlled encodes and more threads:

uavs3enc -i input.yuv -w 1920 -h 1080 -d 8 --fps_num 24000 --fps_den 1001 -p 120 \
  --speed_level 2 --rc_type 1 --rc_crf 28 --wpp_threads 8 --frm_threads 8 -o output.avs3

With --rc_type 1 (CRF) the quality comes from --rc_crf, and -q is ignored.

Option	Meaning
-q	Fixed QP in CQP mode (the default): 0–63 for 8-bit, −16–63 for 10-bit.
--rc_type	0 CQP (default), 1 CRF, 2 ABR, 3 CBR.
--rc_crf	CRF value, 0–63.
--rc_bitrate, --rc_max_bitrate	Target and maximum bitrate in kbit/s for ABR/CBR.
--speed_level	0 to 4. 0 is the default and the slowest; 4 is the fastest.
-p	Intra period in frames; 0 means only the first frame is intra.
--wpp_threads, --frm_threads	Wavefront and frame-level threading.
-f	Maximum number of frames to encode.
--config	Read options from a file; command-line options override it.

Decode and play

The output is a raw AVS3 stream. Decode it with uavs3d, or with FFmpeg built with --enable-libuavs3d, which is not the default.