x265 is an open-source H.265/HVEC encoder that offers very high compression efficiency and performance. There have been significant efforts to optimize the open-source libx265 implementation of the H.265 encoder on Arm Neoverse platforms which supports Neon instructions. The optimized code is available on
Bitbucket
Install GCC for your Arm Linux distribution. Refer to the install guide for additional information.
Install Cmake and other dependencies:
sudo apt update
sudo apt install wget git cmake cmake-curses-gui build-essential -y
If you are running on x86, also install yasm
sudo apt install yasm -y
Clone the repository and navigate to the linux directory.
git clone https://bitbucket.org/multicoreware/x265_git.git
cd x265_git/build/linux
Run the interactive bash script to change the default flags for the build. Then, run make.
./make-Makefiles.bash
make
{{ % notice Note % }}
If you encounter an error regarding an unknown value, you can change the ENABLE_NEON_I8MM flag to OFF using the interactive bash script in the previous step.
error: unknown value ‘armv9-a+i8mm+sve2’ for ‘-march’
{{ % /notice % }}
For detailed instructions refer to this README .
To benchmark the compression efficiency and performance of x265, you will need a set of video streams to run the codec on. You can use the video files from the
Google YouTube UGC data set
with different resolutions.
Download the 360P and 1080P video files:
wget https://storage.googleapis.com/ugc-dataset/original_videos/Sports/360P/Sports_360P-02c3.mkv
wget https://storage.googleapis.com/ugc-dataset/original_videos/Sports/1080P/Sports_1080P-0640.mkv
To benchmark the performance of x265 over 50 frames of the 360P video file, run the command:
./x265 --preset ultrafast --frames 50 Sports_360P-02c3.mkv --input-res 640x360 --fps 24 --output outfile.265 --frame-threads 1 --no-wpp --pools ','
To benchmark the performance of x265, using the 1080P video file, run the command:
./x265 --preset ultrafast --frames 50 Sports_1080P-0640.mkv --input-res 1920x1080 --fps 24 --output outfile.265 --frame-threads 1 --no-wpp --pools ','
You can vary the preset settings on the different resolution images and measure the impact on performance.
For full usage instructions, refer to the command line documentation , or see the help:
./x265 --help
The encoding Frame Rate (Frames per second) for the video files is output at the end of each run.
Shown below is example output from running the codec on the 1080P sample video file:
yuv [info]: 1920x1080 fps 24000/1000 i420p8 frames 0 - 49 of 500
raw [info]: output file: outfile.265
x265 [info]: HEVC encoder version 3.5+38-20255e6f0
x265 [info]: build info [Linux][GCC 9.4.0][32 bit] 8bit
x265 [info]: using cpu capabilities: NEON
x265 [info]: Main profile, Level-4 (Main tier)
x265 [warning]: No thread pool allocated, --lookahead-slices disabled
x265 [info]: Slices : 1
x265 [info]: frame threads / pool features : 1 / none
x265 [info]: Coding QT: max CU size, min CU size : 32 / 16
x265 [info]: Residual QT: max TU size, max depth : 32 / 1 inter / 1 intra
x265 [info]: ME / range / subpel / merge : dia / 57 / 0 / 2
x265 [info]: Lookahead / bframes / badapt : 5 / 3 / 0
x265 [info]: b-pyramid / weightp / weightb : 1 / 0 / 0
x265 [info]: References / ref-limit cu / depth : 1 / off / off
x265 [info]: AQ: mode / str / qg-size / cu-tree : 1 / 0.0 / 32 / 1
x265 [info]: Rate Control / qCompress : CRF-28.0 / 0.60
x265 [info]: tools: rd=2 psy-rd=2.00 early-skip rskip mode=1 tmvp fast-intra
x265 [info]: tools: strong-intra-smoothing deblock
x265 [info]: frame I: 1, Avg QP:32.43 kb/s: 41945.86
x265 [info]: frame P: 13, Avg QP:32.29 kb/s: 30498.79
x265 [info]: frame B: 36, Avg QP:35.31 kb/s: 9951.11
x265 [info]: consecutive B-frames: 14.3% 0.0% 0.0% 85.7%
encoded 50 frames in 13.74s (3.64 fps), 15933.41 kb/s, Avg QP:34.47