X265

Last updated
X265
Developer(s) MulticoreWare
Initial release2013;11 years ago (2013)
Stable release
3.5 [1]   OOjs UI icon edit-ltr-progressive.svg / 16 March 2021;2 years ago (16 March 2021)
Repository
Written in C++, x86 assembly
Standard(s) HEVC
Type Video codec
License GPL-2.0-or-later, [2] or optionally an on-request commercial license [3]
Website x265.org

x265 is an encoder for creating digital video streams in the High Efficiency Video Coding (HEVC/H.265) video compression format developed by the Joint Collaborative Team on Video Coding (JCT-VC). [4] [5] [6] It is available as a command-line app or a software library, under the terms of GNU General Public License (GPL) version 2 or later; however, customers may request a commercial license. [3] [7]

Contents

History

x265 builds on source code from x264, an open-source video encoder for the previous MPEG video coding standard, H.264/MPEG-4 AVC. The project has licensed the rights to use the x264 source code. [3] Development on x265 began in March 2013. [7] MulticoreWare made the source code for x265 publicly available on July 23, 2013. [4] [5]

The x265 project was initially funded by a small group of charter licensee companies that direct the development requirements and receive commercial licenses to use x265 in their products without having to release their products under the GPL 2 license. [3] In February 2014, x265 was integrated into the popular multimedia transcoding tool FFmpeg and its fork Libav. [8]

Version 1.0 was completed in May 2014. [9] The stable version (2.0) was released on July 14, 2016. [10]

Technical details

x265 source code is written in C++ and x86 assembly. [3]

x265 supports the Main, Main 10, Main 12 and Main Still Picture profiles [11] of HEVC (including intra-only profiles), utilizing a bit depth of either 8 bits or 10 bits per sample YCbCr with 4:2:0, 4:2:2 or 4:4:4 chroma subsampling. [12] x265 supports most of the features of x264 including all rate control modes: Constant QP (CQP), Constant Rate Factor (CRF), Average Bit Rate (ABR), 2-pass or multi-pass and video buffering verifier rate control. [13] Visual quality algorithms include CU-Tree (the successor to x264's macroblock-tree), adaptive quantization, b-pyramid, weighted prediction and psycho-visual optimizations (psy-rd and psy-rdoq). A fully lossless mode is also supported. Temporal scalability is supported, allowing for a video to be encoded into a base layer HEVC bitstream that is half the frame rate of the input video frame rate, and an enhancement layer that can be decoded along with the base layer to enable playback at the full frame rate.

In April 2015, at the NAB Show in Las Vegas, MulticoreWare demonstrated high quality real-time 4K 10-bit HEVC encoding [14] at frame rates in excess of 60 FPS on a dual Intel Xeon E5 v3 server, occupying only one standard rack unit.

Quality and efficiency

Judged by the objective quality metric VQM in 2015, x265 delivered video quality on par with the reference encoder of the royalty-free VP9 format that competes with HEVC. [15] A codec comparison from 2015 found x265 to be a leading HEVC implementation measured by SSIM metric. [16] In August 2016, Netflix published a comparison of x264, VP9, and x265 using video clips from 500 movies and TV shows using 6 different quality metrics and found that both VP9 and x265 have 40%–50% better quality at 1080p than x264. Netflix stated that with the VMAF metric (which closely mirrors human visual experience according to the author) x265 performed substantially (19% to 22%) better than VP9. [17]

Usage

x265 can be invoked as a command-line app or integrated into another application through the application programming interface. [18] [19]

Open-source adopters

Open source software projects which utilize x265 for HEVC encoding:

Commercial adopters

Commercial products that utilize x265 for HEVC encoding:

Related Research Articles

<span class="mw-page-title-main">FFmpeg</span> Multimedia framework

FFmpeg is a free and open-source software project consisting of a suite of libraries and programs for handling video, audio, and other multimedia files and streams. At its core is the command-line ffmpeg tool itself, designed for processing of video and audio files. It is widely used for format transcoding, basic editing, video scaling, video post-production effects and standards compliance.

RealVideo, or also spelled as Real Video, is a suite of proprietary video compression formats developed by RealNetworks — the specific format changes with the version. It was first released in 1997 and as of 2008 was at version 10. RealVideo is supported on many platforms, including Windows, Mac, Linux, Solaris, and several mobile phones.

x264 is a free and open-source software library and a command-line utility developed by VideoLAN for encoding video streams into the H.264/MPEG-4 AVC video coding format. It is released under the terms of the GNU General Public License.

<span class="mw-page-title-main">Avidemux</span> Free and open-source transcoding and video editing software

Avidemux is a free and open-source software application for non-linear video editing and transcoding multimedia files. The developers intend it as "a simple tool for simple video processing tasks" and to allow users "to do elementary things in a very straightforward way". It is written in C++ and uses Qt for its graphical user interface, and FFmpeg for its multimedia functions. Starting with version 2.4, Avidemux also offers a command-line interface, and since version 2.6, the original GTK port has not been maintained and is now discontinued.

libavcodec is a free and open-source library of codecs for encoding and decoding video and audio data.

Α video codec is software or a device that provides encoding and decoding for digital video, and which may or may not include the use of video compression and/or decompression. Most codecs are typically implementations of video coding formats.

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Video Acceleration API (VA-API) is an open source application programming interface that allows applications such as VLC media player or GStreamer to use hardware video acceleration capabilities, usually provided by the graphics processing unit (GPU). It is implemented by the free and open-source library libva, combined with a hardware-specific driver, usually provided together with the GPU driver.

<span class="mw-page-title-main">VP8</span> Open and royalty-free video coding format released by Google in 2010

VP8 is an open and royalty-free video compression format released by On2 Technologies in 2008.

High Efficiency Video Coding (HEVC), also known as H.265 and MPEG-H Part 2, is a video compression standard designed as part of the MPEG-H project as a successor to the widely used Advanced Video Coding. In comparison to AVC, HEVC offers from 25% to 50% better data compression at the same level of video quality, or substantially improved video quality at the same bit rate. It supports resolutions up to 8192×4320, including 8K UHD, and unlike the primarily 8-bit AVC, HEVC's higher fidelity Main 10 profile has been incorporated into nearly all supporting hardware.

libvpx Codec library implementing VP8 and VP9 encoders and decoders

libvpx is a free software video codec library from Google and the Alliance for Open Media (AOMedia). It serves as the reference software implementation for the VP8 and VP9 video coding formats, and for AV1 a special fork named libaom that was stripped of backwards compatibility.

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<span class="mw-page-title-main">VP9</span> Open and royalty-free video coding format released by Google in 2013

VP9 is an open and royalty-free video coding format developed by Google.

High Efficiency Video Coding implementations and products covers the implementations and products of High Efficiency Video Coding (HEVC).

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<span class="mw-page-title-main">MulticoreWare</span>

MulticoreWare Inc is a software development company, offering products and services related to HEVC video compression, machine learning, compilers for heterogeneous computing, and software performance optimization services. MulticoreWare's customers include AMD, Microsoft, Google, Qualcomm and Telestream. The company was founded in 2009 and has offices in the United States, China and India.

AOMedia Video 1 (AV1) is an open, royalty-free video coding format initially designed for video transmissions over the Internet. It was developed as a successor to VP9 by the Alliance for Open Media (AOMedia), a consortium founded in 2015 that includes semiconductor firms, video on demand providers, video content producers, software development companies and web browser vendors. The AV1 bitstream specification includes a reference video codec. In 2018, Facebook conducted testing that approximated real-world conditions, and the AV1 reference encoder achieved 34%, 46.2%, and 50.3% higher data compression than libvpx-vp9, x264 High profile, and x264 Main profile respectively.

Versatile Video Coding (VVC), also known as H.266, ISO/IEC 23090-3, and MPEG-I Part 3, is a video compression standard finalized on 6 July 2020, by the Joint Video Experts Team (JVET), a joint video expert team of the VCEG working group of ITU-T Study Group 16 and the MPEG working group of ISO/IEC JTC 1/SC 29. It is the successor to High Efficiency Video Coding. It was developed with two primary goals – improved compression performance and support for a very broad range of applications.

References

  1. ↑ "release: Release notes for v3.5".
  2. ↑ "Bitbucket". bitbucket.org.
  3. 1 2 3 4 5 "x265 Mission Statement". Bitbucket. 2013-07-24. Retrieved 2013-07-24.
  4. 1 2 Joel Hruska (2013-07-23). "H.265 benchmarked: Does the next-generation video codec live up to expectations?". ExtremeTech . Retrieved 2013-07-23.
  5. 1 2 Chris Angelini (2013-07-23). "Next-Gen Video Encoding: x265 Tackles HEVC/H.265". Tom's Hardware . Retrieved 2013-07-23.
  6. ↑ "HEVC / H.265 Explained". x265. Retrieved 2022-02-13.
  7. 1 2 "x265 Development Road Map". Bitbucket. 2013-07-23. Archived from the original on 2015-04-02. Retrieved 2013-07-23.
  8. ↑ Volker Zota (heise online), 14. 2. 2014: Videokodierung: HEVC/H.265-Encoder hält Einzug bei FFmpeg und LibAV
  9. ↑ "multicoreware / x265 / Commits — Bitbucket". bitbucket.org.
  10. ↑ "[x265][ANN] x265 2.0 released". 13 July 2016.
  11. ↑ "Command Line Options — x265 documentation" . Retrieved 2024-03-12.
  12. ↑ "Command Line Options — x265 documentation" . Retrieved 2024-03-12.
  13. ↑ "x265 Documentation — x265 documentation" . Retrieved 2024-03-12.
  14. ↑ "MulticoreWare demonstrates high quality 4K 10-bit real-time HEVC video encoding with x265". Design And Reuse.
  15. ↑ Jan Ozer, April 2015: The Great UHD Codec Debate: Google's VP9 Vs. HEVC/H.265
  16. ↑ Jan Ozer, November 9, 2015: Moscow State Releases First HEVC Comparison
  17. ↑ Ozer, Jan. "Netflix Finds x265 20% More Efficient than VP9 - Streaming Media Magazine". Streaming Media Magazine. Retrieved 2016-11-09.
  18. ↑ "Command Line Options — x265 documentation" . Retrieved 2024-03-12.
  19. ↑ "Application Programming Interface — x265 documentation" . Retrieved 2024-03-12.
  20. ↑ "Avidemux – News".
  21. ↑ "General Documentation".
  22. ↑ "HandBrake: Features".
  23. ↑ "x265 GUI Encoder with Internet Friendly Media Encoder!".
  24. ↑ berrinam (7 May 2023). "MeGUI". SourceForge.
  25. ↑ "OpenShot".
  26. ↑ "ShareX 13.1.0 - changelog". 2020-03-01.
  27. ↑ "Shotcut".
  28. ↑ "StaxRip".
  29. ↑ "x265vfw".
  30. ↑ "BBright – Ultra HD / 4K Video Products and Laser Light Sources". BBright.
  31. ↑ "DaVinci Resolve 16 | Blackmagic Design". www.blackmagicdesign.com. Retrieved 2020-07-17.
  32. ↑ "Squeeze Desktop Pro – Sorenson Media". Sorenson Media. Archived from the original on 2015-09-17. Retrieved 2015-07-22.
  33. ↑ "Video Workflow Automation Software – Vantage Workflow Features & Benefits – Telestream".
  34. ↑ "TMPGEnc Video Mastering Works 6".
  35. ↑ "x265 HEVC Upgrade". x265.
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