x265 Development

x265 uses an open-source development model;

This model is unbeatable, for many reasons…

  • x265 is by far the most widely adopted HEVC encoder.  With more users, x265 is tested on more hardware and software configurations, under a wider variety of settings and with a wider variety of content than any other HEVC encoder.  Many users pull source code updates daily from our development branch, testing new features as soon as they are available.  Bugs are identified more quickly, leading to more robust code.
  • All x265 code changes are public.  Patches (proposed code improvements) are sent through the x265 development mailing list, for review by all x265 developers.  Public code review leads to more robust code.  Issues are identified and resolved before the proposed patch is committed.
  • x265 licensees have the right to modify x265 to better meet their platform or application requirements.  This right comes with the obligation to contribute those changes back to the x265 project before distributing those modifications.  So all x265 adopters benefit from improvements made by other adopters.
  • In addition to the large dedicated x265 development team at MulticoreWare, the x265 project has attracted a number of talented independent developers who have contributed many valuable improvements.
  • Commercial licensees have the rights to create and contribute improvements to x265.  The open source development model makes it extremely easy for every licensee to debug their complete solution, identify and contribute improvements to optimize integration and performance when integrated with higher level applications.
  • As x265 is the reference standard in HEVC encoding, we get terrific support from major semiconductor companies and other large platform companies.


Contribute to x265!

Are you interested in video encoding?  Do you know C/C++?  The x265 development team is always ready to support talented developers.

Today, more than 70% of the bits crossing the Internet are video, but before it gets downloaded or streamed, all of that video needs to first be encoded.  Today, most of that video is encoded in the H.264 format (with x264 leading the way), but adoption of HEVC is ramping up quickly and is expected to dominate in the coming years.  x265 is one of the world’s most widely used software libraries, used by many of the world’s leading movie streaming services, video system operators, video encoding system developers and video software developers.  x265 has been adopted by many leading open source projects including FFMPEG, VLC and Handbrake.  Your contributions will be highly visible, and highly valued.  HEVC software developers are in high demand, and x265 is the perfect project to show the world that you know what you’re doing.  We have a program under which outside developers are compensated for any significant contributions.

It’s easy to join the x265 project as an open-source developer.

First, get to know x265.  x265 Documentation is distributed with the source, and posted on x265.readthedocs.org

Next, get to know the x265 source code.  It’s available from https://bitbucket.org/multicoreware/x265.  If you prefer Git, there is a Git mirror repo on Videolan.org.  We suggest using Mercurial or Tortoise Hg to clone or pull from our repository, and manage your local copy of the x265 source.

Then visit the x265 developer Wiki learn how to configure your development system and compile x265.  There you’ll find more tips on Coding Style.

To figure out what parts of x265 you can help with, take a look at our TODO list.

Lastly, you should read how to Contribute patches to x265.  We require a signed contributor agreement before we can accept changes.