X264 is a GNU licensed free software library used to encode video streams into H.264/MPEG-4 AVC format, which is compatible with Blu-ray players. The H.264/MPEG-4 standard is one of the most commonly used formats for the recording, compression, and distribution of high definition video on the Internet today. H.264 is best known as the standard for Blu-ray disks and the standard that YouTube, iTunes, Microsoft Silverlight, and Adobe Flash Player support. X264 was created to fill the void of not having an open implementation of a video converter to this format and industry continues to develop and use it today.

When was x264 First Developed?

Laurent Aimar originally started the x264 project. He stopped working on the project in 2004 once ATEME hired him. Loren Merritt took over as lead for development of the project and fellow developers Steven Walters, Jason Garrett-Glaser, Anton Mitrofanov, Guillaume Poirier, and David Condrad assisted him.

x264 Features

The x264 project provides both an API and a command line interface for developers and end-users. Other projects that interface with the library in order to encode a video stream into H.264/MPEG4 format use each of the interfaces. The additional features found in the software package include macroblock-tree rate control that tracks how often parts of the frame are used for predicting future frames (controls quality), pyschovisual rate-distortion optimization that attempts to keep similar complexity using a combination of SSD and SATD to measure such, and adaptive quantization in two modes using VAQ. The library also uses SIMD assembly code acceleration and was the first Blu-ray compliant software H.264 encoder on the market in April 2010.

Where Can One Get x264?

A video processing package that supports MPEG4 or Blu-ray encoding may already have the x264 codec in the program! The project also posts a daily tarball at:

ftp://ftp.videolan.org/pub/videolan/x264/snapshots/

and makes the source code available online with unofficial builds for the Windows operating system (OS), also available through the project website.

What Software Packages Use the x264 Codebase?

There are a number of software programs on the market that incorporate the x264 codebase. Some of the ones that officially include the code base (there are a number which do so unofficially) are Avidemux, ELDER, ffdshow, ffmpeg, GordianKnot, Handbrake, LiVES, MeGUI, Mencoder, pspVideo9, RealAnime, StaxRip, TCVP, and the VLC media player.