x265 is a commercially funded open source implementation of the H.265/High Efficiency Video Coding (HEVC) compression standard. The x265 project is led by MulticoreWare, a leading provider of high performance video software libraries. The project also has several corporate sponsors whose generous contributions have allowed the project to exist.
x265 is available under the GNU GPL v2 license. Source code is available from the x265 Project Page. Development is funded through license fees paid by commercial companies, who receive a commercial license which is less restrictive than the GPL v2 (with respect to open-source requirements for the system that integrates x265). Pricing and commercial license terms are available under a Non-Disclosure Agreement. Please contact us by writing to license @ x265.com.
The x265 team has licensed the rights to port and adapt x264 for use in x265. Most of the video encoding algorithms developed for x264 have been incorporated in x265, including rate control functions, the lookahead function, macroblock tree, b-pyramid and adaptive quantization.
What is x264?
x264 is generally accepted as the highest-quality, most efficient H.264/AVC implementation in the world. Various studies have shown year after year that x264 achieves the highest possible quality, at the lowest possible bit rate.
Much of the technology that makes x264 work for H.264/AVC also lends itself well to H.265/HEVC encoding. Key concepts such as the x264 lookahead and adaptive quantization not only apply to H.265, but will in fact be even more powerful due to the increased encoding flexibility within H.265 standard.
More information about x264 can be found here http://www.videolan.org/developers/x264.html. Academic studies comparing x264 with other H.264 compression schemes can be found here:
- MSU study: http://www.compression.ru/video/codec_comparison/h264_2012/
- Performance Analysis and Comparison of JM, Intel IPP and X264 for H.264 Softwares: