|
FFmpeg is a free software project that produces libraries and programs for handling multimedia data. FFmpeg includes libavcodec, an audio/video codec library used by several other projects, libavformat, an audio/video container mux and demux library, and the ffmpeg command line program for transcoding multimedia files. FFmpeg is published under the GNU Lesser General Public License 2.1+ or GNU General Public License 2+ (depending on which options are enabled).〔(【引用サイトリンク】title=FFmpeg License and Legal Considerations )〕 FFmpeg is developed under Linux, but it can be compiled under most operating systems, including Mac OS X, Microsoft Windows, as well as AmigaOS and its heir MorphOS. Most computing platforms and microprocessor instruction set architectures are also supported, like x86 (IA-32 and x86-64), PPC (PowerPC), ARM, DEC Alpha, SPARC, and MIPS. The name of the project is inspired by the MPEG video standards group, together with "FF" for "fast forward". The logo uses a zigzag pattern that shows how MPEG video codecs handle entropy encoding. == History == The project was started by Fabrice Bellard〔 (using the pseudonym "Gérard Lantau") in 2000, and was lead by Michael Niedermayer from 2004 until 2015. Many FFmpeg developers are also part of the MPlayer project. FFmpeg version 0.5 appeared after a long time without formal releases. Meanwhile, the project approximately publishes a new release every three months to be used by "distributors and system integrators", but FFmpeg developers recommend that users compile the software from source using the latest build from their source code Git version control system.〔(【引用サイトリンク】title=ffmpeg.org/download.html#releases )〕 Two video coding formats with corresponding codecs and one container format were invented in the FFmpeg project during its development. The two video codecs are the lossless FFV1, and the lossless and lossy Snow, the development of which has stalled, while its bit-stream format has not been finalized yet, making it experimental since 2011. The multimedia container format called NUT is no longer being actively developed, but still maintained. In summer 2010, Fiona Glaser, Ronald Bultje, and David Conrad of the FFmpeg Team announced the ffvp8 decoder. Through testing, they determined that ffvp8 was faster than Google's own libvpx decoder. Starting with version 0.6, FFmpeg also supported WebM and VP8. Since May 2011, an independent developer offers frequently updated ports of the FFmpeg tools for Windows platforms, to which FFmpeg official website links.〔(【引用サイトリンク】title=Zeranoe FFmpeg )〕 In October, 2013, a native VP9 and the OpenHEVC decoder, an open source High Efficiency Video Coding (HEVC) decoder, were added to FFmpeg. On January 10, 2014, two Google employees announced that over 1000 bugs have been fixed in FFmpeg during the previous two years by means of fuzz testing.〔(FFmpeg and a thousand fixes; January 10, 2014; Google. )〕 FFmpeg 2.5 released in December, 2014, supports an MPEG-DASH muxer. On July 31, 2015, lead maintainer Michael Niedermeyer announced that he would be resigning, in order to help resolve the fork situation with Libav.〔 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「ffmpeg」の詳細全文を読む スポンサード リンク
|