Xvid
2011-04-20
홈페이지: http://www.xvid.org/
Xvid(이전 명칭은 XviD)는 MPEG-4 표준을 따르는 영상 코덱 라이브러리이다. Xvid는 b-프레임, 전체와 1/4 화소 움직임 보상, 루미 마스크, 격자 양자화와 같은 MPEG-4 진보된 단순 프로필 기능을 지원한다. H.263, MPEG과 커스텀 양자화 매트릭스 등도 지원한다.
Xvid는 DivX(Xvid는 DivX를 거꾸로 씀)의 첫 번째 경쟁 코덱이다. DivX는 상용 소프트웨어이지만, Xvid는 자유/오픈 소스 소프트웨어이고, 마이크로소프트 윈도와 맥 OS X만을 지원하는 DivX와는 대조적으로, Xvid는 다양한 플랫폼과 운영 체제에서 사용될 수 있다.
Xvid is a video codec for PC, whereas codec is an abbreviation for [co]der/[dec]oder, hence describes a program to encode and decode digital video. The purpose of encoding video data is to reduce redundancies – that means to make it smaller for faster transmission over computer networks or for more efficient storage on computer disks.
Hence, Xvid can somewhat be seen as a ZIP for video. But unlike ZIP, Xvid is not lossless. That means that a video after compression and decompression with Xvid won’t be identical to the original source. Typically however, a difference to the source is visually imperceptible.
So Xvid removes information that is not important for human perception, which is somewhat similar to MP3 for audio. This enables very high compression rates that allow to effectively work with digital video on home computers at all. To give an example: uncompressed digital video is huge and requires about 100 GB per hour at PAL resolution. The same video would require just 500 MB per hour at very high quality when compressed with Xvid. That is a compression ratio of 200:1.
Xvid is Free Software and released under the GNU GPL license. This means that the source code of the software is publically available and programmers are allowed to make modifications to the code. Also, redistribution of Xvid is permitted but only under the terms of the GPL license.
So the GPL grants recipients more freedoms than it’s common with other software. Therefore, and due to its very high image quality that has been approved in independent tests conducted by third parties the Xvid codec has gained great popularity in the recent past and has become the codec of choice when it comes to exchanging digital video.
다운로드: 1.3.1
Categorized as: Programming
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