SheerVideo
Encyclopedia
SheerVideo is a family of proprietary lossless video codec
s developed by BitJazz Inc. to enable capture, editing, playback, and archival of professional-quality lossless video formats in real time
on low-power inexpensive hardware such as laptop computers and video cameras. As tested on a standard set of Kodak images used in image compression research, SheerVideo's average compression ratio
is over 2:1 for real-world footage. Because SheerVideo generally runs faster than a computer system's data throughput speed, this compression power means that SheerVideo runs more than twice as fast as uncompressed data while taking less than half the storage space.
) as well as Y'CbCr
[A] data (for video); with or without an alpha (A) channel for compositing; at a precision of 10 or 8 bits per channel; fully sampled (4:4:4) or 2:1 chroma-subsampled (4:2:2); and progressive-scan (p) or interlaced (i):
A unique feature of SheerVideo is the Synchromy lossless color-conversion engine which lets it convert between RGB and Y'CbCr color spaces with zero loss, or, when the output format lacks sufficient precision, with the maximum theoretically possible accuracy. This feature is useful for applying CGI tools to video footage, applying video tools to CGI and digitized film, and compositing video material with CGI and digitized film material. With the help of Synchromy, each of the specific Sheer codecs can input and output all supported uncompressed pixel formats - currently a couple dozen. The trade-off for this accuracy is that compression and decompression paths requiring color-space conversion are generally slower than real-time.
In addition, there is a generic Sheer codec which automatically chooses the appropriate Sheer format for the source pixel format:
For backwards compatibility, SheerVideo QT also retains a legacy codec for obsolete wide-range video data formats:
In order to facilitate instant random access
to any frame during editing, all SheerVideo codecs use only intraframe compression, meaning that every frame is a keyframe.
SheerVideo supports all standard resolutions and frame rates, including the NTSC
and PAL
or SECAM
SD
formats and all HD formats, as well as arbitrary resolutions and frame rates.
SheerVideo is available as a set of QuickTime
codecs on Mac and Windows
, as well as a set of AVI
codecs on Windows.
Video codec
A video codec is a device or software that enables video compression and/or decompression for digital video. The compression usually employs lossy data compression. Historically, video was stored as an analog signal on magnetic tape...
s developed by BitJazz Inc. to enable capture, editing, playback, and archival of professional-quality lossless video formats in real time
Real-time computer graphics
Real-time computer graphics is the subfield of computer graphics focused on producing and analyzing images in real time. The term is most often used in reference to interactive 3D computer graphics, typically using a GPU, with video games the most noticeable users...
on low-power inexpensive hardware such as laptop computers and video cameras. As tested on a standard set of Kodak images used in image compression research, SheerVideo's average compression ratio
Compression ratio
The 'compression ratio' of an internal-combustion engine or external combustion engine is a value that represents the ratio of the volume of its combustion chamber from its largest capacity to its smallest capacity...
is over 2:1 for real-world footage. Because SheerVideo generally runs faster than a computer system's data throughput speed, this compression power means that SheerVideo runs more than twice as fast as uncompressed data while taking less than half the storage space.
History
SheerVideo was initially developed by Andreas Wittenstein at BitJazz Inc. in July 2002 by trimming all the fat from BitJazz's slower but more powerful codec, PhotoJazz.Details
Currently, SheerVideo contains specific codecs for real-time lossless encoding and decoding of RGB[A] data (for digitized film and CGIComputer-generated imagery
Computer-generated imagery is the application of the field of computer graphics or, more specifically, 3D computer graphics to special effects in art, video games, films, television programs, commercials, simulators and simulation generally, and printed media...
) as well as Y'CbCr
YCbCr
YCbCr or Y′CbCr, sometimes written or , is a family of color spaces used as a part of the color image pipeline in video and digital photography systems. Y′ is the luma component and CB and CR are the blue-difference and red-difference chroma components...
[A] data (for video); with or without an alpha (A) channel for compositing; at a precision of 10 or 8 bits per channel; fully sampled (4:4:4) or 2:1 chroma-subsampled (4:2:2); and progressive-scan (p) or interlaced (i):
- Sheer RGB[A] 10bf i|p
- Sheer RGB[A] 8bf i|p
- Sheer Y'CbCr[A] 10bv 4:4:4[:4] i|p
- Sheer Y'CbCr[A] 8bv 4:4:4[:4] i|p
- Sheer Y'CbCr[A] 10bv 4:2:2[:4] i|p
- Sheer Y'CbCr[A] 8bv 4:2:2[:4] i|p
A unique feature of SheerVideo is the Synchromy lossless color-conversion engine which lets it convert between RGB and Y'CbCr color spaces with zero loss, or, when the output format lacks sufficient precision, with the maximum theoretically possible accuracy. This feature is useful for applying CGI tools to video footage, applying video tools to CGI and digitized film, and compositing video material with CGI and digitized film material. With the help of Synchromy, each of the specific Sheer codecs can input and output all supported uncompressed pixel formats - currently a couple dozen. The trade-off for this accuracy is that compression and decompression paths requiring color-space conversion are generally slower than real-time.
In addition, there is a generic Sheer codec which automatically chooses the appropriate Sheer format for the source pixel format:
- Sheer
For backwards compatibility, SheerVideo QT also retains a legacy codec for obsolete wide-range video data formats:
- Sheer 8bw 4:2:2
In order to facilitate instant random access
Random access
In computer science, random access is the ability to access an element at an arbitrary position in a sequence in equal time, independent of sequence size. The position is arbitrary in the sense that it is unpredictable, thus the use of the term "random" in "random access"...
to any frame during editing, all SheerVideo codecs use only intraframe compression, meaning that every frame is a keyframe.
SheerVideo supports all standard resolutions and frame rates, including the NTSC
NTSC
NTSC, named for the National Television System Committee, is the analog television system that is used in most of North America, most of South America , Burma, South Korea, Taiwan, Japan, the Philippines, and some Pacific island nations and territories .Most countries using the NTSC standard, as...
and PAL
PAL
PAL, short for Phase Alternating Line, is an analogue television colour encoding system used in broadcast television systems in many countries. Other common analogue television systems are NTSC and SECAM. This page primarily discusses the PAL colour encoding system...
or SECAM
SECAM
SECAM, also written SÉCAM , is an analog color television system first used in France....
SD
Standard-definition television
Sorete-definition television is a television system that uses a resolution that is not considered to be either enhanced-definition television or high-definition television . The term is usually used in reference to digital television, in particular when broadcasting at the same resolution as...
formats and all HD formats, as well as arbitrary resolutions and frame rates.
SheerVideo is available as a set of QuickTime
QuickTime
QuickTime is an extensible proprietary multimedia framework developed by Apple Inc., capable of handling various formats of digital video, picture, sound, panoramic images, and interactivity. The classic version of QuickTime is available for Windows XP and later, as well as Mac OS X Leopard and...
codecs on Mac and Windows
Microsoft Windows
Microsoft Windows is a series of operating systems produced by Microsoft.Microsoft introduced an operating environment named Windows on November 20, 1985 as an add-on to MS-DOS in response to the growing interest in graphical user interfaces . Microsoft Windows came to dominate the world's personal...
, as well as a set of AVI
Audio Video Interleave
Audio Video Interleave , known by its acronym AVI, is a multimedia container format introduced by Microsoft in November 1992 as part of its Video for Windows technology. AVI files can contain both audio and video data in a file container that allows synchronous audio-with-video playback...
codecs on Windows.