A video codec is an electronic circuit or software that compresses or decompresses digital video. It converts uncompressed video to a compressed vice versa. In the context of video compression, "codec" is a concatenation of "encoder" and "decoder"—a device that only compresses is called an encoder, one that only decompresses is a decoder; the compressed data format conforms to a standard video compression specification. The compression is lossy, meaning that the compressed video lacks some information present in the original video. A consequence of this is that decompressed video has lower quality than the original, uncompressed video because there is insufficient information to reconstruct the original video. There are complex relationships between the video quality, the amount of data used to represent the video, the complexity of the encoding and decoding algorithms, sensitivity to data losses and errors, ease of editing, random access, end-to-end delay. Video was stored as an analog signal on magnetic tape.
Around the time when the compact disc entered the market as a digital-format replacement for analog audio, it became feasible to store and convey video in digital form. Because of the large amount of storage and bandwidth needed to record and convey raw video, a method was needed to reduce the amount of data used to represent the raw video. Since engineers and mathematicians have developed a number of solutions for achieving this goal that involve compressing the digital video data. In 1974, discrete cosine transform compression was introduced by Nasir Ahmed, T. Natarajan and K. R. Rao. During the late 1980s, a number of companies began experimenting with DCT lossy compression for video coding, leading to the development of the H.261 standard. H.261 was the first practical video coding standard, was developed by a number of companies, including Hitachi, PictureTel, NTT, BT, Toshiba, among others. Since H. 261, DCT compression has been adopted by all the major video coding standards. The most popular video coding standards used for codecs have been the MPEG standards.
MPEG-1 was developed by the Motion Picture Experts Group in 1991, it was designed to compress VHS-quality video. It was succeeded in 1994 by MPEG-2/H.262, developed by a number of companies Sony and Mitsubishi Electric. MPEG-2 became the standard video format for SD digital television. In 1999, it was followed by MPEG-4/H.263, a major leap forward for video compression technology. It was developed by a number of companies Mitsubishi Electric and Panasonic; the most used video coding format, as of 2016, is H.264/MPEG-4 AVC. It was developed in 2003 by a number of organizations Panasonic, Godo Kaisha IP Bridge and LG Electronics. H.264 is the main video encoding standard for Blu-ray Discs, is used by streaming internet services such as YouTube, Vimeo, iTunes Store, web software such as Adobe Flash Player and Microsoft Silverlight, various HDTV broadcasts over terrestrial and satellite television. AVC has been succeeded by HEVC, developed in 2013, it is patented, with the majority of patents belonging to Samsung Electronics, GE, NTT and JVC Kenwood.
Video codecs are used in DVD players, Internet video, video on demand, digital cable, digital terrestrial television, videotelephony and a variety of other applications. In particular, they are used in applications that record or transmit video, which may not be feasible with the high data volumes and bandwidths of uncompressed video. For example, they are used in operating theaters to record surgical operations, in IP cameras in security systems, in remotely operated underwater vehicles and unmanned aerial vehicles. Video codecs seek to represent a fundamentally analog data set in a digital format; because of the design of analog video signals, which represent luminance and color information separately, a common first step in image compression in codec design is to represent and store the image in a YCbCr color space. The conversion to YCbCr provides two benefits: first, it improves compressibility by providing decorrelation of the color signals, it is common to represent the ratios of information stored in these different channels in the following way Y:Cb:Cr.
Different codecs use different chroma subsampling ratios as appropriate to their compression needs. Video compression schemes for Web and DVD make use of a 4:2:1 color sampling pattern, the DV standard uses 4:1:1 sampling ratios. Professional video codecs designed to function at much higher bitrates and to record a greater amount of color information for post-production manipulation sample in 4:2:2 and 4:4:4 ratios. Examples of these codecs include Panasonic's DVCPRO50 and DVCPROHD codecs, Sony's HDCAM-SR, Panasonic's HDD5, Apple's Prores HQ 422, it is worth noting that video codecs can operate in RGB space as well. These codecs tend not to sample the red and blue channels in different ratios, since there is less perceptual motivation for doing so—just the blue channel could be undersampled; some amount of spatial and temporal downsampling may be used to reduce the raw data rate before the basic encoding process. The most popular encoding transform is the 8x8 discrete cosine transform. Codecs which make use of a wavelet transform are entering the market, especially
The J. H. Gakey House in Boise, Idaho, is a 2-story brick Bungalow designed by Tourtellotte & Hummel and constructed by Lemon & Doolittle in 1910; the house features a hip roof with attic dormers. Lintels and window sills are trimmed with stone; the house includes a large, cross facade porch with square posts decorated by geometric ornaments below the capitals. The Gakey house was added to the National Register of Historic Places in 1982. In 1910 the Idaho Statesman described the house as "one of the first of its kind in the city." The newspaper noted wide overhanging eaves to protect second floor windows from direct sunlight, natural ventilation, air pockets behind the brick veneer to keep the house warm and dry in winter. The house included pieces of built in furniture. John H. Gakey arrived in Boise City in 1882, having moved from Wyoming. Although a resident of Boise, Gakey owned a large sheep ranch near Nampa. Gakey married Martha Elizabeth Baker in Boise in 1886. By 1910, the year of construction of the J.
H. Gakey House, Mrs. Gakey was being treated for stomach cancer, she died of the disease before the Gakeys could occupy their new home. John Gakey never lived in the house, he sold it to its first occupant, Frank Blackinger, in 1911. Gakey was remarried in 1918 to Elizabeth Lynch in Boise, the Gakeys sold their Nampa ranch and moved to Napa, California, in 1947. John Gakey died in Napa in 1953. In the early 20th century, a stop on the Boise Interurban Railway, Southern Division, was named "Gakey" in reference to its proximity to the John Gakey ranch near Nampa. American Foursquare architecture Media related to J. H. Gakey House at Wikimedia Commons
Immortal Records is an imprint record label an independent record label/imprint based in Los Angeles, California. Founded in 1994 by Amanda Scheer Demme and Happy Walters, the company had helped launched the careers of such influential acts as Korn, Thirty Seconds to Mars, Incubus over the years; the label had released soundtracks, including Judgment Night, Blade II, Masters of Horror. Thirty Seconds to Mars – 30 Seconds to Mars Thirty Seconds to Mars – A Beautiful Lie Adema – Kill the Headlights A – How Ace Are Buildings Agent Sparks – Red Rover TheBleedingAlarm – Beauty in Destruction Brazil – The Philosophy of Velocity A Change of Pace – Prepare The Masses A Change of Pace – An Offer You Can't Refuse A Santa Cause: It's a Punk Rock Christmas Deadsy – Phantasmagore The Finals – Plan Your Getaway Far – Tin Cans With Strings To You Far - Water & Solutions Funkdoobiest - Which Doobie U B? Funkdoobiest - Brothas Doobie His Boy Elroy – His Boy Elroy Hot Rod Circuit – The Underground Is a Dying Breed Incubus – Enjoy Incubus Incubus – S.
C. I. E. N. C. E. Incubus – Make Yourself Incubus – Morning View Incubus – A Crow Left of the Murder... Incubus - If Not Now, When? Korn – Korn Korn – Life Is Peachy Korn – Follow the Leader Korn – Issues Korn – Untouchables Korn – Take a Look in the Mirror No One – No One Scary Kids Scaring Kids – The City Sleeps in Flames Scary Kids Scaring Kids – After Dark EP Scary Kids Scaring Kids – Scary Kids Scaring Kids Switched – Subject to Change Transmatic – Transmatic Tyler Read – Only Rock and Roll Can Save Us Now U. S. Crush – U. S. Crush The Urge – Receiving The Gift of Flavor The Urge – Master of Styles The Urge – Too Much Stereo Waking Ashland – Telescopes Waking Ashland – The Well The Who – Live from Toronto List of record labels: I–Q Immortal Records albums Official Web site