Information about Ccir 601
CCIR 601 is the old name of a standard published by the CCIR (now ITU-R) for encoding interlaced analogue video signals in digital form. The new name of the standard is ITU-R BT.601, but the old name is still in common use in informal contexts. It includes methods of encoding 525 line 60 Hz and 625-line 50 Hz signals, both with 720 luminance samples and 360 chrominance samples per line. The colour encoding system is known as , that being the ratio of Y:Cb:Cr samples (luminance data:blue chroma data:red chroma data). For a pair of pixels, the data are stored in the order Y1:Y2:Cb:Cr, with the chrominance samples co-sited with the first luminance sample.
The CCIR 601 signal can be regarded as if it is a digitally encoded analog component video signal, and thus includes data for the horizontal and vertical sync and blanking intervals. Regardless of the frame rate, the luminance sampling frequency is 13.5 MHz. The luminance sample is at least 8 bits, and the chrominance samples are at least 4 bits each.
The first version of CCIR 601 defined only a parallel interface, but later versions introduced the bit-serial family of serial digital video interfaces that are now commonly used. The 8 bit serial protocol (216 Mbit/s) was once used in D1 digital tape recording. Modern standards use an encoding table to expand the data to 9 or 10 bits for improved behavior over long transmission lines. The 9 bit serial version has a data rate of 243 Mbit/s. By far, the most common version of the interface is the 10-bit Serial Digital Interface (which was later standardized as SMPTE 259M), which is now a ubiquitous interconnect standard for professional video equipment which operates on standard-definition digital video. This format, originally used in D5 digital tape recording, has a data rate of 270 Mbit/s. Additionally, a 360 Mbit/s version of the interface has been defined, which is sometimes used in widescreen applications.
There is an 8 bit version in which only data from the active video periods are transmitted, with a bit rate of only 165.9 Mbit/s.
In each 8 bit luminance sample, the value 16 is used for black and 235 for white, to allow for overshoot and undershoot. The values 0 and 255 are used for sync encoding. The Cb and Cr samples use the value 128 to encode a zero value, as used when encoding a white, grey or black area.
The CCIR 601 video raster format has been re-used in a number of later standards, including MPEG.
The CCIR 601 signal can be regarded as if it is a digitally encoded analog component video signal, and thus includes data for the horizontal and vertical sync and blanking intervals. Regardless of the frame rate, the luminance sampling frequency is 13.5 MHz. The luminance sample is at least 8 bits, and the chrominance samples are at least 4 bits each.
The first version of CCIR 601 defined only a parallel interface, but later versions introduced the bit-serial family of serial digital video interfaces that are now commonly used. The 8 bit serial protocol (216 Mbit/s) was once used in D1 digital tape recording. Modern standards use an encoding table to expand the data to 9 or 10 bits for improved behavior over long transmission lines. The 9 bit serial version has a data rate of 243 Mbit/s. By far, the most common version of the interface is the 10-bit Serial Digital Interface (which was later standardized as SMPTE 259M), which is now a ubiquitous interconnect standard for professional video equipment which operates on standard-definition digital video. This format, originally used in D5 digital tape recording, has a data rate of 270 Mbit/s. Additionally, a 360 Mbit/s version of the interface has been defined, which is sometimes used in widescreen applications.
There is an 8 bit version in which only data from the active video periods are transmitted, with a bit rate of only 165.9 Mbit/s.
In each 8 bit luminance sample, the value 16 is used for black and 235 for white, to allow for overshoot and undershoot. The values 0 and 255 are used for sync encoding. The Cb and Cr samples use the value 128 to encode a zero value, as used when encoding a white, grey or black area.
The CCIR 601 video raster format has been re-used in a number of later standards, including MPEG.
References
- International Telecommunications Union, ITU-R BT.601
See also
CCIR is a four-letter abbreviation that may stand for:
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- Campaign for Comprehensive Immigration Reform, a Washington, DC organization for immigrant rights
- California Coalition for Immigration Reform
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The ITU Radiocommunication Sector (ITU-R) is one of the three sectors (divisions or units) of the International Telecommunication Union (ITU) and is responsible for radio communication.
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Interlace is a technique of improving the picture quality of a video signal without consuming any extra bandwidth. It was invented by RCA engineer Randall C. Ballard in the 1930s.
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Video (Latin for "I see", first person singular present, indicative of videre, "to see") is the technology of electronically capturing, recording, processing, storing, transmitting, and reconstructing a sequence of still images representing scenes in motion.
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hertz (symbol: Hz) is the SI unit of frequency. Its base unit is cycle/s or s-1 (also called inverse seconds, reciprocal seconds). In English, hertz is used as both singular and plural.
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As applied to video signals, luma represents the brightness in an image (the "black and white" or achromatic portion of the image). Luma is typically paired with chroma. Luma represents the achromatic image without any color, while the chroma components represent the color
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Chrominance (chroma for short), is the signal used in many video systems to carry the color information of the picture separately from the accompanying luma signal.
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Color or colour[1] (see spelling differences) is the visual perceptual property corresponding in humans to the categories called red, yellow, blue, black, etc.
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D-1 format was the first major professional digital video format, introduced in 1986 through efforts by SMPTE engineering committees.
D-1 stored uncompressed digitized component video, encoded at using the CCIR 601 raster format, along with PCM audio tracks as well as
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D-1 stored uncompressed digitized component video, encoded at using the CCIR 601 raster format, along with PCM audio tracks as well as
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Serial Digital Interface (SDI), standardized in ITU-R BT.656 and SMPTE 259M, is a digital video interface used for broadcast-grade video. A related standard, known as High Definition Serial Digital Interface
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widescreen image is a film, computer, or television image with a wider aspect ratio than the standard Academy frame developed during the classical Hollywood cinema era. Silent film was projected at a ratio of four units wide to three units tall, often expressed as 4:3 or 1.33:1.
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Moving Picture Experts Group, commonly referred to as simply MPEG, is a working group of ISO/IEC charged with the development of video and audio encoding standards. Its first meeting was in May of 1988 in Ottawa, Canada.
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YCbCr or Y'CbCr is a family of color spaces used in video and digital photography systems. Y' is the luma component and Cb and Cr are the blue and red chroma components. The prime on the Y is to distinguish the luma from luminance.
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Chroma subsampling is the practice of implementing more resolution for the (quantity representative of) luminance than the (quantity representative of) color. It is used in many video encoding schemes (both analog and digital) and also in JPEG encoding.
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D-1 format was the first major professional digital video format, introduced in 1986 through efforts by SMPTE engineering committees.
D-1 stored uncompressed digitized component video, encoded at using the CCIR 601 raster format, along with PCM audio tracks as well as
..... Click the link for more information.
D-1 stored uncompressed digitized component video, encoded at using the CCIR 601 raster format, along with PCM audio tracks as well as
..... Click the link for more information.
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