EP0279799A2
Expired / Lapsed
EP
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Method and means for variable length coding
Assignee: Telia Co AB
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Filing: 1988-02-11
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Granted: —
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Expires: 2008-02-11
Abstract
Abstract A method and a means for variable length coding for coding and decoding a block, with the information-carrying information being concentrated to the beginning of the block and terminated by a continuous succession of zeros, wherein two code trees are utilized, the first of which is utilized for coding and decoding the first part of the block up to and including the word before the last non-zero and a character EOB, and the second code tree is specially designed for coding the last non-zero word. A switching means provides for a switching being done between the two code trees and associated means after EOB and before the last non-zero.
Inventors
- 👤 Harald Drusewitz
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-10-31 11:47
CPC Classifications
H; H03; H03M; H03M7/00; H03M7/30; H03M7/40; H03M7/42
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
107 words
A method for transmitting in variable length coding of a block with uncoded information, this information having a structure with the words carrying information being concentrated at the beginning of a block and terminated by a continuous succession of zeros, characterized in that the last non-zero word is detected and that two code trees are utilized, the first code tree being used for coding the first part of the block up to and including the word before the last-zero word, whereupon a character EOB, indicating the end of a block, is coded and a switching is done to the second code tree for coding the last word.
Claim 2
Independent Claim
107 words
A method for transmitting in variable length coding of a block with uncoded information, this information having a structure with the words carrying information being concentrated at the beginning of a block and terminated by a continuous succession of zeros, characterized in that the last non-zero word is detected and that two code trees are utilized, the first code tree being used for coding the first part of the block up to and including the word before the last-zero word, whereupon a character EOB, indicating the end of a block, is coded and a switching is done to the second code tree for coding the last word.
Claim 3
Dependent Claim
72 words
A method for receiving in variable length coding, the received information being coded according to claim 1, characterized in that EOB is detected and that two code trees are utilized, the first code tree being used for decoding the first part of the block up to and including EOB, whereupon a switching is done to the second code tree for decoding the last non-zero word, whereupon the block is completed with zeros.
Claim 4
Dependent Claim
170 words
Transmitting means for variable length coding for performing the method according to claim 1, comprising a detecting means (DET) for the last non-zero word in a block with uncoded information, characterized in that the means further comprises two coding means (VLC1, VLC2), the first (VLC1) utilizing a first code tree (A) for coding the words in a first part of the block up to and including the word before the last non-zero and the second coding means (VLC2) utilizing a second code tree (B, C or D) for coding the last non-zero word in the block, a switching means, which, after the EOB has been transmitted in a coded form, switches the entering picture information from the input of the first encoder to the input of the second encoder and simultaneously switches the output signal of the transmitting means from the first encoder to the second encoder, the second code tree (B) having the same structure as the first code tree (A) though having a different implication of the codes.
Claim 5
Dependent Claim
138 words
Receiving means for variable length coding for receiving signals from the transmitting means according to claim 3, comprising a detecting means (DET) for EOB, characterized in that the means comprises two decoding means (VLC1⁻¹, VLC2⁻¹), the first (VLC1⁻¹) utilizing a first code tree (A) for decoding the word in a first part of the block up to and including EOB, and the second decoding means (VLC2⁻¹) utilizing a second code tree, corresponding to the second code tree in the transmitting means (B, C or D) for decoding the last non-zero word in the block, a switching means, which, when EOB has been decoded, switches the entering received signal from the first decoding means (VLC1⁻¹) to the second decoding means (VLC2⁻¹) and simultaneously switches the output of the receiver from the first decoding means to the second decoding means.
References Cited (Backward Citations)
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