METHOD FOR DECODING PREFIX CODES OF ALTERNATING LENGTH Russian patent published in 2008 - IPC H03M7/42 

FIELD: technology for decoding prefix codes of alternating length, such as Huffman codes, and, in particular, combined decoding circuit which uses transformation table decoding and prefix-oriented decoding.

SUBSTANCE: in accordance to the method, from the stream of bits a number of bits is read, which is not less than maximally possible length of alternating length code, given number of bits is extracted, which is used as index for data structure, which contains at least the decoded value and the trustworthiness indicator. The trustworthiness indicator is used to determine, whether the encoding should be continued, or whether the trustworthy decoded value should be received from data structure and excessive bits returned to bit stream. If the decoded value is determined to be untrustworthy, the decoding is continued, and the decoding method which estimates length of code prefix and number of significant bits which correspond to produced length estimate, is applied to bits that were initially read from the bit stream.

EFFECT: ensured fast encoding of alternating length codes, when a subset of most often used codes with relatively short prefixes may be determined.

3 cl, 3 dwg, 1 app