Systems and methods for decoding compressed data

• Main Author: SUBRAMANIAM GIRISH
• Format: Patent
• Language: English
• Published: 07.06.2005
• Edition: 7
• Subjects: BASIC ELECTRONIC CIRCUITRY; CODE CONVERSION IN GENERAL; CODING; DECODING; ELECTRICITY; ENSURING THE SAFETY OF RAILWAY TRAFFIC; GUIDING RAILWAY TRAFFIC; PERFORMING OPERATIONS; RAILWAYS; TRANSPORTING

A method of decoding an encoded bitstream. The method includes performing a table lookup. Addresses into the table are generated using selected numbers of bits drawn from the bitstream in response to values stored in the table entries. A table entry may contain an index offset and a number of bits to extract from the bitstream. Alternatively, the table entry may contain the decode result. The value of a result tag in the entry signals which of the alternatives is contained in the entry. The table is recursively accessed until a portion of the bitstream is decoded. Any remaining portion of the bitstream is decoded similarly. An initial index into the table is determined from a number of bits of the bitstream corresponding to the length of the smallest code word in the codetable used to encode the bitstream.