Huffman decoder

• US 5,604,498 A
• Filed: 06/30/1995
• Issued: 02/18/1997
• Est. Priority Date: 06/30/1994
• Status: Expired due to Term

• Current Assignee: Samsung Electronics Co. Ltd.
• Original Assignee: Samsung Electronics Co. Ltd.
• Inventors: Park, Heon-chul
• Primary Examiner(s): Young, Brian K.
• Application Number:
  US08/496,881
• Time in Patent Office: 599 Days
• Field of Search: 341/65, 341/67, 341/106
• US Class Current: 341/65
• CPC Class Codes: G06T 9/005 Statistical coding, e.g. Huffman, run length coding
• CPC Class Codes: H03M 7/425 for the decoding process only

Abstract

A Huffman decoder includes a first latch for storing the current variable-length-encoded data, a second latch for storing the previous variable-length-encoded data, a single decoder for receiving the word size and outputting a selection signal, a data requirement signal generator for generating a data requirement signal when the added word size is over a predetermined size after summing the word sizes, a multiplexer for receiving the outputs of the first and second latches to select a predetermined bit according to the selection signal, a data rotator for cyclic-shifting the output of the multiplexer according to the word size to form a reconstructed data and outputting the reconstructed data, an addressing portion for comparing the reconstructed data with a predetermined value and decoding the data, and a memory for storing the size of the variable-length-encoded word and the fixed-length code corresponding thereto which are output according to the output of the addressing portion.

Claims

1. A Huffman decoder for receiving variable-length-encoded data and outputting a fixed-length code corresponding to the data reconstructed in a Huffman table selected according to a table selection signal, which comprises:

a first latch for storing the current variable-length-encoded data;

a second latch for storing the previous variable-length-encoded data;

a single decoder for receiving the word size and outputting a selection signal;

a data requirement signal generator for generating a data requirement signal when the added word size is over a predetermined size after summing the word sizes;

a multiplexer for receiving the outputs of said first and second latches, to select a predetermined bit according to said selection signal;

a data rotator for cyclic-shifting the output of said multiplexer according to said word size to form a reconstructed data, and outputting said reconstructed data;

an addressing portion for comparing said reconstructed data with a predetermined value and decoding the data; and

a memory for storing the size of said variable-length-encoded word and the fixed-length code corresponding thereto which are output according to the output of said addressing portion.

2. A Huffman decoder as claimed in claim 1, wherein said addressing portion comprises:

comparators for receiving the upper bits of the rotated data output from said data rotator and comparing an address set in comparators with the received upper bits; and

binary decoders which are activated by the output of said comparators, for receiving and decoding the lower bits of said rotated data.

3. A Huffman decoder as claimed in claim 1, further comprising a table selector for selecting a specific Huffman table among a plurality of Huffman tables according to said table selection signal.