The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Jun. 16, 1998
Filed:
Dec. 05, 1995
James N Maertens, Sunnyvale, CA (US);
Kyung In Han, Somerville, MA (US);
Mitsubishi Semiconductor America, Inc., Durham, NC (US);
Abstract
A variable length decoder comprises a bitstream feeder connected to a header analyzer, and a block data decoder coupled to the feeder. The bitstream feeder includes a barrel shifter to output a 32-bit bitstream to the header analyzer, block data decoder and control circuit. The header analyzer detects the start codes of the MPEG header layers and decodes the parameters of the MPEG layers contained in the encoded bitstream. Further, the header analyzer decodes the quantization factors of 8.times.8 pixel data which have been converted into 64 DCT coefficients. The block data decoder includes a macroblock decoder connected to a block decoder. The macroblock decoder outputs a header.sub.-- start signal, and activates the block decoder. The block decoder includes a code table for decoding 64 coefficients in each of the 6 block layers based on a binary pattern of a predetermined number of bits of the bitstream. The six block layers are decoded within 384 clock cycles. The control circuit monitors the functions of the bitstream feeder, the header analyzer and the block data decoder.