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:
Sep. 19, 2006
Filed:
Oct. 23, 2002
Taku Nakamura, Yokohama, JP;
Naoki Yamamoto, Yokohama, JP;
Takuya Imaide, Fujisawa, JP;
Hiroyasu Ohtsubo, Yokohama, JP;
Taku Nakamura, Yokohama, JP;
Naoki Yamamoto, Yokohama, JP;
Takuya Imaide, Fujisawa, JP;
Hiroyasu Ohtsubo, Yokohama, JP;
Hitachi, Ltd., Tokyo, JP;
Abstract
In a bitstream transcoder, the computational cost and the memory area are suppressed so that stream transcoding is performed with a reduced number of times of computing and a reduced memory area. The transcoder includes a VLD portionfor performing VLD on a bitstream encoded in MPEG-2 to output quantized DCT coefficients; an IQ portionfor receiving the coefficients, and outputting inverse-quantized DCT coefficients; a coefficient tablefor storing a transformation matrix obtained by multiplying transformation matrices for operating band-limiting filter, IDCT, down-sampling and DCT, respectively, together in advance; a DCT scaling portionfor performing down-sampling on the DCT coefficients by use of the transformation matrix; a Q portionfor outputting quantized DCT coefficients down-sampled horizontally and vertically; and a VLC portionfor encoding the quantized DCT coefficients in MPEG-4 to output a bitstream.