Method and apparatus for scaling a compressed video bitstream
US5889561A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Nov 4, 1994 |
| Grant date | Mar 30, 1999 |
| Priority date | — |
| Expiry date | Nov 4, 2014 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04N19/61
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A method and apparatus for scaling the bitstream of a compressed video signal includes partial decoding hardware (38, 41) to permit excising of higher frequency AC DCT coefficients or re-quantizing quantized data with a coarser quantization factor. The scaling is performed on a block (macroblock) basis in a manner which linearly scales the amount of compressed data per block. An analyzer (40) generates a profile of cumulative partially decompressed data over a video frame, and bitstream scaling (42) is performed in a manner which insures that a profile of the scaled signal substantially comports with the profile of the original data.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.