Reduced-quality resolution digital video encoder/decoder
US5870144A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Mar 28, 1997 |
| Grant date | Feb 9, 1999 |
| Priority date | — |
| Expiry date | Mar 28, 2017 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04N19/59
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A DV codec process for reduced-quality size decoding of DV encoded video data receives a DV encoded bit stream. Compressed macroblock information and DCT information, including a DC coefficient value, is read for a current DCT block. It is determined whether the current DCT block is a still DCT block. If the current DCT block is a still DCT block, run length decoding is performed to obtain a number of low frequency AC coefficient values for the current still DCT block and a reduced coefficient inverse discrete cosine transform is performed on the low frequency AC coefficient values to yield decoded pixel values for the current still DCT block. If the current DCT block is a motion DCT block, run length decoding is performed to obtain a number of low frequency AC coefficient values for the current motion DCT block and a reduced coefficient inverse discrete cosine transform is performed on the low frequency AC coefficient values to yield decoded pixel values for the current motion DCT block. The codec produces one-quarter size or full-size images.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.