Method and system for detecting intra-coded pictures and for extracting intra DCT precision and macroblock-level coding parameters from uncompressed digital video
US6990146B2 · kind B2 · utility
Assignee
Inventor
Key dates
| Filing date | Nov 16, 2001 |
| Grant date | Jan 24, 2006 |
| Priority date | — |
| Expiry date | Sep 19, 2023 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04N19/85
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
The present invention relates to a method and system for extracting coding parameters from uncoded video data. Encoded video data is decoded using an MPEG decoder to produce decompressed video data. A DC computation operation is performed to recover an intra-dc-precision level from the decompressed video data, such that if the intra-dc-precision level is less than a first predetermined threshold, the decompressed video data is classified as an intra-coded picture. If the intra-dc-precision level is equal to the first predetermined threshold, a discrete cosine transform (DCT) is performed to produce a set of DCT coefficients for at least one AC frequency band in the decompressed video data. Then, an average quantizer step size is computed based on the AC data and if the average quantizer step size is greater than a second predetermined threshold, the decompressed video data being processed is classified as an intra-coded picture. Thereafter, the quantization matrix data of a frame of the decompressed video data is extracted. In addition, a quantizer scale and a DCT type value for each block of the decompressed video data is extracted.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.