Advanced bi-directional predictive coding of video frames
US7609763B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Jul 18, 2003 |
| Grant date | Oct 27, 2009 |
| Priority date | — |
| Expiry date | Jun 10, 2026 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04N19/587
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
Techniques and tools for coding/decoding of video images, and in particular, B-frames, are described. In one aspect, a video encoder/decoder determines a fraction for a current image in a sequence. The fraction represents an estimated temporal distance position for the current image relative to an interval between a reference images for the current image. The video encoder/decoder processes the fraction along with a motion vector for a first reference image, resulting in a representation of motion (e.g., constant or variable velocity motion) in the current image. Other aspects are also described, including intra B-frames, forward and backward buffers for motion vector prediction, bitplane encoding of direct mode prediction information, multiple motion vector resolutions/interpolation filters for B-frames, proactive dropping of B-frames, and signaling of dropped predicted frames.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.