Multiple speed fast forward/rewind compressed video delivery system
US6327421A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Mar 10, 1998 |
| Grant date | Dec 4, 2001 |
| Priority date | — |
| Expiry date | Mar 10, 2018 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04N9/8227
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
The invention supports visual fast-forward play and rewind at multiple speeds using a single ancillary data stream. The storage required by this data stream is approximately the same as the storage required by a single ancillary data stream used in conventional single speed fast-forward and rewind schemes. The method of the invention includes the following steps. A bitstream of the original sequence of MPEG compressed pictures is stored for normal play. Then a sub-sequence of the original sequence, consisting of every n-th picture, is compressed as I-pictures, while ensuring that all pictures in the compressed stream have equal numbers of bits. This is the ancillary stream. A client request for fast-forward play is responded to by transmitting a subset of I-pictures from the ancillary stream. A fast-reverse play request is satisfied in the same manner except that the I-frames are transmitted in the reverse order.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.