Remultiplexing variable rate bitstreams using a delay buffer and rate estimation
US6327275A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | May 19, 1998 |
| Grant date | Dec 4, 2001 |
| Priority date | — |
| Expiry date | May 19, 2018 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04N21/2365
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A system for remultiplexing packets that are provided at variable rates in digital bitstreams using a delay buffer and rate estimation. A bitstream with specific packet types provided at different rates is extracted from a multiplex and combined with other fixed or variable rate bit streams in such a way that timing delivery constraints on the extracted variable rate bitstream are followed. The extracted bitstream is smoothed to reduce variations in the data rate. The smoothed bitstream is then processed in first and second parallel paths. In the first path, selected packets are discarded to obtain a retained data stream. The data rate of the retained data stream is estimated and provided to a control. In the second path, the smoothed bitstream is delayed according to at least the processing time of the rate estimator in the first path, then the selected packets are discarded to obtain a delayed, retained data stream. The retained data stream in the second path is then remultiplexed with other data streams at a rate near the estimated data rate. For example, the invention is suitable for use at a cable television headend which grooms and remultiplexes digital transport streams that…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.