System and method for compressing video data for video conferencing at a reduced frame rate
US5966166A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Nov 7, 1996 |
| Grant date | Oct 12, 1999 |
| Priority date | — |
| Expiry date | Nov 7, 2016 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04N7/122
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
The compression of composite video data is provided in order to reduce bandwidth and thereby increase the amount of bandwidth available for transmission. Composite video signals that include a plurality of fields are received at a selected clock frequency. A first selected number of fields is stored and a second selected number of fields is dropped. In a Frequency Division Multiplexing mode, the data is read out at a fraction of the selected clock frequency corresponding to the stored portion. In a Time Division Multiplexing mode, the data is read out at the selected clock frequency during selected intervals having a duration corresponding to the time it took to receive the stored fields. No data is read out during an interval having a duration equal to the time it took to scan the dropped fields, such time being allocated to the compressed information from other users of the same shared transmission medium.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.