Apparatus for and method of predictive time stamping of isochronous data packets transmitted over an IEEE 1394-1995 serial bus network
US6680944B1 · kind B1 · utility
Assignees
Inventors
Key dates
| Filing date | Mar 9, 1998 |
| Grant date | Jan 20, 2004 |
| Priority date | — |
| Expiry date | Mar 9, 2018 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04N21/43632
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
In order to predictively time stamp isochronous data packets transmitted over an IEEE 1394-1995 serial bus network, an application, which is to send a stream of isochronous data packets to a receiving node, first transmits a number of dummy frames each consisting of a number of packets. Preferably, these isochronous data packets make up frames of video data. From these dummy packets, the application obtains the time stamp values within the common isochronous packet (CIP) header of each packet. Using these obtained time stamp values, the application calculates a presentation time value for each data frame to be transmitted. The obtained time stamp value from a transmitted video frame is used to calculate the presentation time for a video frame which is a number of frames ahead within the transmit queue. Once the presentation time value for a frame is calculated, that value is then inserted by the application into the CIP header for the first packet within that frame and the frame is sent to the transmit queue for transmission to the receiving node over the IEEE 1394-1995 serial bus network.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.