Synchronizing an audio-visual stream synchronized to a clock with a video display that is synchronized to a different clock
US5951690A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Dec 9, 1996 |
| Grant date | Sep 14, 1999 |
| Priority date | — |
| Expiry date | Dec 9, 2016 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH04N5/85
- WIPO fieldAudio-visual technology
- WIPO sectorElectrical engineering
Abstract
A DVD player that integrates a DVD device into a personal computer is provided. As such, the personal computer is able to output audio-visual works from a DVD CD-ROM. When integrating a DVD device with a personal computer, various problems must be overcome. For example, in a personal computer, the video display is controlled by a graphics controller, and in order to render an audio-visual stream in a personal computer, the audio-visual stream and the graphics controller must be synchronized. The synchronization problem arises because the graphics controller only displays data at the beginning of 33.4 millisecond time intervals. Thus, although the audio portion may be played almost immediately, the video portion may have to wait for up to 33.4 milliseconds before being displayed. In this manner, the audio portion and the video portion become unsynchronized which means that the audio portion plays before the corresponding video portion is displayed. The DVD player solves this problem by synchronizing the start of the audio-visual stream with the graphics controller so that the time at which a video sequence is displayed coincides with one of the graphics controller's 33.4 millisecond…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.