A system and method for capturing a modern multimedia presentation.
Original Publication Date: 2002-Apr-15
Included in the Prior Art Database: 2003-Jun-20
Modern presentations tend to involve a presenter, and some form of multimedia [presentation, application demonstration, etc], usually supplied by a laptop/computer. There is sometimes a need to archive these presentations for later viewing, or to enable them for 'webcasting' or later broadcast via a network. One solution is to video the presenter, however there is no universal method that can be used to record the output from a laptop. This method allows the output of the multimedia to be captured, with minimal loss of quality, and with transparency to the presenter. The one common point between multimedia output from different presentations is the SVGA output connector, usually intended to link to a projector, or monitor. The advantage of capturing at this place is the lack of dependancy on any particular presentation software, operating system, or third party utilities to be installed on the presenter's laptop. From the presenter's point of view it is just like connecting to a projector/monitor. There is a need for digital capture of an SVGA signal, and the subsequent conversion back to a framebuffer like memory. Many products exist to capture composite video, or svideo, or rs170 video, but not SVGA signals directly. A current alternative way to get an SVGA signal back to data within a computer, involves encoding the SVGA signal into composite video [using a pc to tv encoding device], then capturing this with a standard video capture unit [such as a bt848 bases device]. The disadvantage to this approach is the limited bandwith [and therefore resolution] of the composite video signal, holding a rough maximum of 800x600. With many presentations being in 1024x768, or above, data is lost using this alternative process. The most common data output would probably be foils [generally static slides of text/charts]. By capturing these from the SVGA signal, frame by frame, many frames would be the same. When changes occur the time delta between this and the last different frame can be stored with a copy of the old frame. In effect this allows for the storing of the foil just displayed, with information on how long it was displayed for. A potential improvement would then involve image comparison of the stored foils, searching for duplicates, [where the presenter may have switched back to an earlier foil for an explanation] which could be removed, and the information instead coded as a 'playlist', of foil numbers, and time durations per entry in the list.