The feud between Intel and Microsoft on how to improve video playback performance in Windows (see ``Intel's VDI Speeds Up Video, Miffs Microsoft,'' November 1993 BYTE).
Intel and Microsoft have jointly developed the DCI (Display Control Interface) specification for accelerated video and graphics playback on PCs running multimedia applications under Windows. Microsoft planned to release a DCI development kit in September, and drivers that conform to the new specification are expected to arrive in force this fall.
DCI lets PCs play video clips at a faster rate and in bigger windows than previously. This happens thanks to a data path that provides a direct connection from the software video driver to the graphics display subsystem and frame buffer.
Th
e DCI specification also defines a method to access the advanced video and graphics features that are designed into the latest generation of sophisticated graphics controllers. Among these features are color space conversion, image clipping, filtering and scaling, and overlaying.
DCI supplements the Windows GDI (Graphical Device Interface) drawing engine when sending movies to the screen. Bypassing the GDI for certain operations reduces call overheads and results in fewer dropped frames when a video is played back. DCI-compliant drivers will detect the presence of graphics accelerator boards to off-load video operations from the system CPU, resulting in even better performance.
``Intel's VDI Speeds Up Video, Miffs Microsoft''
