You Can Improve Video Playback by Using DirectVideo

The information in this article applies to:

• Microsoft Game SDK version 1.0

DirectVideo is designed to provide transparent video playback speed improvements with video cards offering DirectDraw support. Video playback applications do not require recompilation because DirectVideo does not introduce any new APIs; DirectVideo is simply an MCIAVI draw handler that uses DirectDraw. Draw handlers are responsible for drawing the stream data, as demonstrated in the MCIPUZZL sample found in the Win32 Software Development Kit.

DirectVideo is available only from independent video board manufacturers who distribute it with their hardware and hardware-specific drivers. Application developers will benefit from DirectVideo as new video boards hit the market that offer the key capabilities listed below.

The hardware improvements that DirectVideo makes available include:

• Overlay support for true color video, even on the primary display surface.
• Hardware stretching of full screen videos, even on slow CPUs.
• Reduced tearing. Tearing refers to instances in which the top portion of the video image (from the last frame) remains visible during construction of the next frame image. Using DirectDraw, DirectVideo can determine which scan line the monitor's electron gun is building up, and selectively hold the new frame. Then, when the electron gun is within the upper region of the video image the new frame is rendered.