Capabilities

A logo can be any artwork that is formatted as a 24-bit .BMP file. Typically a logo is a small graphic that is placed at the lower left of the image. In a technical application, however, a logo could be, for example, a crosshair pattern placed at the center of the image. The logo can theoretically be any size. However, the CPU must actively draw the image on every frame of video, and drawing a very large image, even if it is mostly transparent, will degrade overall performance in high-throughput applications.

The driver can draw a logo on captured or streaming video, on preview video, or on DibDraw overlays. It cannot, however draw a logo on DirectDraw overlays – if you attempt to do so, everything will work fine, except that the logo will not be visible.

A logo’s rectangle can be partially transparent so that the underlying video is visible. The transparent areas are defined by a key color – a particular (red, green, blue) value that is specially interpreted by the driver. For example, the sample logos use cyan with red, green and blue values of (0, 128, 128) as the key color.

A logo can be displayed in either of two styles – normal and embossed. In normal style, the logo’s non-transparent pixels simply replace whatever video underlies it. In embossed or translucent style, the logos non-transparent pixels are averaged with the underlying video pixels, resulting in a more subtle effect.

Here are the detailed steps for setting up a logo:

Step 0 - Before You Start