Finding a Filter That Supports Full-Screen Mode

The first option is to search for a filter in the filter graph that supports full-screen mode directly. When asked to go into full-screen mode, the IVideoWindow PID first scans all filters supporting IVideoWindow in the filter graph. The PID calls IVideoWindow::get_FullScreenMode on each filter and, if the filter returns E_NOTIMP (the default), assumes that the filter has no inherent support for full-screen playback. If the filter returns anything else, then that filter becomes the nominated filter for full-screen playback. This means that any calls to the Filter Graph Manager to set the full-screen mode on or off will be sent directly to that nominated filter. This mechanism allows filters to be extended to support full-screen support directly. Most normal window-based renderers do not need to support this feature.