WST Decoder Filter

The WST Decoder is a kernel-mode filter that accepts decoded World Standard Teletext data from the WST Codec and delivers the bitmaps to Pin 2 on the Overlay Mixer using fonts supplied by Microsoft. Only Western European languages are supported at this time; no Unicode fonts are currently provided.

The WST Decoder filter appears in GraphEdit under the "WDM Streaming VBI Codecs" category. Because this is a kernel-mode filter, applications cannot co-create it directly, but must use the System Device Enumerator to instantiate it, as described in Enumerating Devices and Filters. This filter can be added to the graph automatically by calling ICaptureGraphBuilder2::RenderStream on the output pin of the WST Codec.