The KSNODETYPE_PROLOGIC_ENCODER node represents a Dolby Surround Pro Logic encoder. The node accepts a four-channel input stream with channels for left, right, center, and back speakers. The node encodes the input stream as a surround-encoded stereo output stream.
The functionality of the KSNODETYPE_PROLOGIC_ENCODER node is complementary to the KSNODETYPE_PROLOGIC_DECODER node, which takes a surround-encoded stereo input stream and decodes it into a four-channel stream with channels for left, right, center, and back speakers.
In Microsoft Windows XP and later, the KMixer system driver has a KSNODETYPE_PROLOGIC_ENCODER node.
A KSNODETYPE_PROLOGIC_ENCODER node should support the KSPROPERTY_AUDIO_SURROUND_ENCODE property, which is used to enable and disable the node.