Common Control Nodes and Filters

The types of control nodes and filters that are shown in the figures in the Control Nodes, Filters and Hardware section are common to the reception of digital satellite, terrestrial, and cable broadcasts. However, you can create other node types and filters for a wide variety of broadcast media and devices as well. It is important to remember that each control node need not correspond to a single BDA device filter. In some cases, a single BDA device filter can encapsulate more than one control node.

The following list describes control nodes and filters that are commonly found in Broadcast Architecture:

Network Provider
A network provider filter (or network provider) routes a digital television signal to and through BDA devices. A variety of broadcast providers currently transmit digital television signals over three basic network types--satellite, cable and antenna. These digital signals are transmitted in formats defined by multiple standards, including ATSC, DVB-S, DVB-C, and DVB-T. BDA devices receive and manage these digital signals.

A network provider:

• is the source filter in a filter graph, although no data actually passes through it.

• exists for each network type or can be created for a new network type.

• participates in the graph building process.

• communicates with other filters in the graph through property and method sets of BDA minidrivers that initialized such filters.

Each network provider can build a different graph configuration for its associated network type. Applications pass tune requests to a network provider, which in turn passes the information to a BDA minidriver. See the Broadcast Architecture section of the Microsoft Windows SDK documentation for more information.

Tuner
This control node filters the particular frequency that carries the transport stream. It can appear inside a filter by itself or together with other control nodes.

Demodulator
A control node that translates the analog signal into a digital bit stream. It can appear inside a filter by itself or together with other control nodes.

Capture
A filter that moves the data into host memory.

PID Filter
A control node that selects one or more elementary data streams from the transport stream. This is the primary function of a demultiplexer. It can appear inside a filter by itself or together with other control nodes.

MPE Parser
A filter that parses IP data from a stream containing MPEG-2 private sections.

IPSink
A filter that accepts IP packets as data samples and forwards the data to the NDIS TCP/IP stack.

NDISIP
An NDIS miniport driver that acts as a receiver for a network adapter for the data that the IPSink filter passes.

Note   Starting with Windows Vista, the IPSink filter is not supported.