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ICaptionServiceDescriptor Interface

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This topic applies to Update Rollup 2 for Microsoft Windows XP Media Center Edition 2005 and later.

The ICaptionServiceDescriptor interface enables the client to get caption service descriptors from a Program and System Information Protocol (PSIP) table in an ATSC stream. The content advisor descriptor may be present in the event information table (EIT). For more information, refer to ATSC Standard A/65B, Program and System Information Protocol for Terrestrial Broadcast and Cable (Revision B).

Methods

The ICaptionServiceDescriptor interface inherits the methods of the IUnknown interface.

In addition, ICaptionServiceDescriptor defines the following methods.

Method Description

GetCaptionServiceNumber

Returns the Service Number for a specified caption service.

GetCCType

Queries whether a caption service contains Digital Television Closed Captioning (DTVCC) or line-21 closed captioning.

GetEasyReader

Queries whether a caption service contains "Easy Reader" captions.

GetLanguageCode

Returns the language code for a specified caption service.

GetNumberOfServices

Returns the number of caption services.

GetWideAspectRatio

Queries whether a caption service is formatted for wide-screen displays.

Remarks

To obtain a pointer to this interface, do the following:

  1. Call IAtscPsipParser::GetEIT to get the IATSC_EIT interface.
  2. Call IATSC_EIT::GetRecordDescriptorByTag and pass in the caption service descriptor tag (0x86). If the descriptor is present, the method returns an IGenericDescriptor pointer.
  3. Query the returned IGenericDescriptor pointer for the ICaptionServiceDescriptor interface.

Requirements

Header Declared in Atscpsipparser.h.

See Also

BDA Interfaces

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Build date: 12/4/2008