IXDSToRat::ParseXDSBytePair Method

Article
01/07/2009

This topic applies to Windows XP Service Pack 1 or later.
The ParseXDSBytePair method parses a single byte pair from an XDS stream. If the byte pair is the last pair in a completed ratings packet, the method returns the rating information.

Syntax

HRESULT ParseXDSBytePair(
  [in]   BYTE byte1,
  [in]   BYTE byte2,
  [out]  EnTvRat_System *pEnSystem,
  [out]  EnTvRat_GenericLevel *pEnLevel,
  [out]  LONG *plBfEnAttributes
);

Parameters

byte1 [in]
The first byte of the byte pair.
byte2 [in]
The second byte of the byte pair.
pEnSystem [out]
Receives the rating system, as a member of the EnTvRat_System enumeration type.
pEnLevel [out]
Receives the rating level, as a member of the EnTvRat_GenericLevel enumeration type. The meaning of this value depends on the rating system.
plBfEnAttributes [out]
Receives a bitwise combination of zero or more flags from the BfEnTvRat_GenericAttributes enumeration. These flags specify additional content attributes, such as violence or adult language. They do not apply to every rating system.

Return Value

The method returns an HRESULT. Possible values include those in the following table.

Return code	Description
S_OK	The method succeeded.
S_FALSE	No rating has been detected in the stream yet.

Remarks

The XDS Codec filter calls this method to pass XDS data to the XDSToRat object, one pair of bytes at a time. The XDSToRat object must store enough information between calls to be able to parse a complete ratings packet.

This method returns S_FALSE until the XDSToRat object decodes a complete ratings packet. At that point, the method returns S_OK and returns the rating information in the pEnSystem, pEnLevel, and plBfEnAttributes parameters. Subsequent calls return S_FALSE again until the next packet is decoded.

Ratings values may be delivered by either the XDS Content Advisory packet, or the Composite Packet-1 packet. For details, see sections 9.5.1.5 and 9.5.1.10, respectively, of the EIA/CEA-608B specification.

This method should also detect the Current Class Program Identificaton Number and Program Name packets indicating the end of show and return an S_OK value along with the values in the following table.

Return the following values for non-ratings packets.

Parameter	Value
pEnSystem	TvRat-SystemDontKnow
pEnLevel	TvRat_LevelDontKnow
plBfEnAttributes	BfAttrNone

For details, see section 9.5.1.5.4 (General Content Advisory Requirements) of the EIA/CEA-608-B specification.

Requirements

Header

Declared in Tvratings.h.

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