IAMLine21Decoder::GetDecoderLevel method (il21dec.h)

Article
4/26/2023

[The feature associated with this page, DirectShow, is a legacy feature. It has been superseded by MediaPlayer, IMFMediaEngine, and Audio/Video Capture in Media Foundation. Those features have been optimized for Windows 10 and Windows 11. Microsoft strongly recommends that new code use MediaPlayer, IMFMediaEngine and Audio/Video Capture in Media Foundation instead of DirectShow, when possible. Microsoft suggests that existing code that uses the legacy APIs be rewritten to use the new APIs if possible.]

The GetDecoderLevel method retrieves the closed-captioned decoder level.

Syntax

HRESULT GetDecoderLevel(
  AM_LINE21_CCLEVEL *lpLevel
);

Parameters

lpLevel

Pointer to a variable that receives a member of the AM_LINE21_CCLEVEL enumeration. The returned value is always AM_L21_CCLEVEL_TC2 (TeleCaption II).

Return value

Returns an HRESULT value. Possible values include the following.

Return code	Description
E_INVALIDARG	Invalid argument
S_OK	Success

Remarks

TeleCaption I and TeleCaption II are standards for closed caption decoders. The Line 21 Decoder filter supports TeleCaption II, which is backward compatible with TeleCaption I.

Requirements

Requirement	Value
Minimum supported client	Windows 2000 Professional [desktop apps only]
Minimum supported server	Windows 2000 Server [desktop apps only]
Target Platform	Windows
Header	il21dec.h
Library	Strmiids.lib

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