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IAMTuner::SignalPresent method (strmif.h)

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[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 It has been superseded by MediaPlayer, IMFMediaEngine, and Audio/Video Capture in Media Foundation.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 SignalPresent method retrieves the strength of the signal on a given channel.

Syntax

HRESULT SignalPresent(
  [out] long *plSignalStrength
);

Parameters

[out] plSignalStrength

Pointer to a variable that receives a value indicating whether a signal is present on the current channel. Can be one of the following values.

Value Description
AMTUNER_HASNOSIGNALSTRENGTH -1
AMTUNER_NOSIGNAL 0
AMTUNER_SIGNALPRESENT 1
 

A value of AMTUNER_HASNOSIGNALSTRENGTH means the signal strength cannot be determined at this time.

Return value

Returns an HRESULT value.

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 strmif.h (include Dshow.h)
Library Strmiids.lib

See also

Error and Success Codes

IAMTuner Interface