ISpRecoContext::SetVoice

Article
06/30/2006

This method sets the voice associated with the speech recognition context.

HRESULT SetVoice(
  ISpVoice* pVoice,
  BOOL fAllowFormatChanges
);

Parameters

pVoice
[in] Pointer to an object implementing ISpVoice to associate with the speech recognition context. If this value is NULL, the currently associated voice is released.
fAllowFormatChanges
[in] Value specifying if the engine allows the voice format alteration. Set this value to TRUE if the alteration is allowed, and to FALSE otherwise. See Remarks section.

Return Values

The following table shows the possible return values.

Value	Description
S_OK	Function completed successfully.
E_POINTER	pVoice is invalid or bad.
FAILED(hr)	Appropriate error message.

Remarks

If fAllowFormatChanges is TRUE, then the Voice's output format will be the same format as the associated SR engine's audio input format (see ISpRecognizer and ISpSREngine::GetInputAudioFormat). Using the same audio format for input and output source is useful for sound cards that do not support full-duplex audio (such as input format must match output format). If the input format quality is lower than the output format quality, the output format quality will be down-sampled to the lower quality.

After calling ISpRecoContext::SetVoice, an application that calls ISpRecoContext::GetVoice will retrieve the originally "set" ISpVoice interface pointer.

Example

The following code snippet illustrates the use of this method and "barge-in" setup.

HRESULT hr = S_OK;
// create a shared recognition context
hr = cpRecoContext.CoCreateInstance(CLSID_SpSharedRecoContext);
// Check hr
// create a voice
hr = cpVoice.CoCreateInstance(CLSID_SpVoice);
// Check hr
// associate the voice with the context (with same audio format as context)
hr = cpRecoContext->SetVoice(cpVoice, TRUE);
// Check hr
// tell the associated Voice to stop speaking when the SR Engine hears a
recognizable sound
hr = cpRecoContext->SetVoicePurgeEvent(SPFEI(SPEI_SOUND_START));
// Check hr

Requirements

OS Versions: Windows CE .NET 4.1 and later.
Header: Sapi.h, Sapi.idl.
Link Library: Sapilib.lib.

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