SAPI中SetOutput调用问题

[测试230]

SAPI的C接口调用。

代码如下

ISpStream *pWavStream;
ISpVoice *pVoice;
CoInitialize(NULL);
if(  S_OK != CoCreateInstance(&CLSID_SpVoice, 
					NULL, 
					CLSCTX_ALL, 
					&IID_ISpVoice,	
					(void **)&pVoice)
					
	)
{
	apt_log(APT_LOG_MARK, APT_PRIO_DEBUG, "pVoice init failed");				
}

if( S_OK != CoCreateInstance(&CLSID_SpStream, 
					NULL, 
					CLSCTX_ALL, 
					&IID_ISpStream,	
					(void **)&pWavStream)
					
	)
{
    apt_log(APT_LOG_MARK, APT_PRIO_DEBUG, "pWavStream init failed");	
}

hr =pVoice->lpVtbl->SetOutput(pVoice,pWavStream,TRUE);

SetOutput调用的返回码是0x80045001。
找不到对应的错误原因，这样调用有问题吗？
pWavStream这个参数用法是否正确？