减少捕获音视频时申请内存次数

减少音频视频捕获过程中频繁申请内存。

client/Audio.cpp

@@ -147,10 +147,7 @@ LPBYTE CAudio::GetRecordBuffer(LPDWORD dwBufferSize)
 	{
 		return NULL;
 	}	
-	if (dwBufferSize == NULL)
-	{
-		return NULL;
-	}	
+
 	SetEvent(m_hStartRecord);
 	WaitForSingleObject(m_hEventWaveIn, INFINITE);
 	*dwBufferSize = m_ulBufferLength;