C++ küçük bir problemim var

void CIOCPSocket2::SendCompressingPacket(const char *pData, int len) 
  { 
  	int out_index=0; 
  	char outbuff[49152];memset(outbuff, 0x00, 49152); 
   
  	 
  		lzf_compress(pData, len,outbuff,out_index); 
   
  }

unsigned int  
  lzf_compress (const void *const in_data,  unsigned int in_len, 
                void             *out_data, unsigned int out_len);

error LNK2001: unresolved external symbol "unsigned int __cdecl lzf_compress(void const * const,unsigned int,void *,unsigned int)" (?lzf_compress@@YAIQBXIPAXI@Z)