XviD on PPC85XX CPU

Hello Everybody:

       I am to port xvid engine for  MPC85xx(Motorola/Freescale PowerPC ). 

       My developing evironment is as follows:
       
        1  host  :  Windows XP,   gcc, gas
        2  target:  MPC8540 ,  

       I will compile the code on the host, and then download the object files

to the MPC target .

       My question is:

1)       I noticed that xvid have only idct assemble code ,but no dct code in the 

xvidcore-1.2.1\xvidcore\src\dct\ppc_asm   directory. 

       I am curious about that!  If no dct assemble code, does it mean that 

the  coding speed will be very slow on  PPC platform????

2)       In addition, I wonder  where can I find   <altivec.h> ??

          altivec.h is included in the PPC asm files. But I can not find this altivec.h on my xvid package.
 

       Thansk to all of you who have viewed my questions!

                                                                  Ice,  
                                                                   May 13, 2009