Add a new xvid-style IDCT using SSE2.

Originally committed as revision 12843 to svn://svn.ffmpeg.org/ffmpeg/trunk

libavcodec/Makefile

@@ -375,6 +375,7 @@ OBJS += i386/fdct_mmx.o \
         i386/motion_est_mmx.o \
         i386/simple_idct_mmx.o \
         i386/idct_mmx_xvid.o \
+        i386/idct_sse2_xvid.o \
         i386/fft_sse.o \
         i386/fft_3dn.o \
         i386/fft_3dn2.o \

libavcodec/i386/dsputil_mmx.c

@@ -2124,7 +2124,12 @@ void dsputil_init_mmx(DSPContext* c, AVCodecContext *avctx)
             }else if(idct_algo==FF_IDCT_CAVS){
                     c->idct_permutation_type= FF_TRANSPOSE_IDCT_PERM;
             }else if(idct_algo==FF_IDCT_XVIDMMX){
-                if(mm_flags & MM_MMXEXT){
+                if(mm_flags & MM_SSE2){
+                    c->idct_put= ff_idct_xvid_sse2_put;
+                    c->idct_add= ff_idct_xvid_sse2_add;
+                    c->idct    = ff_idct_xvid_sse2;
+                    c->idct_permutation_type= FF_SSE2_IDCT_PERM;
+                }else if(mm_flags & MM_MMXEXT){
                     c->idct_put= ff_idct_xvid_mmx2_put;
                     c->idct_add= ff_idct_xvid_mmx2_add;
                     c->idct    = ff_idct_xvid_mmx2;

libavcodec/i386/idct_xvid.h

@@ -28,5 +28,8 @@
 
 void ff_idct_xvid_mmx(short *block);
 void ff_idct_xvid_mmx2(short *block);
+void ff_idct_xvid_sse2(short *block);
+void ff_idct_xvid_sse2_put(uint8_t *dest, int line_size, short *block);
+void ff_idct_xvid_sse2_add(uint8_t *dest, int line_size, short *block);
 
 #endif /* FFMPEG_IDCT_XVID_H */