fixing encoding at high QPs (was broken after the dct accuracy increase due to...

fixing encoding at high QPs (was broken after the dct accuracy increase due to too small inverse table)

Originally committed as revision 901 to svn://svn.ffmpeg.org/ffmpeg/trunk

libavcodec/i386/mpegvideo_mmx_template.c

@@ -46,9 +46,9 @@ static int RENAME(dct_quantize)(MpegEncContext *s,
     if (s->mb_intra) {
         int dummy;
         if (n < 4)
-            q = s->y_dc_scale<<3;
+            q = s->y_dc_scale;
         else
-            q = s->c_dc_scale<<3;
+            q = s->c_dc_scale;
         /* note: block[0] is assumed to be positive */
         if (!s->h263_aic) {
 #if 1
@@ -56,7 +56,7 @@ static int RENAME(dct_quantize)(MpegEncContext *s,
         	"xorl %%edx, %%edx	\n\t"
         	"mul %%ecx		\n\t"
         	: "=d" (level), "=a"(dummy)
-        	: "a" (block[0] + (q >> 1)), "c" (inverse[q])
+        	: "a" ((block[0]>>2) + q), "c" (inverse[q<<1])
         );
 #else
         asm volatile (
@@ -64,13 +64,13 @@ static int RENAME(dct_quantize)(MpegEncContext *s,
         	"divw %%cx		\n\t"
         	"movzwl %%ax, %%eax	\n\t"
         	: "=a" (level)
-        	: "a" (block[0] + (q >> 1)), "c" (q)
+        	: "a" ((block[0]>>2) + q), "c" (q<<1)
         	: "%edx"
         );
 #endif
         } else
             /* For AIC we skip quant/dequant of INTRADC */
-            level = block[0]>>3;
+            level = (block[0] + 4)>>3;
             
         block[0]=0; //avoid fake overflow
 //        temp_block[0] = (block[0] + (q >> 1)) / q;