negative stride and h_size-=8 fix

Originally committed as revision 22247 to svn://svn.mplayerhq.hu/mplayer/trunk/libswscale

libswscale/yuv2rgb_template.c

@@ -133,7 +133,7 @@ static inline int RENAME(yuv420_rgb16)(SwsContext *c, uint8_t* src[], int srcStr
     }
 
     h_size= (c->dstW+7)&~7;
-    if(h_size*2 > dstStride[0]) h_size-=8;
+    if(h_size*2 > FFABS(dstStride[0])) h_size-=8;
     
     __asm__ __volatile__ ("pxor %mm4, %mm4;" /* zero mm4 */ );
 //printf("%X %X %X %X %X %X %X %X %X %X\n", (int)&c->redDither, (int)&b5Dither, (int)src[0], (int)src[1], (int)src[2], (int)dst[0],
@@ -228,7 +228,7 @@ static inline int RENAME(yuv420_rgb15)(SwsContext *c, uint8_t* src[], int srcStr
     }
 
     h_size= (c->dstW+7)&~7;
-    if(h_size*2 > dstStride[0]) h_size-=8;
+    if(h_size*2 > FFABS(dstStride[0])) h_size-=8;
     
     __asm__ __volatile__ ("pxor %mm4, %mm4;" /* zero mm4 */ );
 //printf("%X %X %X %X %X %X %X %X %X %X\n", (int)&c->redDither, (int)&b5Dither, (int)src[0], (int)src[1], (int)src[2], (int)dst[0],
@@ -317,7 +317,7 @@ static inline int RENAME(yuv420_rgb24)(SwsContext *c, uint8_t* src[], int srcStr
     }
 
     h_size= (c->dstW+7)&~7;
-    if(h_size*3 > dstStride[0]) h_size-=8;
+    if(h_size*3 > FFABS(dstStride[0])) h_size-=8;
     
     __asm__ __volatile__ ("pxor %mm4, %mm4;" /* zero mm4 */ );
 
@@ -463,7 +463,7 @@ static inline int RENAME(yuv420_rgb32)(SwsContext *c, uint8_t* src[], int srcStr
     }
 
     h_size= (c->dstW+7)&~7;
-    if(h_size*4 > dstStride[0]) h_size-=8;
+    if(h_size*4 > FFABS(dstStride[0])) h_size-=8;
     
     __asm__ __volatile__ ("pxor %mm4, %mm4;" /* zero mm4 */ );