h264pred: use unsigned types for pixel values, fix signed overflows

Signed-off-by: Mans Rullgard <mans@mansr.com>

libavcodec/h264pred.c

@@ -40,7 +40,7 @@
 #undef BIT_DEPTH
 
 static void pred4x4_vertical_vp8_c(uint8_t *src, const uint8_t *topright, int stride){
-    const int lt= src[-1-1*stride];
+    const unsigned lt = src[-1-1*stride];
     LOAD_TOP_EDGE
     LOAD_TOP_RIGHT_EDGE
     uint32_t v = PACK_4U8((lt + 2*t0 + t1 + 2) >> 2,
@@ -55,7 +55,7 @@ static void pred4x4_vertical_vp8_c(uint8_t *src, const uint8_t *topright, int st
 }
 
 static void pred4x4_horizontal_vp8_c(uint8_t *src, const uint8_t *topright, int stride){
-    const int lt= src[-1-1*stride];
+    const unsigned lt = src[-1-1*stride];
     LOAD_LEFT_EDGE
 
     AV_WN32A(src+0*stride, ((lt + 2*l0 + l1 + 2) >> 2)*0x01010101);
@@ -290,7 +290,7 @@ static void pred16x16_tm_vp8_c(uint8_t *src, int stride){
 
 static void pred8x8_left_dc_rv40_c(uint8_t *src, int stride){
     int i;
-    int dc0;
+    unsigned dc0;
 
     dc0=0;
     for(i=0;i<8; i++)
@@ -305,7 +305,7 @@ static void pred8x8_left_dc_rv40_c(uint8_t *src, int stride){
 
 static void pred8x8_top_dc_rv40_c(uint8_t *src, int stride){
     int i;
-    int dc0;
+    unsigned dc0;
 
     dc0=0;
     for(i=0;i<8; i++)
@@ -320,7 +320,7 @@ static void pred8x8_top_dc_rv40_c(uint8_t *src, int stride){
 
 static void pred8x8_dc_rv40_c(uint8_t *src, int stride){
     int i;
-    int dc0=0;
+    unsigned dc0 = 0;
 
     for(i=0;i<4; i++){
         dc0+= src[-1+i*stride] + src[i-stride];

libavcodec/h264pred_template.c

@@ -121,28 +121,28 @@ static void FUNCC(pred4x4_129_dc)(uint8_t *_src, const uint8_t *topright, int _s
 
 
 #define LOAD_TOP_RIGHT_EDGE\
-    const int av_unused t4= topright[0];\
-    const int av_unused t5= topright[1];\
-    const int av_unused t6= topright[2];\
-    const int av_unused t7= topright[3];\
+    const unsigned av_unused t4 = topright[0];\
+    const unsigned av_unused t5 = topright[1];\
+    const unsigned av_unused t6 = topright[2];\
+    const unsigned av_unused t7 = topright[3];\
 
 #define LOAD_DOWN_LEFT_EDGE\
-    const int av_unused l4= src[-1+4*stride];\
-    const int av_unused l5= src[-1+5*stride];\
-    const int av_unused l6= src[-1+6*stride];\
-    const int av_unused l7= src[-1+7*stride];\
+    const unsigned av_unused l4 = src[-1+4*stride];\
+    const unsigned av_unused l5 = src[-1+5*stride];\
+    const unsigned av_unused l6 = src[-1+6*stride];\
+    const unsigned av_unused l7 = src[-1+7*stride];\
 
 #define LOAD_LEFT_EDGE\
-    const int av_unused l0= src[-1+0*stride];\
-    const int av_unused l1= src[-1+1*stride];\
-    const int av_unused l2= src[-1+2*stride];\
-    const int av_unused l3= src[-1+3*stride];\
+    const unsigned av_unused l0 = src[-1+0*stride];\
+    const unsigned av_unused l1 = src[-1+1*stride];\
+    const unsigned av_unused l2 = src[-1+2*stride];\
+    const unsigned av_unused l3 = src[-1+3*stride];\
 
 #define LOAD_TOP_EDGE\
-    const int av_unused t0= src[ 0-1*stride];\
-    const int av_unused t1= src[ 1-1*stride];\
-    const int av_unused t2= src[ 2-1*stride];\
-    const int av_unused t3= src[ 3-1*stride];\
+    const unsigned av_unused t0 = src[ 0-1*stride];\
+    const unsigned av_unused t1 = src[ 1-1*stride];\
+    const unsigned av_unused t2 = src[ 2-1*stride];\
+    const unsigned av_unused t3 = src[ 3-1*stride];\
 
 static void FUNCC(pred4x4_down_right)(uint8_t *_src, const uint8_t *topright, int _stride){
     pixel *src = (pixel*)_src;