vpx_ports/mem_ops.h: clear some -Wconversion warnings

not strictly necessary, but allows projects using '-Wconversion
-Wno-sign-conversion' to reuse these headers.

Change-Id: Id1398d726c90173ccba9aea66798fcef6f20fa23

vpx_ports/mem_ops.h

@@ -168,8 +168,8 @@ mem_get_s_generic(le, 32)
 static VPX_INLINE void mem_put_be16(void *vmem, MEM_VALUE_T val) {
   MAU_T *mem = (MAU_T *)vmem;
 
-  mem[0] = (val >> 8) & 0xff;
-  mem[1] = (val >> 0) & 0xff;
+  mem[0] = (MAU_T)((val >> 8) & 0xff);
+  mem[1] = (MAU_T)((val >> 0) & 0xff);
 }
 
 #undef  mem_put_be24
@@ -177,9 +177,9 @@ static VPX_INLINE void mem_put_be16(void *vmem, MEM_VALUE_T val) {
 static VPX_INLINE void mem_put_be24(void *vmem, MEM_VALUE_T val) {
   MAU_T *mem = (MAU_T *)vmem;
 
-  mem[0] = (val >> 16) & 0xff;
-  mem[1] = (val >>  8) & 0xff;
-  mem[2] = (val >>  0) & 0xff;
+  mem[0] = (MAU_T)((val >> 16) & 0xff);
+  mem[1] = (MAU_T)((val >>  8) & 0xff);
+  mem[2] = (MAU_T)((val >>  0) & 0xff);
 }
 
 #undef  mem_put_be32
@@ -187,10 +187,10 @@ static VPX_INLINE void mem_put_be24(void *vmem, MEM_VALUE_T val) {
 static VPX_INLINE void mem_put_be32(void *vmem, MEM_VALUE_T val) {
   MAU_T *mem = (MAU_T *)vmem;
 
-  mem[0] = (val >> 24) & 0xff;
-  mem[1] = (val >> 16) & 0xff;
-  mem[2] = (val >>  8) & 0xff;
-  mem[3] = (val >>  0) & 0xff;
+  mem[0] = (MAU_T)((val >> 24) & 0xff);
+  mem[1] = (MAU_T)((val >> 16) & 0xff);
+  mem[2] = (MAU_T)((val >>  8) & 0xff);
+  mem[3] = (MAU_T)((val >>  0) & 0xff);
 }
 
 #undef  mem_put_le16
@@ -198,8 +198,8 @@ static VPX_INLINE void mem_put_be32(void *vmem, MEM_VALUE_T val) {
 static VPX_INLINE void mem_put_le16(void *vmem, MEM_VALUE_T val) {
   MAU_T *mem = (MAU_T *)vmem;
 
-  mem[0] = (val >>  0) & 0xff;
-  mem[1] = (val >>  8) & 0xff;
+  mem[0] = (MAU_T)((val >> 0) & 0xff);
+  mem[1] = (MAU_T)((val >> 8) & 0xff);
 }
 
 #undef  mem_put_le24
@@ -207,9 +207,9 @@ static VPX_INLINE void mem_put_le16(void *vmem, MEM_VALUE_T val) {
 static VPX_INLINE void mem_put_le24(void *vmem, MEM_VALUE_T val) {
   MAU_T *mem = (MAU_T *)vmem;
 
-  mem[0] = (val >>  0) & 0xff;
-  mem[1] = (val >>  8) & 0xff;
-  mem[2] = (val >> 16) & 0xff;
+  mem[0] = (MAU_T)((val >>  0) & 0xff);
+  mem[1] = (MAU_T)((val >>  8) & 0xff);
+  mem[2] = (MAU_T)((val >> 16) & 0xff);
 }
 
 #undef  mem_put_le32
@@ -217,10 +217,10 @@ static VPX_INLINE void mem_put_le24(void *vmem, MEM_VALUE_T val) {
 static VPX_INLINE void mem_put_le32(void *vmem, MEM_VALUE_T val) {
   MAU_T *mem = (MAU_T *)vmem;
 
-  mem[0] = (val >>  0) & 0xff;
-  mem[1] = (val >>  8) & 0xff;
-  mem[2] = (val >> 16) & 0xff;
-  mem[3] = (val >> 24) & 0xff;
+  mem[0] = (MAU_T)((val >>  0) & 0xff);
+  mem[1] = (MAU_T)((val >>  8) & 0xff);
+  mem[2] = (MAU_T)((val >> 16) & 0xff);
+  mem[3] = (MAU_T)((val >> 24) & 0xff);
 }
 
 #endif  // VPX_PORTS_MEM_OPS_H_

vpx_ports/mem_ops_aligned.h

@@ -28,8 +28,8 @@
  * could redefine these macros.
  */
 #define swap_endian_16(val,raw) do {\
-    val = ((raw>>8) & 0x00ff) \
-          | ((raw<<8) & 0xff00);\
+    val = (uint16_t)(((raw>>8) & 0x00ff) \
+          | ((raw<<8) & 0xff00));\
   } while(0)
 #define swap_endian_32(val,raw) do {\
     val = ((raw>>24) & 0x000000ff) \