hqdn3d: Fix out of array read in LOWPASS

Fixes ticket1752

Commit message by commiter
Signed-off-by: Michael Niedermayer <michaelni@gmx.at>

libavfilter/vf_hqdn3d.c

@@ -50,10 +50,9 @@ void ff_hqdn3d_row_10_x86(uint8_t *src, uint8_t *dst, uint16_t *line_ant, uint16
 void ff_hqdn3d_row_16_x86(uint8_t *src, uint8_t *dst, uint16_t *line_ant, uint16_t *frame_ant, ptrdiff_t w, int16_t *spatial, int16_t *temporal);
 
 #define LUT_BITS (depth==16 ? 8 : 4)
-#define RIGHTSHIFT(a,b) (((a)+(((1<<(b))-1)>>1))>>(b))
-#define LOAD(x) ((depth==8 ? src[x] : AV_RN16A(src+(x)*2)) << (16-depth))
-#define STORE(x,val) (depth==8 ? dst[x] = RIGHTSHIFT(val, 16-depth)\
-                    : AV_WN16A(dst+(x)*2, RIGHTSHIFT(val, 16-depth)))
+#define LOAD(x) (((depth==8 ? src[x] : AV_RN16A(src+(x)*2)) << (16-depth)) + (((1<<(16-depth))-1)>>1))
+#define STORE(x,val) (depth==8 ? dst[x] = (val) >> (16-depth)\
+                    : AV_WN16A(dst+(x)*2, (val) >> (16-depth)))
 
 av_always_inline
 static uint32_t lowpass(int prev, int cur, int16_t *coef, int depth)

libavfilter/x86/hqdn3d.asm

@@ -39,6 +39,7 @@ SECTION .text
 %endif
 %if %3 != 16
     shl    %1, 16-%3
+    add    %1, (1<<(15-%3))-1
 %endif
 %endmacro
 
@@ -86,7 +87,6 @@ ALIGN 16
     mov       [frameantq+xq*2], t0w
     movifnidn dstq, dstmp
 %if %1 != 16
-    add    t0d, (1<<(15-%1))-1
     shr    t0d, 16-%1 ; could eliminate this by storing from t0h, but only with some contraints on register allocation
 %endif
 %if %1 == 8