From: "Ronald S. Bultje" <[email protected]>
Found-by: Mateusz "j00ru" Jurczyk and Gynvael Coldwind
CC: [email protected]
---
libavcodec/cabac_functions.h | 6 ++++--
libavcodec/x86/cabac.h | 12 ++++++++----
2 files changed, 12 insertions(+), 6 deletions(-)
diff --git a/libavcodec/cabac_functions.h b/libavcodec/cabac_functions.h
index b150aab..4c74cf7 100644
--- a/libavcodec/cabac_functions.h
+++ b/libavcodec/cabac_functions.h
@@ -47,7 +47,8 @@ static void refill(CABACContext *c){
c->low+= c->bytestream[0]<<1;
#endif
c->low -= CABAC_MASK;
- c->bytestream+= CABAC_BITS/8;
+ if (c->bytestream < c->bytestream_end)
+ c->bytestream += CABAC_BITS / 8;
}
static inline void renorm_cabac_decoder_once(CABACContext *c){
@@ -74,7 +75,8 @@ static void refill2(CABACContext *c){
#endif
c->low += x<<i;
- c->bytestream+= CABAC_BITS/8;
+ if (c->bytestream < c->bytestream_end)
+ c->bytestream += CABAC_BITS/8;
}
static av_always_inline int get_cabac_inline(CABACContext *c, uint8_t * const
state){
diff --git a/libavcodec/x86/cabac.h b/libavcodec/x86/cabac.h
index 3c3652d..6ff62ac 100644
--- a/libavcodec/x86/cabac.h
+++ b/libavcodec/x86/cabac.h
@@ -51,7 +51,7 @@
"xor "tmp" , "ret" \n\t"
#endif /* HAVE_FAST_CMOV */
-#define BRANCHLESS_GET_CABAC(ret, statep, low, lowword, range, tmp, tmpbyte,
byte) \
+#define BRANCHLESS_GET_CABAC(ret, statep, low, lowword, range, tmp, tmpbyte,
byte, end) \
"movzbl "statep" , "ret" \n\t"\
"mov "range" , "tmp" \n\t"\
"and $0xC0 , "range" \n\t"\
@@ -66,6 +66,8 @@
"test "lowword" , "lowword" \n\t"\
" jnz 1f \n\t"\
"mov "byte" , %%"REG_c" \n\t"\
+ "cmp %%"REG_c" , "end" \n\t"\
+ "jl 1f \n\t"\
"add"OPSIZE" $2 , "byte" \n\t"\
"movzwl (%%"REG_c") , "tmp" \n\t"\
"lea -1("low") , %%ecx \n\t"\
@@ -90,10 +92,10 @@ static av_always_inline int
get_cabac_inline_x86(CABACContext *c,
__asm__ volatile(
BRANCHLESS_GET_CABAC("%0", "(%5)", "%1", "%w1", "%2",
- "%3", "%b3", "%4")
+ "%3", "%b3", "%4", "%6")
:"=&r"(bit), "+&r"(c->low), "+&r"(c->range), "=&q"(tmp),
"+m"(c->bytestream)
- :"r"(state)
+ :"r"(state), "m"(c->bytestream_end)
: "%"REG_c, "memory"
);
return bit & 1;
@@ -122,6 +124,8 @@ static av_always_inline int
get_cabac_bypass_sign_x86(CABACContext *c, int val)
"movzwl (%1), %%edx \n\t"
"bswap %%edx \n\t"
"shrl $15, %%edx \n\t"
+ "cmp %1, %5 \n\t"
+ "jl 1f \n\t"
"add $2, %1 \n\t"
"addl %%edx, %%eax \n\t"
"mov %1, %3 \n\t"
@@ -129,7 +133,7 @@ static av_always_inline int
get_cabac_bypass_sign_x86(CABACContext *c, int val)
"movl %%eax, %2 \n\t"
:"+c"(val), "=&r"(tmp), "+m"(c->low), "+m"(c->bytestream)
- :"m"(c->range)
+ :"m"(c->range), "m"(c->bytestream_end)
: "%eax", "%edx"
);
return val;
--
1.7.7.4
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