fix possible overflow with memmove

[ffmpeg] / libavcodec / dsputil.c

diff --git a/libavcodec/dsputil.c b/libavcodec/dsputil.c
index 6c0be5d7e9c2289c541cff8ef5555aa226fad89e..055486d493b2857c344e5fab2979f4ff73d8d0ef 100644 (file)
--- a/libavcodec/dsputil.c
+++ b/libavcodec/dsputil.c
@@ -32,6 +32,7 @@
 #include "mpegvideo.h"
 #include "simple_idct.h"
 #include "faandct.h"
+#include "faanidct.h"
 #include "h263.h"
 #include "snow.h"
 
@@ -50,8 +51,9 @@ void ff_add_png_paeth_prediction(uint8_t *dst, uint8_t *src, uint8_t *top, int w
 uint8_t ff_cropTbl[256 + 2 * MAX_NEG_CROP] = {0, };
 uint32_t ff_squareTbl[512] = {0, };
 
-static const unsigned long pb_7f = 0x7f7f7f7f7f7f7f7fUL;
-static const unsigned long pb_80 = 0x8080808080808080UL;
+// 0x7f7f7f7f or 0x7f7f7f7f7f7f7f7f or whatever, depending on the cpu's native arithmetic size
+#define pb_7f (~0UL/255 * 0x7f)
+#define pb_80 (~0UL/255 * 0x80)
 
 const uint8_t ff_zigzag_direct[64] = {
     0,   1,  8, 16,  9,  2,  3, 10,
@@ -3304,16 +3306,16 @@ static void diff_bytes_c(uint8_t *dst, uint8_t *src1, uint8_t *src2, int w){
     long i;
 #ifndef HAVE_FAST_UNALIGNED
     if((long)src2 & (sizeof(long)-1)){
-    for(i=0; i+7<w; i+=8){
-        dst[i+0] = src1[i+0]-src2[i+0];
-        dst[i+1] = src1[i+1]-src2[i+1];
-        dst[i+2] = src1[i+2]-src2[i+2];
-        dst[i+3] = src1[i+3]-src2[i+3];
-        dst[i+4] = src1[i+4]-src2[i+4];
-        dst[i+5] = src1[i+5]-src2[i+5];
-        dst[i+6] = src1[i+6]-src2[i+6];
-        dst[i+7] = src1[i+7]-src2[i+7];
-    }
+        for(i=0; i+7<w; i+=8){
+            dst[i+0] = src1[i+0]-src2[i+0];
+            dst[i+1] = src1[i+1]-src2[i+1];
+            dst[i+2] = src1[i+2]-src2[i+2];
+            dst[i+3] = src1[i+3]-src2[i+3];
+            dst[i+4] = src1[i+4]-src2[i+4];
+            dst[i+5] = src1[i+5]-src2[i+5];
+            dst[i+6] = src1[i+6]-src2[i+6];
+            dst[i+7] = src1[i+7]-src2[i+7];
+        }
     }else
 #endif
     for(i=0; i<=w-sizeof(long); i+=sizeof(long)){
@@ -4045,6 +4047,11 @@ void dsputil_init(DSPContext* c, AVCodecContext *avctx)
             c->idct_add= ff_wmv2_idct_add_c;
             c->idct    = ff_wmv2_idct_c;
             c->idct_permutation_type= FF_NO_IDCT_PERM;
+        }else if(avctx->idct_algo==FF_IDCT_FAAN){
+            c->idct_put= ff_faanidct_put;
+            c->idct_add= ff_faanidct_add;
+            c->idct    = ff_faanidct;
+            c->idct_permutation_type= FF_NO_IDCT_PERM;
         }else{ //accurate/default
             c->idct_put= ff_simple_idct_put;
             c->idct_add= ff_simple_idct_add;