ref: c619f6cb0f16d083a290168c8613f8e506a9fd27
parent: e1a8b6c8d5be343b1952227dae486c5a6c902d36
parent: d4cdb683a48fc25bd3d32f53964023828f13cdbf
author: Yaowu Xu <yaowu@google.com>
date: Mon Apr 18 03:44:33 EDT 2011
Merge "fixed an overflow in ssim calculation"
--- a/vp8/encoder/ssim.c
+++ b/vp8/encoder/ssim.c
@@ -290,8 +290,8 @@
}
}
-const static long long c1 = 426148; // (256^2*(.01*255)^2
-const static long long c2 = 3835331; //(256^2*(.03*255)^2
+const static long long cc1 = 26634; // (64^2*(.01*255)^2
+const static long long cc2 = 239708; // (64^2*(.03*255)^2
static double similarity
(
@@ -303,11 +303,20 @@
int count
)
{- long long ssim_n = (2*sum_s*sum_r+ c1)*(2*count*sum_sxr-2*sum_s*sum_r+c2);
+ long long ssim_n, ssim_d;
+ long long c1, c2;
- long long ssim_d = (sum_s*sum_s +sum_r*sum_r+c1)*
- (count*sum_sq_s-sum_s*sum_s + count*sum_sq_r-sum_r*sum_r +c2) ;
+ //scale the constants by number of pixels
+ c1 = (cc1*count*count)>>12;
+ c2 = (cc2*count*count)>>12;
+ ssim_n = (2*sum_s*sum_r+ c1)*((long long) 2*count*sum_sxr-
+ (long long) 2*sum_s*sum_r+c2);
+
+ ssim_d = (sum_s*sum_s +sum_r*sum_r+c1)*
+ ((long long)count*sum_sq_s-(long long)sum_s*sum_s +
+ (long long)count*sum_sq_r-(long long) sum_r*sum_r +c2) ;
+
return ssim_n * 1.0 / ssim_d;
}
@@ -332,18 +341,33 @@
const vp8_variance_rtcd_vtable_t *rtcd)
{unsigned long sum_s=0,sum_r=0,sum_sq_s=0,sum_sq_r=0,sum_sxr=0;
- double ssim3;
- long long ssim_n;
- long long ssim_d;
+ long long ssim3;
+ long long ssim_n,ssim_n1,ssim_n2;
+ long long ssim_d,ssim_d1,ssim_d2;
+ long long ssim_t1,ssim_t2;
+ long long c1, c2;
+ // normalize by 256/64
+ c1 = cc1*16;
+ c2 = cc2*16;
+
rtcd->ssimpf(s, sp, r, rp, &sum_s, &sum_r, &sum_sq_s, &sum_sq_r, &sum_sxr);
- ssim_n = (2*sum_s*sum_r+ c1)*(2*256*sum_sxr-2*sum_s*sum_r+c2);
+ ssim_n1 = (2*sum_s*sum_r+ c1);
- ssim_d = (sum_s*sum_s +sum_r*sum_r+c1)*
- (256*sum_sq_s-sum_s*sum_s + 256*sum_sq_r-sum_r*sum_r +c2) ;
+ ssim_n2 =((long long) 2*256*sum_sxr-(long long) 2*sum_s*sum_r+c2);
- ssim3 = 256 * (ssim_d-ssim_n) / ssim_d;
- return (long)( 256*ssim3 * ssim3 );
+ ssim_d1 =((long long)sum_s*sum_s +(long long)sum_r*sum_r+c1);
+
+ ssim_d2 = (256 * (long long) sum_sq_s-(long long) sum_s*sum_s +
+ (long long) 256*sum_sq_r-(long long) sum_r*sum_r +c2) ;
+
+ ssim_t1 = 256 - 256 * ssim_n1 / ssim_d1;
+ ssim_t2 = 256 - 256 * ssim_n2 / ssim_d2;
+
+ ssim3 = 256 *ssim_t1 * ssim_t2;
+ if(ssim3 <0 )
+ ssim3=0;
+ return (long)( ssim3 );
}
// TODO: (jbb) this 8x8 window might be too big + we may want to pick pixels
// such that the window regions overlap block boundaries to penalize blocking
@@ -361,18 +385,20 @@
)
{int i,j;
-
+ int samples =0;
double ssim_total=0;
- // we can sample points as frequently as we like start with 1 per 8x8
- for(i=0; i < height; i+=8, img1 += stride_img1*8, img2 += stride_img2*8)
+ // we can sample points as frequently as we like start with 1 per 4x4
+ for(i=0; i < height-8; i+=4, img1 += stride_img1*4, img2 += stride_img2*4)
{- for(j=0; j < width; j+=8 )
+ for(j=0; j < width-8; j+=4 )
{- ssim_total += ssim_8x8(img1, stride_img1, img2, stride_img2, rtcd);
+ double v = ssim_8x8(img1+j, stride_img1, img2+j, stride_img2, rtcd);
+ ssim_total += v;
+ samples++;
}
}
- ssim_total /= (width/8 * height /8);
+ ssim_total /= samples;
return ssim_total;
}
@@ -405,4 +431,4 @@
*weight = 1;
return ssimv;
-}
+}
\ No newline at end of file
--- a/vp8/encoder/x86/ssim_opt.asm
+++ b/vp8/encoder/x86/ssim_opt.asm
@@ -16,12 +16,12 @@
paddusw xmm14, xmm4 ; sum_r
movdqa xmm1, xmm3
pmaddwd xmm1, xmm1
- paddq xmm13, xmm1 ; sum_sq_s
+ paddd xmm13, xmm1 ; sum_sq_s
movdqa xmm2, xmm4
pmaddwd xmm2, xmm2
- paddq xmm12, xmm2 ; sum_sq_r
+ paddd xmm12, xmm2 ; sum_sq_r
pmaddwd xmm3, xmm4
- paddq xmm11, xmm3 ; sum_sxr
+ paddd xmm11, xmm3 ; sum_sxr
%endmacro
; Sum across the register %1 starting with q words
@@ -66,6 +66,7 @@
push rbp
mov rbp, rsp
SHADOW_ARGS_TO_STACK 9
+ SAVE_XMM
push rsi
push rdi
; end prolog
@@ -115,19 +116,20 @@
SUM_ACROSS_Q xmm11
mov rdi,arg(4)
- movq [rdi], xmm15;
+ movd [rdi], xmm15;
mov rdi,arg(5)
- movq [rdi], xmm14;
+ movd [rdi], xmm14;
mov rdi,arg(6)
- movq [rdi], xmm13;
+ movd [rdi], xmm13;
mov rdi,arg(7)
- movq [rdi], xmm12;
+ movd [rdi], xmm12;
mov rdi,arg(8)
- movq [rdi], xmm11;
+ movd [rdi], xmm11;
; begin epilog
pop rdi
pop rsi
+ RESTORE_XMM
UNSHADOW_ARGS
pop rbp
ret
@@ -154,6 +156,7 @@
push rbp
mov rbp, rsp
SHADOW_ARGS_TO_STACK 9
+ SAVE_XMM
push rsi
push rdi
; end prolog
@@ -174,11 +177,8 @@
NextRow2:
;grab source and reference pixels
- movq xmm5, [rsi]
- movq xmm6, [rdi]
-
- movdqa xmm3, xmm5
- movdqa xmm4, xmm6
+ movq xmm3, [rsi]
+ movq xmm4, [rdi]
punpcklbw xmm3, xmm0 ; low_s
punpcklbw xmm4, xmm0 ; low_r
@@ -197,19 +197,20 @@
SUM_ACROSS_Q xmm11
mov rdi,arg(4)
- movq [rdi], xmm15;
+ movd [rdi], xmm15;
mov rdi,arg(5)
- movq [rdi], xmm14;
+ movd [rdi], xmm14;
mov rdi,arg(6)
- movq [rdi], xmm13;
+ movd [rdi], xmm13;
mov rdi,arg(7)
- movq [rdi], xmm12;
+ movd [rdi], xmm12;
mov rdi,arg(8)
- movq [rdi], xmm11;
+ movd [rdi], xmm11;
; begin epilog
pop rdi
pop rsi
+ RESTORE_XMM
UNSHADOW_ARGS
pop rbp
ret
--
⑨