Changeset 221 for libmpc/branches/r2d/libmpcenc/quant.c

Timestamp:

02/17/07 21:18:35 (17 years ago)

Author:

r2d

Message:

• speed optimizations

File:

• libmpc/branches/r2d/libmpcenc/quant.c (modified) (1 diff)

libmpc/branches/r2d/libmpcenc/quant.c

@@ -158 +158 @@
 ISNR_Schaetzer ( const float* input, const float SNRcomp, const int res )
 {
-    int    k;
-    const float  fac    = A [res];
-        const float  invfac = C [res];
+        const float  fac    = A [res] * NoiseInjectionCompensation1D [res];
+        const float  invfac = C [res] / NoiseInjectionCompensation1D [res];
     float  signal = 1.e-30f;
     float  error = 1.e-30f;
-    float  err, sig;
+        const float * in_end = input + 36;
 
     // Summation of the absolute power and the quadratic error
-    for ( k = 0; k < 36; k++ ) {
-        sig = input[k] * NoiseInjectionCompensation1D [res];
-                err = mpc_nearbyintf(sig * fac) * invfac - sig;
-
+        do {
+                float  err;
+                err = mpc_nearbyintf(input[0] * fac) * invfac - input[0];
         error += err * err;
-        signal += sig * sig;
-    }
+                signal += input[0] * input[0];
+
+                err = mpc_nearbyintf(input[1] * fac) * invfac - input[1];
+                error += err * err;
+                signal += input[1] * input[1];
+
+                err = mpc_nearbyintf(input[2] * fac) * invfac - input[2];
+                error += err * err;
+                signal += input[2] * input[2];
+
+                err = mpc_nearbyintf(input[3] * fac) * invfac - input[3];
+                error += err * err;
+                signal += input[3] * input[3];
+
+                input += 4;
+
+        } while (input < in_end);
+
+        error *= NoiseInjectionCompensation1D [res] * NoiseInjectionCompensation1D [res];
+        signal *= NoiseInjectionCompensation1D [res] * NoiseInjectionCompensation1D [res];
 
     // Utilization of SNRcomp only if SNR > 1 !!!