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Pseudo-masking curve for the MDCT

--- a/libcelt/psy.c

+++ b/libcelt/psy.c

@@ -61,6 +61,7 @@

       decayR[i] = pow(.1f, deriv);

       /* decay corresponding to -25dB/Bark */

       decayL[i] = pow(0.0031623f, deriv);

+      //printf ("%f %f\n", decayL[i], decayR[i]);

    }

    /* Compute right slope (-10 dB/Bark) */

    mem=psd[0];

@@ -117,3 +118,20 @@

 }

+void compute_mdct_masking(float *X, float *mask, int len, int Fs)

+{

+   int i;

+   float psd[len];

+   float mem;

+   for (i=0;i<len;i++)

+      mask[i] = X[i]*X[i];

+   for (i=1;i<len-1;i++)

+      psd[i] = .5*mask[i] + .25*(mask[i-1]+mask[i+1]);

+   //psd[0] = .5*mask[0]+.25*(mask[1]+mask[2]);

+   psd[0] = .5*mask[0]+.5*mask[1];

+   psd[len-1] = .5*(mask[len-1]+mask[len-2]);

+   /* TODO: Do tone masking */

+   /* Noise masking */

+   spreading_func(psd, mask, len, Fs);

+   

+}

--- a/libcelt/psy.h

+++ b/libcelt/psy.h

@@ -33,4 +33,6 @@

 void compute_masking(float *X, float *mask, int len, int Fs);

+void compute_mdct_masking(float *X, float *mask, int len, int Fs);

+

 #endif /* PSY_H */