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Analysis refactoring for fixed-point scaling

Now scaling the energy to the same value is would be in floating-point

--- a/src/analysis.c

+++ b/src/analysis.c

@@ -290,6 +290,15 @@

       2.163313f, 1.260756f, 1.116868f, 1.918795f

 };

+#ifdef FIXED_POINT

+/* For fixed-point, the input is +/-2^15 shifted up by SIG_SHIFT, so we need to

+   compensate for that in the energy. */

+#define SCALE_COMPENS (1.f/((opus_int32)1<<(15+SIG_SHIFT)))

+#define SCALE_ENER(e) ((SCALE_COMPENS*SCALE_COMPENS)*(e))

+#else

+#define SCALE_ENER(e) (e)

+#endif

+

 static void tonality_analysis(TonalityAnalysisState *tonal, const CELTMode *celt_mode, const void *x, int len, int offset, int c1, int c2, int C, int lsb_depth, downmix_func downmix)

 {

     int i, b;

@@ -461,10 +470,7 @@

        {

           float binE = out[i].r*(float)out[i].r + out[N-i].r*(float)out[N-i].r

                      + out[i].i*(float)out[i].i + out[N-i].i*(float)out[N-i].i;

-#ifdef FIXED_POINT

-          /* FIXME: It's probably best to change the BFCC filter initial state instead */

-          binE *= 5.55e-17f;

-#endif

+          binE = SCALE_ENER(binE);

           E += binE;

           tE += binE*MAX32(0, tonality[i]);

           nE += binE*2.f*(.5f-noisiness[i]);

@@ -559,9 +565,6 @@

     bandwidth = 0;

     maxE = 0;

     noise_floor = 5.7e-4f/(1<<(IMAX(0,lsb_depth-8)));

-#ifdef FIXED_POINT

-    noise_floor *= 1<<(15+SIG_SHIFT);

-#endif

     noise_floor *= noise_floor;

     for (b=0;b<NB_TBANDS;b++)

     {

@@ -576,6 +579,7 @@

                      + out[i].i*(float)out[i].i + out[N-i].i*(float)out[N-i].i;

           E += binE;

        }

+       E = SCALE_ENER(E);

        maxE = MAX32(maxE, E);

        tonal->meanE[b] = MAX32((1-alphaE2)*tonal->meanE[b], E);

        E = MAX32(E, tonal->meanE[b]);

@@ -597,7 +601,7 @@

        float E = hp_ener*(1.f/(240*240));

 #ifdef FIXED_POINT

        /* silk_resampler_down2_hp() shifted right by an extra 8 bits. */

-       E *= ((opus_int32)1 << 2*SIG_SHIFT)*256.f;

+       E *= 256.f*(1.f/Q15ONE)*(1.f/Q15ONE);

 #endif

        maxE = MAX32(maxE, E);

        tonal->meanE[b] = MAX32((1-alphaE2)*tonal->meanE[b], E);