1 /********************************************************************
3 * THIS FILE IS PART OF THE OggVorbis SOFTWARE CODEC SOURCE CODE. *
4 * USE, DISTRIBUTION AND REPRODUCTION OF THIS LIBRARY SOURCE IS *
5 * GOVERNED BY A BSD-STYLE SOURCE LICENSE INCLUDED WITH THIS SOURCE *
6 * IN 'COPYING'. PLEASE READ THESE TERMS BEFORE DISTRIBUTING. *
8 * THE OggVorbis SOURCE CODE IS (C) COPYRIGHT 1994-2001 *
9 * by the XIPHOPHORUS Company http://www.xiph.org/ *
11 ********************************************************************
13 function: linear scale -> dB, Bark and Mel scales
14 last mod: $Id: scales.h,v 1.20 2002/03/07 03:41:03 xiphmont Exp $
16 ********************************************************************/
25 #ifdef VORBIS_IEEE_FLOAT32
26 static float unitnorm(float x){
27 ogg_uint32_t *ix=(ogg_uint32_t *)&x;
28 *ix=(*ix&0x80000000UL)|(0x3f800000UL);
32 static float todB_LOOKUP[256]={
33 -140.277330f, -139.633636f, -139.034372f, -138.473797f,
34 -137.450747f, -136.535597f, -135.707743f, -134.951972f,
35 -134.256730f, -133.613036f, -133.013772f, -132.453198f,
36 -131.430147f, -130.514997f, -129.687144f, -128.931372f,
37 -128.236130f, -127.592437f, -126.993172f, -126.432598f,
38 -125.409547f, -124.494397f, -123.666544f, -122.910772f,
39 -122.215530f, -121.571837f, -120.972572f, -120.411998f,
40 -119.388947f, -118.473797f, -117.645944f, -116.890173f,
41 -116.194930f, -115.551237f, -114.951972f, -114.391398f,
42 -113.368347f, -112.453198f, -111.625344f, -110.869573f,
43 -110.174331f, -109.530637f, -108.931372f, -108.370798f,
44 -107.347748f, -106.432598f, -105.604744f, -104.848973f,
45 -104.153731f, -103.510037f, -102.910773f, -102.350198f,
46 -101.327148f, -100.411998f, -99.584144f, -98.828373f,
47 -98.133131f, -97.489437f, -96.890173f, -96.329598f,
48 -95.306548f, -94.391398f, -93.563544f, -92.807773f,
49 -92.112531f, -91.468837f, -90.869573f, -90.308998f,
50 -89.285948f, -88.370798f, -87.542944f, -86.787173f,
51 -86.091931f, -85.448237f, -84.848973f, -84.288398f,
52 -83.265348f, -82.350198f, -81.522344f, -80.766573f,
53 -80.071331f, -79.427637f, -78.828373f, -78.267799f,
54 -77.244748f, -76.329598f, -75.501745f, -74.745973f,
55 -74.050731f, -73.407038f, -72.807773f, -72.247199f,
56 -71.224148f, -70.308998f, -69.481145f, -68.725373f,
57 -68.030131f, -67.386438f, -66.787173f, -66.226599f,
58 -65.203548f, -64.288399f, -63.460545f, -62.704774f,
59 -62.009531f, -61.365838f, -60.766573f, -60.205999f,
60 -59.182948f, -58.267799f, -57.439945f, -56.684174f,
61 -55.988932f, -55.345238f, -54.745973f, -54.185399f,
62 -53.162349f, -52.247199f, -51.419345f, -50.663574f,
63 -49.968332f, -49.324638f, -48.725374f, -48.164799f,
64 -47.141749f, -46.226599f, -45.398745f, -44.642974f,
65 -43.947732f, -43.304038f, -42.704774f, -42.144199f,
66 -41.121149f, -40.205999f, -39.378145f, -38.622374f,
67 -37.927132f, -37.283438f, -36.684174f, -36.123599f,
68 -35.100549f, -34.185399f, -33.357545f, -32.601774f,
69 -31.906532f, -31.262838f, -30.663574f, -30.102999f,
70 -29.079949f, -28.164799f, -27.336945f, -26.581174f,
71 -25.885932f, -25.242238f, -24.642974f, -24.082400f,
72 -23.059349f, -22.144199f, -21.316346f, -20.560574f,
73 -19.865332f, -19.221639f, -18.622374f, -18.061800f,
74 -17.038749f, -16.123599f, -15.295746f, -14.539974f,
75 -13.844732f, -13.201039f, -12.601774f, -12.041200f,
76 -11.018149f, -10.103000f, -9.275146f, -8.519375f,
77 -7.824132f, -7.180439f, -6.581174f, -6.020600f,
78 -4.997549f, -4.082400f, -3.254546f, -2.498775f,
79 -1.803533f, -1.159839f, -0.560574f, 0.000000f,
80 1.023050f, 1.938200f, 2.766054f, 3.521825f,
81 4.217067f, 4.860761f, 5.460025f, 6.020600f,
82 7.043650f, 7.958800f, 8.786654f, 9.542425f,
83 10.237667f, 10.881361f, 11.480625f, 12.041200f,
84 13.064250f, 13.979400f, 14.807254f, 15.563025f,
85 16.258267f, 16.901961f, 17.501225f, 18.061800f,
86 19.084850f, 20.000000f, 20.827854f, 21.583625f,
87 22.278867f, 22.922561f, 23.521825f, 24.082400f,
88 25.105450f, 26.020600f, 26.848453f, 27.604225f,
89 28.299467f, 28.943161f, 29.542425f, 30.102999f,
90 31.126050f, 32.041200f, 32.869053f, 33.624825f,
91 34.320067f, 34.963760f, 35.563025f, 36.123599f,
92 37.146650f, 38.061800f, 38.889653f, 39.645424f,
93 40.340667f, 40.984360f, 41.583625f, 42.144199f,
94 43.167250f, 44.082399f, 44.910253f, 45.666024f,
95 46.361266f, 47.004960f, 47.604225f, 48.164799f,
96 49.187850f, 50.102999f, 50.930853f, 51.686624f
99 static float todB(const float *x){
100 ogg_int32_t *i=(ogg_int32_t *)x;
101 ogg_int32_t temp=((*i&0x7fffffff)-0x33c7ffff)>>20;
102 if(temp<0)return -400.f;
103 return(todB_LOOKUP[temp]);
106 #define todB_nn(x) todB(x)
110 static float unitnorm(float x){
115 #define todB(x) (*(x)==0?-400.f:log(*(x)**(x))*4.34294480f)
116 #define todB_nn(x) (*(x)==0.f?-400.f:log(*(x))*8.6858896f)
120 #define fromdB(x) (exp((x)*.11512925f))
122 /* The bark scale equations are approximations, since the original
123 table was somewhat hand rolled. The below are chosen to have the
124 best possible fit to the rolled tables, thus their somewhat odd
125 appearance (these are more accurate and over a longer range than
126 the oft-quoted bark equations found in the texts I have). The
127 approximations are valid from 0 - 30kHz (nyquist) or so.
129 all f in Hz, z in Bark */
131 #define toBARK(n) (13.1f*atan(.00074f*(n))+2.24f*atan((n)*(n)*1.85e-8f)+1e-4f*(n))
132 #define fromBARK(z) (102.f*(z)-2.f*pow(z,2.f)+.4f*pow(z,3.f)+pow(1.46f,z)-1.f)
133 #define toMEL(n) (log(1.f+(n)*.001f)*1442.695f)
134 #define fromMEL(m) (1000.f*exp((m)/1442.695f)-1000.f)
136 /* Frequency to octave. We arbitrarily declare 63.5 Hz to be octave
139 #define toOC(n) (log(n)*1.442695f-5.965784f)
140 #define fromOC(o) (exp(((o)+5.965784f)*.693147f))