1/* Copyright (C) 2005 Jean-Marc Valin, CSIRO, Christopher Montgomery
2   File: vorbis_psy.h
3
4   Redistribution and use in source and binary forms, with or without
5   modification, are permitted provided that the following conditions
6   are met:
7
8   - Redistributions of source code must retain the above copyright
9   notice, this list of conditions and the following disclaimer.
10
11   - Redistributions in binary form must reproduce the above copyright
12   notice, this list of conditions and the following disclaimer in the
13   documentation and/or other materials provided with the distribution.
14
15   - Neither the name of the Xiph.org Foundation nor the names of its
16   contributors may be used to endorse or promote products derived from
17   this software without specific prior written permission.
18
19   THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
20   ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
21   LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
22   A PARTICULAR PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR
23   CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
24   EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
25   PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
26   PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
27   LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
28   NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
29   SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
30*/
31
32#ifndef VORBIS_PSY_H
33#define VORBIS_PSY_H
34
35#ifdef VORBIS_PSYCHO
36
37#include "smallft.h"
38#define P_BANDS 17      /* 62Hz to 16kHz */
39#define NOISE_COMPAND_LEVELS 40
40
41
42#define todB(x)   ((x)>1e-13?log((x)*(x))*4.34294480f:-30)
43#define fromdB(x) (exp((x)*.11512925f))
44
45/* The bark scale equations are approximations, since the original
46   table was somewhat hand rolled.  The below are chosen to have the
47   best possible fit to the rolled tables, thus their somewhat odd
48   appearance (these are more accurate and over a longer range than
49   the oft-quoted bark equations found in the texts I have).  The
50   approximations are valid from 0 - 30kHz (nyquist) or so.
51
52   all f in Hz, z in Bark */
53
54#define toBARK(n)   (13.1f*atan(.00074f*(n))+2.24f*atan((n)*(n)*1.85e-8f)+1e-4f*(n))
55#define fromBARK(z) (102.f*(z)-2.f*pow(z,2.f)+.4f*pow(z,3.f)+pow(1.46f,z)-1.f)
56
57/* Frequency to octave.  We arbitrarily declare 63.5 Hz to be octave
58   0.0 */
59
60#define toOC(n)     (log(n)*1.442695f-5.965784f)
61#define fromOC(o)   (exp(((o)+5.965784f)*.693147f))
62
63
64typedef struct {
65
66  float noisewindowlo;
67  float noisewindowhi;
68  int   noisewindowlomin;
69  int   noisewindowhimin;
70  int   noisewindowfixed;
71  float noiseoff[P_BANDS];
72  float noisecompand[NOISE_COMPAND_LEVELS];
73
74} VorbisPsyInfo;
75
76
77
78typedef struct {
79  int n;
80  int rate;
81  struct drft_lookup lookup;
82  VorbisPsyInfo *vi;
83
84  float *window;
85  float *noiseoffset;
86  long  *bark;
87
88} VorbisPsy;
89
90
91VorbisPsy *vorbis_psy_init(int rate, int size);
92void vorbis_psy_destroy(VorbisPsy *psy);
93void compute_curve(VorbisPsy *psy, float *audio, float *curve);
94void curve_to_lpc(VorbisPsy *psy, float *curve, float *awk1, float *awk2, int ord);
95
96#endif
97#endif
98