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 64 typedef 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 78 typedef 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 91 VorbisPsy *vorbis_psy_init(int rate, int size); 92 void vorbis_psy_destroy(VorbisPsy *psy); 93 void compute_curve(VorbisPsy *psy, float *audio, float *curve); 94 void curve_to_lpc(VorbisPsy *psy, float *curve, float *awk1, float *awk2, int ord); 95 96 #endif 97 #endif 98
