Alexandre Lision | 8af73cb | 2013-12-10 14:11:20 -0500 | [diff] [blame] | 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 |