| /* Copyright (C) 2005 Jean-Marc Valin, CSIRO, Christopher Montgomery |
| File: vorbis_psy.h |
| |
| Redistribution and use in source and binary forms, with or without |
| modification, are permitted provided that the following conditions |
| are met: |
| |
| - Redistributions of source code must retain the above copyright |
| notice, this list of conditions and the following disclaimer. |
| |
| - Redistributions in binary form must reproduce the above copyright |
| notice, this list of conditions and the following disclaimer in the |
| documentation and/or other materials provided with the distribution. |
| |
| - Neither the name of the Xiph.org Foundation nor the names of its |
| contributors may be used to endorse or promote products derived from |
| this software without specific prior written permission. |
| |
| THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS |
| ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT |
| LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR |
| A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR |
| CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, |
| EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, |
| PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR |
| PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF |
| LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING |
| NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS |
| SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. |
| */ |
| |
| #ifndef VORBIS_PSY_H |
| #define VORBIS_PSY_H |
| |
| #ifdef VORBIS_PSYCHO |
| |
| #include "smallft.h" |
| #define P_BANDS 17 /* 62Hz to 16kHz */ |
| #define NOISE_COMPAND_LEVELS 40 |
| |
| |
| #define todB(x) ((x)>1e-13?log((x)*(x))*4.34294480f:-30) |
| #define fromdB(x) (exp((x)*.11512925f)) |
| |
| /* The bark scale equations are approximations, since the original |
| table was somewhat hand rolled. The below are chosen to have the |
| best possible fit to the rolled tables, thus their somewhat odd |
| appearance (these are more accurate and over a longer range than |
| the oft-quoted bark equations found in the texts I have). The |
| approximations are valid from 0 - 30kHz (nyquist) or so. |
| |
| all f in Hz, z in Bark */ |
| |
| #define toBARK(n) (13.1f*atan(.00074f*(n))+2.24f*atan((n)*(n)*1.85e-8f)+1e-4f*(n)) |
| #define fromBARK(z) (102.f*(z)-2.f*pow(z,2.f)+.4f*pow(z,3.f)+pow(1.46f,z)-1.f) |
| |
| /* Frequency to octave. We arbitrarily declare 63.5 Hz to be octave |
| 0.0 */ |
| |
| #define toOC(n) (log(n)*1.442695f-5.965784f) |
| #define fromOC(o) (exp(((o)+5.965784f)*.693147f)) |
| |
| |
| typedef struct { |
| |
| float noisewindowlo; |
| float noisewindowhi; |
| int noisewindowlomin; |
| int noisewindowhimin; |
| int noisewindowfixed; |
| float noiseoff[P_BANDS]; |
| float noisecompand[NOISE_COMPAND_LEVELS]; |
| |
| } VorbisPsyInfo; |
| |
| |
| |
| typedef struct { |
| int n; |
| int rate; |
| struct drft_lookup lookup; |
| VorbisPsyInfo *vi; |
| |
| float *window; |
| float *noiseoffset; |
| long *bark; |
| |
| } VorbisPsy; |
| |
| |
| VorbisPsy *vorbis_psy_init(int rate, int size); |
| void vorbis_psy_destroy(VorbisPsy *psy); |
| void compute_curve(VorbisPsy *psy, float *audio, float *curve); |
| void curve_to_lpc(VorbisPsy *psy, float *curve, float *awk1, float *awk2, int ord); |
| |
| #endif |
| #endif |