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