1 /*****************************************************************************
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3 *****************************************************************************
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4 * Copyright (C) 2006 the VideoLAN team
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5 * $Id: equalizer.c 13905 2006-01-12 23:10:04Z dionoea $
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7 * Authors: Antti Huovilainen
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8 * Sigmund A. Helberg <dnumgis@videolan.org>
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10 * This program is free software; you can redistribute it and/or modify
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11 * it under the terms of the GNU General Public License as published by
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12 * the Free Software Foundation; either version 2 of the License, or
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13 * (at your option) any later version.
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15 * This program is distributed in the hope that it will be useful,
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16 * but WITHOUT ANY WARRANTY; without even the implied warranty of
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17 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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18 * GNU General Public License for more details.
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20 * You should have received a copy of the GNU General Public License
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21 * along with this program; if not, write to the Free Software
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22 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston MA 02110-1301, USA.
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23 *****************************************************************************/
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25 /*****************************************************************************
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27 *****************************************************************************/
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28 #include <stdlib.h> /* malloc(), free() */
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32 #include <vlc/vlc.h>
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34 #include <vlc/aout.h>
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35 #include "aout_internal.h"
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37 /*****************************************************************************
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39 *****************************************************************************/
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40 static int Open ( vlc_object_t * );
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41 static void Close( vlc_object_t * );
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42 static void CalcPeakEQCoeffs( float, float, float, float, float * );
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43 static void CalcShelfEQCoeffs( float, float, float, int, float, float * );
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44 static void ProcessEQ( float *, float *, float *, int, int, float *, int );
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45 static void DoWork( aout_instance_t *, aout_filter_t *,
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46 aout_buffer_t *, aout_buffer_t * );
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49 set_description( _("Parametric Equalizer") );
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50 set_shortname( N_("Parametric Equalizer" ) );
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51 set_capability( "audio filter", 0 );
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52 set_category( CAT_AUDIO );
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53 set_subcategory( SUBCAT_AUDIO_AFILTER );
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55 add_float( "param-eq-lowf", 100, NULL, N_("Low freq (Hz)"),NULL, VLC_FALSE );
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56 add_float_with_range( "param-eq-lowgain", 0, -20.0, 20.0, NULL,
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57 N_("Low freq gain (Db)"), NULL,VLC_FALSE );
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58 add_float( "param-eq-highf", 10000, NULL, N_("High freq (Hz)"),NULL, VLC_FALSE );
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59 add_float_with_range( "param-eq-highgain", 0, -20.0, 20.0, NULL,
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60 N_("High freq gain (Db)"), NULL,VLC_FALSE );
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61 add_float( "param-eq-f1", 300, NULL, N_("Freq 1 (Hz)"),NULL, VLC_FALSE );
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62 add_float_with_range( "param-eq-gain1", 0, -20.0, 20.0, NULL,
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63 N_("Freq 1 gain (Db)"), NULL,VLC_FALSE );
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64 add_float_with_range( "param-eq-q1", 3, 0.1, 100.0, NULL,
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65 N_("Freq 1 Q"), NULL,VLC_FALSE );
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66 add_float( "param-eq-f2", 1000, NULL, N_("Freq 2 (Hz)"),NULL, VLC_FALSE );
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67 add_float_with_range( "param-eq-gain2", 0, -20.0, 20.0, NULL,
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68 N_("Freq 2 gain (Db)"), NULL,VLC_FALSE );
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69 add_float_with_range( "param-eq-q2", 3, 0.1, 100.0, NULL,
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70 N_("Freq 2 Q"), NULL,VLC_FALSE );
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71 add_float( "param-eq-f3", 3000, NULL, N_("Freq 3 (Hz)"),NULL, VLC_FALSE );
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72 add_float_with_range( "param-eq-gain3", 0, -20.0, 20.0, NULL,
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73 N_("Freq 3 gain (Db)"), NULL,VLC_FALSE );
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74 add_float_with_range( "param-eq-q3", 3, 0.1, 100.0, NULL,
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75 N_("Freq 3 Q"), NULL,VLC_FALSE );
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77 set_callbacks( Open, Close );
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80 /*****************************************************************************
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82 *****************************************************************************/
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83 typedef struct aout_filter_sys_t
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85 /* Filter static config */
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86 float f_lowf, f_lowgain;
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87 float f_f1, f_Q1, f_gain1;
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88 float f_f2, f_Q2, f_gain2;
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89 float f_f3, f_Q3, f_gain3;
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90 float f_highf, f_highgain;
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91 /* Filter computed coeffs */
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96 } aout_filter_sys_t;
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101 /*****************************************************************************
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103 *****************************************************************************/
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104 static int Open( vlc_object_t *p_this )
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106 aout_filter_t *p_filter = (aout_filter_t *)p_this;
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107 aout_filter_sys_t *p_sys;
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108 vlc_bool_t b_fit = VLC_TRUE;
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111 if( p_filter->input.i_format != VLC_FOURCC('f','l','3','2' ) ||
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112 p_filter->output.i_format != VLC_FOURCC('f','l','3','2') )
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115 p_filter->input.i_format = VLC_FOURCC('f','l','3','2');
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116 p_filter->output.i_format = VLC_FOURCC('f','l','3','2');
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117 msg_Warn( p_filter, "Bad input or output format" );
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119 if ( !AOUT_FMTS_SIMILAR( &p_filter->input, &p_filter->output ) )
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122 memcpy( &p_filter->output, &p_filter->input,
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123 sizeof(audio_sample_format_t) );
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124 msg_Warn( p_filter, "input and output formats are not similar" );
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129 return VLC_EGENERIC;
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132 p_filter->pf_do_work = DoWork;
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133 p_filter->b_in_place = VLC_TRUE;
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135 /* Allocate structure */
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136 p_sys = p_filter->p_sys = malloc( sizeof( aout_filter_sys_t ) );
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138 p_sys->f_lowf = config_GetFloat( p_this, "param-eq-lowf");
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139 p_sys->f_lowgain = config_GetFloat( p_this, "param-eq-lowgain");
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140 p_sys->f_highf = config_GetFloat( p_this, "param-eq-highf");
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141 p_sys->f_highgain = config_GetFloat( p_this, "param-eq-highgain");
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143 p_sys->f_f1 = config_GetFloat( p_this, "param-eq-f1");
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144 p_sys->f_Q1 = config_GetFloat( p_this, "param-eq-q1");
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145 p_sys->f_gain1 = config_GetFloat( p_this, "param-eq-gain1");
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147 p_sys->f_f2 = config_GetFloat( p_this, "param-eq-f2");
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148 p_sys->f_Q2 = config_GetFloat( p_this, "param-eq-q2");
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149 p_sys->f_gain2 = config_GetFloat( p_this, "param-eq-gain2");
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151 p_sys->f_f3 = config_GetFloat( p_this, "param-eq-f3");
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152 p_sys->f_Q3 = config_GetFloat( p_this, "param-eq-q3");
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153 p_sys->f_gain3 = config_GetFloat( p_this, "param-eq-gain3");
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156 i_samplerate = p_filter->input.i_rate;
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157 CalcPeakEQCoeffs(p_sys->f_f1, p_sys->f_Q1, p_sys->f_gain1,
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158 i_samplerate, p_sys->coeffs+0*5);
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159 CalcPeakEQCoeffs(p_sys->f_f2, p_sys->f_Q2, p_sys->f_gain2,
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160 i_samplerate, p_sys->coeffs+1*5);
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161 CalcPeakEQCoeffs(p_sys->f_f3, p_sys->f_Q3, p_sys->f_gain3,
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162 i_samplerate, p_sys->coeffs+2*5);
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163 CalcShelfEQCoeffs(p_sys->f_lowf, 1, p_sys->f_lowgain, 0,
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164 i_samplerate, p_sys->coeffs+3*5);
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165 CalcShelfEQCoeffs(p_sys->f_highf, 1, p_sys->f_highgain, 0,
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166 i_samplerate, p_sys->coeffs+4*5);
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167 p_sys->p_state = (float*)calloc( p_filter->input.i_channels*5*4,
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170 return VLC_SUCCESS;
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173 static void Close( vlc_object_t *p_this )
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175 aout_filter_t *p_filter = (aout_filter_t *)p_this;
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176 free( p_filter->p_sys->p_state );
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177 free( p_filter->p_sys );
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180 /*****************************************************************************
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181 * DoWork: process samples buffer
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182 *****************************************************************************
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184 *****************************************************************************/
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185 static void DoWork( aout_instance_t * p_aout, aout_filter_t * p_filter,
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186 aout_buffer_t * p_in_buf, aout_buffer_t * p_out_buf )
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188 p_out_buf->i_nb_samples = p_in_buf->i_nb_samples;
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189 p_out_buf->i_nb_bytes = p_in_buf->i_nb_bytes;
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191 ProcessEQ( (float*)p_in_buf->p_buffer, (float*)p_out_buf->p_buffer,
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192 p_filter->p_sys->p_state,
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193 p_filter->input.i_channels, p_in_buf->i_nb_samples,
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194 p_filter->p_sys->coeffs, 5 );
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198 * Calculate direct form IIR coefficients for peaking EQ
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205 * Equations taken from RBJ audio EQ cookbook
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206 * (http://www.musicdsp.org/files/Audio-EQ-Cookbook.txt)
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208 static void CalcPeakEQCoeffs( float f0, float Q, float gainDB, float Fs,
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217 // Provide sane limits to avoid overflow
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218 if (Q < 0.1f) Q = 0.1f;
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219 if (Q > 100) Q = 100;
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220 if (f0 > Fs/2*0.95f) f0 = Fs/2*0.95f;
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221 if (gainDB < -40) gainDB = -40;
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222 if (gainDB > 40) gainDB = 40;
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224 A = pow(10, gainDB/40);
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225 w0 = 2*3.141593f*f0/Fs;
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226 alpha = sin(w0)/(2*Q);
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235 // Store values to coeffs and normalize by 1/a0
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244 * Calculate direct form IIR coefficients for low/high shelf EQ
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251 * Equations taken from RBJ audio EQ cookbook
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252 * (http://www.musicdsp.org/files/Audio-EQ-Cookbook.txt)
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254 static void CalcShelfEQCoeffs( float f0, float slope, float gainDB, int high,
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255 float Fs, float *coeffs )
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263 // Provide sane limits to avoid overflow
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264 if (f0 > Fs/2*0.95f) f0 = Fs/2*0.95f;
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265 if (gainDB < -40) gainDB = -40;
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266 if (gainDB > 40) gainDB = 40;
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268 A = pow(10, gainDB/40);
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269 w0 = 2*3.141593f*f0/Fs;
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270 alpha = sin(w0)/2 * sqrt( (A + 1/A)*(1/slope - 1) + 2 );
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274 b0 = A*( (A+1) + (A-1)*cos(w0) + 2*sqrt(A)*alpha );
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275 b1 = -2*A*( (A-1) + (A+1)*cos(w0) );
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276 b2 = A*( (A+1) + (A-1)*cos(w0) - 2*sqrt(A)*alpha );
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277 a0 = (A+1) - (A-1)*cos(w0) + 2*sqrt(A)*alpha;
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278 a1 = 2*( (A-1) - (A+1)*cos(w0) );
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279 a2 = (A+1) - (A-1)*cos(w0) - 2*sqrt(A)*alpha;
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283 b0 = A*( (A+1) - (A-1)*cos(w0) + 2*sqrt(A)*alpha );
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284 b1 = 2*A*( (A-1) - (A+1)*cos(w0));
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285 b2 = A*( (A+1) - (A-1)*cos(w0) - 2*sqrt(A)*alpha );
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286 a0 = (A+1) + (A-1)*cos(w0) + 2*sqrt(A)*alpha;
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287 a1 = -2*( (A-1) + (A+1)*cos(w0));
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288 a2 = (A+1) + (A-1)*cos(w0) - 2*sqrt(A)*alpha;
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290 // Store values to coeffs and normalize by 1/a0
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299 src is assumed to be interleaved
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300 dest is assumed to be interleaved
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301 size of state is 4*channels*eqCount
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302 samples is not premultiplied by channels
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303 size of coeffs is 5*eqCount
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305 void ProcessEQ( float *src, float *dest, float *state,
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306 int channels, int samples, float *coeffs,
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310 float b0, b1, b2, a1, a2;
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312 float *src1, *dest1;
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313 float *coeffs1, *state1;
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316 for (i = 0; i < samples; i++)
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319 for (chn = 0; chn < channels; chn++)
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323 /* Direct form 1 IIRs */
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324 for (eq = 0; eq < eqCount; eq++)
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332 y = x*b0 + state1[0]*b1 + state1[1]*b2 - state1[2]*a1 - state1[3]*a2;
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333 state1[1] = state1[0];
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335 state1[3] = state1[2];
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