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Commit eb19c5d5 authored by Ron Wright's avatar Ron Wright Committed by Jean-Baptiste Kempf
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Equalizer: support new samplerates and bands 

Support for more samplerate than 44100 and 48000
Support for classic ISO bands instead of Winamp ones
Signed-off-by: default avatarJean-Baptiste Kempf <jb@videolan.org>
parent b54ea14f
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Showing with 74 additions and 52 deletions
modules/audio_filter/equalizer.c
View file @ eb19c5d5
/*****************************************************************************
* equalizer.c:
*****************************************************************************
* Copyright (C) 2004-2009 the VideoLAN team
* Copyright (C) 2004-2012 the VideoLAN team
* $Id$
*
* Authors: Laurent Aimar <fenrir@via.ecp.fr>
......@@ -39,11 +39,11 @@
#include <vlc_filter.h>
#include "equalizer_presets.h"
/* TODO:
* - add tables for other rates ( 22500, 11250, ...)
* - optimize a bit (you can hardly do slower ;)
* - add tables for more bands (15 and 32 would be cool), maybe with auto coeffs
* computation (not too hard once the Q is found).
* computation (not too hard once the Q is found).
* - support for external preset
* - callback to handle preset changes on the fly
* - ...
......@@ -64,6 +64,11 @@ static void Close( vlc_object_t * );
"provide 10 values between -20dB and 20dB, separated by spaces, " \
"e.g. \"0 2 4 2 0 -2 -4 -2 0 2\"." )
#define VLC_BANDS_TEXT N_( "Use VLC frequency bands" )
#define VLC_BANDS_LONGTEXT N_( \
"Use the VLC frequency bands. Otherwise, use the ISO Standard " \
"frequency bands." )
#define TWOPASS_TEXT N_( "Two pass" )
#define TWOPASS_LONGTEXT N_( "Filter the audio twice. This provides a more " \
"intense effect.")
......@@ -85,6 +90,8 @@ vlc_module_begin ()
BANDS_LONGTEXT, true )
add_bool( "equalizer-2pass", false, TWOPASS_TEXT,
TWOPASS_LONGTEXT, true )
add_bool( "equalizer-vlcfreqs", true, VLC_BANDS_TEXT,
VLC_BANDS_LONGTEXT, true )
add_float( "equalizer-preamp", 12.0, PREAMP_TEXT,
PREAMP_LONGTEXT, true )
set_callbacks( Open, Close )
......@@ -225,39 +232,67 @@ typedef struct
} eqz_config_t;
/* Value from equ-xmms */
static const eqz_config_t eqz_config_44100_10b =
/* The frequency tables */
static const float f_vlc_frequency_table_10b[EQZ_BANDS_MAX] =
{
10,
{
{ 60, 0.003013, 0.993973, 1.993901 },
{ 170, 0.008490, 0.983019, 1.982437 },
{ 310, 0.015374, 0.969252, 1.967331 },
{ 600, 0.029328, 0.941343, 1.934254 },
{ 1000, 0.047918, 0.904163, 1.884869 },
{ 3000, 0.130408, 0.739184, 1.582718 },
{ 6000, 0.226555, 0.546889, 1.015267 },
{ 12000, 0.344937, 0.310127, -0.181410 },
{ 14000, 0.366438, 0.267123, -0.521151 },
{ 16000, 0.379009, 0.241981, -0.808451 },
}
60, 170, 310, 600, 1000, 3000, 6000, 12000, 14000, 16000,
};
static const float f_iso_frequency_table_10b[EQZ_BANDS_MAX] =
{
31.25, 62.5, 125, 250, 500, 1000, 2000, 4000, 8000, 16000,
};
static const eqz_config_t eqz_config_48000_10b =
/* Equalizer coefficient calculation function based on equ-xmms */
static void EqzCoeffs( int i_rate, float f_octave_percent,
bool b_use_vlc_freqs,
eqz_config_t *p_eqz_config )
{
10,
const float *f_freq_table_10b = b_use_vlc_freqs
? f_vlc_frequency_table_10b
: f_iso_frequency_table_10b;
float f_rate = (float) i_rate;
float f_nyquist_freq = 0.5 * f_rate;
float f_octave_factor = pow( 2.0, 0.5 * f_octave_percent );
float f_octave_factor_1 = 0.5 * ( f_octave_factor + 1.0 );
float f_octave_factor_2 = 0.5 * ( f_octave_factor - 1.0 );
p_eqz_config->i_band = EQZ_BANDS_MAX;
for( int i = 0; i < EQZ_BANDS_MAX; i++ )
{
{ 60, 0.002769, 0.994462, 1.994400 },
{ 170, 0.007806, 0.984388, 1.983897 },
{ 310, 0.014143, 0.971714, 1.970091 },
{ 600, 0.027011, 0.945978, 1.939979 },
{ 1000, 0.044203, 0.911595, 1.895241 },
{ 3000, 0.121223, 0.757553, 1.623767 },
{ 6000, 0.212888, 0.574224, 1.113145 },
{ 12000, 0.331347, 0.337307, 0.000000 },
{ 14000, 0.355263, 0.289473, -0.333740 },
{ 16000, 0.371900, 0.256201, -0.628100 }
float f_freq = f_freq_table_10b[i];
p_eqz_config->band[i].f_frequency = f_freq;
if( f_freq <= f_nyquist_freq )
{
float f_theta_1 = ( 2.0 * M_PI * f_freq ) / f_rate;
float f_theta_2 = f_theta_1 / f_octave_factor;
float f_sin = sin( f_theta_2 ) * 0.5;
float f_sin_prd = sin( f_theta_2 * f_octave_factor_1 )
* sin( f_theta_2 * f_octave_factor_2 );
/* The equation from equ-xmms simplifies to something similar to
* this when you restrict the domain to all valid frequencies at or
* below the Nyquist frequency (the interval 0 <= f_theta_1 <= Pi).
* (This result for the root is twice that returned by equ-xmms,
* but the more efficient calculations for alpha, beta, and gamma
* below compensate for this.) */
float f_root = ( f_sin - f_sin_prd ) / ( f_sin + f_sin_prd );
p_eqz_config->band[i].f_alpha = ( 1.0 - f_root ) * 0.5;
p_eqz_config->band[i].f_beta = f_root;
p_eqz_config->band[i].f_gamma = ( 1.0 + f_root ) * cos( f_theta_1 );
}
else
{
/* Any frequency beyond the Nyquist frequency is no good... */
p_eqz_config->band[i].f_alpha =
p_eqz_config->band[i].f_beta =
p_eqz_config->band[i].f_gamma = 0.0;
}
}
};
}
static inline float EqzConvertdB( float db )
{
......@@ -279,30 +314,17 @@ static inline float EqzConvertdB( float db )
static int EqzInit( filter_t *p_filter, int i_rate )
{
filter_sys_t *p_sys = p_filter->p_sys;
const eqz_config_t *p_cfg;
eqz_config_t cfg;
int i, ch;
vlc_value_t val1, val2, val3;
vlc_object_t *p_aout = p_filter->p_parent;
int i_ret = VLC_ENOMEM;
/* Select the config */
if( i_rate == 48000 )
{
p_cfg = &eqz_config_48000_10b;
}
else if( i_rate == 44100 )
{
p_cfg = &eqz_config_44100_10b;
}
else
{
/* TODO compute the coeffs on the fly */
msg_Err( p_filter, "rate not supported" );
return VLC_EGENERIC;
}
bool b_vlcFreqs = var_InheritBool( p_aout, "equalizer-vlcfreqs" );
EqzCoeffs( i_rate, 1.0, b_vlcFreqs, &cfg );
/* Create the static filter config */
p_sys->i_band = p_cfg->i_band;
p_sys->i_band = cfg.i_band;
p_sys->f_alpha = malloc( p_sys->i_band * sizeof(float) );
p_sys->f_beta = malloc( p_sys->i_band * sizeof(float) );
p_sys->f_gamma = malloc( p_sys->i_band * sizeof(float) );
......@@ -311,9 +333,9 @@ static int EqzInit( filter_t *p_filter, int i_rate )
for( i = 0; i < p_sys->i_band; i++ )
{
p_sys->f_alpha[i] = p_cfg->band[i].f_alpha;
p_sys->f_beta[i] = p_cfg->band[i].f_beta;
p_sys->f_gamma[i] = p_cfg->band[i].f_gamma;
p_sys->f_alpha[i] = cfg.band[i].f_alpha;
p_sys->f_beta[i] = cfg.band[i].f_beta;
p_sys->f_gamma[i] = cfg.band[i].f_gamma;
}
/* Filter dyn config */
......@@ -396,7 +418,7 @@ static int EqzInit( filter_t *p_filter, int i_rate )
for( i = 0; i < p_sys->i_band; i++ )
{
msg_Dbg( p_filter, " %d Hz -> factor:%f alpha:%f beta:%f gamma:%f",
(int)p_cfg->band[i].f_frequency, p_sys->f_amp[i],
(int)cfg.band[i].f_frequency, p_sys->f_amp[i],
p_sys->f_alpha[i], p_sys->f_beta[i], p_sys->f_gamma[i]);
}
return VLC_SUCCESS;
......
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