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simplified filtering, VST fixes

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git-svn-id: https://lmms.svn.sf.net/svnroot/lmms/trunk/lmms@478 0778d3d1-df1d-0410-868b-ea421aaaa00d
This commit is contained in:
Javier Serrano Polo
2007-04-25 20:48:18 +00:00
parent 416d208cc3
commit f94614cd77
11 changed files with 108 additions and 92 deletions
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138
include/basic_filters.h
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@@ -46,7 +46,6 @@ template<ch_cnt_t CHANNELS = DEFAULT_CHANNELS>
class basicFilters
{
public:
enum filterTypes
{
LOWPASS,
@@ -56,9 +55,7 @@ public:
NOTCH,
ALLPASS,
MOOG,
SIMPLE_FLT_CNT,
DOUBLE_LOWPASS = 16+LOWPASS,
DOUBLE_MOOG = 16+MOOG
SIMPLE_FLT_CNT
} ;
static inline float minQ( void )
@@ -66,14 +63,23 @@ public:
return( 0.01f );
}
static inline filterTypes getFilterType( const int _idx )
inline void setFilterType( const int _idx )
{
if( _idx < SIMPLE_FLT_CNT )
m_double_filter = _idx >= SIMPLE_FLT_CNT;
if( !m_double_filter )
{
return( static_cast<filterTypes>( _idx ) );
m_type = static_cast<filterTypes>( _idx );
return;
}
return( static_cast<filterTypes>( DOUBLE_LOWPASS + _idx -
SIMPLE_FLT_CNT ) );
m_type = static_cast<filterTypes>( LOWPASS + _idx -
SIMPLE_FLT_CNT );
if( m_subFilter == NULL )
{
m_subFilter = new basicFilters<CHANNELS>(
static_cast<sample_rate_t>(
m_sampleRate ) );
}
m_subFilter->m_type = m_type;
}
inline basicFilters( const sample_rate_t _sample_rate ) :
@@ -82,6 +88,7 @@ public:
m_b2a0( 0.0f ),
m_a1a0( 0.0f ),
m_a2a0( 0.0f ),
m_double_filter( FALSE ),
m_sampleRate( _sample_rate ),
m_subFilter( NULL )
{
@@ -109,27 +116,26 @@ public:
switch( m_type )
{
case MOOG:
case DOUBLE_MOOG:
{
sample_t x = _in0 - m_r*m_y4[_chnl];
// four cascaded onepole filters
// (bilinear transform)
m_y1[_chnl] = tLimit(
x*m_p + m_oldx[_chnl]*m_p -
m_k*m_y1[_chnl],
( x + m_oldx[_chnl] ) * m_p
- m_k * m_y1[_chnl],
-10.0f, 10.0f );
m_y2[_chnl] = tLimit(
m_y1[_chnl]*m_p+m_oldy1[_chnl]*
m_p - m_k*m_y2[_chnl],
( m_y1[_chnl] + m_oldy1[_chnl] ) * m_p
- m_k * m_y2[_chnl],
-10.0f, 10.0f );
m_y3[_chnl] = tLimit(
m_y2[_chnl]*m_p+m_oldy2[_chnl]*
m_p - m_k*m_y3[_chnl],
( m_y2[_chnl] + m_oldy2[_chnl] ) * m_p
- m_k * m_y3[_chnl],
-10.0f, 10.0f );
m_y4[_chnl] = tLimit(
m_y3[_chnl]*m_p+m_oldy3[_chnl]*
m_p - m_k*m_y4[_chnl],
( m_y3[_chnl] + m_oldy3[_chnl] ) * m_p
- m_k * m_y4[_chnl],
-10.0f, 10.0f );
m_oldx[_chnl] = x;
@@ -222,7 +228,7 @@ public:
break;
}
if( m_subFilter != NULL )
if( m_double_filter )
{
return( m_subFilter->update( out, _chnl ) );
}
@@ -232,12 +238,6 @@ public:
}
void setType( const filterTypes _type )
{
m_type = _type;
}
inline void calcFilterCoeffs( float _freq, float _q
/*, const bool _q_is_bandwidth = FALSE*/ )
{
@@ -246,30 +246,22 @@ public:
// bad noise out of the filter...
_q = tMax( _q, minQ() );
switch( m_type )
if( m_type == MOOG )
{
case DOUBLE_MOOG:
{
if( m_subFilter == NULL )
{
m_subFilter =
new basicFilters<CHANNELS>(
static_cast<sample_rate_t>( m_sampleRate ) );
m_subFilter->setType( MOOG );
}
m_subFilter->calcFilterCoeffs( _freq, _q );
}
// [ 0 - 0.5 ]
const float f = _freq / m_sampleRate;
// (Empirical tunning)
m_p = ( 3.6f - 3.2f * f ) * f;
m_k = 2.0f * m_p - 1;
m_r = _q * powf( M_E, ( 1 - m_p ) * 1.386249f );
case MOOG:
if( m_double_filter )
{
// [ 0 - 1 ]
const float f = 2 * _freq / m_sampleRate;
// (Empirical tunning)
m_k = 3.6f * f - 1.6f * f * f - 1;
m_p = ( m_k + 1 ) * 0.5f;
m_r = _q * powf( M_E, ( 1 - m_p ) * 1.386249f );
return;
m_subFilter->m_r = m_r;
m_subFilter->m_p = m_p;
m_subFilter->m_k = m_k;
}
return;
/* case DOUBLE_MOOG2:
{
@@ -297,9 +289,6 @@ public:
m_r = 4 * _q * kacr;
break;
}*/
default:
break;
}
// other filters
@@ -316,62 +305,53 @@ public:
const float a0 = 1.0f / ( 1.0f + alpha );
m_a1a0 = -2.0f * tcos * a0;
m_a2a0 = ( 1.0f - alpha ) * a0;
switch( m_type )
{
case LOWPASS:
case DOUBLE_LOWPASS:
m_b0a0 = ( 1.0f - tcos ) * 0.5f * a0;
m_b1a0 = ( 1.0f - tcos ) * a0;
m_b0a0 = m_b1a0 * 0.5f;
m_b2a0 = m_b0a0;//((1.0f-tcos)/2.0f)*a0;
m_a1a0 = -2.0f * tcos * a0;
if( m_type == DOUBLE_LOWPASS )
{
if( m_subFilter == NULL )
{
m_subFilter =
new basicFilters<CHANNELS>( static_cast<sample_rate_t>(
m_sampleRate ) );
m_subFilter->setType( LOWPASS );
}
m_subFilter->calcFilterCoeffs( _freq,
_q );
}
break;
case HIPASS:
m_b0a0 = ( 1.0f + tcos ) * 0.5f * a0;
m_b1a0 = ( -1.0f - tcos ) * a0;
m_b0a0 = m_b1a0 * -0.5f;
m_b2a0 = m_b0a0;//((1.0f+tcos)/2.0f)*a0;
m_a1a0 = -2.0f * tcos * a0;
break;
case BANDPASS_CSG:
m_b0a0 = tsin * 0.5f * a0;
m_b1a0 = 0.0f;
m_b2a0 = -tsin * 0.5f * a0;
m_a1a0 = -2.0f * tcos * a0;
m_b0a0 = tsin * 0.5f * a0;
m_b2a0 = -m_b0a0;
break;
case BANDPASS_CZPG:
m_b0a0 = alpha * a0;
m_b1a0 = 0.0f;
m_b2a0 = -alpha * a0;
m_a1a0 = -2.0f * tcos * a0;
m_b0a0 = alpha * a0;
m_b2a0 = -m_b0a0;
break;
case NOTCH:
m_b1a0 = m_a1a0;
m_b0a0 = a0;
m_b1a0 = -2.0f * tcos * a0;
m_b2a0 = a0;
m_a1a0 = m_b1a0;//(-2.0f*tcos)*a0;
break;
case ALLPASS:
m_b0a0 = ( 1.0f - alpha ) * a0;
m_b1a0 = -2.0f * tcos * a0;
m_b1a0 = m_a1a0;
m_b0a0 = m_a2a0;
m_b2a0 = 1.0f;//(1.0f+alpha)*a0;
m_a1a0 = m_b1a0;//(-2.0f*tcos)*a0;
//m_a2a0 = m_b0a0;//(1.0f-alpha)*a0;
break;
default:
break;
}
m_a2a0 = ( 1.0f - alpha ) * a0;
if( m_double_filter )
{
m_subFilter->m_b0a0 = m_b0a0;
m_subFilter->m_b1a0 = m_b1a0;
m_subFilter->m_b2a0 = m_b2a0;
m_subFilter->m_a1a0 = m_a1a0;
m_subFilter->m_a2a0 = m_a2a0;
}
}
@@ -391,9 +371,11 @@ private:
frame m_y1, m_y2, m_y3, m_y4, m_oldx, m_oldy1, m_oldy2, m_oldy3;
filterTypes m_type;
bool m_double_filter;
float m_sampleRate;
basicFilters<CHANNELS> * m_subFilter;
} ;