// ---------------------------------------------------------------------------
// harmonify
// ---------------------------------------------------------------------------
//! Apply the reference envelope to a Partial.
//!
//! \pre The Partial p must be labeled with its harmonic number.
//
void Harmonifier::harmonify( Partial & p ) const
{
// compute absolute magnitude thresholds:
static const double FadeRangeDB = 10;
const double BeginFade = std::pow( 10., 0.05 * (_freqFixThresholdDb+FadeRangeDB) );
const double Threshold = std::pow( 10., 0.05 * _freqFixThresholdDb );
const double OneOverFadeSpan = 1. / ( BeginFade - Threshold );
double fscale = (double)p.label() / _refPartial.label();
for ( Partial::iterator it = p.begin(); it != p.end(); ++it )
{
Breakpoint & bp = it.breakpoint();
if ( bp.amplitude() < BeginFade )
{
// alpha is the harmonic frequency weighting:
// when alpha is 1, the harmonic frequency is used,
// when alpha is 0, the breakpoint frequency is
// unmodified.
double alpha =
std::min( ( BeginFade - bp.amplitude() ) * OneOverFadeSpan, 1. );
// alpha is scaled by the weigthing envelope
alpha *= _weight->valueAt( it.time() );
double fRef = _refPartial.frequencyAt( it.time() );
bp.setFrequency( ( alpha * ( fRef * fscale ) ) +
( (1 - alpha) * bp.frequency() ) );
}
}
}
// ---------------------------------------------------------------------------
// TimeShifter function call operator
// ---------------------------------------------------------------------------
// Shift the time of all the Breakpoints in a Partial by a constant amount.
//
void
TimeShifter::operator()( Partial & p ) const
{
// Since the Breakpoint times are immutable, the only way to
// shift the Partial in time is to construct a new Partial and
// assign it to the argument p.
Partial result;
result.setLabel( p.label() );
for ( Partial::iterator pos = p.begin(); pos != p.end(); ++pos )
{
result.insert( pos.time() + offset, pos.breakpoint() );
}
p = result;
}
// ----------- test_distill_overlapping2 -----------
//
static void test_distill_overlapping2( void )
{
std::cout << "\t--- testing distill on two "
"temporally-overlapping Partials... ---\n\n";
// Fabricate two Partials, overlapping temporally, give
// them the same label, and distill them.
Partial p1;
p1.insert( 0, Breakpoint( 100, 0.4, 0, 0 ) );
p1.insert( 0.3, Breakpoint( 100, 0.4, 0, .1 ) );
p1.setLabel( 12 );
Partial p2;
p2.insert( 0.2, Breakpoint( 200, 0.3, 0, 0 ) );
p2.insert( 0.35, Breakpoint( 210, 0.3, 0.2, .1 ) );
p2.setLabel( 12 );
PartialList l;
l.push_back( p1 );
l.push_back( p2 );
const double fade = .01; // 10 ms
Distiller d( fade );
d.distill( l );
for ( Partial::iterator distit = l.front().begin(); distit != l.front().end(); ++distit )
{
cout << distit.time() << " " << distit.breakpoint().frequency() << endl;
}
// Fabricate the Partial that the distillation should
// produce.
Partial compare;
// first Breakpoint from p1
compare.insert( 0, Breakpoint( 100, 0.4, 0, 0 ) );
// null Breakpoint at 0+fade
double t = 0 + fade;
compare.insert( t, Breakpoint( p1.frequencyAt(t), 0,
p1.bandwidthAt(t), p1.phaseAt(t) ) );
// interpolated Breakpoint at .18 (.2 - 2*fade)
//double t = 0.2 - (2*fade);
//compare.insert( t, p1.parametersAt( t ) );
// null Breakpoint at .19 (.2-fade)
// bandwidth introduced in the overlap region:
// 0.4^2 / (0.3^2 + 0.4^2) = 0.64
// amp = sqrt(0.3^2 + 0.4^2) = .5
// no, actually zero-amplitude Breakpoints are
// introduced with zero bandwidth.
t = 0.2 - fade;
compare.insert( t, Breakpoint( p2.frequencyAt(t), 0,
0, // 0.64,
p2.phaseAt(t) ) );
// first Breakpoint from p2:
compare.insert( 0.2, Breakpoint( 200, 0.5, 0.64, 0 ) );
// second Breakpoint from p2
compare.insert( 0.35, Breakpoint( 210, 0.3, 0.2, .1 ) );
compare.setLabel( 12 );
// compare Partials (distilled Partials
// should be in label order):
TEST( l.size() == 1 );
TEST( l.begin()->numBreakpoints() == compare.numBreakpoints() );
TEST( l.begin()->label() == compare.label() );
Partial::iterator distit = l.begin()->begin();
Partial::iterator compareit = compare.begin();
while ( compareit != compare.end() )
{
SAME_PARAM_VALUES( distit.time(), compareit.time() );
SAME_PARAM_VALUES( distit->frequency(), compareit->frequency() );
SAME_PARAM_VALUES( distit->amplitude(), compareit->amplitude() );
SAME_PARAM_VALUES( distit->bandwidth(), compareit->bandwidth() );
SAME_PARAM_VALUES( distit->phase(), compareit->phase() );
++compareit;
++distit;
}
}
// ---------------------------------------------------------------------------
// dilate
// ---------------------------------------------------------------------------
//! Replace the Partial envelope with a new envelope having the
//! same Breakpoints at times computed to align temporal features
//! in the sorted sequence of initial time points with their
//! counterparts the sorted sequence of target time points.
//!
//! Depending on the specification of initial and target time
//! points, the dilated Partial may have Breakpoints at times
//! less than 0, even if the original Partial did not.
//!
//! It is possible to have duplicate time points in either sequence.
//! Duplicate initial time points result in very localized stretching.
//! Duplicate target time points result in very localized compression.
//!
//! If all initial time points are greater than 0, then an implicit
//! time point at 0 is assumed in both initial and target sequences,
//! so the onset of a sound can be stretched without explcitly specifying a
//! zero point in each vector. (This seems most intuitive, and only looks
//! like an inconsistency if clients are using negative time points in
//! their Dilator, or Partials having Breakpoints before time 0, both
//! of which are probably unusual circumstances.)
//!
//! \param p is the Partial to dilate.
//
void
Dilator::dilate( Partial & p ) const
{
debugger << "dilating Partial having " << p.numBreakpoints()
<< " Breakpoints" << endl;
// sanity check:
Assert( _initial.size() == _target.size() );
// don't dilate if there's no time points, or no Breakpoints:
if ( 0 == _initial.size() ||
0 == p.numBreakpoints() )
{
return;
}
// create the new Partial:
Partial newp;
newp.setLabel( p.label() );
// timepoint index:
int idx = 0;
for ( Partial::const_iterator iter = p.begin(); iter != p.end(); ++iter )
{
// find the first initial time point later
// than the currentTime:
double currentTime = iter.time();
idx = std::distance( _initial.begin(),
std::lower_bound( _initial.begin(), _initial.end(), currentTime ) );
Assert( idx == _initial.size() || currentTime <= _initial[idx] );
// compute a new time for the Breakpoint at pIter:
double newtime = 0;
if ( idx == 0 )
{
// all time points in _initial are later than
// the currentTime; stretch if no zero time
// point has been specified, otherwise, shift:
if ( _initial[idx] != 0. )
newtime = currentTime * _target[idx] / _initial[idx];
else
newtime = _target[idx] + (currentTime - _initial[idx]);
}
else if ( idx == _initial.size() )
{
// all time points in _initial are earlier than
// the currentTime; shift:
//
// note: size is already known to be > 0, so
// idx-1 is safe
newtime = _target[idx-1] + (currentTime - _initial[idx-1]);
}
else
{
// currentTime is between the time points at idx and
// idx-1 in _initial; shift and stretch:
//
// note: size is already known to be > 0, so
// idx-1 is safe
Assert( _initial[idx-1] < _initial[idx] ); // currentTime can't wind up
// between two equal times
double stretch = (_target[idx] - _target[idx-1]) / (_initial[idx] - _initial[idx-1]);
newtime = _target[idx-1] + ((currentTime - _initial[idx-1]) * stretch);
}
// add a Breakpoint at the computed time:
newp.insert( newtime, iter.breakpoint() );
}
// new Breakpoints need to be added to the Partial at times corresponding
// to all target time points that are after the first Breakpoint and
// before the last, otherwise, Partials may be briefly out of tune with
// each other, since our Breakpoints are non-uniformly distributed in time:
for ( idx = 0; idx < _initial.size(); ++ idx )
{
if ( _initial[idx] <= p.startTime() )
{
continue;
}
else if ( _initial[idx] >= p.endTime() )
{
break;
}
else
{
newp.insert( _target[idx],
Breakpoint( p.frequencyAt(_initial[idx]), p.amplitudeAt(_initial[idx]),
p.bandwidthAt(_initial[idx]), p.phaseAt(_initial[idx]) ) );
}
}
// store the new Partial:
p = newp;
}