// ---------------------------------------------------------------------------
// freq_distance
// ---------------------------------------------------------------------------
// Helper function, used in formPartials().
// Returns the (positive) frequency distance between a Breakpoint
// and the last Breakpoint in a Partial.
//
inline double
PartialBuilder::freq_distance( const Partial & partial, const SpectralPeak & pk )
{
double normBpFreq = pk.frequency() / mFreqWarping->valueAt( pk.time() );
double normPartialEndFreq =
partial.last().frequency() / mFreqWarping->valueAt( partial.endTime() );
return std::fabs( normPartialEndFreq - normBpFreq );
}
Iter
find_overlapping( Partial & p, double minGapTime, Iter start, Iter end)
{
for ( Iter it = start; it != end; ++it )
{
// skip if other partial is already sifted out.
if ( (*it)->label() == 0 )
continue;
// skip the source Partial:
// (identity test: compare addresses)
// (this is a sanity check, should not happen since
// src should be at position end)
Assert( (*it) != &p );
// test for overlap:
if ( p.startTime() < (*it)->endTime() + minGapTime &&
p.endTime() + minGapTime > (*it)->startTime() )
{
// Does the overlapping Partial have longer duration?
// (this should never be true, since the Partials
// are sorted by duration)
Assert( p.duration() <= (*it)->duration() );
#if Debug_Loris
debugger << "Partial starting " << p.startTime() << ", "
<< p.begin().breakpoint().frequency() << " ending "
<< p.endTime() << ", " << (--p.end()).breakpoint().frequency()
<< " zapped by overlapping Partial starting "
<< (*it)->startTime() << ", " << (*it)->begin().breakpoint().frequency()
<< " ending " << (*it)->endTime() << ", "
<< (--(*it)->end()).breakpoint().frequency() << endl;
#endif
return it;
}
}
// no overlapping Partial found:
return end;
}
// ---------------------------------------------------------------------------
// fadeInAndOut (STATIC)
// ---------------------------------------------------------------------------
// Add zero-amplitude Breakpoints to the ends of a Partial if necessary.
// Do this to all Partials before distilling to make distillation easier.
//
static void fadeInAndOut( Partial & p, double fadeTime )
{
if ( p.first().amplitude() != 0 )
{
p.insert(
p.startTime() - fadeTime,
BreakpointUtils::makeNullBefore( p.first(), fadeTime ) );
}
if ( p.last().amplitude() != 0 )
{
p.insert(
p.endTime() + fadeTime,
BreakpointUtils::makeNullAfter( p.last(), fadeTime ) );
}
}
// ---------------------------------------------------------------------------
// fixPhaseBetween
//
//! Fix the phase travel between two times by adjusting the
//! frequency and phase of Breakpoints between those two times.
//!
//! This algorithm assumes that there is nothing interesting about the
//! phases of the intervening Breakpoints, and modifies their frequencies
//! as little as possible to achieve the correct amount of phase travel
//! such that the frequencies and phases at the specified times
//! match the stored values. The phases of all the Breakpoints between
//! the specified times are recomputed.
//!
//! THIS DOES NOT YET TREAT NULL BREAKPOINTS DIFFERENTLY FROM OTHERS.
//!
//! \pre There must be at least one Breakpoint in the
//! Partial between the specified times tbeg and tend.
//! \post The phases and frequencies of the Breakpoints in the
//! range have been recomputed such that an oscillator
//! initialized to the parameters of the first Breakpoint
//! will arrive at the parameters of the last Breakpoint,
//! and all the intervening Breakpoints will be matched.
//! \param p The partial whose phases and frequencies will be recomputed.
//! The Breakpoint at this position is unaltered.
//! \param tbeg The phases and frequencies of Breakpoints later than the
//! one nearest this time will be modified.
//! \param tend The phases and frequencies of Breakpoints earlier than the
//! one nearest this time will be modified. Should be greater
//! than tbeg, or else they will be swapped.
//
void fixPhaseBetween( Partial & p, double tbeg, double tend )
{
if ( tbeg > tend )
{
std::swap( tbeg, tend );
}
// for Partials that do not extend over the entire
// specified time range, just recompute phases from
// beginning or end of the range:
if ( p.endTime() < tend )
{
// OK if start time is also after tbeg, will
// just recompute phases from start of p.
fixPhaseAfter( p, tbeg );
}
else if ( p.startTime() > tbeg )
{
fixPhaseBefore( p, tend );
}
else
{
// invariant:
// p begins before tbeg and ends after tend.
Partial::iterator b = p.findNearest( tbeg );
Partial::iterator e = p.findNearest( tend );
// if there is a null Breakpoint n between b and e, then
// should fix forward from b to n, and backward from
// e to n. Otherwise, do this complicated thing.
Partial::iterator nullbp = std::find_if( b, e, BreakpointUtils::isNull );
if ( nullbp != e )
{
fixPhaseForward( b, nullbp );
fixPhaseBackward( nullbp, e );
}
else
{
fixPhaseBetween( b, e );
}
}
}
// ---------------------------------------------------------------------------
// absorb
// ---------------------------------------------------------------------------
//! Absorb another Partial's energy as noise (bandwidth),
//! by accumulating the other's energy as noise energy
//! in the portion of this Partial's envelope that overlaps
//! (in time) with the other Partial's envelope.
//
void
Partial::absorb( const Partial & other )
{
Partial::iterator it = findAfter( other.startTime() );
while ( it != end() && !(it.time() > other.endTime()) )
{
// only non-null (non-zero-amplitude) Breakpoints
// abosrb noise energy because null Breakpoints
// are used especially to reset the Partial phase,
// and are not part of the normal analyasis data:
if ( it->amplitude() > 0 )
{
// absorb energy from other at the time
// of this Breakpoint:
double a = other.amplitudeAt( it.time() );
it->addNoiseEnergy( a * a );
}
++it;
}
}
// ---------------------------------------------------------------------------
// merge (STATIC)
// ---------------------------------------------------------------------------
// Merge the Breakpoints in the specified iterator range into the
// distilled Partial. The beginning of the range may overlap, and
// will replace, some non-zero-amplitude portion of the distilled
// Partial. Assume that there is no such overlap at the end of the
// range (could check), because findContribution only leaves overlap
// at the beginning of the range.
//
static void merge( Partial::const_iterator beg,
Partial::const_iterator end,
Partial & destPartial, double fadeTime,
double gapTime = 0. )
{
// absorb energy in distilled Partial that overlaps the
// range to merge:
Partial toMerge( beg, end );
toMerge.absorb( destPartial );
fadeInAndOut( toMerge, fadeTime );
// find the first Breakpoint in destPartial that is after the
// range of merged Breakpoints, plus the required gap:
Partial::iterator removeEnd = destPartial.findAfter( toMerge.endTime() + gapTime );
// if this Breakpoint has non-zero amplitude, need to leave time
// for a fade in:
while ( removeEnd != destPartial.end() &&
removeEnd.breakpoint().amplitude() != 0 &&
removeEnd.time() < toMerge.endTime() + gapTime + fadeTime )
{
++removeEnd;
}
// find the first Breakpoint in the destination Partial that needs
// to be removed because it is in the overlap region:
Partial::iterator removeBegin = destPartial.findAfter( toMerge.startTime() - gapTime );
// if beforeMerge has non-zero amplitude, need to leave time
// for a fade out:
if ( removeBegin != destPartial.begin() )
{
Partial::iterator beforeMerge = --Partial::iterator(removeBegin);
while ( removeBegin != destPartial.begin() &&
beforeMerge.breakpoint().amplitude() != 0 &&
beforeMerge.time() > toMerge.startTime() - gapTime - fadeTime )
{
--removeBegin;
if ( beforeMerge != destPartial.begin() )
{
--beforeMerge;
}
}
}
// remove the Breakpoints in the merge range from destPartial:
double rbt = (removeBegin != destPartial.end())?(removeBegin.time()):(destPartial.endTime());
double ret = (removeEnd != destPartial.end())?(removeEnd.time()):(destPartial.endTime());
Assert( rbt <= ret );
destPartial.erase( removeBegin, removeEnd );
// how about doing the fades here instead?
// fade in if necessary:
if ( removeEnd != destPartial.end() &&
removeEnd.breakpoint().amplitude() != 0 )
{
Assert( removeEnd.time() - fadeTime > toMerge.endTime() );
// update removeEnd so that we don't remove this
// null we are inserting:
destPartial.insert(
removeEnd.time() - fadeTime,
BreakpointUtils::makeNullBefore( removeEnd.breakpoint(), fadeTime ) );
}
if ( removeEnd != destPartial.begin() )
{
Partial::iterator beforeMerge = --Partial::iterator(removeEnd);
if ( beforeMerge.breakpoint().amplitude() > 0 )
{
Assert( beforeMerge.time() + fadeTime < toMerge.startTime() );
destPartial.insert(
beforeMerge.time() + fadeTime,
BreakpointUtils::makeNullAfter( beforeMerge.breakpoint(), fadeTime ) );
}
}
// insert the Breakpoints in the range:
for ( Partial::const_iterator insert = toMerge.begin(); insert != toMerge.end(); ++insert )
{
destPartial.insert( insert.time(), insert.breakpoint() );
}
}
// ---------------------------------------------------------------------------
// helper predicates
// ---------------------------------------------------------------------------
static bool ends_earlier( const Partial & lhs, const Partial & rhs )
{
return lhs.endTime() < rhs.endTime();
}
bool operator() ( const Partial & p ) const
{ return p.endTime() < t; }
// ---------------------------------------------------------------------------
// synthesize
// ---------------------------------------------------------------------------
//! Synthesize a bandwidth-enhanced sinusoidal Partial. Zero-amplitude
//! Breakpoints are inserted at either end of the Partial to reduce
//! turn-on and turn-off artifacts, as described above. The synthesizer
//! will resize the buffer as necessary to accommodate all the samples,
//! including the fade out. Previous contents of the buffer are not
//! overwritten. Partials with start times earlier than the Partial fade
//! time will have shorter onset fades. Partials are not rendered at
//! frequencies above the half-sample rate.
//!
//! \param p The Partial to synthesize.
//! \return Nothing.
//! \pre The partial must have non-negative start time.
//! \post This Synthesizer's sample buffer (vector) has been
//! resized to accommodate the entire duration of the
//! Partial, p, including fade out at the end.
//! \throw InvalidPartial if the Partial has negative start time.
//
void
Synthesizer::synthesize( Partial p )
{
if ( p.numBreakpoints() == 0 )
{
debugger << "Synthesizer ignoring a partial that contains no Breakpoints" << endl;
return;
}
if ( p.startTime() < 0 )
{
Throw( InvalidPartial, "Tried to synthesize a Partial having start time less than 0." );
}
debugger << "synthesizing Partial from " << p.startTime() * m_srateHz
<< " to " << p.endTime() * m_srateHz << " starting phase "
<< p.initialPhase() << " starting frequency "
<< p.first().frequency() << endl;
// better to compute this only once:
const double OneOverSrate = 1. / m_srateHz;
// use a Resampler to quantize the Breakpoint times and
// correct the phases:
Resampler quantizer( OneOverSrate );
quantizer.setPhaseCorrect( true );
quantizer.quantize( p );
// resize the sample buffer if necessary:
typedef unsigned long index_type;
index_type endSamp = index_type( ( p.endTime() + m_fadeTimeSec ) * m_srateHz );
if ( endSamp+1 > m_sampleBuffer->size() )
{
// pad by one sample:
m_sampleBuffer->resize( endSamp+1 );
}
// compute the starting time for synthesis of this Partial,
// m_fadeTimeSec before the Partial's startTime, but not before 0:
double itime = ( m_fadeTimeSec < p.startTime() ) ? ( p.startTime() - m_fadeTimeSec ) : 0.;
index_type currentSamp = index_type( (itime * m_srateHz) + 0.5 ); // cheap rounding
// reset the oscillator:
// all that really needs to happen here is setting the frequency
// correctly, the phase will be reset again in the loop over
// Breakpoints below, and the amp and bw can start at 0.
m_osc.resetEnvelopes( BreakpointUtils::makeNullBefore( p.first(), p.startTime() - itime ), m_srateHz );
// cache the previous frequency (in Hz) so that it
// can be used to reset the phase when necessary
// in the sample computation loop below (this saves
// having to recompute from the oscillator's radian
// frequency):
double prevFrequency = p.first().frequency();
// synthesize linear-frequency segments until
// there aren't any more Breakpoints to make segments:
double * bufferBegin = &( m_sampleBuffer->front() );
for ( Partial::const_iterator it = p.begin(); it != p.end(); ++it )
{
index_type tgtSamp = index_type( (it.time() * m_srateHz) + 0.5 ); // cheap rounding
Assert( tgtSamp >= currentSamp );
// if the current oscillator amplitude is
// zero, and the target Breakpoint amplitude
// is not, reset the oscillator phase so that
// it matches exactly the target Breakpoint
// phase at tgtSamp:
if ( m_osc.amplitude() == 0. )
{
// recompute the phase so that it is correct
// at the target Breakpoint (need to do this
// because the null Breakpoint phase was computed
// from an interval in seconds, not samples, so
// it might be inaccurate):
//
// double favg = 0.5 * ( prevFrequency + it.breakpoint().frequency() );
// double dphase = 2 * Pi * favg * ( tgtSamp - currentSamp ) / m_srateHz;
//
double dphase = Pi * ( prevFrequency + it.breakpoint().frequency() )
* ( tgtSamp - currentSamp ) * OneOverSrate;
m_osc.setPhase( it.breakpoint().phase() - dphase );
}
m_osc.oscillate( bufferBegin + currentSamp, bufferBegin + tgtSamp,
it.breakpoint(), m_srateHz );
currentSamp = tgtSamp;
// remember the frequency, may need it to reset the
// phase if a Null Breakpoint is encountered:
prevFrequency = it.breakpoint().frequency();
}
// render a fade out segment:
m_osc.oscillate( bufferBegin + currentSamp, bufferBegin + endSamp,
BreakpointUtils::makeNullAfter( p.last(), m_fadeTimeSec ), m_srateHz );
}
// ---------------------------------------------------------------------------
// 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;
}
