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temporal: revert changes that created two different omegas; fix computation of ::superclock_at() for decelerando

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changes in tempo can be negative (decelerando/slowing down), and thus so can _omega. We cannot call log() or its
cousins on negative values, so in this scenario use an alternate expression for "t from b" in the tempo.pdf paper
This commit is contained in:
Paul Davis 2022-05-20 09:06:18 -06:00
parent 40f8dc69dd
commit 9dd4931247
2 changed files with 58 additions and 55 deletions
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97
libs/temporal/tempo.cc
View File

@ -1,3 +1,4 @@
/*
Copyright (C) 2017 Paul Davis
@ -417,9 +418,8 @@ TempoPoint::set_state (XMLNode const & node, int version)
int ret;
if ((ret = Tempo::set_state (node, version)) == 0) {
if (node.get_property (X_("omega_beats"), _omega_beats)) {
}
if (node.get_property (X_("omega_sclocks"), _omega_sclocks)) {
if (node.get_property (X_("omega"), _omega)) {
/* XXX ?? */
}
}
@ -431,26 +431,23 @@ TempoPoint::get_state () const
{
XMLNode& base (Tempo::get_state());
Point::add_state (base);
base.set_property (X_("omega_beats"), _omega_beats);
base.set_property (X_("omega_sclocks"), _omega_sclocks);
base.set_property (X_("omega"), _omega);
return base;
}
TempoPoint::TempoPoint (TempoMap const & map, XMLNode const & node)
: Point (map, node)
, Tempo (node)
, _omega_beats (0)
, _omega_sclocks (0)
, _omega (0)
{
node.get_property (X_("omega_beats"), _omega_beats);
node.get_property (X_("omega_sclocks"), _omega_sclocks);
node.get_property (X_("omega"), _omega);
}
/* To understand the math(s) behind ramping, see the file doc/tempo.{pdf,tex}
*/
void
TempoPoint::compute_omega_from_next_tempo (TempoPoint const & next, TimeDomain domain)
TempoPoint::compute_omega_from_next_tempo (TempoPoint const & next)
{
superclock_t end_scpqn;
@ -463,29 +460,24 @@ TempoPoint::compute_omega_from_next_tempo (TempoPoint const & next, TimeDomain d
}
if (superclocks_per_quarter_note () == end_scpqn) {
_omega_beats = 0.0;
_omega_sclocks = 0.0;
_omega = 0.0;
return;
}
if (domain == BeatTime) {
compute_omega_from_quarter_duration (next.beats() - beats(), end_scpqn);
} else {
compute_omega_from_audio_duration (superclock_to_samples (next.sclock() - sclock(), TEMPORAL_SAMPLE_RATE), end_scpqn);
}
compute_omega_from_quarter_duration (next.beats() - beats(), end_scpqn);
}
void
TempoPoint::compute_omega_from_quarter_duration (Beats const & quarter_duration, superclock_t end_scpqn)
{
_omega_beats = ((1.0/end_scpqn) - (1.0/superclocks_per_quarter_note())) / DoubleableBeats (quarter_duration).to_double();
DEBUG_TRACE (DEBUG::TemporalMap, string_compose ("computed omega from qtr duration = %1%2 dur was %3\n", std::setprecision(12),_omega_beats, quarter_duration));
_omega = ((1.0/end_scpqn) - (1.0/superclocks_per_quarter_note())) / DoubleableBeats (quarter_duration).to_double();
DEBUG_TRACE (DEBUG::TemporalMap, string_compose ("computed omega from qtr duration = %1%2 dur was %3 start speed %4 end speed %5\n", std::setprecision(12),_omega, quarter_duration, superclocks_per_quarter_note(), end_scpqn));
}
void
TempoPoint::compute_omega_from_audio_duration (samplecnt_t audio_duration, superclock_t end_scpqn)
{
_omega_sclocks = (1.0 / (samples_to_superclock (audio_duration, TEMPORAL_SAMPLE_RATE))) * log ((double) superclocks_per_note_type() / end_scpqn);
DEBUG_TRACE (DEBUG::TemporalMap, string_compose ("computed omega from audio duration= %1%2 dur was %3\n", std::setprecision(12),_omega_sclocks, audio_duration));
_omega = (1.0 / (samples_to_superclock (audio_duration, TEMPORAL_SAMPLE_RATE))) * log ((double) superclocks_per_note_type() / end_scpqn);
DEBUG_TRACE (DEBUG::TemporalMap, string_compose ("computed omega from audio duration= %1%2 dur was %3\n", std::setprecision(12),_omega, audio_duration));
}
superclock_t
@ -510,7 +502,23 @@ TempoPoint::superclock_at (Temporal::Beats const & qn) const
return _sclock + (spqn * delta.get_beats()) + int_div_round ((spqn * delta.get_ticks()), superclock_t (Temporal::ticks_per_beat));
}
return _sclock + llrint (log1p (superclocks_per_quarter_note() * _omega_beats * DoubleableBeats (qn - _quarters).to_double()) / _omega_beats);
superclock_t r;
if (_omega < -1) {
r = _sclock + llrint (log (-(superclocks_per_quarter_note() * _omega * DoubleableBeats (qn - _quarters).to_double()) - 1.0) / -_omega);
} else {
r = _sclock + llrint (log1p (superclocks_per_quarter_note() * _omega * DoubleableBeats (qn - _quarters).to_double()) / _omega);
}
if (r < 0) {
std::cerr << "scpqn = " << superclocks_per_quarter_note() << std::endl;
std::cerr << " for " << qn << " @ " << _quarters << " | " << _sclock << " + log1p (" << superclocks_per_quarter_note() * _omega * DoubleableBeats (qn - _quarters).to_double() << " = "
<< log1p (superclocks_per_quarter_note() * _omega * DoubleableBeats (qn - _quarters).to_double())
<< " => "
<< r << std::endl;
abort ();
}
return r;
}
superclock_t
@ -520,7 +528,7 @@ TempoPoint::superclocks_per_note_type_at (timepos_t const &pos) const
return _superclocks_per_note_type;
}
return _superclocks_per_note_type * exp (-_omega_sclocks * (pos.superclocks() - sclock()));
return _superclocks_per_note_type * exp (-_omega * (pos.superclocks() - sclock()));
}
Temporal::Beats
@ -572,7 +580,7 @@ TempoPoint::quarters_at_superclock (superclock_t sc) const
return _quarters + Beats (b, t);
}
const double b = (exp (_omega_sclocks * (sc - _sclock)) - 1) / (superclocks_per_quarter_note() * _omega_sclocks);
const double b = (exp (_omega * (sc - _sclock)) - 1) / (superclocks_per_quarter_note() * _omega);
return _quarters + Beats::from_double (b);
}
@ -1210,7 +1218,7 @@ TempoMap::reset_starting_at (superclock_t sc)
DEBUG_TRACE (DEBUG::MapReset, string_compose ("considering omega comp for %1 with nxt = %2\n", *tp, nxt_tempo));
if (tp->ramped() && nxt_tempo) {
tp->compute_omega_from_next_tempo (*nxt_tempo, BeatTime);
tp->compute_omega_from_next_tempo (*nxt_tempo);
}
}
@ -1234,17 +1242,6 @@ TempoMap::reset_starting_at (superclock_t sc)
}
}
/* Now compute omega_sclock for ramped sections, after we've
* repositioned everything in audio time.
*/
for (Tempos::iterator tp = _tempos.begin(); tp != _tempos.end(); ++tp) {
const TempoPoint* nxt_tempo = next_tempo (*tp);
if (tp->ramped() && nxt_tempo) {
tp->compute_omega_from_next_tempo (*nxt_tempo, AudioTime);
}
}
DEBUG_TRACE (DEBUG::MapReset, "RESET DONE\n");
#ifndef NDEBUG
if (DEBUG_ENABLED(DEBUG::MapReset)) {
@ -1878,6 +1875,7 @@ TempoMap::get_grid (TempoMapPoints& ret, superclock_t start, superclock_t end, u
assert (!_meters.empty());
assert (!_points.empty());
dump (std::cout);
DEBUG_TRACE (DEBUG::Grid, string_compose (">>> GRID START %1 .. %2 (barmod = %3)\n", start, end, bar_mod));
TempoPoint const * tp = 0;
@ -2060,18 +2058,26 @@ TempoMap::get_grid (TempoMapPoints& ret, superclock_t start, superclock_t end, u
* point. Consider adding a grid point for this point.
*/
start = p->sclock();
bbt = p->bbt();
beats = p->beats();
if (bar_mod != 0) {
if (bbt.is_bar() && (bar_mod == 1 || ((bbt.bars % bar_mod == 0)))) {
ret.push_back (TempoMapPoint (*this, metric, start, beats, bbt));
if (p->bbt().is_bar() && (bar_mod == 1 || ((p->bbt().bars % bar_mod == 0)))) {
ret.push_back (TempoMapPoint (*this, metric, p->sclock(), p->beats(), p->bbt()));
/* reset our notion of where we are */
start = p->sclock();
bbt = p->bbt();
beats = p->beats();
DEBUG_TRACE (DEBUG::Grid, string_compose ("G %1\t %2\n", metric, ret.back()));
} else {
DEBUG_TRACE (DEBUG::Grid, string_compose ("-- skip %1 not on bar_mod %2\n", bbt, bar_mod));
}
} else {
start = p->sclock();
bbt = p->bbt();
beats = p->beats();
ret.push_back (TempoMapPoint (*this, metric, start, beats, bbt));
DEBUG_TRACE (DEBUG::Grid, string_compose ("G %1\t %2\n", metric, ret.back()));
}
@ -2122,6 +2128,7 @@ TempoMap::get_grid (TempoMapPoints& ret, superclock_t start, superclock_t end, u
*/
metric = TempoMetric (*tp, *mp);
DEBUG_TRACE (DEBUG::Grid, string_compose ("metric changed, now using %1\n", metric));
p = nxt;
}
@ -2230,8 +2237,7 @@ std::operator<<(std::ostream& str, TempoPoint const & t)
} else {
str << ' ' << " !ramp to " << t.end_note_types_per_minute();
}
str << " omega/b = " << std::setprecision(12) << t.omega_beats();
str << " omega/s = " << std::setprecision(12) << t.omega_sclocks();
str << " omega = " << std::setprecision(12) << t.omega();
}
return str;
}
@ -2273,8 +2279,7 @@ std::operator<<(std::ostream& str, TempoMapPoint const & tmp)
}
if (tmp.is_explicit_tempo() && tmp.tempo().ramped()) {
str << " ramp omega/b = " << tmp.tempo().omega_beats();
str << " omega/s = " << tmp.tempo().omega_sclocks();
str << " ramp omega = " << tmp.tempo().omega();
}
return str;

16
libs/temporal/temporal/tempo.h
View File

@ -372,8 +372,8 @@ typedef boost::intrusive::list_base_hook<boost::intrusive::tag<struct tempo_tag>
class /*LIBTEMPORAL_API*/ TempoPoint : public Tempo, public tempo_hook, public virtual Point
{
public:
LIBTEMPORAL_API TempoPoint (TempoMap const & map, Tempo const & t, superclock_t sc, Beats const & b, BBT_Time const & bbt) : Point (map, sc, b, bbt), Tempo (t), _omega_beats (0), _omega_sclocks (0) {}
LIBTEMPORAL_API TempoPoint (Tempo const & t, Point const & p) : Point (p), Tempo (t), _omega_beats (0), _omega_sclocks (0) {}
LIBTEMPORAL_API TempoPoint (TempoMap const & map, Tempo const & t, superclock_t sc, Beats const & b, BBT_Time const & bbt) : Point (map, sc, b, bbt), Tempo (t), _omega (0.) {}
LIBTEMPORAL_API TempoPoint (Tempo const & t, Point const & p) : Point (p), Tempo (t), _omega (0.) {}
LIBTEMPORAL_API TempoPoint (TempoMap const & map, XMLNode const &);
/* just change the tempo component, without moving */
@ -403,10 +403,9 @@ class /*LIBTEMPORAL_API*/ TempoPoint : public Tempo, public tempo_hook, public v
return (superclock_ticks_per_second() * 60.0) / superclocks_per_note_type_at (pos);
}
LIBTEMPORAL_API double omega_beats() const { return _omega_beats; }
LIBTEMPORAL_API double omega_sclocks() const { return _omega_sclocks; }
LIBTEMPORAL_API void compute_omega_from_next_tempo (TempoPoint const & next_tempo, TimeDomain);
LIBTEMPORAL_API bool actually_ramped () const { return Tempo::ramped() && (( _omega_beats != 0) || (_omega_sclocks != 0)); }
LIBTEMPORAL_API double omega() const { return _omega; }
LIBTEMPORAL_API void compute_omega_from_next_tempo (TempoPoint const & next_tempo);
LIBTEMPORAL_API bool actually_ramped () const { return Tempo::ramped() && ( _omega != 0); }
LIBTEMPORAL_API XMLNode& get_state () const;
LIBTEMPORAL_API int set_state (XMLNode const&, int version);
@ -422,8 +421,7 @@ class /*LIBTEMPORAL_API*/ TempoPoint : public Tempo, public tempo_hook, public v
LIBTEMPORAL_API Beats quarters_at_superclock (superclock_t sc) const;
private:
double _omega_beats;
double _omega_sclocks;
double _omega;
void compute_omega_from_quarter_duration (Beats const & quarter_duration, superclock_t end_scpqn);
void compute_omega_from_audio_duration (samplecnt_t audio_duration, superclock_t end_scpqn);
@ -491,7 +489,7 @@ class LIBTEMPORAL_API TempoMetric {
if (!_tempo->actually_ramped()) {
return _tempo->superclocks_per_note_type ();
}
return _tempo->superclocks_per_note_type() * exp (-_tempo->omega_sclocks() * (sc - _tempo->sclock()));
return _tempo->superclocks_per_note_type() * exp (-_tempo->omega() * (sc - _tempo->sclock()));
}
superclock_t superclocks_per_grid_at (superclock_t sc) const {