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Fix framewalk_to_beats with non-beat-aligned starting positions.

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git-svn-id: svn://localhost/ardour2/branches/3.0@10956 d708f5d6-7413-0410-9779-e7cbd77b26cf
This commit is contained in:
Carl Hetherington 2011-12-09 22:53:50 +00:00
parent 73461494d7
commit 6af96fd59d
3 changed files with 101 additions and 3 deletions
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34
libs/ardour/tempo.cc
View file

@ -2118,6 +2118,8 @@ TempoMap::framewalk_to_beats (framepos_t pos, framecnt_t distance) const
frames_per_beat = tempo->frames_per_beat (_frame_rate, *meter);
double last_dpos = 0;
while (ddist > 0) {
/* if we're nearly at the end, but have a fractional beat left,
@ -2131,6 +2133,7 @@ TempoMap::framewalk_to_beats (framepos_t pos, framecnt_t distance) const
/* walk one beat */
last_dpos = dpos;
ddist -= frames_per_beat;
dpos += frames_per_beat;
beats += 1.0;
@ -2140,7 +2143,34 @@ TempoMap::framewalk_to_beats (framepos_t pos, framecnt_t distance) const
*/
if (i != metrics->end()) {
if ((*i)->frame() <= (framepos_t) dpos) {
double const f = (*i)->frame ();
if (f <= (framepos_t) dpos) {
/* We just went past a tempo/meter section start at (*i)->frame(),
which will be on a beat.
So what we have is
(*i)->frame() [f]
beat beat beat beat
| | | |
| | | |
^ ^
| |
| new
| dpos [q]
last
dpos [p]
We need to go back to last_dpos (1 beat ago) and re-add
(f - p) beats using the old frames per beat and (q - f) beats
using the new.
*/
beats -= 1;
beats += (f - last_dpos) / frames_per_beat;
if ((t = dynamic_cast<const TempoSection*>(*i)) != 0) {
tempo = t;
@ -2149,6 +2179,8 @@ TempoMap::framewalk_to_beats (framepos_t pos, framecnt_t distance) const
}
++i;
frames_per_beat = tempo->frames_per_beat (_frame_rate, *meter);
beats += (dpos - f) / frames_per_beat;
}
}
}

68
libs/ardour/test/framewalk_to_beats_test.cc
View file

@ -23,11 +23,75 @@ FramewalkToBeatsTest::singleTempoTest ()
map.add_meter (meter, BBT_Time (1, 1, 0));
map.add_tempo (tempo, BBT_Time (1, 1, 0));
/* Add 1 beats-worth of frames to a 2 beat starting point */
/* Walk 1 beats-worth of frames from beat 3 */
double r = map.framewalk_to_beats (frames_per_beat * 2, frames_per_beat * 1);
CPPUNIT_ASSERT (r == 1);
/* Add 6 beats-worth of frames to a 3 beat starting point */
/* Walk 6 beats-worth of frames from beat 4 */
r = map.framewalk_to_beats (frames_per_beat * 3, frames_per_beat * 6);
CPPUNIT_ASSERT (r == 6);
/* Walk 1.5 beats-worth of frames from beat 3 */
r = map.framewalk_to_beats (frames_per_beat * 2, frames_per_beat * 1.5);
CPPUNIT_ASSERT (r == 1.5);
/* Walk 1.5 beats-worth of frames from beat 2.5 */
r = map.framewalk_to_beats (frames_per_beat * 2.5, frames_per_beat * 1.5);
CPPUNIT_ASSERT (r == 1.5);
}
void
FramewalkToBeatsTest::doubleTempoTest ()
{
int const sampling_rate = 48000;
TempoMap map (sampling_rate);
Meter meter (4, 4);
map.add_meter (meter, BBT_Time (1, 1, 0));
/*
120bpm at bar 1, 240bpm at bar 4
120bpm = 24e3 samples per beat
240bpm = 12e3 samples per beat
*/
/*
120bpm 240bpm
0 beats 12 beats
0 frames 288e3 frames
| | | | |
| 1.1 1.2 1.3 1.4 | 2.1 2.2 2.3.2.4 | 3.1 3.2 3.3 3.4 | 4.1 4.2 4.3 4.4 |
*/
Tempo tempoA (120);
map.add_tempo (tempoA, BBT_Time (1, 1, 0));
Tempo tempoB (240);
map.add_tempo (tempoB, BBT_Time (4, 1, 0));
/* Now some tests */
/* Walk 1 beat from 1.2 */
double r = map.framewalk_to_beats (24e3, 24e3);
assert (r == 1);
/* Walk 2 beats from 3.3 to 4.1 (over the tempo change) */
r = map.framewalk_to_beats (264e3, (24e3 + 12e3));
assert (r == 2);
/* Walk 2.5 beats from 3.3-and-a-half to 4.2 (over the tempo change) */
r = map.framewalk_to_beats (264e3 - 12e3, (24e3 + 12e3 + 12e3));
assert (r == 2.5);
/* Walk 3 beats from 3.3-and-a-half to 4.2-and-a-half (over the tempo change) */
r = map.framewalk_to_beats (264e3 - 12e3, (24e3 + 12e3 + 12e3 + 6e3));
assert (r == 3);
/* Walk 3.5 beats from 3.3-and-a-half to 4.3 (over the tempo change) */
r = map.framewalk_to_beats (264e3 - 12e3, (24e3 + 12e3 + 12e3 + 12e3));
assert (r == 3.5);
}

2
libs/ardour/test/framewalk_to_beats_test.h
View file

@ -6,6 +6,7 @@ class FramewalkToBeatsTest : public CppUnit::TestFixture
{
CPPUNIT_TEST_SUITE (FramewalkToBeatsTest);
CPPUNIT_TEST (singleTempoTest);
CPPUNIT_TEST (doubleTempoTest);
CPPUNIT_TEST_SUITE_END ();
public:
@ -13,5 +14,6 @@ public:
void tearDown () {}
void singleTempoTest ();
void doubleTempoTest ();
};