ardour/livetrax
13
0
Fork 0
Code

triggerbox: add heuristic to extract bpm from filename

Browse Source 
If found, we do not do analysis of the audio data
This commit is contained in:
Paul Davis 2021-12-11 21:05:22 -07:00
parent c233609c7c
commit 96e1735646
1 changed files with 53 additions and 11 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

64
libs/ardour/triggerbox.cc
View File

@ -1,6 +1,7 @@
#include <algorithm>
#include <iostream>
#include <cstdlib>
#include <sstream>
#include <glibmm.h>
@ -405,7 +406,7 @@ pframes_t
Trigger::maybe_compute_next_transition (samplepos_t start_sample, Temporal::Beats const & start, Temporal::Beats const & end, pframes_t dest_offset, bool passthru)
{
using namespace Temporal;
/* This should never be called by a stopped trigger */
assert (_state != Stopped);
@ -714,17 +715,58 @@ AudioTrigger::determine_tempo ()
{
using namespace Temporal;
/* now potentially stretch it to match our tempo.
*
* We do not handle tempo changes at present, and should probably issue
* a warming about this.
/* check the name to see if there's a (heuristically obvious) hint
* about the tempo.
*/
string str = _region->name();
string::size_type bi;
string::size_type ni;
double text_tempo = -1.;
if (((bi = str.find ("bpm")) != string::npos) ||
((bi = str.find ("BPM")) != string::npos)) {
string sub (str.substr (0, bi));
if ((ni = sub.find_last_of ("0123456789.,_-")) != string::npos) {
int nni = ni; /* ni is unsigned, nni is signed */
while (nni >= 0) {
if (!isdigit (sub[nni]) &&
(sub[nni] != '.') &&
(sub[nni] != ',')) {
break;
}
--nni;
}
if (nni > 0) {
std::stringstream p (sub.substr (nni + 1));
p >> text_tempo;
if (!p) {
text_tempo = -1.;
} else {
_apparent_tempo = text_tempo;
std::cerr << "from filename, tempo = " << _apparent_tempo << std::endl;
}
}
}
}
TempoMap::SharedPtr tm (TempoMap::use());
if (_barcnt == 0) {
/* We don't have too many good choices here. Triggers can fire at any
* time, so there's no special place on the tempo map that we can use
* to get the meter from and thus compute an apparent bar count for
* this region. Our solution for now: just use the first meter.
*/
TempoMetric const & metric (tm->metric_at (timepos_t (AudioTime)));
if (text_tempo < 0) {
TempoMetric const & metric (tm->metric_at (timepos_t (AudioTime)));
breakfastquay::MiniBPM mbpm (_box.session().sample_rate());
mbpm.setBPMRange (metric.tempo().quarter_notes_per_minute () * 0.75, metric.tempo().quarter_notes_per_minute() * 1.5);
@ -737,12 +779,12 @@ AudioTrigger::determine_tempo ()
}
cerr << name() << " Estimated bpm " << _apparent_tempo << " from " << (double) data_length / _box.session().sample_rate() << " seconds\n";
const double seconds = (double) data_length / _box.session().sample_rate();
const double quarters = (seconds / 60.) * _apparent_tempo;
_barcnt = quarters / metric.meter().divisions_per_bar();
}
const double seconds = (double) data_length / _box.session().sample_rate();
const double quarters = (seconds / 60.) * _apparent_tempo;
_barcnt = quarters / metric.meter().divisions_per_bar();
/* use initial tempo in map (assumed for now to be the only one */
const samplecnt_t one_bar = tm->bbt_duration_at (timepos_t (AudioTime), BBT_Offset (1, 0, 0)).samples();