framewalk_to_beats_test.cc

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#include "framewalk_to_beats_test.h"
#include "ardour/tempo.h"
#include "timecode/bbt_time.h"

CPPUNIT_TEST_SUITE_REGISTRATION (FramewalkToBeatsTest);

using namespace std;
using namespace ARDOUR;
using namespace Timecode;

void
FramewalkToBeatsTest::singleTempoTest ()
{
        int const sampling_rate = 48000;
        int const bpm = 120;

        double const frames_per_beat = (60 / double (bpm)) * double (sampling_rate);
        
        TempoMap map (sampling_rate);
        Tempo tempo (bpm);
        Meter meter (4, 4);

        map.add_meter (meter, BBT_Time (1, 1, 0));
        map.add_tempo (tempo, BBT_Time (1, 1, 0));

        /* Walk 1 beats-worth of frames from beat 3 */
        double r = map.framewalk_to_beats (frames_per_beat * 2, frames_per_beat * 1).to_double();
        CPPUNIT_ASSERT_EQUAL (1.0, r);

        /* Walk 6 beats-worth of frames from beat 4 */
        r = map.framewalk_to_beats (frames_per_beat * 3, frames_per_beat * 6).to_double();
        CPPUNIT_ASSERT_EQUAL (6.0, r);

        /* Walk 1.5 beats-worth of frames from beat 3 */
        r = map.framewalk_to_beats (frames_per_beat * 2, frames_per_beat * 1.5).to_double();
        CPPUNIT_ASSERT_EQUAL (1.5, r);

        /* 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).to_double();
        CPPUNIT_ASSERT_EQUAL (1.5, r);
}

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
          24e3 frames per beat                            12e3 frames per beat
          |               |               |               |               |
          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 5.1
          0   1   2   3   4   5   6   7   8   9   10  11  12  13  14  15  16

        */

        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).to_double();
        CPPUNIT_ASSERT_EQUAL (1.0, r);

        /* Walk 2 beats from 3|3 to 4|1 (over the tempo change) */
        r = map.framewalk_to_beats (240e3, (24e3 + 24e3)).to_double();
        CPPUNIT_ASSERT_EQUAL (2.0, r);

        /* Walk 2.5 beats from 3|3.5 to 4.2 (over the tempo change) */
        r = map.framewalk_to_beats (264e3 - 12e3, (24e3 + 12e3 + 12e3)).to_double();
        CPPUNIT_ASSERT_EQUAL (2.5, r);
        /* Walk 3 beats from 3|4.5 to 4|3.5 (over the tempo change) */
        r = map.framewalk_to_beats (264e3 - 12e3, (24e3 + 12e3 + 12e3 + 6e3)).to_double();
        CPPUNIT_ASSERT_EQUAL (3.0, r);

        /* Walk 3.5 beats from 3|4.5 to 4.4 (over the tempo change) */
        r = map.framewalk_to_beats (264e3 - 12e3, (24e3 + 12e3 + 12e3 + 12e3)).to_double();
        CPPUNIT_ASSERT_EQUAL (3.5, r);
}

void
FramewalkToBeatsTest::tripleTempoTest ()
{
        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 2, 160bpm at bar 3
          
          120bpm = 24e3 samples per beat
          160bpm = 18e3 samples per beat
          240bpm = 12e3 samples per beat
        */
        

        /*
          
          120bpm            240bpm            160bpm
          0 beats           4 beats           8 beats
          0 frames          96e3 frames       144e3 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 (2, 1, 0));
        Tempo tempoC (160);
        map.add_tempo (tempoC, BBT_Time (3, 1, 0));

        /* Walk from 1|3 to 4|1 */
        double r = map.framewalk_to_beats (2 * 24e3, (2 * 24e3) + (4 * 12e3) + (4 * 18e3)).to_double();
        CPPUNIT_ASSERT_EQUAL (10.0, r);
}