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DummyBackend: add sine-sweep generators

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This commit is contained in:
Robin Gareus 2014-09-24 17:24:25 +02:00
parent 86672a5c5c
commit 6dfb8c5c8a
2 changed files with 70 additions and 22 deletions
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84
libs/backends/dummy/dummy_audiobackend.cc
View file

@ -86,11 +86,13 @@ DummyAudioBackend::enumerate_devices () const
_device_status.push_back (DeviceStatus (_("Silence"), true));
_device_status.push_back (DeviceStatus (_("Sine Wave"), true));
_device_status.push_back (DeviceStatus (_("Square Wave"), true));
_device_status.push_back (DeviceStatus (_("Kroneker Delta"), true));
_device_status.push_back (DeviceStatus (_("Impulses"), true));
_device_status.push_back (DeviceStatus (_("Uniform White Noise"), true));
_device_status.push_back (DeviceStatus (_("Gaussian White Noise"), true));
_device_status.push_back (DeviceStatus (_("Pink Noise"), true));
_device_status.push_back (DeviceStatus (_("Pink Noise (low CPU)"), true));
_device_status.push_back (DeviceStatus (_("Sine Sweep"), true));
_device_status.push_back (DeviceStatus (_("Sine Sweep Swell"), true));
}
return _device_status;
}
@ -680,8 +682,12 @@ DummyAudioBackend::register_system_ports()
gt = DummyAudioPort::SineWave;
} else if (_device == _("Square Wave")) {
gt = DummyAudioPort::SquareWave;
} else if (_device == _("Kroneker Delta")) {
} else if (_device == _("Impulses")) {
gt = DummyAudioPort::KronekerDelta;
} else if (_device == _("Sine Sweep")) {
gt = DummyAudioPort::SineSweep;
} else if (_device == _("Sine Sweep Swell")) {
gt = DummyAudioPort::SineSweepSwell;
} else {
gt = DummyAudioPort::Silence;
}
@ -1364,8 +1370,10 @@ DummyAudioPort::DummyAudioPort (DummyAudioBackend &b, const std::string& name, P
, _b5 (0)
, _b6 (0)
, _wavetable (0)
, _tbl_length (0)
, _tbl_offset (0)
, _gen_period (0)
, _gen_offset (0)
, _gen_perio2 (0)
, _gen_count2 (0)
, _pass (false)
, _rn1 (0)
{
@ -1390,17 +1398,40 @@ void DummyAudioPort::setup_generator (GeneratorType const g, float const sampler
case Silence:
break;
case KronekerDelta:
_tbl_length = (5 + randi() % (int)(samplerate / 20.f));
_gen_period = (5 + randi() % (int)(samplerate / 20.f));
break;
case SquareWave:
_tbl_length = (5 + randi() % (int)(samplerate / 20.f)) & ~1;
_gen_period = (5 + randi() % (int)(samplerate / 20.f)) & ~1;
break;
case SineWave:
_gen_period = 5 + randi() % (int)(samplerate / 20.f);
_wavetable = (Sample*) malloc (_gen_period * sizeof(Sample));
for (uint32_t i = 0 ; i < _gen_period; ++i) {
_wavetable[i] = .12589f * sinf(2.0f * M_PI * (float)i / (float)_gen_period); // -18dBFS
}
break;
case SineSweep:
case SineSweepSwell:
{
_tbl_length = 5 + randi() % (int)(samplerate / 20.f);
_wavetable = (Sample*) malloc( _tbl_length * sizeof(Sample));
for (uint32_t i = 0 ; i < _tbl_length; ++i) {
_wavetable[i] = .12589f * sinf(2.0f * M_PI * (float)i / (float)_tbl_length); // -18dBFS
_gen_period = 5 * samplerate + randi() % (int)(samplerate * 10.f);
_wavetable = (Sample*) malloc (_gen_period * sizeof(Sample));
_gen_perio2 = 1 | (int)ceilf (_gen_period * .89f); // Volume Swell period
const double f_min = 20.;
const double f_max = samplerate * .5;
#ifdef LINEAR_SWEEP
const double b = (f_max - f_min) / (2. * samplerate * _gen_period);
const double a = f_min / samplerate;
#else
const double b = log (f_max / f_min) / _gen_period;
const double a = f_min / (b * samplerate);
#endif
for (uint32_t i = 0 ; i < _gen_period; ++i) {
#ifdef LINEAR_SWEEP
const double phase = i * (a + b * i);
#else
const double phase = a * exp (b * i) - a;
#endif
_wavetable[i] = (float)sin (2. * M_PI * (phase - floor (phase)));
}
}
break;
@ -1443,38 +1474,51 @@ void DummyAudioPort::generate (const pframes_t n_samples)
memset (_buffer, 0, n_samples * sizeof (Sample));
break;
case SquareWave:
assert(_tbl_length > 0);
assert(_gen_period > 0);
for (pframes_t i = 0 ; i < n_samples; ++i) {
if (_tbl_offset < _tbl_length * .5f) {
if (_gen_offset < _gen_period * .5f) {
_buffer[i] = .40709f; // -6dBFS
} else {
_buffer[i] = -.40709f;
}
_tbl_offset = (_tbl_offset + 1) % _tbl_length;
_gen_offset = (_gen_offset + 1) % _gen_period;
}
break;
case KronekerDelta:
assert(_tbl_length > 0);
assert(_gen_period > 0);
memset (_buffer, 0, n_samples * sizeof (Sample));
for (pframes_t i = 0; i < n_samples; ++i) {
if (_tbl_offset == 0) {
if (_gen_offset == 0) {
_buffer[i] = 1.0f;
}
_tbl_offset = (_tbl_offset + 1) % _tbl_length;
_gen_offset = (_gen_offset + 1) % _gen_period;
}
break;
case SineSweepSwell:
assert(_wavetable && _gen_period > 0);
{
const float vols = 2.f / (float)_gen_perio2;
for (pframes_t i = 0; i < n_samples; ++i) {
const float g = fabsf (_gen_count2 * vols - 1.0);
_buffer[i] = g * _wavetable[_gen_offset];
_gen_offset = (_gen_offset + 1) % _gen_period;
_gen_count2 = (_gen_count2 + 1) % _gen_perio2;
}
}
break;
case SineWave:
assert(_wavetable && _tbl_length > 0);
case SineSweep:
assert(_wavetable && _gen_period > 0);
{
pframes_t written = 0;
while (written < n_samples) {
const uint32_t remain = n_samples - written;
const uint32_t to_copy = std::min(remain, _tbl_length - _tbl_offset);
const uint32_t to_copy = std::min(remain, _gen_period - _gen_offset);
memcpy((void*)&_buffer[written],
(void*)&_wavetable[_tbl_offset],
(void*)&_wavetable[_gen_offset],
to_copy * sizeof(Sample));
written += to_copy;
_tbl_offset = (_tbl_offset + to_copy) % _tbl_length;
_gen_offset = (_gen_offset + to_copy) % _gen_period;
}
}
break;

8
libs/backends/dummy/dummy_audiobackend.h
View file

@ -153,6 +153,8 @@ class DummyAudioPort : public DummyPort {
SineWave,
SquareWave,
KronekerDelta,
SineSweep,
SineSweepSwell,
};
void setup_generator (GeneratorType const, float const);
@ -168,8 +170,10 @@ class DummyAudioPort : public DummyPort {
float _b0, _b1, _b2, _b3, _b4, _b5, _b6;
// generated sinf() samples
Sample * _wavetable;
uint32_t _tbl_length;
uint32_t _tbl_offset;
uint32_t _gen_period;
uint32_t _gen_offset;
uint32_t _gen_perio2;
uint32_t _gen_count2;
// gaussian noise generator
float grandf ();