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add a midi->audio dummy backend mode.

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this allows to easily debug latency compensation
as well as visualize lost midi events.
This commit is contained in:
Robin Gareus 2015-01-11 15:58:28 +01:00
parent c7affd79c2
commit 4d370b8942
2 changed files with 52 additions and 4 deletions
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54
libs/backends/dummy/dummy_audiobackend.cc
View File

@ -322,6 +322,7 @@ DummyAudioBackend::enumerate_midi_options () const
_midi_options.push_back (_("8 in, 8 out, Silence"));
_midi_options.push_back (_("Midi Event Generators"));
_midi_options.push_back (_("8 in, 8 out, Loopback"));
_midi_options.push_back (_("MIDI to Audio, Loopback"));
}
return _midi_options;
}
@ -347,6 +348,10 @@ DummyAudioBackend::set_midi_option (const std::string& opt)
_n_midi_inputs = _n_midi_outputs = 8;
_midi_mode = MidiLoopback;
}
else if (opt == _("MIDI to Audio, Loopback")) {
_n_midi_inputs = _n_midi_outputs = UINT32_MAX;
_midi_mode = MidiToAudio;
}
else {
_n_midi_inputs = _n_midi_outputs = 0;
}
@ -748,10 +753,14 @@ DummyAudioBackend::register_system_ports()
gt = DummyAudioPort::Silence;
}
if (_midi_mode == MidiToAudio) {
gt = DummyAudioPort::Loopback;
}
const int a_ins = _n_inputs > 0 ? _n_inputs : 8;
const int a_out = _n_outputs > 0 ? _n_outputs : 8;
const int m_ins = _n_midi_inputs;
const int m_out = _n_midi_outputs;
const int m_ins = _n_midi_inputs == UINT_MAX ? 0 : _n_midi_inputs;
const int m_out = _n_midi_outputs == UINT_MAX ? a_ins : _n_midi_outputs;
/* with 'Loopback' there is exactly once cycle latency, divide it between In + Out; */
const size_t l_in = _samples_per_period * .25;
@ -1161,7 +1170,7 @@ DummyAudioBackend::main_process_thread ()
}
_processed_samples += _samples_per_period;
if (_device == _("Loopback")) {
if (_device == _("Loopback") && _midi_mode != MidiToAudio) {
int opn = 0;
int opc = _system_outputs.size();
for (std::vector<DummyAudioPort*>::const_iterator it = _system_inputs.begin (); it != _system_inputs.end (); ++it, ++opn) {
@ -1179,6 +1188,15 @@ DummyAudioBackend::main_process_thread ()
(*it)->set_loopback (op->const_buffer());
}
}
else if (_midi_mode == MidiToAudio) {
int opn = 0;
int opc = _system_midi_out.size();
for (std::vector<DummyAudioPort*>::const_iterator it = _system_inputs.begin (); it != _system_inputs.end (); ++it, ++opn) {
DummyMidiPort* op = _system_midi_out[(opn % opc)];
op->get_buffer(0); // mix-down
(*it)->midi_to_wavetable (op->const_buffer(), _samples_per_period);
}
}
if (!_freewheeling) {
const int64_t nomial_time = 1e6 * _samples_per_period / _samplerate;
@ -1585,6 +1603,34 @@ void DummyAudioPort::setup_generator (GeneratorType const g, float const sampler
}
}
void DummyAudioPort::midi_to_wavetable (DummyMidiBuffer const * const src, size_t n_samples)
{
memset(_wavetable, 0, n_samples * sizeof(float));
/* generate an audio spike for every midi message
* to verify layency-compensation alignment
* (here: midi-out playback-latency + audio-in capture-latency)
*/
for (DummyMidiBuffer::const_iterator it = src->begin (); it != src->end (); ++it) {
const pframes_t t = (*it)->timestamp();
assert(t < n_samples);
// somewhat arbitrary mapping for quick visual feedback
float v = -.5f;
if ((*it)->size() == 3) {
const unsigned char *d = (*it)->const_data();
if ((d[0] & 0xf0) == 0x90) { // note on
v = .25f + d[2] / 512.f;
}
else if ((d[0] & 0xf0) == 0x80) { // note off
v = .3f - d[2] / 640.f;
}
else if ((d[0] & 0xf0) == 0xb0) { // CC
v = -.1f - d[2] / 256.f;
}
}
_wavetable[t] += v;
}
}
float DummyAudioPort::grandf ()
{
// Gaussian White Noise
@ -1859,7 +1905,7 @@ DummyMidiEvent::DummyMidiEvent (const pframes_t timestamp, const uint8_t* data,
{
if (size > 0) {
_data = (uint8_t*) malloc (size);
memcpy (_data, data, size);
memcpy (_data, data, size);
}
}

2
libs/backends/dummy/dummy_audiobackend.h
View File

@ -160,6 +160,7 @@ class DummyAudioPort : public DummyPort {
};
void setup_generator (GeneratorType const, float const);
void fill_wavetable (const float* d, size_t n_samples) { assert(_wavetable != 0); memcpy(_wavetable, d, n_samples * sizeof(float)); }
void midi_to_wavetable (DummyMidiBuffer const * const src, size_t n_samples);
private:
Sample _buffer[8192];
@ -368,6 +369,7 @@ class DummyAudioBackend : public AudioBackend {
MidiNoEvents,
MidiGenerator,
MidiLoopback,
MidiToAudio,
};
std::string _instance_name;