Add velocity2db() and db2velocity() as math functions

MTG · May 27, 2024 · ed89c21 · ed89c21
1 parent c50c337
commit ed89c21
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Showing 4 changed files with 61 additions and 2 deletions.
diff --git a/src/essentia/essentiamath.h b/src/essentia/essentiamath.h
@@ -818,6 +818,10 @@ inline int db2velocity (Real decibels, Real hearingThreshold) {
   return velocity;
 }
 
+inline Real velocity2db(int velocity, Real hearingThreshold) {
+  return -(hearingThreshold * velocity / 127 -hearingThreshold);
+}
+
 inline int argmin(const std::vector<Real>& input) {
   if (input.empty())
     throw EssentiaException("trying to get argmin of empty array");

diff --git a/src/python/essentia/utils.py b/src/python/essentia/utils.py
@@ -99,6 +99,14 @@ def note2hz(arg1, arg2=440.0):
     return _essentia.note2hz( _c.convertData(arg1, _c.Edt.STRING),
                               _c.convertData(arg2, _c.Edt.REAL) )
 
+def velocity2db(arg1, arg2=-96):
+    return _essentia.velocity2db( _c.convertData(arg1, _c.Edt.INTEGER),
+                                  _c.convertData(arg2, _c.Edt.REAL) )
+
+def db2velocity(arg1, arg2=-96):
+    return _essentia.db2velocity( _c.convertData(arg1, _c.Edt.REAL),
+                                  _c.convertData(arg2, _c.Edt.REAL) )
+
 def equivalentKey(arg):
     return _essentia.equivalentKey( _c.convertData(arg, _c.Edt.STRING) )
 
@@ -127,6 +135,7 @@ def derivative(array):
 	    'note2root', 'note2octave',
             'midi2note', 'note2midi',
             'hz2note', 'note2hz',
+            'velocity2db', 'db2velocity',
             'postProcessTicks',
             'normalize', 'derivative',
             'equivalentKey', 'lin2log']
diff --git a/src/python/globalfuncs.cpp b/src/python/globalfuncs.cpp
@@ -504,7 +504,7 @@ hzToNote(PyObject* notUsed, PyObject* args) {
     return NULL;
   }
 
-  std::string note = hz2note( Real( PyFloat_AS_DOUBLE(argsV[0]) ), Real( PyFloat_AS_DOUBLE(argsV[1])) );
+  std::string note = hz2note( Real( PyFloat_AS_DOUBLE(argsV[0]) ), Real( PyFloat_AS_DOUBLE(argsV[1]) ) );
   const char *c_note = note.c_str();
   return PyString_FromString( c_note );
 }
@@ -519,10 +519,38 @@ noteToHz(PyObject* notUsed, PyObject* args) {
     return NULL;
   }
 
-  Real hz = note2hz( PyString_AS_STRING(argsV[0]), Real( PyFloat_AS_DOUBLE(argsV[1])) );
+  Real hz = note2hz( PyString_AS_STRING(argsV[0]), Real( PyFloat_AS_DOUBLE(argsV[1]) ) );
   return PyFloat_FromDouble( hz );
 }
 
+static PyObject*
+velocityToDb(PyObject* notUsed, PyObject* args) {
+  // parse args to get Source alg, name and source alg and source name
+  vector<PyObject*> argsV = unpack(args);
+  if (argsV.size() != 2 ||
+  (!PyLong_Check(argsV[0]) || !PyFloat_Check(argsV[1]))) {
+    PyErr_SetString(PyExc_ValueError, "expecting arguments (int velocity, Real hearingThreshold)");
+    return NULL;
+  }
+
+  Real db = velocity2db( long( PyLong_AsLong(argsV[0]) ), Real( PyFloat_AS_DOUBLE(argsV[1]) ) );
+  return PyFloat_FromDouble( db );
+}
+
+static PyObject*
+dbToVelocity(PyObject* notUsed, PyObject* args) {
+  // parse args to get Source alg, name and source alg and source name
+  vector<PyObject*> argsV = unpack(args);
+  if (argsV.size() != 2 ||
+  (!PyFloat_Check(argsV[0]) || !PyFloat_Check(argsV[1]))) {
+    PyErr_SetString(PyExc_ValueError, "expecting arguments (Real decibels, Real hearingThreshold)");
+    return NULL;
+  }
+
+  long velocity = db2velocity( Real( PyFloat_AS_DOUBLE(argsV[0])), Real( PyFloat_AS_DOUBLE(argsV[1])) );
+  return PyLong_FromLong( int(velocity) );
+}
+
 static PyObject*
 getEquivalentKey(PyObject* notUsed, PyObject* arg) {
   if (!PyString_Check(arg)) {
@@ -1144,6 +1172,8 @@ static PyMethodDef Essentia__Methods[] = {
   { "note2octave",   noteToOctave,     METH_O, "Returns the octave of a note" },
   { "hz2note",       hzToNote,         METH_VARARGS, "Converts a frequency in Hz to a note - applying the international pitch standard A4=440Hz" },
   { "note2hz",       noteToHz,         METH_VARARGS, "Converts a note - applying the international pitch standard A4=440Hz - into a frequency in Hz" },
+  { "velocity2db",   velocityToDb,     METH_VARARGS, "Converts a velocity to a measure in dB" },
+  { "db2velocity",   dbToVelocity,     METH_VARARGS, "Converts a dB measure of power to velocity [0-127]" },
   { "lin2db",        linToDb,          METH_O, "Converts a linear measure of power to a measure in dB" },
   { "db2lin",        dbToLin,          METH_O, "Converts a dB measure of power to a linear measure" },
   { "db2pow",        dbToPow,          METH_O, "Converts a dB measure of power to a linear measure" },

diff --git a/test/src/unittests/base/test_utils.py b/test/src/unittests/base/test_utils.py
@@ -170,6 +170,22 @@ def testNoteToHz(self):
         expected_hz = 440
         self.assertEqual(expected_hz, note2hz(note))
 
+    def testDbToVelocity(self):
+        decibels = 0
+        expected_velocity = 127
+        self.assertEqual(expected_velocity, db2velocity(decibels))
+        decibels = -96
+        expected_velocity = 0
+        self.assertEqual(expected_velocity, db2velocity(decibels))
+
+    def testVelocityToDb(self):
+        velocity = 127
+        expected_decibels = 0
+        self.assertEqual(expected_decibels, velocity2db(velocity))
+        velocity = 0
+        expected_decibels = -96
+        self.assertEqual(expected_decibels, velocity2db(velocity))
+
 
 suite = allTests(TestUtils)