Changes in python/lib/aubio/midiconv.py [3aad0b1:a3e152a]

File:

• python/lib/aubio/midiconv.py (modified) (3 diffs)

python/lib/aubio/midiconv.py

@@ -2 +2 @@
 """ utilities to convert midi note number to and from note names """
 
-__all__ = ['note2midi', 'midi2note', 'freq2note']
+import sys
+from ._aubio import freqtomidi, miditofreq
 
-import sys
+__all__ = ['note2midi', 'midi2note', 'freq2note', 'note2freq']
+
 py3 = sys.version_info[0] == 3
 if py3:
@@ -13 +15 @@
     int_instances = (int, long)
 
+
 def note2midi(note):
-    " convert note name to midi note number, e.g. [C-1, G9] -> [0, 127] "
-    _valid_notenames = {'C': 0, 'D': 2, 'E': 4, 'F': 5, 'G': 7, 'A': 9, 'B': 11}
+    """Convert note name to midi note number.
+
+    Input string `note` should be composed of one note root
+    and one octave, with optionally one modifier in between.
+
+    List of valid components:
+
+    - note roots: `C`, `D`, `E`, `F`, `G`, `A`, `B`,
+    - modifiers: `b`, `#`, as well as unicode characters
+      `𝄫`, `♭`, `♮`, `♯` and `𝄪`,
+    - octave numbers: `-1` -> `11`.
+
+    Parameters
+    ----------
+    note : str
+        note name
+
+    Returns
+    -------
+    int
+        corresponding midi note number
+
+    Examples
+    --------
+    >>> aubio.note2midi('C#4')
+    61
+    >>> aubio.note2midi('B♭5')
+    82
+
+    Raises
+    ------
+    TypeError
+        If `note` was not a string.
+    ValueError
+        If an error was found while converting `note`.
+
+    See Also
+    --------
+    midi2note, freqtomidi, miditofreq
+    """
+    _valid_notenames = {'C': 0, 'D': 2, 'E': 4, 'F': 5, 'G': 7,
+                        'A': 9, 'B': 11}
     _valid_modifiers = {
-            u'𝄫': -2,                        # double flat
-            u'♭': -1, 'b': -1, '\u266d': -1, # simple flat
-            u'♮': 0, '\u266e': 0, None: 0,   # natural
-            '#': +1, u'♯': +1, '\u266f': +1, # sharp
-            u'𝄪': +2,                        # double sharp
+            u'𝄫': -2,                         # double flat
+            u'♭': -1, 'b': -1, '\u266d': -1,  # simple flat
+            u'♮': 0, '\u266e': 0, None: 0,    # natural
+            '#': +1, u'♯': +1, '\u266f': +1,  # sharp
+            u'𝄪': +2,                         # double sharp
             }
     _valid_octaves = range(-1, 10)
     if not isinstance(note, str_instances):
-        raise TypeError("a string is required, got %s (%s)" % (note, str(type(note))))
+        msg = "a string is required, got {:s} ({:s})"
+        raise TypeError(msg.format(str(type(note)), repr(note)))
     if len(note) not in range(2, 5):
-        raise ValueError("string of 2 to 4 characters expected, got %d (%s)" \
-                         % (len(note), note))
-    notename, modifier, octave = [None]*3
+        msg = "string of 2 to 4 characters expected, got {:d} ({:s})"
+        raise ValueError(msg.format(len(note), note))
+    notename, modifier, octave = [None] * 3
 
     if len(note) == 4:
@@ -52 +96 @@
         raise ValueError("%s is not a valid octave" % octave)
 
-    midi = 12 + octave * 12 + _valid_notenames[notename] + _valid_modifiers[modifier]
+    midi = (octave + 1) * 12 + _valid_notenames[notename] \
+                             + _valid_modifiers[modifier]
     if midi > 127:
         raise ValueError("%s is outside of the range C-2 to G8" % note)
     return midi
 
+
 def midi2note(midi):
-    " convert midi note number to note name, e.g. [0, 127] -> [C-1, G9] "
+    """Convert midi note number to note name.
+
+    Parameters
+    ----------
+    midi : int [0, 128]
+        input midi note number
+
+    Returns
+    -------
+    str
+        note name
+
+    Examples
+    --------
+    >>> aubio.midi2note(70)
+    'A#4'
+    >>> aubio.midi2note(59)
+    'B3'
+
+    Raises
+    ------
+    TypeError
+        If `midi` was not an integer.
+    ValueError
+        If `midi` is out of the range `[0, 128]`.
+
+    See Also
+    --------
+    note2midi, miditofreq, freqtomidi
+    """
     if not isinstance(midi, int_instances):
         raise TypeError("an integer is required, got %s" % midi)
     if midi not in range(0, 128):
-        raise ValueError("an integer between 0 and 127 is excepted, got %d" % midi)
-    _valid_notenames = ['C', 'C#', 'D', 'D#', 'E', 'F', 'F#', 'G', 'G#', 'A', 'A#', 'B']
+        msg = "an integer between 0 and 127 is excepted, got {:d}"
+        raise ValueError(msg.format(midi))
+    _valid_notenames = ['C', 'C#', 'D', 'D#', 'E', 'F', 'F#', 'G', 'G#',
+                        'A', 'A#', 'B']
     return _valid_notenames[midi % 12] + str(int(midi / 12) - 1)
 
+
 def freq2note(freq):
-    " convert frequency in Hz to nearest note name, e.g. [0, 22050.] -> [C-1, G9] "
-    from aubio import freqtomidi
-    return midi2note(int(freqtomidi(freq)))
+    """Convert frequency in Hz to nearest note name.
+
+    Parameters
+    ----------
+    freq : float [0, 23000[
+        input frequency, in Hz
+
+    Returns
+    -------
+    str
+        name of the nearest note
+
+    Example
+    -------
+    >>> aubio.freq2note(440)
+    'A4'
+    >>> aubio.freq2note(220.1)
+    'A3'
+    """
+    nearest_note = int(freqtomidi(freq) + .5)
+    return midi2note(nearest_note)
+
+
+def note2freq(note):
+    """Convert note name to corresponding frequency, in Hz.
+
+    Parameters
+    ----------
+    note : str
+        input note name
+
+    Returns
+    -------
+    freq : float [0, 23000[
+        frequency, in Hz
+
+    Example
+    -------
+    >>> aubio.note2freq('A4')
+    440
+    >>> aubio.note2freq('A3')
+    220.1
+    """
+    midi = note2midi(note)
+    return miditofreq(midi)