Add vibrato

Author: eriknyquist

README.rst

@@ -9,8 +9,8 @@ into usable musical data.
 
 The Polyphonic Tone Text Transfer Language (PTTTL) is a way to describe polyphonic
 melodies, and is a superset of Nokia's
-`RTTTL <https://en.wikipedia.org/wiki/Ring_Tone_Transfer_Language>`_ format,
-used for monophonic ringtones.
+`RTTTL <https://en.wikipedia.org/wiki/Ring_Tone_Transfer_Language>`_ format, extending
+it to enable polyphony and vibrato.
 
 
 API documentation
@@ -95,16 +95,18 @@ contents.
 *default values* section
 ========================
 
-The very first statement is the *default value* section and is identical to
+The very first statement is the *default value* section and is the same as
 the section of the same name from the RTTTL format.
 
 ::
 
-  b=123, d=8, o=4
+  b=123, d=8, o=4, f=7, v=10
 
 * *b* - beat, tempo: tempo in BPM (Beats Per Minute)
 * *d* - duration: default duration of a note if none is specified
 * *o* - octave: default octave of a note if none is specified
+* *f* - frequency: default vibrato frequency if none is specified, in Hz
+* *v* - variance: default vibrato variance from the main pitch if none is specified, in Hz
 
 *data* section
 ==============
@@ -160,6 +162,19 @@ Octave
 
 Valid values for note octave are between **0** and **8**.
 
+Vibrato
+-------
+
+Optionally, vibrato maybe enabled and configured for an individual note. This is
+done by adding a ``v`` at the end of the note, and optionally a frequency and variance
+value seperated by a ``-`` character. For example:
+
+* ``4c#v`` refers to a C# quarter note with vibrato enabled, using default settings
+* ``4c#v10`` refers to a C# quarter note with vibrato enabled, using a vibrato frequency of 10Hz,
+   and the default value for vibrato variance
+* ``4c#v10-15`` refers to a C# quarter note with vibrato enabled, using a vibrato frequency of 10Hz,
+  with a maximum vibrato variance of 15Hz from the main pitch.
+
 Example
 =======
 

ptttl/audio.py

@@ -42,7 +42,9 @@ def _generate_samples(parsed, amplitude, wavetype):
             if note.pitch <= 0.0:
                 mixer.add_silence(i, duration=note.duration)
             else:
-                mixer.add_tone(i, frequency=note.pitch, duration=note.duration)
+                mixer.add_tone(i, frequency=note.pitch, duration=note.duration,
+                               vibrato_frequency=note.vibrato_frequency,
+                               vibrato_variance=note.vibrato_variance)
 
     return mixer.mix()
 

ptttl/parser.py

@@ -22,6 +22,14 @@
     "b": 493.883301256
 }
 
+
+DEFAULT_VIBRATO_FREQ_HZ = 7.0
+DEFAULT_VIBRATO_VAR_HZ = 20.0
+DEFAULT_OCTAVE = 4
+DEFAULT_DURATION = 8
+DEFAULT_BPM = 123
+
+
 class PTTTLSyntaxError(Exception):
     """
     Raised by PTTTLParser when ptttl data is malformed and cannot be parsed
@@ -58,14 +66,29 @@ def _invalid_note(note):
 def _invalid_octave(note):
     raise PTTTLValueError("invalid octave in note '%s'" % note)
 
+def _invalid_vibrato(vdata):
+    raise PTTTLValueError("invalid vibrato settings: '%s'" % note)
+
+
 def _int_setting(key, val):
     ret = None
 
     try:
         ret = int(val)
     except ValueError:
         raise PTTTLValueError("expecting an integer for '%s' setting in "
-            "PTTTL script" % key)
+                              "PTTTL script" % key)
+
+    return ret
+
+def _float_setting(key, val):
+    ret = None
+
+    try:
+        ret = float(val)
+    except ValueError:
+        raise PTTTLValueError("expecting a floating point value for '%s' setting in "
+                              "PTTTL script" % key)
 
     return ret
 
@@ -79,15 +102,38 @@ class PTTTLNote(object):
 
     :ivar float pitch: Note pitch in Hz
     :ivar float duration: Note duration in seconds
+    :ivar float vfreq: Vibrato frequency in Hz
+    :ivar float vvar: Vibrato variance from main pitch in Hz
     """
-    def __init__(self, pitch, duration):
+    def __init__(self, pitch, duration, vfreq=None, vvar=None):
         self.pitch = pitch
         self.duration = duration
+        self.vibrato_frequency = vfreq
+        self.vibrato_variance = vvar
+
+    def has_vibrato(self):
+        """
+        Returns True if vibrato frequency and variance are non-zero
+
+        :return: True if vibrato is non-zero
+        :rtype: bool
+        """
+        if None in [self.vibrato_frequency, self.vibrato_variance]:
+            return False
+
+        if 0.0 in [self.vibrato_frequency, self.vibrato_variance]:
+            return False
+
+        return (self.vibrato_frequency > 0.0) and (self.vibrato_variance > 0.0)
 
     def __str__(self):
-        return "%s(pitch=%.4f, duration=%.4f)" % (self.__class__.__name__,
-                                                  self.pitch,
-                                                  self.duration)
+        ret = "%s(pitch=%.4f, duration=%.4f" % (self.__class__.__name__,
+                                                self.pitch,
+                                                self.duration)
+        if self.has_vibrato():
+            ret += ", vibrato=%.1f:%.1f" % (self.vibrato_frequency, self.vibrato_variance)
+
+        return ret + ")"
 
     def __repr__(self):
         return self.__str__()
@@ -99,10 +145,22 @@ class PTTTLData(object):
     May contain multiple tracks, where each track is a list of PTTTLNote objects.
 
     :ivar [[PTTTLNote]] tracks: List of tracks. Each track is a list of PTTTLNote objects.
+    :ivar float bpm: playback speed in BPM (beats per minute).
+    :ivar int default_octave: Default octave to use when none is specified
+    :ivar int default_duration: Default note duration to use when none is specified
+    :ivar float default_vibrato_freq: Default vibrato frequency when none is specified, in Hz
+    :ivar float default_vibrato_var: Default vibrato variance when none is specified, in Hz
     """
-    def __init__(self):
+    def __init__(self, bpm=DEFAULT_BPM, default_octave=DEFAULT_OCTAVE,
+                 default_duration=DEFAULT_DURATION, default_vibrato_freq=DEFAULT_VIBRATO_FREQ_HZ,
+                 default_vibrato_var=DEFAULT_VIBRATO_VAR_HZ):
+        self.bpm = bpm
+        self.default_octave = default_octave
+        self.default_duration = default_duration
+        self.default_vibrato_freq = default_vibrato_freq
+        self.default_vibrato_var = default_vibrato_var
         self.tracks = []
-    
+
     def add_track(self, notes):
         self.tracks.append(notes)
 
@@ -149,6 +207,12 @@ def _parse_config_line(self, conf):
         if not values:
             raise PTTTLSyntaxError("no valid configuration found in PTTTL script")
 
+        bpm = None
+        default = None
+        octave = None
+        vfreq = None
+        vvar = None
+
         for value in values:
             fields = value.split('=')
             if len(fields) != 2:
@@ -170,6 +234,10 @@ def _parse_config_line(self, conf):
                 octave = _int_setting(key, val)
                 if not self._is_valid_octave(octave):
                     _invalid_value(key, val)
+            elif key == 'f':
+                vfreq = _float_setting(key, val)
+            elif key == 'v':
+                vvar = _float_setting(key, val)
             else:
                 _unrecognised_setting(key)
 
@@ -182,23 +250,32 @@ def _parse_config_line(self, conf):
         if not default:
             _missing_setting('d')
 
-        return bpm, default, octave
+        return bpm, default, octave, vfreq, vvar
 
     def _note_time_to_secs(self, note_time, bpm):
         # Time in seconds for a whole note (4 beats) given current BPM.
         whole = (60.0 / float(bpm)) * 4.0
 
         return whole / float(note_time)
 
-    def _parse_note(self, string, bpm, default, octave):
+    def _parse_note(self, string, bpm, default, octave, vfreq, vvar):
         i = 0
         orig = string
         sawdot = False
         dur = default
+        vibrato_freq = None
+        vibrato_var = None
+        vdata = None
+
+        fields = string.split('v')
+        if len(fields) == 2:
+            string = fields[0]
+            vdata = fields[1]
 
         if len(string) == 0:
             raise PTTTLSyntaxError("Missing notes after comma")
 
+        # Get the note duration; if there is one, it should be the first thing
         while i < len(string) and string[i].isdigit():
             if i > 1:
                 _invalid_note_duration(orig)
@@ -214,8 +291,10 @@ def _parse_note(self, string, bpm, default, octave):
             if not string[0].isalpha():
                 _invalid_note(orig)
 
+        # Calculate note duration in real seconds
         duration = self._note_time_to_secs(dur, bpm)
 
+        # Now, look for the musical note value, which should be next
         string = string[i:]
 
         i = 0
@@ -234,8 +313,8 @@ def _parse_note(self, string, bpm, default, octave):
         i = 0
 
         if note == 'p':
+            # This note is a rest
             pitch = -1
-
         else:
             if note not in NOTES:
                 _invalid_note(orig)
@@ -261,13 +340,37 @@ def _parse_note(self, string, bpm, default, octave):
             else:
                 pitch = raw_pitch
 
+            string = string[i:].strip()
+            i = 0
+
         if sawdot or ((i < len(string)) and string[-1] == '.'):
             duration += (duration / 2.0)
 
-        return PTTTLNote(pitch, duration)
+        if vdata is not None:
+            if vdata.strip() == '':
+                vibrato_freq = vfreq
+                vibrato_var = vvar
+            else:
+                fields = vdata.split('-')
+                if len(fields) == 2:
+                    try:
+                        vibrato_freq = float(fields[0])
+                        vibrato_var = float(fields[1])
+                    except:
+                        _invalid_vibrato(vdata)
+
+                elif len(fields) == 1:
+                    try:
+                        vibrato_freq = float(vdata)
+                    except:
+                        _invalid_vibrato(vdata)
 
-    def _parse_notes(self, track_list, bpm, default, octave):
-        ret = PTTTLData()
+                    vibrato_var = vvar
+
+        return PTTTLNote(pitch, duration, vibrato_freq, vibrato_var)
+
+    def _parse_notes(self, track_list, bpm, default, octave, vfreq, vvar):
+        ret = PTTTLData(bpm, octave, default, vfreq, vvar)
 
         for track in track_list:
             if track.strip() == "":
@@ -276,7 +379,7 @@ def _parse_notes(self, track_list, bpm, default, octave):
             buf = []
             fields = track.split(',')
             for note in fields:
-                note = self._parse_note(note.strip(), bpm, default, octave)
+                note = self._parse_note(note.strip(), bpm, default, octave, vfreq, vvar)
                 buf.append(note)
 
             ret.add_track(buf)
@@ -299,7 +402,7 @@ def parse(self, ptttl_string):
             raise PTTTLSyntaxError('expecting 3 colon-seperated fields')
 
         self.name = fields[0].strip()
-        bpm, default, octave = self._parse_config_line(fields[1])
+        bpm, default, octave, vfreq, vvar = self._parse_config_line(fields[1])
 
         numtracks = -1
         blocks = fields[2].split(';')
@@ -322,4 +425,9 @@ def parse(self, ptttl_string):
                 if i < (len(trackdata) - 1):
                     tracks[j] += ","
 
-        return self._parse_notes(tracks, bpm, default, octave)
+        if vfreq is None:
+            vfreq = DEFAULT_VIBRATO_FREQ_HZ
+        if vvar is None:
+            vvar = DEFAULT_VIBRATO_VAR_HZ
+
+        return self._parse_notes(tracks, bpm, default, octave, vfreq, vvar)