"""Piano-roll output interface."""
from operator import attrgetter
from typing import TYPE_CHECKING
import numpy as np
from numpy import ndarray
from pypianoroll import Multitrack, Track
from ..classes import DEFAULT_VELOCITY
if TYPE_CHECKING:
from ..music import Music
[docs]def to_pypianoroll(music: "Music") -> Multitrack:
"""Return a Music object as a Multitrack object.
Parameters
----------
music : :class:`muspy.Music`
Music object to convert.
Returns
-------
multitrack : :class:`pypianoroll.Multitrack`
Converted Multitrack object.
"""
length = (music.get_end_time() // music.resolution + 1) * music.resolution
# Tracks
tracks = []
for track in music.tracks:
pianoroll = np.zeros((length, 128))
for note in track.notes:
if note.velocity is not None:
pianoroll[note.time : note.end, note.pitch] = note.velocity
else:
pianoroll[note.time : note.end, note.pitch] = DEFAULT_VELOCITY
track = Track(
program=track.program,
is_drum=track.is_drum,
name=track.name if track.name is not None else "",
pianoroll=pianoroll,
)
tracks.append(track)
# Tempos
if not music.tempos:
tempo_arr = None
else:
last_tempo_time = max((tempo.time for tempo in music.tempos))
tempo_arr = 120.0 * np.ones(last_tempo_time + 1)
qpm = 120.0
position = 0
for tempo in music.tempos:
tempo_arr[position : tempo.time] = qpm
tempo_arr[tempo.time] = tempo.qpm
position = tempo.time + 1
qpm = tempo.qpm
if music.metadata is not None:
name = music.metadata.title if music.metadata.title is not None else ""
return Multitrack(
resolution=music.resolution,
tracks=tracks,
tempo=tempo_arr,
# downbeat=music.downbeats if music.downbeats else None,
name=name,
)
[docs]def to_pianoroll_representation(
music: "Music", encode_velocity: bool = True
) -> ndarray:
"""Encode notes into piano-roll representation.
Parameters
----------
music : :class:`muspy.Music`
Music object to encode.
encode_velocity : bool
Whether to encode velocities. If True, a binary-valued array
will be return. Otherwise, an integer array will be return.
Defaults to True.
Returns
-------
ndarray, dtype=uint8 or bool, shape=(?, 128)
Encoded array in piano-roll representation.
"""
# Collect notes
notes = []
for track in music.tracks:
notes.extend(track.notes)
# Raise an error if no notes are found
if not notes:
raise RuntimeError("No notes found.")
# Sort the notes
notes.sort(key=attrgetter("time", "pitch", "duration", "velocity"))
if not notes:
return np.zeros((1, 128), np.uint8)
# Initialize the array
length = max((note.end for note in notes))
if encode_velocity:
array = np.zeros((length + 1, 128), np.uint8)
else:
array = np.zeros((length + 1, 128), np.bool)
# Encode notes
for note in notes:
if note.velocity is not None:
if encode_velocity:
array[note.time : note.end, note.pitch] = note.velocity
else:
array[note.time : note.end, note.pitch] = note.velocity > 0
elif encode_velocity:
array[note.time : note.end, note.pitch] = DEFAULT_VELOCITY
else:
array[note.time : note.end, note.pitch] = True
return array