"""Piano-roll output interface."""
import math
from operator import attrgetter
from typing import TYPE_CHECKING, Union
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()
# 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:
tempo_arr = np.full(length, 120.0)
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
tempo_arr[position:] = qpm
# Downbeats
if not music.beats:
downbeat_arr = None
else:
downbeat_arr = np.zeros(length, bool)
for beat in music.beats:
if beat.is_downbeat:
downbeat_arr[beat.time] = True
has_title = music.metadata is not None and music.metadata.title is not None
return Multitrack(
name=music.metadata.title if has_title else None,
resolution=music.resolution,
tempo=tempo_arr,
downbeat=downbeat_arr,
tracks=tracks,
)
[docs]def to_pianoroll_representation(
music: "Music",
encode_velocity: bool = True,
dtype: Union[np.dtype, type, str] = None,
) -> ndarray:
"""Encode notes into piano-roll representation.
Parameters
----------
music : :class:`muspy.Music`
Music object to encode.
encode_velocity : bool, default: True
Whether to encode velocities. If True, a binary-valued array
will be return. Otherwise, an integer array will be return.
dtype : np.dtype, type or str, optional
Data type of the return array. Defaults to uint8 if
`encode_velocity` is True, otherwise bool.
Returns
-------
ndarray, shape=(?, 128)
Encoded array in piano-roll representation.
"""
if dtype is None:
dtype = np.uint8 if encode_velocity else bool
# 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((0, 128), dtype)
# Initialize the array
length = max((note.end for note in notes))
array = np.zeros((length + 1, 128), dtype)
# 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