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# SPDX-FileCopyrightText: 2016 Ole Martin Bjorndalen <ombdalen@gmail.com>
#
# SPDX-License-Identifier: MIT
from .specs import CHANNEL_MESSAGES, MIN_PITCHWHEEL, SPEC_BY_TYPE
def _encode_pitchwheel(msg):
pitch = msg['pitch'] - MIN_PITCHWHEEL
return [0xe0 | msg['channel'], pitch & 0x7f, pitch >> 7]
def _encode_sysex(msg):
return [0xf0] + list(msg['data']) + [0xf7]
def _encode_quarter_frame(msg):
return [0xf1, msg['frame_type'] << 4 | msg['frame_value']]
def _encode_songpos(data):
pos = data['pos']
return [0xf2, pos & 0x7f, pos >> 7]
def _encode_note_off(msg):
return [0x80 | msg['channel'], msg['note'], msg['velocity']]
def _encode_note_on(msg):
return [0x90 | msg['channel'], msg['note'], msg['velocity']]
def _encode_control_change(msg):
return [0xb0 | msg['channel'], msg['control'], msg['value']]
_SPECIAL_CASES = {
'pitchwheel': _encode_pitchwheel,
'sysex': _encode_sysex,
'quarter_frame': _encode_quarter_frame,
'songpos': _encode_songpos,
# These are so common that they get special cases to speed things up.
'note_off': _encode_note_off,
'note_on': _encode_note_on,
'control_change': _encode_control_change,
}
def encode_message(msg):
"""Encode msg dict as a list of bytes.
TODO: Add type and value checking.
(Can be turned off with keyword argument.)
This is not a part of the public API.
"""
encode = _SPECIAL_CASES.get(msg['type'])
if encode:
return encode(msg)
else:
spec = SPEC_BY_TYPE[msg['type']]
status_byte = spec['status_byte']
if status_byte in CHANNEL_MESSAGES:
status_byte |= msg['channel']
data = [msg[name] for name in spec['value_names'] if name != 'channel']
return [status_byte] + data
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