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#!/usr/bin/python3
import sys
import time
import signal
import getopt
import pyaudio
import platform
from ctypes import *
if platform.system() == 'Windows':
adl = CDLL("libADLMIDI.dll")
else:
adl = CDLL("libADLMIDI.so")
_FREQUENCY = 44100
playing = True
# Allows to quit by Ctrl+C
def catch_signal(signum, frame):
global playing
playing = False
print("Caught Ctrl+C!")
class MidiPlayer:
"""A streaming IMF music player."""
SAMPLE_SIZE = 2 # 16-bit
CHANNELS = 2 # stereo
BUFFER_SAMPLE_COUNT = 1024 # Max allowed: 512
def __init__(self, freq=_FREQUENCY):
"""Initializes the PyAudio and OPL synth."""
self._freq = freq
# Prepare PyAudio
self._audio = pyaudio.PyAudio()
# Prepare buffers.
self._data = create_string_buffer(MidiPlayer.BUFFER_SAMPLE_COUNT * MidiPlayer.SAMPLE_SIZE * MidiPlayer.CHANNELS)
self._stream = None # Created later.
self._opl = adl.adl_init(freq)
self._song = None
def set_bank_no(self, bank_no):
if adl.adl_setBank(self._opl, bank_no):
print("%s" % c_char_p(adl.adl_errorInfo(self._opl)).value)
return False
return True
def set_bank_file(self, bank_file):
if adl.adl_openBankFile(self._opl, bank_file.encode()) < 0:
print("%s" % c_char_p(adl.adl_errorInfo(self._opl)).value)
return False
return True
def set_loop_enabled(self, loop_en):
adl.adl_setLoopEnabled(self._opl, 1 if loop_en else 0)
def _create_stream(self, start=True):
"""Create a new PyAudio stream."""
self._stream = self._audio.open(
format=self._audio.get_format_from_width(MidiPlayer.SAMPLE_SIZE),
channels=MidiPlayer.CHANNELS,
frames_per_buffer=MidiPlayer.BUFFER_SAMPLE_COUNT,
rate=self._freq,
output=True,
start=start, # Don't start playing immediately!
stream_callback=self._callback)
def set_song(self, song):
self._song = song
if adl.adl_openFile(self._opl, self._song.encode()) < 0:
print("%s" % c_char_p(adl.adl_errorInfo(self._opl)).value.decode())
return False
return True
# noinspection PyUnusedLocal
def _callback(self, input_data, frame_count, time_info, status):
global playing
got = adl.adl_play(self._opl, int(MidiPlayer.BUFFER_SAMPLE_COUNT * 2), cast(self._data, POINTER(c_short)));
if got <= 0:
playing = False
return None, pyaudio.paComplete
return self._data, pyaudio.paContinue
def play(self, repeat=False):
global playing
"""Starts playing the song at the current position."""
self.repeat = repeat
if self._song is None:
playing = False
return
# If a stream exists and it is not active and not stopped, it needs to be closed and a new one created.
if self._stream is not None and not self._stream.is_active() and not self._stream.is_stopped():
self._stream.close() # close for good measure.
self._stream = None
# If there's no stream at this point, create one.
if self._stream is None:
self._create_stream(False)
self._stream.start_stream()
def pause(self):
"""Stops the PyAudio stream, but does not rewind the playback position."""
self._stream.stop_stream()
def stop(self):
"""Stops the PyAudio stream and resets the playback position."""
self._stream.stop_stream()
def close(self):
"""Closes the PyAudio stream and terminates it."""
if self._stream is not None:
self._stream.stop_stream()
self._stream.close()
self._stream = None
self._audio.terminate()
adl.adl_close(self._opl)
def usage(arg):
print('usage: %s [-b <embedded bank number>|-bf <external bank file>] [-l 0|1] <file>' % arg, file=sys.stderr)
sys.exit(2)
if __name__ == '__main__':
bank_no = 72
bank_file = None
enable_loop = False
sample_rate = 44100
opts, args = getopt.getopt(sys.argv[1:], 'b:bg:l:')
for o, a in opts:
if o == '-b':
bank_no = int(a)
if o == '-l':
enable_loop = int(a) == 1
elif o == '-bg':
bank_file = a
if not args:
usage(sys.argv[0])
midi_file = args[0]
MIDIPlay = MidiPlayer(sample_rate)
if bank_file:
if not MIDIPlay.set_bank_file(bank_file):
exit(1)
print("Using bank file: %s" % bank_file)
else:
if not MIDIPlay.set_bank_no(bank_no):
exit(1)
print("Using embedded bank: %d" % bank_no)
MIDIPlay.set_loop_enabled(enable_loop)
if not MIDIPlay.set_song(midi_file):
exit(1)
MIDIPlay.play()
signal.signal(signal.SIGINT, catch_signal)
print("Playing MIDI file %s..." % (midi_file))
while playing:
time.sleep(0.1)
MIDIPlay.stop()
MIDIPlay.close()
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