helpers/music_file.py

   1 import threading
   2 import pydub
   3 import time
   4 from transitions.extensions import HierarchicalMachine as Machine
   5
   6 import os.path
   7
   8 import audioop
   9
  10 from .lock import Lock
  11 from . import Config, gain, debug_print, error_print
  12 from .mixer import Mixer
  13 from .music_effect import GainEffect
  14
  15 file_lock = Lock("file")
  16
  17 class MusicFile:
  18     STATES = [
  19         'initial',
  20         'loading',
  21         'failed',
  22         {
  23             'name': 'loaded',
  24             'children': [
  25                 'playing',
  26                 'paused',
  27                 'stopping'
  28             ]
  29         }
  30     ]
  31     TRANSITIONS = [
  32         {
  33             'trigger': 'load',
  34             'source': 'initial',
  35             'dest': 'loading',
  36             'after': 'poll_loaded'
  37         },
  38         {
  39             'trigger': 'fail',
  40             'source': 'loading',
  41             'dest': 'failed'
  42         },
  43         {
  44             'trigger': 'success',
  45             'source': 'loading',
  46             'dest': 'loaded'
  47         },
  48         {
  49             'trigger': 'start_playing',
  50             'source': 'loaded',
  51             'dest': 'loaded_playing'
  52         },
  53         {
  54             'trigger': 'pause',
  55             'source': 'loaded_playing',
  56             'dest': 'loaded_paused'
  57         },
  58         {
  59             'trigger': 'unpause',
  60             'source': 'loaded_paused',
  61             'dest': 'loaded_playing'
  62         },
  63         {
  64             'trigger': 'stop_playing',
  65             'source': ['loaded_playing','loaded_paused'],
  66             'dest': 'loaded_stopping'
  67         },
  68         {
  69             'trigger': 'stopped',
  70             'source': '*',
  71             'dest': 'loaded',
  72             'before': 'trigger_stopped_events',
  73             'conditions': ['is_in_use']
  74         }
  75     ]
  76
  77     def __init__(self, filename, mapping, name=None, gain=1):
  78         Machine(model=self, states=self.STATES,
  79                 transitions=self.TRANSITIONS, initial='initial',
  80                 ignore_invalid_triggers=True)
  81
  82         self.loaded_callbacks = []
  83         self.mapping = mapping
  84         self.filename = filename
  85         self.name = name or filename
  86         self.audio_segment = None
  87         self.initial_volume_factor = gain
  88         self.music_lock = Lock("music__" + filename)
  89
  90         threading.Thread(name="MSMusicLoad", target=self.load).start()
  91
  92     # Machine related events
  93     def on_enter_loading(self):
  94         with file_lock:
  95             try:
  96                 debug_print("Loading « {} »".format(self.name))
  97                 self.mixer = self.mapping.mixer or Mixer()
  98                 initial_db_gain = gain(self.initial_volume_factor * 100)
  99                 self.audio_segment = pydub.AudioSegment \
 100                         .from_file(self.filename) \
 101                         .set_frame_rate(Config.frame_rate) \
 102                         .set_channels(Config.channels) \
 103                         .set_sample_width(Config.sample_width) \
 104                         .apply_gain(initial_db_gain)
 105                 self.sound_duration = self.audio_segment.duration_seconds
 106             except Exception as e:
 107                 error_print("failed to load « {} »: {}".format(self.name, e))
 108                 self.loading_error = e
 109                 self.fail()
 110             else:
 111                 self.success()
 112                 debug_print("Loaded « {} »".format(self.name))
 113
 114     def on_enter_loaded(self):
 115         self.gain_effects = []
 116         self.set_gain(0, absolute=True)
 117         self.current_audio_segment = None
 118         self.volume = 100
 119         self.wait_event = threading.Event()
 120         self.current_loop = 0
 121
 122     def on_enter_loaded_playing(self):
 123         self.mixer.add_file(self)
 124
 125     # Machine related states
 126     def is_in_use(self):
 127         return self.is_loaded(allow_substates=True) and not self.is_loaded()
 128
 129     def is_in_use_not_stopping(self):
 130         return self.is_loaded_playing() or self.is_loaded_paused()
 131
 132     # Machine related triggers
 133     def trigger_stopped_events(self):
 134         self.mixer.remove_file(self)
 135         self.wait_event.set()
 136
 137     # Actions and properties called externally
 138     @property
 139     def sound_position(self):
 140         if self.is_in_use():
 141             return self.current_frame / self.current_audio_segment.frame_rate
 142         else:
 143             return 0
 144
 145     def play(self, fade_in=0, volume=100, loop=0, start_at=0):
 146         self.set_gain(gain(volume) + self.mapping.master_gain, absolute=True)
 147         self.volume = volume
 148         if loop < 0:
 149             self.last_loop = float('inf')
 150         else:
 151             self.last_loop = loop
 152
 153         with self.music_lock:
 154             self.current_audio_segment = self.audio_segment
 155             self.current_frame = int(start_at * self.audio_segment.frame_rate)
 156
 157         self.start_playing()
 158
 159         if fade_in > 0:
 160             db_gain = gain(self.volume, 0)[0]
 161             self.set_gain(-db_gain)
 162             self.add_fade_effect(db_gain, fade_in)
 163
 164     def seek(self, value=0, delta=False):
 165         if not self.is_in_use_not_stopping():
 166             return
 167
 168         with self.music_lock:
 169             self.abandon_all_effects()
 170             if delta:
 171                 frame_count = int(self.audio_segment.frame_count())
 172                 frame_diff = int(value * self.audio_segment.frame_rate)
 173                 self.current_frame += frame_diff
 174                 while self.current_frame < 0:
 175                     self.current_loop -= 1
 176                     self.current_frame += frame_count
 177                 while self.current_frame > frame_count:
 178                     self.current_loop += 1
 179                     self.current_frame -= frame_count
 180                 if self.current_loop < 0:
 181                     self.current_loop = 0
 182                     self.current_frame = 0
 183                 if self.current_loop > self.last_loop:
 184                     self.current_loop = self.last_loop
 185                     self.current_frame = frame_count
 186             else:
 187                 self.current_frame = max(
 188                         0,
 189                         int(value * self.audio_segment.frame_rate))
 190
 191     def stop(self, fade_out=0, wait=False, set_wait_id=None):
 192         if self.is_loaded_playing():
 193             ms = int(self.sound_position * 1000)
 194             ms_fo = max(1, int(fade_out * 1000))
 195
 196             new_audio_segment = self.current_audio_segment[: ms+ms_fo] \
 197                 .fade_out(ms_fo)
 198             with self.music_lock:
 199                 self.current_audio_segment = new_audio_segment
 200             self.stop_playing()
 201             if wait:
 202                 if set_wait_id is not None:
 203                     self.mapping.add_wait_id(set_wait_id, self.wait_event)
 204                 self.wait_end()
 205         else:
 206             self.stopped()
 207
 208     def abandon_all_effects(self):
 209         db_gain = 0
 210         for gain_effect in self.gain_effects:
 211             db_gain += gain_effect.get_last_gain()
 212
 213         self.gain_effects = []
 214         self.set_gain(db_gain)
 215
 216     def set_volume(self, value, delta=False, fade=0):
 217         [db_gain, self.volume] = gain(
 218                 value + int(delta) * self.volume,
 219                 self.volume)
 220
 221         self.set_gain_with_effect(db_gain, fade=fade)
 222
 223     def set_gain_with_effect(self, db_gain, fade=0):
 224         if not self.is_in_use():
 225             return
 226
 227         if fade > 0:
 228             self.add_fade_effect(db_gain, fade)
 229         else:
 230             self.set_gain(db_gain)
 231
 232     def wait_end(self):
 233         self.wait_event.clear()
 234         self.wait_event.wait()
 235
 236     # Let other subscribe for an event when they are ready
 237     def subscribe_loaded(self, callback):
 238         with file_lock:
 239             if self.is_loaded(allow_substates=True):
 240                 callback(True)
 241             elif self.is_failed():
 242                 callback(False)
 243             else:
 244                 self.loaded_callbacks.append(callback)
 245
 246     def poll_loaded(self):
 247         for callback in self.loaded_callbacks:
 248             callback(self.is_loaded())
 249         self.loaded_callbacks = []
 250
 251     # Callbacks
 252     def finished_callback(self):
 253         self.stopped()
 254
 255     def play_callback(self, out_data_length, frame_count):
 256         if self.is_loaded_paused():
 257             return b'\0' * out_data_length
 258
 259         with self.music_lock:
 260             [data, nb_frames] = self.get_next_sample(frame_count)
 261             if nb_frames < frame_count:
 262                 if self.is_loaded_playing() and\
 263                         self.current_loop < self.last_loop:
 264                     self.current_loop += 1
 265                     self.current_frame = 0
 266                     [new_data, new_nb_frames] = self.get_next_sample(
 267                             frame_count - nb_frames)
 268                     data += new_data
 269                     nb_frames += new_nb_frames
 270                 elif nb_frames == 0:
 271                     # FIXME: too slow when mixing multiple streams
 272                     threading.Thread(
 273                             name="MSFinishedCallback",
 274                             target=self.finished_callback).start()
 275
 276             return data.ljust(out_data_length, b'\0')
 277
 278     # Helpers
 279     def set_gain(self, db_gain, absolute=False):
 280         if absolute:
 281             self.db_gain = db_gain
 282         else:
 283             self.db_gain += db_gain
 284
 285     def get_next_sample(self, frame_count):
 286         fw = self.audio_segment.frame_width
 287
 288         data = b""
 289         nb_frames = 0
 290
 291         segment = self.current_audio_segment
 292         max_val = int(segment.frame_count())
 293
 294         start_i = max(self.current_frame, 0)
 295         end_i   = min(self.current_frame + frame_count, max_val)
 296         data += segment._data[start_i*fw : end_i*fw]
 297         nb_frames += end_i - start_i
 298         self.current_frame += end_i - start_i
 299
 300         volume_factor = self.volume_factor(self.effects_next_gain(nb_frames))
 301
 302         data = audioop.mul(data, Config.sample_width, volume_factor)
 303
 304         return [data, nb_frames]
 305
 306     def add_fade_effect(self, db_gain, fade_duration):
 307         if not self.is_in_use():
 308             return
 309
 310         self.gain_effects.append(GainEffect(
 311             "fade",
 312             self.current_audio_segment,
 313             self.current_loop,
 314             self.sound_position,
 315             self.sound_position + fade_duration,
 316             gain=db_gain))
 317
 318     def effects_next_gain(self, frame_count):
 319         db_gain = 0
 320         for gain_effect in self.gain_effects:
 321             [new_gain, last_gain] = gain_effect.get_next_gain(
 322                     self.current_frame,
 323                     self.current_loop,
 324                     frame_count)
 325             if last_gain:
 326                 self.set_gain(new_gain)
 327                 self.gain_effects.remove(gain_effect)
 328             else:
 329                 db_gain += new_gain
 330         return db_gain
 331
 332
 333     def volume_factor(self, additional_gain=0):
 334         return 10 ** ( (self.db_gain + additional_gain) / 20)
 335