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             # if a child has no transitions, then it is bubbled to the parent,
  53             # and we don't want that. Not useful in that machine precisely.
  54             'conditions': ['is_loaded']
  55         },
  56         {
  57             'trigger': 'pause',
  58             'source': 'loaded_playing',
  59             'dest': 'loaded_paused'
  60         },
  61         {
  62             'trigger': 'unpause',
  63             'source': 'loaded_paused',
  64             'dest': 'loaded_playing'
  65         },
  66         {
  67             'trigger': 'stop_playing',
  68             'source': ['loaded_playing','loaded_paused'],
  69             'dest': 'loaded_stopping'
  70         },
  71         {
  72             'trigger': 'stopped',
  73             'source': '*',
  74             'dest': 'loaded',
  75             'before': 'trigger_stopped_events',
  76             'conditions': ['is_in_use']
  77         }
  78     ]
  79
  80     def __init__(self, filename, mapping, name=None, gain=1):
  81         Machine(model=self, states=self.STATES,
  82                 transitions=self.TRANSITIONS, initial='initial',
  83                 ignore_invalid_triggers=True)
  84
  85         self.loaded_callbacks = []
  86         self.mapping = mapping
  87         self.filename = filename
  88         self.name = name or filename
  89         self.audio_segment = None
  90         self.initial_volume_factor = gain
  91         self.music_lock = Lock("music__" + filename)
  92
  93         threading.Thread(name="MSMusicLoad", target=self.load).start()
  94
  95     # Machine related events
  96     def on_enter_loading(self):
  97         with file_lock:
  98             try:
  99                 debug_print("Loading « {} »".format(self.name))
 100                 self.mixer = self.mapping.mixer or Mixer()
 101                 initial_db_gain = gain(self.initial_volume_factor * 100)
 102                 self.audio_segment = pydub.AudioSegment \
 103                         .from_file(self.filename) \
 104                         .set_frame_rate(Config.frame_rate) \
 105                         .set_channels(Config.channels) \
 106                         .set_sample_width(Config.sample_width) \
 107                         .apply_gain(initial_db_gain)
 108                 self.sound_duration = self.audio_segment.duration_seconds
 109             except Exception as e:
 110                 error_print("failed to load « {} »: {}".format(self.name, e))
 111                 self.loading_error = e
 112                 self.fail()
 113             else:
 114                 self.success()
 115                 debug_print("Loaded « {} »".format(self.name))
 116
 117     def on_enter_loaded(self):
 118         self.cleanup()
 119
 120     def cleanup(self):
 121         self.gain_effects = []
 122         self.set_gain(0, absolute=True)
 123         self.current_audio_segment = None
 124         self.volume = 100
 125         self.wait_event = threading.Event()
 126         self.current_loop = 0
 127
 128     def on_enter_loaded_playing(self):
 129         self.mixer.add_file(self)
 130
 131     # Machine related states
 132     def is_in_use(self):
 133         return self.is_loaded(allow_substates=True) and not self.is_loaded()
 134
 135     def is_in_use_not_stopping(self):
 136         return self.is_loaded_playing() or self.is_loaded_paused()
 137
 138     # Machine related triggers
 139     def trigger_stopped_events(self):
 140         self.mixer.remove_file(self)
 141         self.wait_event.set()
 142         self.cleanup()
 143
 144     # Actions and properties called externally
 145     @property
 146     def sound_position(self):
 147         if self.is_in_use():
 148             return self.current_frame / self.current_audio_segment.frame_rate
 149         else:
 150             return 0
 151
 152     def play(self, fade_in=0, volume=100, loop=0, start_at=0):
 153         self.set_gain(gain(volume) + self.mapping.master_gain, absolute=True)
 154         self.volume = volume
 155         if loop < 0:
 156             self.last_loop = float('inf')
 157         else:
 158             self.last_loop = loop
 159
 160         with self.music_lock:
 161             self.current_audio_segment = self.audio_segment
 162             self.current_frame = int(start_at * self.audio_segment.frame_rate)
 163
 164         self.start_playing()
 165
 166         if fade_in > 0:
 167             db_gain = gain(self.volume, 0)[0]
 168             self.set_gain(-db_gain)
 169             self.add_fade_effect(db_gain, fade_in)
 170
 171     def seek(self, value=0, delta=False):
 172         if not self.is_in_use_not_stopping():
 173             return
 174
 175         with self.music_lock:
 176             self.abandon_all_effects()
 177             if delta:
 178                 frame_count = int(self.audio_segment.frame_count())
 179                 frame_diff = int(value * self.audio_segment.frame_rate)
 180                 self.current_frame += frame_diff
 181                 while self.current_frame < 0:
 182                     self.current_loop -= 1
 183                     self.current_frame += frame_count
 184                 while self.current_frame > frame_count:
 185                     self.current_loop += 1
 186                     self.current_frame -= frame_count
 187                 if self.current_loop < 0:
 188                     self.current_loop = 0
 189                     self.current_frame = 0
 190                 if self.current_loop > self.last_loop:
 191                     self.current_loop = self.last_loop
 192                     self.current_frame = frame_count
 193             else:
 194                 self.current_frame = max(
 195                         0,
 196                         int(value * self.audio_segment.frame_rate))
 197
 198     def stop(self, fade_out=0, wait=False, set_wait_id=None):
 199         if self.is_loaded_playing():
 200             ms = int(self.sound_position * 1000)
 201             ms_fo = max(1, int(fade_out * 1000))
 202
 203             new_audio_segment = self.current_audio_segment[: ms+ms_fo] \
 204                 .fade_out(ms_fo)
 205             with self.music_lock:
 206                 self.current_audio_segment = new_audio_segment
 207             self.stop_playing()
 208             if wait:
 209                 if set_wait_id is not None:
 210                     self.mapping.add_wait_id(set_wait_id, self.wait_event)
 211                 self.wait_end()
 212         else:
 213             self.stopped()
 214
 215     def abandon_all_effects(self):
 216         db_gain = 0
 217         for gain_effect in self.gain_effects:
 218             db_gain += gain_effect.get_last_gain()
 219
 220         self.gain_effects = []
 221         self.set_gain(db_gain)
 222
 223     def set_volume(self, value, delta=False, fade=0):
 224         [db_gain, self.volume] = gain(
 225                 value + int(delta) * self.volume,
 226                 self.volume)
 227
 228         self.set_gain_with_effect(db_gain, fade=fade)
 229
 230     def set_gain_with_effect(self, db_gain, fade=0):
 231         if not self.is_in_use():
 232             return
 233
 234         if fade > 0:
 235             self.add_fade_effect(db_gain, fade)
 236         else:
 237             self.set_gain(db_gain)
 238
 239     def wait_end(self):
 240         self.wait_event.clear()
 241         self.wait_event.wait()
 242
 243     # Let other subscribe for an event when they are ready
 244     def subscribe_loaded(self, callback):
 245         # FIXME: should lock to be sure we have no race, but it makes the
 246         # initialization screen not showing until everything is loaded
 247         if self.is_loaded(allow_substates=True):
 248             callback(True)
 249         elif self.is_failed():
 250             callback(False)
 251         else:
 252             self.loaded_callbacks.append(callback)
 253
 254     def poll_loaded(self):
 255         for callback in self.loaded_callbacks:
 256             callback(self.is_loaded())
 257         self.loaded_callbacks = []
 258
 259     # Callbacks
 260     def finished_callback(self):
 261         self.stopped()
 262
 263     def play_callback(self, out_data_length, frame_count):
 264         if self.is_loaded_paused():
 265             return b'\0' * out_data_length
 266
 267         with self.music_lock:
 268             [data, nb_frames] = self.get_next_sample(frame_count)
 269             if nb_frames < frame_count:
 270                 if self.is_loaded_playing() and\
 271                         self.current_loop < self.last_loop:
 272                     self.current_loop += 1
 273                     self.current_frame = 0
 274                     [new_data, new_nb_frames] = self.get_next_sample(
 275                             frame_count - nb_frames)
 276                     data += new_data
 277                     nb_frames += new_nb_frames
 278                 elif nb_frames == 0:
 279                     # FIXME: too slow when mixing multiple streams
 280                     threading.Thread(
 281                             name="MSFinishedCallback",
 282                             target=self.finished_callback).start()
 283
 284             return data.ljust(out_data_length, b'\0')
 285
 286     # Helpers
 287     def set_gain(self, db_gain, absolute=False):
 288         if absolute:
 289             self.db_gain = db_gain
 290         else:
 291             self.db_gain += db_gain
 292
 293     def get_next_sample(self, frame_count):
 294         fw = self.audio_segment.frame_width
 295
 296         data = b""
 297         nb_frames = 0
 298
 299         segment = self.current_audio_segment
 300         max_val = int(segment.frame_count())
 301
 302         start_i = max(self.current_frame, 0)
 303         end_i   = min(self.current_frame + frame_count, max_val)
 304         data += segment._data[start_i*fw : end_i*fw]
 305         nb_frames += end_i - start_i
 306         self.current_frame += end_i - start_i
 307
 308         volume_factor = self.volume_factor(self.effects_next_gain(nb_frames))
 309
 310         data = audioop.mul(data, Config.sample_width, volume_factor)
 311
 312         return [data, nb_frames]
 313
 314     def add_fade_effect(self, db_gain, fade_duration):
 315         if not self.is_in_use():
 316             return
 317
 318         self.gain_effects.append(GainEffect(
 319             "fade",
 320             self.current_audio_segment,
 321             self.current_loop,
 322             self.sound_position,
 323             self.sound_position + fade_duration,
 324             gain=db_gain))
 325
 326     def effects_next_gain(self, frame_count):
 327         db_gain = 0
 328         for gain_effect in self.gain_effects:
 329             [new_gain, last_gain] = gain_effect.get_next_gain(
 330                     self.current_frame,
 331                     self.current_loop,
 332                     frame_count)
 333             if last_gain:
 334                 self.set_gain(new_gain)
 335                 self.gain_effects.remove(gain_effect)
 336             else:
 337                 db_gain += new_gain
 338         return db_gain
 339
 340
 341     def volume_factor(self, additional_gain=0):
 342         return 10 ** ( (self.db_gain + additional_gain) / 20)
 343