Add option to not remove preceding silence in AbsTokenizer (#110)

* fix reqs

* add support for preceding silence

aria/tokenizer/tokenizer.py

@@ -72,20 +72,20 @@ def tokenize(self, midi_dict: MidiDict, **kwargs):
  required. For instance, in fine-tuning tokenizer you may want to insert
  additional tokens. The default behavior is to call tokenize_midi_dict.
  """
- return self._tokenize_midi_dict(midi_dict)
+ return self._tokenize_midi_dict(midi_dict, **kwargs)
 
  def _detokenize_midi_dict(self, tokenized_seq: list):
  """Abstract method for de-tokenizing a sequence of tokens into a
  MidiDict Object."""
  raise NotImplementedError
 
- def detokenize(self, tokenized_seq: list):
+ def detokenize(self, tokenized_seq: list, **kwargs):
  """Detokenizes a MidiDict object.
 
  This function should be overridden if additional are required during
  detokenization. The default behavior is to call detokenize_midi_dict.
  """
- return self._detokenize_midi_dict(tokenized_seq)
+ return self._detokenize_midi_dict(tokenized_seq, **kwargs)
 
  def export_data_aug(cls):
  """Abstract method for exporting a list of all data augmentation
@@ -411,7 +411,9 @@ def truncate_by_time(self, tokenized_seq: list, trunc_time_ms: int):
 
  return tokenized_seq
 
- def _tokenize_midi_dict(self, midi_dict: MidiDict):
+ def _tokenize_midi_dict(
+ self, midi_dict: MidiDict, remove_preceding_silence: bool = True
+ ):
  ticks_per_beat = midi_dict.ticks_per_beat
  midi_dict.remove_instruments(self.config["ignore_instruments"])
 
@@ -450,9 +452,13 @@ def _tokenize_midi_dict(self, midi_dict: MidiDict):
  prefix.insert(0, ("prefix", "genre", genre))
  random.shuffle(prefix)
 
- # NOTE: Any preceding silence is removed implicitly
  tokenized_seq = []
- initial_onset_tick = midi_dict.note_msgs[0]["data"]["start"]
+
+ if remove_preceding_silence is False:
+ initial_onset_tick = 0
+ else:
+ initial_onset_tick = midi_dict.note_msgs[0]["data"]["start"]
+
  curr_time_since_onset = 0
  for _, msg in enumerate(midi_dict.note_msgs):
  # Extract msg data
@@ -543,12 +549,14 @@ def _detokenize_midi_dict(self, tokenized_seq: list):
 
  # Add non-drum instrument_msgs, breaks at first note token
  channel_idx = 0
+ curr_tick = 0
  for idx, tok in enumerate(tokenized_seq):
  if channel_idx == 9: # Skip channel reserved for drums
  channel_idx += 1
 
  if tok in self.special_tokens:
- # Skip special tokens
+ if tok == self.time_tok:
+ curr_tick += self.abs_time_step
  continue
  elif (
  tok[0] == "prefix"
@@ -590,7 +598,6 @@ def _detokenize_midi_dict(self, tokenized_seq: list):
 
  # Note messages
  note_msgs = []
- curr_tick = 0
  for tok_1, tok_2, tok_3 in zip(
  tokenized_seq[start:],
  tokenized_seq[start + 1 :],