Added per-token confidence to each segment in decoding.py

- Implemented per-token confidence tracking in GreedyDecoder and BeamSearchDecoder.
- Updated DecodingResult to include tokens_probs.
- Enhanced token update methods to calculate and store token probabilities.
- Improved finalization methods to handle token probabilities.
- Modified DecodingTask to manage per-token confidence during the decoding process.
This commit is contained in:
Ashish Patel 2024-07-29 18:15:53 +05:30 committed by GitHub
parent 69913d1bd6
commit f4e24bb466
No known key found for this signature in database
GPG Key ID: B5690EEEBB952194

View File

@ -125,6 +125,7 @@ class DecodingResult:
no_speech_prob: float = np.nan
temperature: float = np.nan
compression_ratio: float = np.nan
tokens_probs: list[float] = field(default_factory=list)
class Inference:
@ -218,8 +219,8 @@ class TokenDecoder:
"""Initialize any stateful variables for decoding a new sequence"""
def update(
self, tokens: Tensor, logits: Tensor, sum_logprobs: Tensor
) -> Tuple[Tensor, bool]:
self, tokens: Tensor, logits: Tensor, sum_logprobs: Tensor, tokens_probs: list[list[float]]
) -> Tuple[Tensor, list, bool]:
"""Specify how to select the next token, based on the current trace and logits
Parameters
@ -275,8 +276,8 @@ class GreedyDecoder(TokenDecoder):
self.eot = eot
def update(
self, tokens: Tensor, logits: Tensor, sum_logprobs: Tensor
) -> Tuple[Tensor, bool]:
self, tokens: Tensor, logits: Tensor, sum_logprobs: Tensor, tokens_probs: list
) -> Tuple[Tensor, list, bool]:
if self.temperature == 0:
next_tokens = logits.argmax(dim=-1)
else:
@ -284,18 +285,25 @@ class GreedyDecoder(TokenDecoder):
logprobs = F.log_softmax(logits.float(), dim=-1)
current_logprobs = logprobs[torch.arange(logprobs.shape[0]), next_tokens]
current_probs = torch.exp(current_logprobs)
sum_logprobs += current_logprobs * (tokens[:, -1] != self.eot)
tokens_probs = [t_p + [c_p.item()] for t_p, c_p in zip(tokens_probs, current_probs)]
next_tokens[tokens[:, -1] == self.eot] = self.eot
tokens = torch.cat([tokens, next_tokens[:, None]], dim=-1)
completed = (tokens[:, -1] == self.eot).all()
return tokens, completed
return tokens, tokens_probs, completed
def finalize(self, tokens: Tensor, sum_logprobs: Tensor):
# make sure each sequence has at least one EOT token at the end
def finalize(
self, tokens: Tensor, tokens_probs: list, sum_logprobs: Tensor
) -> Tuple[Tensor, list, list]:
tokens = F.pad(tokens, (0, 1), value=self.eot)
return tokens, sum_logprobs.tolist()
tokens_probs = [[ t + [1.0] for t in s] for s in tokens_probs]
return tokens, tokens_probs, sum_logprobs.tolist()
class BeamSearchDecoder(TokenDecoder):
@ -321,37 +329,39 @@ class BeamSearchDecoder(TokenDecoder):
self.finished_sequences = None
def update(
self, tokens: Tensor, logits: Tensor, sum_logprobs: Tensor
) -> Tuple[Tensor, bool]:
self, tokens: Tensor, logits: Tensor, sum_logprobs: Tensor, tokens_probs: list
) -> Tuple[Tensor, list, bool]:
if tokens.shape[0] % self.beam_size != 0:
raise ValueError(f"{tokens.shape}[0] % {self.beam_size} != 0")
n_audio = tokens.shape[0] // self.beam_size
if self.finished_sequences is None: # for the first update
if self.finished_sequences is None:
self.finished_sequences = [{} for _ in range(n_audio)]
logprobs = F.log_softmax(logits.float(), dim=-1)
next_tokens, source_indices, finished_sequences = [], [], []
for i in range(n_audio):
scores, sources, finished = {}, {}, {}
scores, sources, finished, probs = {}, {}, {}, {}
# STEP 1: calculate the cumulative log probabilities for possible candidates
for j in range(self.beam_size):
idx = i * self.beam_size + j
prefix = tokens[idx].tolist()
for logprob, token in zip(*logprobs[idx].topk(self.beam_size + 1)):
prob = torch.exp(logprob).item()
new_logprob = (sum_logprobs[idx] + logprob).item()
sequence = tuple(prefix + [token.item()])
scores[sequence] = new_logprob
sources[sequence] = idx
# STEP 2: rank the candidates and keep the top beam_size sequences for each audio
probs[sequence] = tokens_probs[idx] + [prob]
saved = 0
for sequence in sorted(scores, key=scores.get, reverse=True):
if sequence[-1] == self.eot:
finished[sequence] = scores[sequence]
finished[sequence] = (scores[sequence], probs[sequence])
else:
sum_logprobs[len(next_tokens)] = scores[sequence]
tokens_probs[len(next_tokens)] = probs[sequence]
next_tokens.append(sequence)
source_indices.append(sources[sequence])
@ -364,44 +374,42 @@ class BeamSearchDecoder(TokenDecoder):
tokens = torch.tensor(next_tokens, device=tokens.device)
self.inference.rearrange_kv_cache(source_indices)
# add newly finished sequences to self.finished_sequences
assert len(self.finished_sequences) == len(finished_sequences)
for previously_finished, newly_finished in zip(
self.finished_sequences, finished_sequences
):
for previously_finished, newly_finished in zip(self.finished_sequences, finished_sequences):
for seq in sorted(newly_finished, key=newly_finished.get, reverse=True):
if len(previously_finished) >= self.max_candidates:
break # the candidate list is full
break
previously_finished[seq] = newly_finished[seq]
# mark as completed if all audio has enough number of samples
completed = all(
len(sequences) >= self.max_candidates
for sequences in self.finished_sequences
len(sequences) >= self.max_candidates for sequences in self.finished_sequences
)
return tokens, completed
def finalize(self, preceding_tokens: Tensor, sum_logprobs: Tensor):
# collect all finished sequences, including patience, and add unfinished ones if not enough
return tokens, tokens_probs, completed
def finalize(
self, preceding_tokens: Tensor, preceding_tokens_prob: list, sum_logprobs: Tensor
) -> Tuple[list, list, list]:
sum_logprobs = sum_logprobs.cpu()
for i, sequences in enumerate(self.finished_sequences):
if (
len(sequences) < self.beam_size
): # when not enough sequences are finished
if len(sequences) < self.beam_size:
for j in list(np.argsort(sum_logprobs[i]))[::-1]:
sequence = preceding_tokens[i, j].tolist() + [self.eot]
sequences[tuple(sequence)] = sum_logprobs[i][j].item()
sequences[tuple(sequence)] = (sum_logprobs[i][j].item(), preceding_tokens_prob[i][j] + [1.0])
if len(sequences) >= self.beam_size:
break
tokens: List[List[Tensor]] = [
[torch.tensor(seq) for seq in sequences.keys()]
for sequences in self.finished_sequences
[torch.tensor(seq) for seq in sequences.keys()] for sequences in self.finished_sequences
]
sum_logprobs: List[List[float]] = [
list(sequences.values()) for sequences in self.finished_sequences
[v[0] for v in sequences.values()] for sequences in self.finished_sequences
]
return tokens, sum_logprobs
tokens_probs: list[list[list[float]]] = [
[v[1] for v in sequences.values()] for sequences in self.finished_sequences
]
return tokens, tokens_probs, sum_logprobs
class LogitFilter:
@ -700,7 +708,8 @@ class DecodingTask:
logit_filter.apply(logits, tokens)
# expand the tokens tensor with the selected next tokens
tokens, completed = self.decoder.update(tokens, logits, sum_logprobs)
tokens, tokens_probs, completed = self.decoder.update(tokens, logits, sum_logprobs, tokens_probs)
if completed or tokens.shape[-1] > self.n_ctx:
break
@ -734,7 +743,7 @@ class DecodingTask:
tokens = tokens.repeat_interleave(self.n_group, dim=0).to(audio_features.device)
# call the main sampling loop
tokens, sum_logprobs, no_speech_probs = self._main_loop(audio_features, tokens)
tokens, sum_logprobs, no_speech_probs, tokens_probs = self._main_loop(audio_features, tokens)
# reshape the tensors to have (n_audio, n_group) as the first two dimensions
audio_features = audio_features[:: self.n_group]
@ -747,8 +756,10 @@ class DecodingTask:
# get the final candidates for each group, and slice between the first sampled token and EOT
tokens, sum_logprobs = self.decoder.finalize(tokens, sum_logprobs)
tokens: List[List[Tensor]] = [
[t[self.sample_begin : (t == tokenizer.eot).nonzero()[0, 0]] for t in s]
for s in tokens
[t[self.sample_begin : (t == tokenizer.eot).nonzero()[0, 0]] for t in s] for s in tokens
]
tokens_probs: list[list[list[float]]] = [
[probs[:tokens.shape[0]]for probs, tokens in zip(s, t)] for s, t in zip(tokens_probs, tokens)
]
# select the top-ranked sample in each group