in whisper/decoding.py [0:0]
def run(self, mel: Tensor) -> List[DecodingResult]:
self.decoder.reset()
tokenizer: Tokenizer = self.tokenizer
n_audio: int = mel.shape[0]
audio_features: Tensor = self._get_audio_features(mel) # encoder forward pass
tokens: Tensor = torch.tensor([self.initial_tokens]).repeat(n_audio, 1)
# detect language if requested, overwriting the language token
languages, language_probs = self._detect_language(audio_features, tokens)
if self.options.task == "lang_id":
return [
DecodingResult(
audio_features=features, language=language, language_probs=probs
)
for features, language, probs in zip(
audio_features, languages, language_probs
)
]
# repeat text tensors by the group size, for beam search or best-of-n sampling
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)
# reshape the tensors to have (n_audio, n_group) as the first two dimensions
audio_features = audio_features[:: self.n_group]
no_speech_probs = no_speech_probs[:: self.n_group]
assert audio_features.shape[0] == len(no_speech_probs) == n_audio
tokens = tokens.reshape(n_audio, self.n_group, -1)
sum_logprobs = sum_logprobs.reshape(n_audio, self.n_group)
# 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
]
# select the top-ranked sample in each group
selected = self.sequence_ranker.rank(tokens, sum_logprobs)
tokens: List[List[int]] = [t[i].tolist() for i, t in zip(selected, tokens)]
texts: List[str] = [tokenizer.decode(t).strip() for t in tokens]
sum_logprobs: List[float] = [lp[i] for i, lp in zip(selected, sum_logprobs)]
avg_logprobs: List[float] = [
lp / (len(t) + 1) for t, lp in zip(tokens, sum_logprobs)
]
fields = (
texts,
languages,
tokens,
audio_features,
avg_logprobs,
no_speech_probs,
)
if len(set(map(len, fields))) != 1:
raise RuntimeError(f"inconsistent result lengths: {list(map(len, fields))}")
return [
DecodingResult(
audio_features=features,
language=language,
tokens=tokens,
text=text,
avg_logprob=avg_logprob,
no_speech_prob=no_speech_prob,
temperature=self.options.temperature,
compression_ratio=compression_ratio(text),
)
for text, language, tokens, features, avg_logprob, no_speech_prob in zip(
*fields
)
]