def recog_v2(args):
"""Decode with custom models that implements ScorerInterface.
Notes:
The previous backend espnet.asr.pytorch_backend.asr.recog
only supports E2E and RNNLM
Args:
args (namespace): The program arguments.
See py:func:`espnet.bin.asr_recog.get_parser` for details
"""
logging.warning("experimental API for custom LMs is selected by --api v2")
if args.batchsize > 1:
raise NotImplementedError("multi-utt batch decoding is not implemented")
if args.streaming_mode is not None:
raise NotImplementedError("streaming mode is not implemented")
if args.word_rnnlm:
raise NotImplementedError("word LM is not implemented")
set_deterministic_pytorch(args)
model, train_args = load_trained_model(args.model)
assert isinstance(model, ASRInterface)
if args.quantize_config is not None:
q_config = set([getattr(torch.nn, q) for q in args.quantize_config])
else:
q_config = {torch.nn.Linear}
if args.quantize_asr_model:
logging.info("Use quantized asr model for decoding")
# See https://github.com/espnet/espnet/pull/3616 for more information.
if (
torch.__version__ < LooseVersion("1.4.0")
and "lstm" in train_args.etype
and torch.nn.LSTM in q_config
):
raise ValueError(
"Quantized LSTM in ESPnet is only supported with torch 1.4+."
)
if args.quantize_dtype == "float16" and torch.__version__ < LooseVersion(
"1.5.0"
):
raise ValueError(
"float16 dtype for dynamic quantization is not supported with torch "
"version < 1.5.0. Switching to qint8 dtype instead."
)
dtype = getattr(torch, args.quantize_dtype)
model = torch.quantization.quantize_dynamic(model, q_config, dtype=dtype)
model.eval()
load_inputs_and_targets = LoadInputsAndTargets(
mode="asr",
load_output=False,
sort_in_input_length=False,
preprocess_conf=train_args.preprocess_conf
if args.preprocess_conf is None
else args.preprocess_conf,
preprocess_args={"train": False},
)
if args.rnnlm:
lm_args = get_model_conf(args.rnnlm, args.rnnlm_conf)
# NOTE: for a compatibility with less than 0.5.0 version models
lm_model_module = getattr(lm_args, "model_module", "default")
lm_class = dynamic_import_lm(lm_model_module, lm_args.backend)
lm = lm_class(len(train_args.char_list), lm_args)
torch_load(args.rnnlm, lm)
if args.quantize_lm_model:
logging.info("Use quantized lm model")
dtype = getattr(torch, args.quantize_dtype)
lm = torch.quantization.quantize_dynamic(lm, q_config, dtype=dtype)
lm.eval()
else:
lm = None
if args.ngram_model:
from espnet.nets.scorers.ngram import NgramFullScorer
from espnet.nets.scorers.ngram import NgramPartScorer
if args.ngram_scorer == "full":
ngram = NgramFullScorer(args.ngram_model, train_args.char_list)
else:
ngram = NgramPartScorer(args.ngram_model, train_args.char_list)
else:
ngram = None
scorers = model.scorers()
scorers["lm"] = lm
scorers["ngram"] = ngram
scorers["length_bonus"] = LengthBonus(len(train_args.char_list))
weights = dict(
decoder=1.0 - args.ctc_weight,
ctc=args.ctc_weight,
lm=args.lm_weight,
ngram=args.ngram_weight,
length_bonus=args.penalty,
)
beam_search = BeamSearch(
beam_size=args.beam_size,
vocab_size=len(train_args.char_list),
weights=weights,
scorers=scorers,
sos=model.sos,
eos=model.eos,
token_list=train_args.char_list,
pre_beam_score_key=None if args.ctc_weight == 1.0 else "full",
)
# TODO(karita): make all scorers batchfied
if args.batchsize == 1:
non_batch = [
k
for k, v in beam_search.full_scorers.items()
if not isinstance(v, BatchScorerInterface)
]
if len(non_batch) == 0:
beam_search.__class__ = BatchBeamSearch
logging.info("BatchBeamSearch implementation is selected.")
else:
logging.warning(
f"As non-batch scorers {non_batch} are found, "
f"fall back to non-batch implementation."
)
if args.ngpu > 1:
raise NotImplementedError("only single GPU decoding is supported")
if args.ngpu == 1:
device = "cuda"
else:
device = "cpu"
dtype = getattr(torch, args.dtype)
logging.info(f"Decoding device={device}, dtype={dtype}")
model.to(device=device, dtype=dtype).eval()
beam_search.to(device=device, dtype=dtype).eval()
# read json data
with open(args.recog_json, "rb") as f:
js = json.load(f)["utts"]
new_js = {}
with torch.no_grad():
for idx, name in enumerate(js.keys(), 1):
logging.info("(%d/%d) decoding " + name, idx, len(js.keys()))
batch = [(name, js[name])]
feat = load_inputs_and_targets(batch)[0][0]
enc = model.encode(torch.as_tensor(feat).to(device=device, dtype=dtype))
nbest_hyps = beam_search(
x=enc, maxlenratio=args.maxlenratio, minlenratio=args.minlenratio
)
nbest_hyps = [
h.asdict() for h in nbest_hyps[: min(len(nbest_hyps), args.nbest)]
]
new_js[name] = add_results_to_json(
js[name], nbest_hyps, train_args.char_list
)
with open(args.result_label, "wb") as f:
f.write(
json.dumps(
{"utts": new_js}, indent=4, ensure_ascii=False, sort_keys=True
).encode("utf_8")
)
def test_batch_beam_search_equal(
model_class,
args,
ctc_weight,
lm_nn,
lm_args,
lm_weight,
ngram_weight,
bonus,
device,
dtype,
):
if device == "cuda" and not torch.cuda.is_available():
pytest.skip("no cuda device is available")
if device == "cpu" and dtype == "float16":
pytest.skip(
"cpu float16 implementation is not available in pytorch yet")
# seed setting
torch.manual_seed(123)
torch.backends.cudnn.deterministic = True
# https://github.com/pytorch/pytorch/issues/6351
torch.backends.cudnn.benchmark = False
dtype = getattr(torch, dtype)
model, x, ilens, y, data, train_args = prepare(model_class,
args,
mtlalpha=ctc_weight)
model.eval()
char_list = train_args.char_list
lm = dynamic_import_lm(lm_nn, backend="pytorch")(len(char_list), lm_args)
lm.eval()
root = os.path.dirname(os.path.abspath(__file__))
ngram = NgramFullScorer(os.path.join(root, "beam_search_test.arpa"),
args.char_list)
# test previous beam search
args = Namespace(
beam_size=3,
penalty=bonus,
ctc_weight=ctc_weight,
maxlenratio=0,
lm_weight=lm_weight,
ngram_weight=ngram_weight,
minlenratio=0,
nbest=5,
)
# new beam search
scorers = model.scorers()
if lm_weight != 0:
scorers["lm"] = lm
if ngram_weight != 0:
scorers["ngram"] = ngram
scorers["length_bonus"] = LengthBonus(len(char_list))
weights = dict(
decoder=1.0 - ctc_weight,
ctc=ctc_weight,
lm=args.lm_weight,
ngram=args.ngram_weight,
length_bonus=args.penalty,
)
model.to(device, dtype=dtype)
model.eval()
with torch.no_grad():
enc = model.encode(x[0, :ilens[0]].to(device, dtype=dtype))
legacy_beam = BeamSearch(
beam_size=args.beam_size,
vocab_size=len(char_list),
weights=weights,
scorers=scorers,
token_list=train_args.char_list,
sos=model.sos,
eos=model.eos,
pre_beam_score_key=None if ctc_weight == 1.0 else "decoder",
)
legacy_beam.to(device, dtype=dtype)
legacy_beam.eval()
beam = BatchBeamSearch(
beam_size=args.beam_size,
vocab_size=len(char_list),
weights=weights,
scorers=scorers,
token_list=train_args.char_list,
sos=model.sos,
eos=model.eos,
)
beam.to(device, dtype=dtype)
beam.eval()
with torch.no_grad():
legacy_nbest_bs = legacy_beam(x=enc,
maxlenratio=args.maxlenratio,
minlenratio=args.minlenratio)
nbest_bs = beam(x=enc,
maxlenratio=args.maxlenratio,
minlenratio=args.minlenratio)
for i, (expected, actual) in enumerate(zip(legacy_nbest_bs, nbest_bs)):
assert expected.yseq.tolist() == actual.yseq.tolist()
numpy.testing.assert_allclose(expected.score.cpu(),
actual.score.cpu(),
rtol=1e-6)
def __init__(
self,
asr_train_config: Union[Path, str] = None,
asr_model_file: Union[Path, str] = None,
transducer_conf: dict = None,
lm_train_config: Union[Path, str] = None,
lm_file: Union[Path, str] = None,
ngram_scorer: str = "full",
ngram_file: Union[Path, str] = None,
token_type: str = None,
bpemodel: str = None,
device: str = "cpu",
maxlenratio: float = 0.0,
minlenratio: float = 0.0,
batch_size: int = 1,
dtype: str = "float32",
beam_size: int = 20,
ctc_weight: float = 0.5,
lm_weight: float = 1.0,
ngram_weight: float = 0.9,
penalty: float = 0.0,
nbest: int = 1,
streaming: bool = False,
enh_s2t_task: bool = False,
quantize_asr_model: bool = False,
quantize_lm: bool = False,
quantize_modules: List[str] = ["Linear"],
quantize_dtype: str = "qint8",
):
assert check_argument_types()
task = ASRTask if not enh_s2t_task else EnhS2TTask
if quantize_asr_model or quantize_lm:
if quantize_dtype == "float16" and torch.__version__ < LooseVersion(
"1.5.0"):
raise ValueError(
"float16 dtype for dynamic quantization is not supported with "
"torch version < 1.5.0. Switch to qint8 dtype instead.")
quantize_modules = set(
[getattr(torch.nn, q) for q in quantize_modules])
quantize_dtype = getattr(torch, quantize_dtype)
# 1. Build ASR model
scorers = {}
asr_model, asr_train_args = task.build_model_from_file(
asr_train_config, asr_model_file, device)
if enh_s2t_task:
asr_model.inherite_attributes(inherite_s2t_attrs=[
"ctc",
"decoder",
"eos",
"joint_network",
"sos",
"token_list",
"use_transducer_decoder",
])
asr_model.to(dtype=getattr(torch, dtype)).eval()
if quantize_asr_model:
logging.info("Use quantized asr model for decoding.")
asr_model = torch.quantization.quantize_dynamic(
asr_model, qconfig_spec=quantize_modules, dtype=quantize_dtype)
decoder = asr_model.decoder
ctc = CTCPrefixScorer(ctc=asr_model.ctc, eos=asr_model.eos)
token_list = asr_model.token_list
scorers.update(
decoder=decoder,
ctc=ctc,
length_bonus=LengthBonus(len(token_list)),
)
# 2. Build Language model
if lm_train_config is not None:
lm, lm_train_args = LMTask.build_model_from_file(
lm_train_config, lm_file, device)
if quantize_lm:
logging.info("Use quantized lm for decoding.")
lm = torch.quantization.quantize_dynamic(
lm, qconfig_spec=quantize_modules, dtype=quantize_dtype)
scorers["lm"] = lm.lm
# 3. Build ngram model
if ngram_file is not None:
if ngram_scorer == "full":
from espnet.nets.scorers.ngram import NgramFullScorer
ngram = NgramFullScorer(ngram_file, token_list)
else:
from espnet.nets.scorers.ngram import NgramPartScorer
ngram = NgramPartScorer(ngram_file, token_list)
else:
ngram = None
scorers["ngram"] = ngram
# 4. Build BeamSearch object
if asr_model.use_transducer_decoder:
beam_search_transducer = BeamSearchTransducer(
decoder=asr_model.decoder,
joint_network=asr_model.joint_network,
beam_size=beam_size,
lm=scorers["lm"] if "lm" in scorers else None,
lm_weight=lm_weight,
**transducer_conf,
)
beam_search = None
else:
beam_search_transducer = None
weights = dict(
decoder=1.0 - ctc_weight,
ctc=ctc_weight,
lm=lm_weight,
ngram=ngram_weight,
length_bonus=penalty,
)
beam_search = BeamSearch(
beam_size=beam_size,
weights=weights,
scorers=scorers,
sos=asr_model.sos,
eos=asr_model.eos,
vocab_size=len(token_list),
token_list=token_list,
pre_beam_score_key=None if ctc_weight == 1.0 else "full",
)
# TODO(karita): make all scorers batchfied
if batch_size == 1:
non_batch = [
k for k, v in beam_search.full_scorers.items()
if not isinstance(v, BatchScorerInterface)
]
if len(non_batch) == 0:
if streaming:
beam_search.__class__ = BatchBeamSearchOnlineSim
beam_search.set_streaming_config(asr_train_config)
logging.info(
"BatchBeamSearchOnlineSim implementation is selected."
)
else:
beam_search.__class__ = BatchBeamSearch
logging.info(
"BatchBeamSearch implementation is selected.")
else:
logging.warning(
f"As non-batch scorers {non_batch} are found, "
f"fall back to non-batch implementation.")
beam_search.to(device=device, dtype=getattr(torch, dtype)).eval()
for scorer in scorers.values():
if isinstance(scorer, torch.nn.Module):
scorer.to(device=device, dtype=getattr(torch,
dtype)).eval()
logging.info(f"Beam_search: {beam_search}")
logging.info(f"Decoding device={device}, dtype={dtype}")
# 5. [Optional] Build Text converter: e.g. bpe-sym -> Text
if token_type is None:
token_type = asr_train_args.token_type
if bpemodel is None:
bpemodel = asr_train_args.bpemodel
if token_type is None:
tokenizer = None
elif token_type == "bpe":
if bpemodel is not None:
tokenizer = build_tokenizer(token_type=token_type,
bpemodel=bpemodel)
else:
tokenizer = None
else:
tokenizer = build_tokenizer(token_type=token_type)
converter = TokenIDConverter(token_list=token_list)
logging.info(f"Text tokenizer: {tokenizer}")
self.asr_model = asr_model
self.asr_train_args = asr_train_args
self.converter = converter
self.tokenizer = tokenizer
self.beam_search = beam_search
self.beam_search_transducer = beam_search_transducer
self.maxlenratio = maxlenratio
self.minlenratio = minlenratio
self.device = device
self.dtype = dtype
self.nbest = nbest
def recog_v2(args):
"""Decode with custom models that implements ScorerInterface.
Notes:
The previous backend espnet.asr.pytorch_backend.asr.recog
only supports E2E and RNNLM
Args:
args (namespace): The program arguments.
See py:func:`espnet.bin.asr_recog.get_parser` for details
"""
logging.warning("experimental API for custom LMs is selected by --api v2")
if args.batchsize > 1:
raise NotImplementedError(
"multi-utt batch decoding is not implemented")
if args.streaming_mode is not None:
raise NotImplementedError("streaming mode is not implemented")
if args.word_rnnlm:
raise NotImplementedError("word LM is not implemented")
set_deterministic_pytorch(args)
model, train_args = load_trained_model(args.model)
assert isinstance(model, ASRInterface)
model.eval()
load_inputs_and_targets = LoadInputsAndTargets(
mode="asr",
load_output=False,
sort_in_input_length=False,
preprocess_conf=train_args.preprocess_conf
if args.preprocess_conf is None else args.preprocess_conf,
preprocess_args={"train": False},
)
if args.rnnlm:
lm_args = get_model_conf(args.rnnlm, args.rnnlm_conf)
# NOTE: for a compatibility with less than 0.5.0 version models
lm_model_module = getattr(lm_args, "model_module", "default")
lm_class = dynamic_import_lm(lm_model_module, lm_args.backend)
lm = lm_class(len(train_args.char_list), lm_args)
torch_load(args.rnnlm, lm)
lm.eval()
else:
lm = None
if args.ngram_model:
from espnet.nets.scorers.ngram import NgramFullScorer
from espnet.nets.scorers.ngram import NgramPartScorer
if args.ngram_scorer == "full":
ngram = NgramFullScorer(args.ngram_model, train_args.char_list)
else:
ngram = NgramPartScorer(args.ngram_model, train_args.char_list)
else:
ngram = None
scorers = model.scorers()
scorers["lm"] = lm
scorers["ngram"] = ngram
scorers["length_bonus"] = LengthBonus(len(train_args.char_list))
weights = dict(
decoder=1.0 - args.ctc_weight,
ctc=args.ctc_weight,
lm=args.lm_weight,
ngram=args.ngram_weight,
length_bonus=args.penalty,
)
beam_search = BeamSearch(
beam_size=args.beam_size,
vocab_size=len(train_args.char_list),
weights=weights,
scorers=scorers,
sos=model.sos,
eos=model.eos,
token_list=train_args.char_list,
pre_beam_score_key=None if args.ctc_weight == 1.0 else "full",
)
# TODO(karita): make all scorers batchfied
if args.batchsize == 1:
non_batch = [
k for k, v in beam_search.full_scorers.items()
if not isinstance(v, BatchScorerInterface)
]
if len(non_batch) == 0:
beam_search.__class__ = BatchBeamSearch
logging.info("BatchBeamSearch implementation is selected.")
else:
logging.warning(f"As non-batch scorers {non_batch} are found, "
f"fall back to non-batch implementation.")
if args.ngpu > 1:
raise NotImplementedError("only single GPU decoding is supported")
if args.ngpu == 1:
device = "cuda"
else:
device = "cpu"
dtype = getattr(torch, args.dtype)
logging.info(f"Decoding device={device}, dtype={dtype}")
model.to(device=device, dtype=dtype).eval()
beam_search.to(device=device, dtype=dtype).eval()
# read json data
with open(args.recog_json, "r") as f: # "rb"
content = f.read()
if content.startswith(
"Warning! You haven't set Python environment yet. Go to /content/espnet/tools and generate 'activate_python.sh'"
):
train_json = json.loads(
content[110:]
)["utts"] # 110 is the number of characters for the above WARNING LINE.
else:
train_json = json.loads(content)["utts"] # json.load(f)["utts"]
js = train_json # json.load(f)["utts"]
new_js = {}
with torch.no_grad():
for idx, name in enumerate(js.keys(), 1):
logging.info("(%d/%d) decoding " + name, idx, len(js.keys()))
batch = [(name, js[name])]
feat = load_inputs_and_targets(batch)[0][0]
enc = model.encode(
torch.as_tensor(feat).to(device=device, dtype=dtype))
nbest_hyps = beam_search(x=enc,
maxlenratio=args.maxlenratio,
minlenratio=args.minlenratio)
nbest_hyps = [
h.asdict()
for h in nbest_hyps[:min(len(nbest_hyps), args.nbest)]
]
new_js[name] = add_results_to_json(js[name], nbest_hyps,
train_args.char_list)
with open(args.result_label, "wb") as f:
f.write(
json.dumps({
"utts": new_js
},
indent=4,
ensure_ascii=False,
sort_keys=True).encode("utf_8"))
def __init__(
self,
asr_train_config: Union[Path, str] = None,
asr_model_file: Union[Path, str] = None,
transducer_conf: dict = None,
lm_train_config: Union[Path, str] = None,
lm_file: Union[Path, str] = None,
ngram_scorer: str = "full",
ngram_file: Union[Path, str] = None,
token_type: str = None,
bpemodel: str = None,
device: str = "cpu",
maxlenratio: float = 0.0,
minlenratio: float = 0.0,
batch_size: int = 1,
dtype: str = "float32",
beam_size: int = 20,
ctc_weight: float = 0.5,
lm_weight: float = 1.0,
ngram_weight: float = 0.9,
penalty: float = 0.0,
nbest: int = 1,
streaming: bool = False,
):
assert check_argument_types()
# 1. Build ASR model
scorers = {}
asr_model, asr_train_args = ASRTask.build_model_from_file(
asr_train_config, asr_model_file, device)
asr_model.to(dtype=getattr(torch, dtype)).eval()
decoder = asr_model.decoder
ctc = CTCPrefixScorer(ctc=asr_model.ctc, eos=asr_model.eos)
token_list = asr_model.token_list
scorers.update(
decoder=decoder,
ctc=ctc,
length_bonus=LengthBonus(len(token_list)),
)
# 2. Build Language model
if lm_train_config is not None:
lm, lm_train_args = LMTask.build_model_from_file(
lm_train_config, lm_file, device)
scorers["lm"] = lm.lm
# 3. Build ngram model
if ngram_file is not None:
if ngram_scorer == "full":
from espnet.nets.scorers.ngram import NgramFullScorer
ngram = NgramFullScorer(ngram_file, token_list)
else:
from espnet.nets.scorers.ngram import NgramPartScorer
ngram = NgramPartScorer(ngram_file, token_list)
else:
ngram = None
scorers["ngram"] = ngram
# 4. Build BeamSearch object
if asr_model.use_transducer_decoder:
beam_search_transducer = BeamSearchTransducer(
decoder=asr_model.decoder,
joint_network=asr_model.joint_network,
beam_size=beam_size,
lm=scorers["lm"] if "lm" in scorers else None,
lm_weight=lm_weight,
**transducer_conf,
)
beam_search = None
else:
beam_search_transducer = None
weights = dict(
decoder=1.0 - ctc_weight,
ctc=ctc_weight,
lm=lm_weight,
length_bonus=penalty,
)
beam_search = BeamSearch(
beam_size=beam_size,
weights=weights,
scorers=scorers,
sos=asr_model.sos,
eos=asr_model.eos,
vocab_size=len(token_list),
token_list=token_list,
pre_beam_score_key=None if ctc_weight == 1.0 else "full",
)
# TODO(karita): make all scorers batchfied
if batch_size == 1:
non_batch = [
k for k, v in beam_search.full_scorers.items()
if not isinstance(v, BatchScorerInterface)
]
if len(non_batch) == 0:
if streaming:
beam_search.__class__ = BatchBeamSearchOnlineSim
beam_search.set_streaming_config(asr_train_config)
logging.info(
"BatchBeamSearchOnlineSim implementation is selected."
)
else:
beam_search.__class__ = BatchBeamSearch
logging.info(
"BatchBeamSearch implementation is selected.")
else:
logging.warning(
f"As non-batch scorers {non_batch} are found, "
f"fall back to non-batch implementation.")
beam_search.to(device=device, dtype=getattr(torch, dtype)).eval()
for scorer in scorers.values():
if isinstance(scorer, torch.nn.Module):
scorer.to(device=device, dtype=getattr(torch,
dtype)).eval()
logging.info(f"Beam_search: {beam_search}")
logging.info(f"Decoding device={device}, dtype={dtype}")
# 5. [Optional] Build Text converter: e.g. bpe-sym -> Text
if token_type is None:
token_type = asr_train_args.token_type
if bpemodel is None:
bpemodel = asr_train_args.bpemodel
if token_type is None:
tokenizer = None
elif token_type == "bpe":
if bpemodel is not None:
tokenizer = build_tokenizer(token_type=token_type,
bpemodel=bpemodel)
else:
tokenizer = None
else:
tokenizer = build_tokenizer(token_type=token_type)
converter = TokenIDConverter(token_list=token_list)
logging.info(f"Text tokenizer: {tokenizer}")
self.asr_model = asr_model
self.asr_train_args = asr_train_args
self.converter = converter
self.tokenizer = tokenizer
self.beam_search = beam_search
self.beam_search_transducer = beam_search_transducer
self.maxlenratio = maxlenratio
self.minlenratio = minlenratio
self.device = device
self.dtype = dtype
self.nbest = nbest
def __init__(
self,
st_train_config: Union[Path, str] = None,
st_model_file: Union[Path, str] = None,
lm_train_config: Union[Path, str] = None,
lm_file: Union[Path, str] = None,
ngram_scorer: str = "full",
ngram_file: Union[Path, str] = None,
token_type: str = None,
bpemodel: str = None,
device: str = "cpu",
maxlenratio: float = 0.0,
minlenratio: float = 0.0,
batch_size: int = 1,
dtype: str = "float32",
beam_size: int = 20,
lm_weight: float = 1.0,
ngram_weight: float = 0.9,
penalty: float = 0.0,
nbest: int = 1,
enh_s2t_task: bool = False,
):
assert check_argument_types()
task = STTask if not enh_s2t_task else EnhS2TTask
# 1. Build ST model
scorers = {}
st_model, st_train_args = task.build_model_from_file(
st_train_config, st_model_file, device
)
if enh_s2t_task:
st_model.inherite_attributes(
inherite_s2t_attrs=[
"ctc",
"decoder",
"eos",
"joint_network",
"sos",
"token_list",
"use_transducer_decoder",
]
)
st_model.to(dtype=getattr(torch, dtype)).eval()
decoder = st_model.decoder
token_list = st_model.token_list
scorers.update(
decoder=decoder,
length_bonus=LengthBonus(len(token_list)),
)
# 2. Build Language model
if lm_train_config is not None:
lm, lm_train_args = LMTask.build_model_from_file(
lm_train_config, lm_file, device
)
scorers["lm"] = lm.lm
# 3. Build ngram model
if ngram_file is not None:
if ngram_scorer == "full":
from espnet.nets.scorers.ngram import NgramFullScorer
ngram = NgramFullScorer(ngram_file, token_list)
else:
from espnet.nets.scorers.ngram import NgramPartScorer
ngram = NgramPartScorer(ngram_file, token_list)
else:
ngram = None
scorers["ngram"] = ngram
# 4. Build BeamSearch object
weights = dict(
decoder=1.0,
lm=lm_weight,
ngram=ngram_weight,
length_bonus=penalty,
)
beam_search = BeamSearch(
beam_size=beam_size,
weights=weights,
scorers=scorers,
sos=st_model.sos,
eos=st_model.eos,
vocab_size=len(token_list),
token_list=token_list,
pre_beam_score_key="full",
)
# TODO(karita): make all scorers batchfied
if batch_size == 1:
non_batch = [
k
for k, v in beam_search.full_scorers.items()
if not isinstance(v, BatchScorerInterface)
]
if len(non_batch) == 0:
beam_search.__class__ = BatchBeamSearch
logging.info("BatchBeamSearch implementation is selected.")
else:
logging.warning(
f"As non-batch scorers {non_batch} are found, "
f"fall back to non-batch implementation."
)
beam_search.to(device=device, dtype=getattr(torch, dtype)).eval()
for scorer in scorers.values():
if isinstance(scorer, torch.nn.Module):
scorer.to(device=device, dtype=getattr(torch, dtype)).eval()
logging.info(f"Beam_search: {beam_search}")
logging.info(f"Decoding device={device}, dtype={dtype}")
# 4. [Optional] Build Text converter: e.g. bpe-sym -> Text
if token_type is None:
token_type = st_train_args.token_type
if bpemodel is None:
bpemodel = st_train_args.bpemodel
if token_type is None:
tokenizer = None
elif token_type == "bpe":
if bpemodel is not None:
tokenizer = build_tokenizer(token_type=token_type, bpemodel=bpemodel)
else:
tokenizer = None
else:
tokenizer = build_tokenizer(token_type=token_type)
converter = TokenIDConverter(token_list=token_list)
logging.info(f"Text tokenizer: {tokenizer}")
self.st_model = st_model
self.st_train_args = st_train_args
self.converter = converter
self.tokenizer = tokenizer
self.beam_search = beam_search
self.maxlenratio = maxlenratio
self.minlenratio = minlenratio
self.device = device
self.dtype = dtype
self.nbest = nbest