def get_hierarchical_targets(ys: List[List[int]],
lexicon: k2.Fsa) -> List[Tensor]:
"""Get hierarchical transcripts (i.e., phone level transcripts) from transcripts (i.e., word level transcripts).
Args:
ys: Word level transcripts.
lexicon: Its labels are words, while its aux_labels are phones.
Returns:
List[Tensor]: Phone level transcripts.
"""
if lexicon is None:
return ys
else:
L_inv = lexicon
n_batch = len(ys)
indices = torch.tensor(range(n_batch))
transcripts = k2.create_fsa_vec([k2.linear_fsa(x) for x in ys])
transcripts_lexicon = k2.intersect(transcripts, L_inv)
transcripts_lexicon = k2.arc_sort(k2.connect(transcripts_lexicon))
transcripts_lexicon = k2.remove_epsilon(transcripts_lexicon)
transcripts_lexicon = k2.shortest_path(transcripts_lexicon,
use_double_scores=True)
ys = get_texts(transcripts_lexicon, indices)
ys = [torch.tensor(y) for y in ys]
return ys
def build_num_graphs(self, texts: List[str]) -> k2.Fsa:
'''Convert transcript to an Fsa with the help of lexicon
and word symbol table.
Args:
texts:
Each element is a transcript containing words separated by spaces.
For instance, it may be 'HELLO SNOWFALL', which contains
two words.
Returns:
Return an FST (FsaVec) corresponding to the transcript. Its `labels` are
phone IDs and `aux_labels` are word IDs.
'''
word_ids_list = []
for text in texts:
word_ids = []
for word in text.split(' '):
if word in self.lexicon.words:
word_ids.append(self.lexicon.words[word])
else:
word_ids.append(self.oov_id)
word_ids_list.append(word_ids)
fsa = k2.linear_fsa(word_ids_list, self.device)
fsa = k2.add_epsilon_self_loops(fsa)
assert fsa.device == self.device
num_graphs = k2.intersect(self.L_inv,
fsa,
treat_epsilons_specially=False).invert_()
num_graphs = k2.arc_sort(num_graphs)
return num_graphs
def test_fsa_vec(self):
symbols = [
[1, 3, 5],
[2, 6],
[8, 7, 9],
]
num_symbols = sum([len(s) for s in symbols])
fsa = k2.linear_fsa(symbols)
assert len(fsa.shape) == 3
assert fsa.shape[0] == 3, 'There should be 3 FSAs'
expected_arcs = [
# fsa 0
[0, 1, 1],
[1, 2, 3],
[2, 3, 5],
[3, 4, -1],
# fsa 1
[0, 1, 2],
[1, 2, 6],
[2, 3, -1],
# fsa 2
[0, 1, 8],
[1, 2, 7],
[2, 3, 9],
[3, 4, -1]
]
print(fsa.arcs.values()[:, :-1])
assert torch.allclose(
fsa.arcs.values()[:, :-1], # skip the last field `scores`
torch.tensor(expected_arcs, dtype=torch.int32))
assert torch.allclose(
fsa.scores,
torch.zeros(num_symbols + len(symbols), dtype=torch.float32))
def test_case1(self):
devices = [torch.device('cpu')]
if torch.cuda.is_available():
devices.append(torch.device('cuda'))
for device in devices:
# suppose we have four symbols: <blk>, a, b, c, d
torch_activation = torch.tensor([0.2, 0.2, 0.2, 0.2,
0.2]).to(device)
k2_activation = torch_activation.detach().clone()
# (T, N, C)
torch_activation = torch_activation.reshape(
1, 1, -1).requires_grad_(True)
# (N, T, C)
k2_activation = k2_activation.reshape(1, 1,
-1).requires_grad_(True)
torch_log_probs = torch.nn.functional.log_softmax(
torch_activation, dim=-1) # (T, N, C)
# we have only one sequence and its label is `a`
targets = torch.tensor([1]).to(device)
input_lengths = torch.tensor([1]).to(device)
target_lengths = torch.tensor([1]).to(device)
torch_loss = torch.nn.functional.ctc_loss(
log_probs=torch_log_probs,
targets=targets,
input_lengths=input_lengths,
target_lengths=target_lengths,
reduction='none')
assert torch.allclose(torch_loss,
torch.tensor([1.6094379425049]).to(device))
# (N, T, C)
k2_log_probs = torch.nn.functional.log_softmax(k2_activation,
dim=-1)
supervision_segments = torch.tensor([[0, 0, 1]], dtype=torch.int32)
dense_fsa_vec = k2.DenseFsaVec(k2_log_probs,
supervision_segments).to(device)
ctc_topo_inv = k2.arc_sort(
build_ctc_topo([0, 1, 2, 3, 4]).invert_())
linear_fsa = k2.linear_fsa([1])
decoding_graph = k2.intersect(ctc_topo_inv, linear_fsa)
decoding_graph = k2.connect(decoding_graph).invert_().to(device)
target_graph = k2.intersect_dense(decoding_graph, dense_fsa_vec,
100.0)
k2_scores = target_graph.get_tot_scores(log_semiring=True,
use_double_scores=False)
assert torch.allclose(torch_loss, -1 * k2_scores)
torch_loss.backward()
(-k2_scores).backward()
assert torch.allclose(torch_activation.grad, k2_activation.grad)
def compile_one_and_cache(self, text: str) -> Fsa:
tokens = (token if token in self.vocab._sym2id else self.oov
for token in text.split(' '))
word_ids = [self.vocab.get(token) for token in tokens]
fsa = k2.linear_fsa(word_ids)
decoding_graph = k2.connect(k2.intersect(fsa, self.L_inv)).invert_()
decoding_graph = k2.add_epsilon_self_loops(decoding_graph)
return decoding_graph
def test_single_fsa(self):
for device in self.devices:
labels = [2, 0, 0, 0, 5, 8]
src = k2.linear_fsa(labels, device)
dst = k2.linear_fsa_with_self_loops(src)
assert src.device == dst.device
expected_labels = [0, 2, 0, 5, 0, 8, 0, -1]
assert dst.labels.tolist() == expected_labels
def test_case3(self):
devices = [torch.device('cpu')]
if torch.cuda.is_available():
devices.append(torch.device('cuda'))
for device in devices:
# (T, N, C)
torch_activation = torch.tensor([[
[-5, -4, -3, -2, -1],
[-10, -9, -8, -7, -6],
[-15, -14, -13, -12, -11.],
]]).permute(1, 0, 2).to(device).requires_grad_(True)
torch_activation = torch_activation.to(torch.float32)
torch_activation.requires_grad_(True)
k2_activation = torch_activation.detach().clone().requires_grad_(
True)
torch_log_probs = torch.nn.functional.log_softmax(
torch_activation, dim=-1) # (T, N, C)
# we have only one sequence and its labels are `b,c`
targets = torch.tensor([2, 3]).to(device)
input_lengths = torch.tensor([3]).to(device)
target_lengths = torch.tensor([2]).to(device)
torch_loss = torch.nn.functional.ctc_loss(
log_probs=torch_log_probs,
targets=targets,
input_lengths=input_lengths,
target_lengths=target_lengths,
reduction='none')
act = k2_activation.permute(1, 0, 2) # (T, N, C) -> (N, T, C)
k2_log_probs = torch.nn.functional.log_softmax(act, dim=-1)
supervision_segments = torch.tensor([[0, 0, 3]], dtype=torch.int32)
dense_fsa_vec = k2.DenseFsaVec(k2_log_probs,
supervision_segments).to(device)
ctc_topo_inv = k2.arc_sort(
build_ctc_topo([0, 1, 2, 3, 4]).invert_())
linear_fsa = k2.linear_fsa([2, 3])
decoding_graph = k2.intersect(ctc_topo_inv, linear_fsa)
decoding_graph = k2.connect(decoding_graph).invert_().to(device)
target_graph = k2.intersect_dense(decoding_graph, dense_fsa_vec,
100.0)
k2_scores = target_graph.get_tot_scores(log_semiring=True,
use_double_scores=False)
assert torch.allclose(torch_loss, -1 * k2_scores)
assert torch.allclose(torch_loss,
torch.tensor([4.938850402832]).to(device))
torch_loss.backward()
(-k2_scores).backward()
assert torch.allclose(torch_activation.grad, k2_activation.grad)
def generate_nbest_list(lats: Fsa, num_paths: int) -> Nbest:
'''Generate an n-best list from a lattice.
Args:
lats:
The decoding lattice from the first pass after LM rescoring.
lats is an FsaVec. It can be the return value of
:func:`whole_lattice_rescoring`
num_paths:
Size of n for n-best list. CAUTION: After removing paths
that represent the same token sequences, the number of paths
in different sequences may not be equal.
Return:
Return an Nbest object. Note the returned FSAs don't have epsilon
self-loops.
'''
assert len(lats.shape) == 3
# CAUTION: We use `phones` instead of `tokens` here because
# :func:`compile_HLG` uses `phones`
#
# Note: compile_HLG is from k2-fsa/snowfall
assert hasattr(lats, 'phones')
assert not hasattr(lats, 'tokens')
lats.tokens = lats.phones
# we use tokens instead of phones in the following code
# First, extract `num_paths` paths for each sequence.
# paths is a k2.RaggedTensor with axes [seq][path][arc_pos]
paths = k2.random_paths(lats, num_paths=num_paths, use_double_scores=True)
# token_seqs is a k2.RaggedTensor sharing the same shape as `paths`
# but it contains token IDs. Note that it also contains 0s and -1s.
# The last entry in each sublist is -1.
# Its axes are [seq][path][token_id]
token_seqs = k2.ragged.index(lats.tokens, paths)
# Remove epsilons (0s) and -1 from token_seqs
token_seqs = token_seqs.remove_values_leq(0)
# unique_token_seqs is still a k2.RaggedTensor with axes
# [seq][path]token_id].
# But then number of paths in each sequence may be different.
unique_token_seqs, _, _ = token_seqs.unique(need_num_repeats=False,
need_new2old_indexes=False)
seq_to_path_shape = unique_token_seqs.shape.get_layer(0)
# Remove the seq axis.
# Now unique_token_seqs has only two axes [path][token_id]
unique_token_seqs = unique_token_seqs.remove_axis(0)
token_fsas = k2.linear_fsa(unique_token_seqs)
return Nbest(fsa=token_fsas, shape=seq_to_path_shape)
def compile_one_and_cache(self, text: str) -> k2.Fsa:
tokens = (token if token in self.words else self.oov
for token in text.split(' '))
word_ids = [self.words[token] for token in tokens]
fsa = k2.linear_fsa(word_ids)
decoding_graph = k2.connect(k2.intersect(fsa, self.L_inv)).invert_()
decoding_graph = k2.arc_sort(decoding_graph)
decoding_graph = k2.compose(self.ctc_topo, decoding_graph)
decoding_graph = k2.connect(decoding_graph)
return decoding_graph
def test_random_case1(self):
# 1 sequence
devices = [torch.device('cpu')]
if torch.cuda.is_available():
devices.append(torch.device('cuda', 0))
for device in devices:
T = torch.randint(10, 100, (1,)).item()
C = torch.randint(20, 30, (1,)).item()
torch_activation = torch.rand((1, T + 10, C),
dtype=torch.float32,
device=device).requires_grad_(True)
k2_activation = torch_activation.detach().clone().requires_grad_(
True)
# [N, T, C] -> [T, N, C]
torch_log_probs = torch.nn.functional.log_softmax(
torch_activation.permute(1, 0, 2), dim=-1)
input_lengths = torch.tensor([T]).to(device)
target_lengths = torch.randint(1, T, (1,)).to(device)
targets = torch.randint(1, C - 1,
(target_lengths.item(),)).to(device)
torch_loss = torch.nn.functional.ctc_loss(
log_probs=torch_log_probs,
targets=targets,
input_lengths=input_lengths,
target_lengths=target_lengths,
reduction='none')
k2_log_probs = torch.nn.functional.log_softmax(k2_activation,
dim=-1)
supervision_segments = torch.tensor([[0, 0, T]], dtype=torch.int32)
dense_fsa_vec = k2.DenseFsaVec(k2_log_probs,
supervision_segments).to(device)
ctc_topo_inv = k2.arc_sort(
build_ctc_topo(list(range(C))).invert_())
linear_fsa = k2.linear_fsa([targets.tolist()])
decoding_graph = k2.intersect(ctc_topo_inv, linear_fsa)
decoding_graph = k2.connect(decoding_graph).invert_().to(device)
target_graph = k2.intersect_dense(decoding_graph, dense_fsa_vec,
100.0)
k2_scores = target_graph.get_tot_scores(log_semiring=True,
use_double_scores=False)
assert torch.allclose(torch_loss, -1 * k2_scores)
scale = torch.rand_like(torch_loss) * 100
(torch_loss * scale).sum().backward()
(-k2_scores * scale).sum().backward()
assert torch.allclose(torch_activation.grad,
k2_activation.grad,
atol=1e-2)
def test_single_fsa(self):
symbols = [2, 5, 8]
fsa = k2.linear_fsa(symbols)
assert len(fsa.shape) == 2
assert fsa.shape[0] == len(symbols) + 2, 'There should be 5 states'
assert torch.allclose(
fsa.scores, torch.zeros(len(symbols) + 1, dtype=torch.float32))
assert torch.allclose(
fsa.arcs.values()[:, :-1], # skip the last field `scores`
torch.tensor([[0, 1, 2], [1, 2, 5], [2, 3, 8], [3, 4, -1]],
dtype=torch.int32))
def test_case1(self):
for device in self.devices:
# suppose we have four symbols: <blk>, a, b, c, d
torch_activation = torch.tensor([0.2, 0.2, 0.2, 0.2,
0.2]).to(device)
k2_activation = torch_activation.detach().clone()
# (T, N, C)
torch_activation = torch_activation.reshape(
1, 1, -1).requires_grad_(True)
# (N, T, C)
k2_activation = k2_activation.reshape(1, 1,
-1).requires_grad_(True)
torch_log_probs = torch.nn.functional.log_softmax(
torch_activation, dim=-1) # (T, N, C)
# we have only one sequence and its label is `a`
targets = torch.tensor([1]).to(device)
input_lengths = torch.tensor([1]).to(device)
target_lengths = torch.tensor([1]).to(device)
torch_loss = torch.nn.functional.ctc_loss(
log_probs=torch_log_probs,
targets=targets,
input_lengths=input_lengths,
target_lengths=target_lengths,
reduction='mean')
assert torch.allclose(torch_loss,
torch.tensor([1.6094379425049]).to(device))
# (N, T, C)
k2_log_probs = torch.nn.functional.log_softmax(k2_activation,
dim=-1)
supervision_segments = torch.tensor([[0, 0, 1]], dtype=torch.int32)
dense_fsa_vec = k2.DenseFsaVec(k2_log_probs,
supervision_segments).to(device)
ctc_topo = k2.ctc_topo(4)
linear_fsa = k2.linear_fsa([1])
decoding_graph = k2.compose(ctc_topo, linear_fsa).to(device)
k2_loss = k2.ctc_loss(decoding_graph,
dense_fsa_vec,
reduction='mean',
target_lengths=target_lengths)
assert torch.allclose(torch_loss, k2_loss)
torch_loss.backward()
k2_loss.backward()
assert torch.allclose(torch_activation.grad, k2_activation.grad)
def test_case3(self):
for device in self.devices:
# (T, N, C)
torch_activation = torch.tensor([[
[-5, -4, -3, -2, -1],
[-10, -9, -8, -7, -6],
[-15, -14, -13, -12, -11.],
]]).permute(1, 0, 2).to(device).requires_grad_(True)
torch_activation = torch_activation.to(torch.float32)
torch_activation.requires_grad_(True)
k2_activation = torch_activation.detach().clone().requires_grad_(
True)
torch_log_probs = torch.nn.functional.log_softmax(
torch_activation, dim=-1) # (T, N, C)
# we have only one sequence and its labels are `b,c`
targets = torch.tensor([2, 3]).to(device)
input_lengths = torch.tensor([3]).to(device)
target_lengths = torch.tensor([2]).to(device)
torch_loss = torch.nn.functional.ctc_loss(
log_probs=torch_log_probs,
targets=targets,
input_lengths=input_lengths,
target_lengths=target_lengths,
reduction='mean')
act = k2_activation.permute(1, 0, 2) # (T, N, C) -> (N, T, C)
k2_log_probs = torch.nn.functional.log_softmax(act, dim=-1)
supervision_segments = torch.tensor([[0, 0, 3]], dtype=torch.int32)
dense_fsa_vec = k2.DenseFsaVec(k2_log_probs,
supervision_segments).to(device)
ctc_topo = k2.ctc_topo(4)
linear_fsa = k2.linear_fsa([2, 3])
decoding_graph = k2.compose(ctc_topo, linear_fsa).to(device)
k2_loss = k2.ctc_loss(decoding_graph,
dense_fsa_vec,
reduction='mean',
target_lengths=target_lengths)
expected_loss = torch.tensor([4.938850402832],
device=device) / target_lengths
assert torch.allclose(torch_loss, k2_loss)
assert torch.allclose(torch_loss, expected_loss)
torch_loss.backward()
k2_loss.backward()
assert torch.allclose(torch_activation.grad, k2_activation.grad)
def create_decoding_graph(texts, L, symbols):
word_ids_list = []
for text in texts:
filter_text = [
i if i in symbols._sym2id else '<UNK>' for i in text.split(' ')
]
word_ids = [symbols.get(i) for i in filter_text]
word_ids_list.append(word_ids)
fsa = k2.linear_fsa(word_ids_list)
decoding_graph = k2.intersect(fsa, L).invert_()
decoding_graph = k2.add_epsilon_self_loops(decoding_graph)
return decoding_graph
def test_multiple_fsa(self):
for device in self.devices:
labels = [[2, 0, 0, 0, 5, 0, 0, 0, 8, 0, 0], [1, 2],
[0, 0, 0, 3, 0, 2]]
src = k2.linear_fsa(labels, device)
dst = k2.linear_fsa_with_self_loops(src)
assert src.device == dst.device
expected_labels0 = [0, 2, 0, 5, 0, 8, 0, -1]
expected_labels1 = [0, 1, 0, 2, 0, -1]
expected_labels2 = [0, 3, 0, 2, 0, -1]
expected_labels = expected_labels0 + expected_labels1 + expected_labels2 # noqa
assert dst.labels.tolist() == expected_labels
def create_decoding_graph(texts, graph, symbols):
fsas = []
for text in texts:
filter_text = [
i if i in symbols._sym2id else '<UNK>' for i in text.split(' ')
]
word_ids = [symbols.get(i) for i in filter_text]
fsa = k2.linear_fsa(word_ids)
fsa = k2.arc_sort(fsa)
decoding_graph = k2.intersect(fsa, graph).invert_()
decoding_graph = k2.add_epsilon_self_loops(decoding_graph)
fsas.append(decoding_graph)
return k2.create_fsa_vec(fsas)
def test_case2(self):
for device in self.devices:
# (T, N, C)
torch_activation = torch.arange(1, 16).reshape(1, 3, 5).permute(
1, 0, 2).to(device)
torch_activation = torch_activation.to(torch.float32)
torch_activation.requires_grad_(True)
k2_activation = torch_activation.detach().clone().requires_grad_(
True)
torch_log_probs = torch.nn.functional.log_softmax(
torch_activation, dim=-1) # (T, N, C)
# we have only one sequence and its labels are `c,c`
targets = torch.tensor([3, 3]).to(device)
input_lengths = torch.tensor([3]).to(device)
target_lengths = torch.tensor([2]).to(device)
torch_loss = torch.nn.functional.ctc_loss(
log_probs=torch_log_probs,
targets=targets,
input_lengths=input_lengths,
target_lengths=target_lengths,
reduction='none')
act = k2_activation.permute(1, 0, 2) # (T, N, C) -> (N, T, C)
k2_log_probs = torch.nn.functional.log_softmax(act, dim=-1)
supervision_segments = torch.tensor([[0, 0, 3]], dtype=torch.int32)
dense_fsa_vec = k2.DenseFsaVec(k2_log_probs,
supervision_segments).to(device)
ctc_topo_inv = k2.arc_sort(
build_ctc_topo([0, 1, 2, 3, 4]).invert_())
linear_fsa = k2.linear_fsa([3, 3])
decoding_graph = k2.intersect(ctc_topo_inv, linear_fsa)
decoding_graph = k2.connect(decoding_graph).invert_().to(device)
target_graph = k2.intersect_dense(decoding_graph, dense_fsa_vec,
100.0)
k2_scores = target_graph.get_tot_scores(log_semiring=True,
use_double_scores=False)
assert torch.allclose(torch_loss, -1 * k2_scores)
assert torch.allclose(torch_loss,
torch.tensor([7.355742931366]).to(device))
torch_loss.backward()
(-k2_scores).backward()
assert torch.allclose(torch_activation.grad, k2_activation.grad)
def compile(self, targets: torch.Tensor,
target_lengths: torch.Tensor) -> 'k2.Fsa':
token_ids_list = [
t[:l].tolist() for t, l in zip(targets, target_lengths)
]
# see https://github.com/k2-fsa/k2/issues/835
label_graph = k2.linear_fsa(token_ids_list).to(self.device)
label_graph.aux_labels = label_graph.labels.clone()
decoding_graphs = compose_with_self_loops(self.base_graph, label_graph)
decoding_graphs = k2.arc_sort(decoding_graphs).to(self.device)
# make sure the gradient is not accumulated
decoding_graphs.requires_grad_(False)
return decoding_graphs
def test_random_case1(self):
# 1 sequence
for device in self.devices:
T = torch.randint(10, 100, (1, )).item()
C = torch.randint(20, 30, (1, )).item()
torch_activation = torch.rand((1, T + 10, C),
dtype=torch.float32,
device=device).requires_grad_(True)
k2_activation = torch_activation.detach().clone().requires_grad_(
True)
# [N, T, C] -> [T, N, C]
torch_log_probs = torch.nn.functional.log_softmax(
torch_activation.permute(1, 0, 2), dim=-1)
input_lengths = torch.tensor([T]).to(device)
target_lengths = torch.randint(1, T, (1, )).to(device)
targets = torch.randint(1, C - 1,
(target_lengths.item(), )).to(device)
torch_loss = torch.nn.functional.ctc_loss(
log_probs=torch_log_probs,
targets=targets,
input_lengths=input_lengths,
target_lengths=target_lengths,
reduction='mean')
k2_log_probs = torch.nn.functional.log_softmax(k2_activation,
dim=-1)
supervision_segments = torch.tensor([[0, 0, T]], dtype=torch.int32)
dense_fsa_vec = k2.DenseFsaVec(k2_log_probs,
supervision_segments).to(device)
ctc_topo = k2.ctc_topo(C - 1)
linear_fsa = k2.linear_fsa([targets.tolist()])
decoding_graph = k2.compose(ctc_topo, linear_fsa).to(device)
k2_loss = k2.ctc_loss(decoding_graph,
dense_fsa_vec,
reduction='mean',
target_lengths=target_lengths)
assert torch.allclose(torch_loss, k2_loss)
scale = torch.rand_like(torch_loss) * 100
(torch_loss * scale).sum().backward()
(k2_loss * scale).sum().backward()
assert torch.allclose(torch_activation.grad,
k2_activation.grad,
atol=1e-2)
def test_from_ragged_int_single_fsa(self):
for device in self.devices:
ragged_int = k2.RaggedInt('[ [10 20] ]').to(device)
fsa = k2.linear_fsa(ragged_int)
assert fsa.shape == (1, None, None)
assert fsa.device == device
expected_arcs = torch.tensor([[0, 1, 10], [1, 2, 20], [2, 3, -1]],
dtype=torch.int32,
device=device)
assert torch.all(
torch.eq(
fsa.arcs.values()[:, :-1], # skip the last field `scores`
expected_arcs))
assert torch.all(torch.eq(fsa.scores,
torch.zeros_like(fsa.scores)))
def nbest_am_lm_scores(
lats: k2.Fsa,
num_paths: int,
device: str = "cuda",
batch_size: int = 500,
):
"""Compute am scores with word_seqs
Compatible with both ctc_decoding or TLG decoding.
"""
paths = k2.random_paths(lats, num_paths=num_paths, use_double_scores=True)
if isinstance(lats.aux_labels, torch.Tensor):
word_seqs = k2.ragged.index(lats.aux_labels.contiguous(), paths)
else:
# '_k2.RaggedInt' object has no attribute 'contiguous'
word_seqs = lats.aux_labels.index(paths)
word_seqs = word_seqs.remove_axis(word_seqs.num_axes - 2)
# With ctc_decoding, word_seqs stores token_ids.
# With TLG decoding, word_seqs stores word_ids.
word_seqs = word_seqs.remove_values_leq(0)
unique_word_seqs, num_repeats, new2old = word_seqs.unique(
need_num_repeats=True, need_new2old_indexes=True
)
seq_to_path_shape = unique_word_seqs.shape.get_layer(0)
path_to_seq_map = seq_to_path_shape.row_ids(1)
# used to split final computed tot_scores
seq_to_path_splits = seq_to_path_shape.row_splits(1)
unique_word_seqs = unique_word_seqs.remove_axis(0)
word_fsas = k2.linear_fsa(unique_word_seqs)
word_fsas_with_epsilon_loops = k2.add_epsilon_self_loops(word_fsas)
am_scores, lm_scores = compute_am_scores_and_lm_scores(
lats, word_fsas_with_epsilon_loops, path_to_seq_map, device, batch_size
)
token_seqs = k2.ragged.index(lats.labels.contiguous(), paths)
token_seqs = token_seqs.remove_axis(0)
token_ids, _ = token_seqs.index(new2old, axis=0)
token_ids = token_ids.tolist()
# Now remove repeated tokens and 0s and -1s.
token_ids = [remove_repeated_and_leq(tokens) for tokens in token_ids]
return am_scores, lm_scores, token_ids, new2old, path_to_seq_map, seq_to_path_splits
def test_single_fsa(self):
for device in self.devices:
labels = [2, 5, 8]
fsa = k2.linear_fsa(labels, device)
assert fsa.device == device
assert len(fsa.shape) == 2
assert fsa.shape[0] == len(labels) + 2, 'There should be 5 states'
assert torch.all(torch.eq(fsa.scores,
torch.zeros_like(fsa.scores)))
assert torch.all(
torch.eq(
fsa.arcs.values()[:, :-1], # skip the last field `scores`
torch.tensor([[0, 1, 2], [1, 2, 5], [2, 3, 8], [3, 4, -1]],
dtype=torch.int32,
device=device)))
def test_single_fsa(self):
devices = [torch.device('cpu')]
if torch.cuda.is_available():
devices.append(torch.device('cuda', 0))
for device in devices:
labels = [2, 5, 8]
fsa = k2.linear_fsa(labels, device)
assert fsa.device == device
assert len(fsa.shape) == 2
assert fsa.shape[0] == len(labels) + 2, 'There should be 5 states'
assert torch.allclose(fsa.scores,
torch.zeros(len(labels) + 1).to(fsa.scores))
assert torch.all(
torch.eq(
fsa.arcs.values()[:, :-1], # skip the last field `scores`
torch.tensor([[0, 1, 2], [1, 2, 5], [2, 3, 8], [3, 4, -1]],
dtype=torch.int32,
device=device)))
def test_from_ragged_int_two_fsas(self):
for device in self.devices:
ragged = k2.RaggedTensor([[10, 20], [100, 200, 300]]).to(device)
fsa = k2.linear_fsa(ragged)
assert fsa.shape == (2, None, None)
assert fsa.device == device
expected_arcs = torch.tensor(
[[0, 1, 10], [1, 2, 20], [2, 3, -1], [0, 1, 100], [1, 2, 200],
[2, 3, 300], [3, 4, -1]],
dtype=torch.int32,
device=device)
assert torch.all(
torch.eq(
fsa.arcs.values()[:, :-1], # skip the last field `scores`
expected_arcs))
assert torch.all(torch.eq(fsa.scores,
torch.zeros_like(fsa.scores)))
def compile_one_and_cache(self, text: str) -> k2.Fsa:
'''Convert transcript to an Fsa with the help of lexicon
and word symbol table.
Args:
text:
The transcript containing words separated by spaces.
Returns:
Return an FST corresponding to the transcript. Its `labels` are
phone IDs and `aux_labels` are word IDs.
'''
tokens = (token if token in self.words else self.oov
for token in text.split(' '))
word_ids = [self.words[token] for token in tokens]
fsa = k2.linear_fsa(word_ids)
num_graph = k2.connect(k2.intersect(fsa, self.L_inv)).invert_()
num_graph = k2.arc_sort(num_graph)
return num_graph
def create_decoding_graph(texts, L, symbols):
fsas = []
for text in texts:
filter_text = [
i if i in symbols._sym2id else '<UNK>' for i in text.split(' ')
]
word_ids = [symbols.get(i) for i in filter_text]
fsa = k2.linear_fsa(word_ids)
print("linear fsa is ", fsa)
fsa = k2.arc_sort(fsa)
print("linear fsa, arc-sorted, is ", fsa)
print("begin")
print(k2.is_arc_sorted(k2.get_properties(fsa)))
decoding_graph = k2.intersect(fsa, L).invert_()
print("linear fsa, composed, is ", fsa)
print("decoding graph is ", decoding_graph)
decoding_graph = k2.add_epsilon_self_loops(decoding_graph)
print("decoding graph with self-loops is ", decoding_graph)
fsas.append(decoding_graph)
return k2.create_fsa_vec(fsas)
def get_hierarchical_targets(ys: List[List[int]],
lexicon: k2.Fsa) -> List[Tensor]:
"""Get hierarchical transcripts (i.e., phone level transcripts) from transcripts (i.e., word level transcripts).
Args:
ys: Word level transcripts.
lexicon: Its labels are words, while its aux_labels are phones.
Returns:
List[Tensor]: Phone level transcripts.
"""
if lexicon is None:
return ys
else:
L_inv = lexicon
n_batch = len(ys)
indices = torch.tensor(range(n_batch))
device = L_inv.device
transcripts = k2.create_fsa_vec(
[k2.linear_fsa(x, device=device) for x in ys])
transcripts_with_self_loops = k2.add_epsilon_self_loops(transcripts)
transcripts_lexicon = k2.intersect(L_inv,
transcripts_with_self_loops,
treat_epsilons_specially=False)
# Don't call invert_() above because we want to return phone IDs,
# which is the `aux_labels` of transcripts_lexicon
transcripts_lexicon = k2.remove_epsilon(transcripts_lexicon)
transcripts_lexicon = k2.top_sort(transcripts_lexicon)
transcripts_lexicon = k2.shortest_path(transcripts_lexicon,
use_double_scores=True)
ys = get_texts(transcripts_lexicon, indices)
ys = [torch.tensor(y) for y in ys]
return ys
def test_from_ragged_int_two_fsas(self):
devices = [torch.device('cpu')]
if torch.cuda.is_available():
devices.append(torch.device('cuda', 0))
for device in devices:
ragged_int = k2.RaggedInt('[ [10 20] [100 200 300] ]').to(device)
fsa = k2.linear_fsa(ragged_int)
assert fsa.shape == (2, None, None)
assert fsa.device == device
expected_arcs = torch.tensor(
[[0, 1, 10], [1, 2, 20], [2, 3, -1], [0, 1, 100], [1, 2, 200],
[2, 3, 300], [3, 4, -1]],
dtype=torch.int32,
device=device)
assert torch.all(
torch.eq(
fsa.arcs.values()[:, :-1], # skip the last field `scores`
expected_arcs))
assert torch.all(torch.eq(fsa.scores,
torch.zeros_like(fsa.scores)))
def test_fsa_vec(self):
devices = [torch.device('cpu')]
if torch.cuda.is_available():
devices.append(torch.device('cuda', 0))
for device in devices:
labels = [
[1, 3, 5],
[2, 6],
[8, 7, 9],
]
num_labels = sum([len(s) for s in labels])
fsa = k2.linear_fsa(labels, device)
assert len(fsa.shape) == 3
assert fsa.device == device
assert fsa.shape[0] == 3, 'There should be 3 FSAs'
expected_arcs = [
# fsa 0
[0, 1, 1],
[1, 2, 3],
[2, 3, 5],
[3, 4, -1],
# fsa 1
[0, 1, 2],
[1, 2, 6],
[2, 3, -1],
# fsa 2
[0, 1, 8],
[1, 2, 7],
[2, 3, 9],
[3, 4, -1]
]
assert torch.all(
torch.eq(
fsa.arcs.values()[:, :-1], # skip the last field `scores`
torch.tensor(expected_arcs,
dtype=torch.int32,
device=device)))
assert torch.allclose(
fsa.scores,
torch.zeros(num_labels + len(labels)).to(fsa.scores))
def test_fsa_vec(self):
for device in self.devices:
labels = [
[1, 3, 5],
[2, 6],
[8, 7, 9],
]
fsa = k2.linear_fsa(labels, device)
assert len(fsa.shape) == 3
assert fsa.device == device
assert fsa.shape[0] == 3, 'There should be 3 FSAs'
expected_arcs = [
# fsa 0
[0, 1, 1],
[1, 2, 3],
[2, 3, 5],
[3, 4, -1],
# fsa 1
[0, 1, 2],
[1, 2, 6],
[2, 3, -1],
# fsa 2
[0, 1, 8],
[1, 2, 7],
[2, 3, 9],
[3, 4, -1]
]
assert torch.all(
torch.eq(
fsa.arcs.values()[:, :-1], # skip the last field `scores`
torch.tensor(expected_arcs,
dtype=torch.int32,
device=device)))
assert torch.all(torch.eq(fsa.scores,
torch.zeros_like(fsa.scores)))
