icefall/egs/librispeech/ASR/zipformer/streaming_ctc_decode.py
2023-12-07 11:12:47 +08:00

657 lines
20 KiB
Python
Executable File

#!/usr/bin/env python3
# Copyright 2022-2023 Xiaomi Corporation (Authors: Wei Kang,
# Fangjun Kuang,
# Zengwei Yao,
# Zengrui Jin,)
#
# See ../../../../LICENSE for clarification regarding multiple authors
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
# http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.
"""
Usage:
./zipformer/streaming_decode.py \
--epoch 28 \
--avg 15 \
--causal 1 \
--chunk-size 32 \
--left-context-frames 256 \
--exp-dir ./zipformer/exp \
--decoding-method greedy_search \
--num-decode-streams 2000
"""
import argparse
import logging
import math
from pathlib import Path
from typing import Dict, List, Optional, Tuple
import k2
import numpy as np
import sentencepiece as spm
import torch
from asr_datamodule import LibriSpeechAsrDataModule
from ctc_decode_stream import DecodeStream
from kaldifeat import Fbank, FbankOptions
from lhotse import CutSet
from streaming_decode import (
get_init_states,
stack_states,
streaming_forward,
unstack_states,
)
from torch import nn
from torch.nn.utils.rnn import pad_sequence
from train import add_model_arguments, get_model, get_params
from icefall.checkpoint import (
average_checkpoints,
average_checkpoints_with_averaged_model,
find_checkpoints,
load_checkpoint,
)
from icefall.decode import get_lattice, one_best_decoding
from icefall.utils import (
AttributeDict,
get_texts,
setup_logger,
store_transcripts,
str2bool,
write_error_stats,
)
LOG_EPS = math.log(1e-10)
def get_parser():
parser = argparse.ArgumentParser(
formatter_class=argparse.ArgumentDefaultsHelpFormatter
)
parser.add_argument(
"--epoch",
type=int,
default=20,
help="""It specifies the checkpoint to use for decoding.
Note: Epoch counts from 1.
You can specify --avg to use more checkpoints for model averaging.""",
)
parser.add_argument(
"--iter",
type=int,
default=0,
help="""If positive, --epoch is ignored and it
will use the checkpoint exp_dir/checkpoint-iter.pt.
You can specify --avg to use more checkpoints for model averaging.
""",
)
parser.add_argument(
"--avg",
type=int,
default=1,
help="Number of checkpoints to average. Automatically select "
"consecutive checkpoints before the checkpoint specified by "
"'--epoch' and '--iter'",
)
parser.add_argument(
"--use-averaged-model",
type=str2bool,
default=True,
help="Whether to load averaged model. Currently it only supports "
"using --epoch. If True, it would decode with the averaged model "
"over the epoch range from `epoch-avg` (excluded) to `epoch`."
"Actually only the models with epoch number of `epoch-avg` and "
"`epoch` are loaded for averaging. ",
)
parser.add_argument(
"--exp-dir",
type=str,
default="zipformer/exp",
help="The experiment dir",
)
parser.add_argument(
"--bpe-model",
type=str,
default="data/lang_bpe_500/bpe.model",
help="Path to the BPE model",
)
parser.add_argument(
"--decoding-method",
type=str,
default="greedy_search",
help="""Supported decoding methods are:
greedy_search
modified_beam_search
fast_beam_search
""",
)
parser.add_argument(
"--num_active_paths",
type=int,
default=4,
help="""An interger indicating how many candidates we will keep for each
frame. Used only when --decoding-method is modified_beam_search.""",
)
parser.add_argument(
"--beam",
type=float,
default=4,
help="""A floating point value to calculate the cutoff score during beam
search (i.e., `cutoff = max-score - beam`), which is the same as the
`beam` in Kaldi.
Used only when --decoding-method is fast_beam_search""",
)
parser.add_argument(
"--max-contexts",
type=int,
default=4,
help="""Used only when --decoding-method is
fast_beam_search""",
)
parser.add_argument(
"--max-states",
type=int,
default=32,
help="""Used only when --decoding-method is
fast_beam_search""",
)
parser.add_argument(
"--context-size",
type=int,
default=2,
help="The context size in the decoder. 1 means bigram; 2 means tri-gram",
)
parser.add_argument(
"--num-decode-streams",
type=int,
default=2000,
help="The number of streams that can be decoded parallel.",
)
add_model_arguments(parser)
return parser
def get_decoding_params() -> AttributeDict:
"""Parameters for decoding."""
params = AttributeDict(
{
"feature_dim": 80,
"frame_shift_ms": 10,
"search_beam": 20,
"output_beam": 8,
"min_active_states": 30,
"max_active_states": 10000,
"use_double_scores": True,
}
)
return params
def decode_one_chunk(
params: AttributeDict,
model: nn.Module,
H: Optional[k2.Fsa],
decode_streams: List[DecodeStream],
) -> List[int]:
"""Decode one chunk frames of features for each decode_streams and
return the indexes of finished streams in a List.
Args:
params:
It's the return value of :func:`get_params`.
model:
The neural model.
decode_streams:
A List of DecodeStream, each belonging to a utterance.
Returns:
Return a List containing which DecodeStreams are finished.
"""
device = model.device
chunk_size = int(params.chunk_size)
left_context_len = int(params.left_context_frames)
features = []
feature_lens = []
states = []
processed_lens = [] # Used in fast-beam-search
for stream in decode_streams:
feat, feat_len = stream.get_feature_frames(chunk_size * 2)
features.append(feat)
feature_lens.append(feat_len)
states.append(stream.states)
processed_lens.append(stream.done_frames)
feature_lens = torch.tensor(feature_lens, device=device)
features = pad_sequence(features, batch_first=True, padding_value=LOG_EPS)
# Make sure the length after encoder_embed is at least 1.
# The encoder_embed subsample features (T - 7) // 2
# The ConvNeXt module needs (7 - 1) // 2 = 3 frames of right padding after subsampling
tail_length = chunk_size * 2 + 7 + 2 * 3
if features.size(1) < tail_length:
pad_length = tail_length - features.size(1)
feature_lens += pad_length
features = torch.nn.functional.pad(
features,
(0, 0, 0, pad_length),
mode="constant",
value=LOG_EPS,
)
states = stack_states(states)
encoder_out, encoder_out_lens, new_states = streaming_forward(
features=features,
feature_lens=feature_lens,
model=model,
states=states,
chunk_size=chunk_size,
left_context_len=left_context_len,
)
ctc_output = model.ctc_output(encoder_out) # (N, T, C)
supervision_segments = torch.stack(
(
# supervisions["sequence_idx"],
torch.tensor([index for index, _ in enumerate(decode_streams)]),
torch.div(
0,
params.subsampling_factor,
rounding_mode="floor",
),
torch.div(
feature_lens,
params.subsampling_factor,
rounding_mode="floor",
),
),
1,
).to(torch.int32)
decoding_graph = H
lattice = get_lattice(
nnet_output=ctc_output,
decoding_graph=decoding_graph,
supervision_segments=supervision_segments,
search_beam=params.search_beam,
output_beam=params.output_beam,
min_active_states=params.min_active_states,
max_active_states=params.max_active_states,
subsampling_factor=params.subsampling_factor,
)
best_path = one_best_decoding(
lattice=lattice, use_double_scores=params.use_double_scores
)
# Note: `best_path.aux_labels` contains token IDs, not word IDs
# since we are using H, not HLG here.
#
# token_ids is a lit-of-list of IDs
token_ids = get_texts(best_path)
states = unstack_states(new_states)
finished_streams = []
for i in range(len(decode_streams)):
decode_streams[i].hyp += token_ids[i]
decode_streams[i].states = states[i]
decode_streams[i].done_frames += encoder_out_lens[i]
if decode_streams[i].done:
finished_streams.append(i)
return finished_streams
def decode_dataset(
cuts: CutSet,
params: AttributeDict,
model: nn.Module,
sp: spm.SentencePieceProcessor,
decoding_graph: Optional[k2.Fsa] = None,
) -> Dict[str, List[Tuple[List[str], List[str]]]]:
"""Decode dataset.
Args:
cuts:
Lhotse Cutset containing the dataset to decode.
params:
It is returned by :func:`get_params`.
model:
The neural model.
sp:
The BPE model.
decoding_graph:
The decoding graph. Can be either a `k2.trivial_graph` or HLG, Used
only when --decoding_method is fast_beam_search.
Returns:
Return a dict, whose key may be "greedy_search" if greedy search
is used, or it may be "beam_7" if beam size of 7 is used.
Its value is a list of tuples. Each tuple contains two elements:
The first is the reference transcript, and the second is the
predicted result.
"""
device = model.device
opts = FbankOptions()
opts.device = device
opts.frame_opts.dither = 0
opts.frame_opts.snip_edges = False
opts.frame_opts.samp_freq = 16000
opts.mel_opts.num_bins = 80
log_interval = 100
decode_results = []
# Contain decode streams currently running.
decode_streams = []
for num, cut in enumerate(cuts):
# each utterance has a DecodeStream.
initial_states = get_init_states(model=model, batch_size=1, device=device)
decode_stream = DecodeStream(
params=params,
cut_id=cut.id,
initial_states=initial_states,
decoding_graph=decoding_graph,
device=device,
)
audio: np.ndarray = cut.load_audio()
# audio.shape: (1, num_samples)
assert len(audio.shape) == 2
assert audio.shape[0] == 1, "Should be single channel"
assert audio.dtype == np.float32, audio.dtype
# The trained model is using normalized samples
assert audio.max() <= 1, "Should be normalized to [-1, 1])"
samples = torch.from_numpy(audio).squeeze(0)
fbank = Fbank(opts)
feature = fbank(samples.to(device))
decode_stream.set_features(feature, tail_pad_len=30)
decode_stream.ground_truth = cut.supervisions[0].text
decode_streams.append(decode_stream)
while len(decode_streams) >= params.num_decode_streams:
finished_streams = decode_one_chunk(
params=params, model=model, decode_streams=decode_streams
)
for i in sorted(finished_streams, reverse=True):
decode_results.append(
(
decode_streams[i].id,
decode_streams[i].ground_truth.split(),
sp.decode(decode_streams[i].decoding_result()).split(),
)
)
del decode_streams[i]
if num % log_interval == 0:
logging.info(f"Cuts processed until now is {num}.")
# decode final chunks of last sequences
while len(decode_streams):
finished_streams = decode_one_chunk(
params=params, model=model, H=decoding_graph, decode_streams=decode_streams
)
for i in sorted(finished_streams, reverse=True):
decode_results.append(
(
decode_streams[i].id,
decode_streams[i].ground_truth.split(),
sp.decode(decode_streams[i].decoding_result()).split(),
)
)
del decode_streams[i]
key = "ctc-decoding"
return {key: decode_results}
def save_results(
params: AttributeDict,
test_set_name: str,
results_dict: Dict[str, List[Tuple[List[str], List[str]]]],
):
test_set_wers = dict()
for key, results in results_dict.items():
recog_path = (
params.res_dir / f"recogs-{test_set_name}-{key}-{params.suffix}.txt"
)
results = sorted(results)
store_transcripts(filename=recog_path, texts=results)
logging.info(f"The transcripts are stored in {recog_path}")
# The following prints out WERs, per-word error statistics and aligned
# ref/hyp pairs.
errs_filename = (
params.res_dir / f"errs-{test_set_name}-{key}-{params.suffix}.txt"
)
with open(errs_filename, "w") as f:
wer = write_error_stats(
f, f"{test_set_name}-{key}", results, enable_log=True
)
test_set_wers[key] = wer
logging.info("Wrote detailed error stats to {}".format(errs_filename))
test_set_wers = sorted(test_set_wers.items(), key=lambda x: x[1])
errs_info = (
params.res_dir / f"wer-summary-{test_set_name}-{key}-{params.suffix}.txt"
)
with open(errs_info, "w") as f:
print("settings\tWER", file=f)
for key, val in test_set_wers:
print("{}\t{}".format(key, val), file=f)
s = "\nFor {}, WER of different settings are:\n".format(test_set_name)
note = "\tbest for {}".format(test_set_name)
for key, val in test_set_wers:
s += "{}\t{}{}\n".format(key, val, note)
note = ""
logging.info(s)
@torch.no_grad()
def main():
parser = get_parser()
LibriSpeechAsrDataModule.add_arguments(parser)
args = parser.parse_args()
args.exp_dir = Path(args.exp_dir)
params = get_params()
params.update(vars(args))
params = get_decoding_params()
params.update(vars(args))
params.res_dir = params.exp_dir / "streaming" / params.decoding_method
if params.iter > 0:
params.suffix = f"iter-{params.iter}-avg-{params.avg}"
else:
params.suffix = f"epoch-{params.epoch}-avg-{params.avg}"
assert params.causal, params.causal
assert "," not in params.chunk_size, "chunk_size should be one value in decoding."
assert (
"," not in params.left_context_frames
), "left_context_frames should be one value in decoding."
params.suffix += f"-chunk-{params.chunk_size}"
params.suffix += f"-left-context-{params.left_context_frames}"
# for fast_beam_search
if params.decoding_method == "fast_beam_search":
params.suffix += f"-beam-{params.beam}"
params.suffix += f"-max-contexts-{params.max_contexts}"
params.suffix += f"-max-states-{params.max_states}"
if params.use_averaged_model:
params.suffix += "-use-averaged-model"
setup_logger(f"{params.res_dir}/log-decode-{params.suffix}")
logging.info("Decoding started")
device = torch.device("cpu")
if torch.cuda.is_available():
device = torch.device("cuda", 0)
logging.info(f"Device: {device}")
sp = spm.SentencePieceProcessor()
sp.load(params.bpe_model)
# <blk> and <unk> is defined in local/train_bpe_model.py
params.blank_id = sp.piece_to_id("<blk>")
params.unk_id = sp.piece_to_id("<unk>")
params.vocab_size = sp.get_piece_size()
max_token_id = sp.get_piece_size() - 1
logging.info(params)
logging.info("About to create model")
model = get_model(params)
if not params.use_averaged_model:
if params.iter > 0:
filenames = find_checkpoints(params.exp_dir, iteration=-params.iter)[
: params.avg
]
if len(filenames) == 0:
raise ValueError(
f"No checkpoints found for"
f" --iter {params.iter}, --avg {params.avg}"
)
elif len(filenames) < params.avg:
raise ValueError(
f"Not enough checkpoints ({len(filenames)}) found for"
f" --iter {params.iter}, --avg {params.avg}"
)
logging.info(f"averaging {filenames}")
model.to(device)
model.load_state_dict(average_checkpoints(filenames, device=device))
elif params.avg == 1:
load_checkpoint(f"{params.exp_dir}/epoch-{params.epoch}.pt", model)
else:
start = params.epoch - params.avg + 1
filenames = []
for i in range(start, params.epoch + 1):
if start >= 0:
filenames.append(f"{params.exp_dir}/epoch-{i}.pt")
logging.info(f"averaging {filenames}")
model.to(device)
model.load_state_dict(average_checkpoints(filenames, device=device))
else:
if params.iter > 0:
filenames = find_checkpoints(params.exp_dir, iteration=-params.iter)[
: params.avg + 1
]
if len(filenames) == 0:
raise ValueError(
f"No checkpoints found for"
f" --iter {params.iter}, --avg {params.avg}"
)
elif len(filenames) < params.avg + 1:
raise ValueError(
f"Not enough checkpoints ({len(filenames)}) found for"
f" --iter {params.iter}, --avg {params.avg}"
)
filename_start = filenames[-1]
filename_end = filenames[0]
logging.info(
"Calculating the averaged model over iteration checkpoints"
f" from {filename_start} (excluded) to {filename_end}"
)
model.to(device)
model.load_state_dict(
average_checkpoints_with_averaged_model(
filename_start=filename_start,
filename_end=filename_end,
device=device,
)
)
else:
assert params.avg > 0, params.avg
start = params.epoch - params.avg
assert start >= 1, start
filename_start = f"{params.exp_dir}/epoch-{start}.pt"
filename_end = f"{params.exp_dir}/epoch-{params.epoch}.pt"
logging.info(
f"Calculating the averaged model over epoch range from "
f"{start} (excluded) to {params.epoch}"
)
model.to(device)
model.load_state_dict(
average_checkpoints_with_averaged_model(
filename_start=filename_start,
filename_end=filename_end,
device=device,
)
)
model.to(device)
model.eval()
model.device = device
H = k2.ctc_topo(
max_token=max_token_id,
modified=True,
device=device,
)
num_param = sum([p.numel() for p in model.parameters()])
logging.info(f"Number of model parameters: {num_param}")
librispeech = LibriSpeechAsrDataModule(args)
test_cuts = librispeech.test_cuts()
test_sets = {"test": test_cuts}
for test_set, test_cut in test_sets.items():
results_dict = decode_dataset(
cuts=test_cut,
params=params,
model=model,
sp=sp,
decoding_graph=H,
)
save_results(
params=params,
test_set_name=test_set,
results_dict=results_dict,
)
logging.info("Done!")
if __name__ == "__main__":
main()