icefall/egs/librispeech/ASR/zipformer/onnx_pretrained-streaming-ctc.py

428 lines
13 KiB
Python
Executable File

#!/usr/bin/env python3
# Copyright 2023 Xiaomi Corp. (authors: Fangjun Kuang)
# Copyright 2023 Danqing Fu (danqing.fu@gmail.com)
"""
This script loads ONNX models exported by ./export-onnx-streaming-ctc.py
and uses them to decode waves.
We use the pre-trained model from
https://huggingface.co/zrjin/icefall-asr-multi-zh-hans-zipformer-ctc-streaming-2023-11-05
as an example to show how to use this file.
1. Download the pre-trained model
cd egs/librispeech/ASR
repo_url=https://huggingface.co/zrjin/icefall-asr-multi-zh-hans-zipformer-ctc-streaming-2023-11-05
GIT_LFS_SKIP_SMUDGE=1 git clone $repo_url
repo=$(basename $repo_url)
pushd $repo
git lfs pull --include "exp/pretrained.pt"
cd exp
ln -s pretrained.pt epoch-99.pt
popd
2. Export the model to ONNX
./zipformer/export-onnx-streaming-ctc.py \
--tokens $repo/data/lang_bpe_2000/tokens.txt \
--use-averaged-model 0 \
--epoch 99 \
--avg 1 \
--exp-dir $repo/exp \
--causal True \
--chunk-size 16 \
--left-context-frames 128 \
--use-ctc 1
It will generate the following 2 files inside $repo/exp:
- ctc-epoch-99-avg-1-chunk-16-left-128.int8.onnx
- ctc-epoch-99-avg-1-chunk-16-left-128.onnx
You can use either the ``int8.onnx`` model or just the ``.onnx`` model.
3. Run this file with the exported ONNX models
./zipformer/onnx_pretrained-streaming-ctc.py \
--model-filename $repo/exp/ctc-epoch-99-avg-1-chunk-16-left-128.onnx \
--tokens $repo/data/lang_bpe_2000/tokens.txt \
$repo/test_wavs/DEV_T0000000001.wav
Note: Even though this script only supports decoding a single file,
the exported ONNX models do support batch processing.
"""
import argparse
import logging
from typing import Dict, List, Tuple
import numpy as np
import onnxruntime as ort
import torch
import torchaudio
from kaldifeat import FbankOptions, OnlineFbank, OnlineFeature
def get_parser():
parser = argparse.ArgumentParser(
formatter_class=argparse.ArgumentDefaultsHelpFormatter
)
parser.add_argument(
"--model-filename",
type=str,
required=True,
help="Path to the decoder onnx model. ",
)
parser.add_argument(
"--tokens",
type=str,
help="""Path to tokens.txt.""",
)
parser.add_argument(
"sound_file",
type=str,
help="The input sound file to transcribe. "
"Supported formats are those supported by torchaudio.load(). "
"For example, wav and flac are supported. "
"The sample rate has to be 16kHz.",
)
return parser
class OnnxModel:
def __init__(
self,
model_filename: str,
):
session_opts = ort.SessionOptions()
session_opts.inter_op_num_threads = 1
session_opts.intra_op_num_threads = 1
self.session_opts = session_opts
self.init_model(model_filename)
def init_model(self, model_filename: str):
self.model = ort.InferenceSession(
model_filename,
sess_options=self.session_opts,
providers=["CPUExecutionProvider"],
)
self.init_states()
def init_states(self, batch_size: int = 1):
meta = self.model.get_modelmeta().custom_metadata_map
logging.info(f"meta={meta}")
model_type = meta["model_type"]
assert model_type == "zipformer2", model_type
decode_chunk_len = int(meta["decode_chunk_len"])
T = int(meta["T"])
num_encoder_layers = meta["num_encoder_layers"]
encoder_dims = meta["encoder_dims"]
cnn_module_kernels = meta["cnn_module_kernels"]
left_context_len = meta["left_context_len"]
query_head_dims = meta["query_head_dims"]
value_head_dims = meta["value_head_dims"]
num_heads = meta["num_heads"]
def to_int_list(s):
return list(map(int, s.split(",")))
num_encoder_layers = to_int_list(num_encoder_layers)
encoder_dims = to_int_list(encoder_dims)
cnn_module_kernels = to_int_list(cnn_module_kernels)
left_context_len = to_int_list(left_context_len)
query_head_dims = to_int_list(query_head_dims)
value_head_dims = to_int_list(value_head_dims)
num_heads = to_int_list(num_heads)
logging.info(f"decode_chunk_len: {decode_chunk_len}")
logging.info(f"T: {T}")
logging.info(f"num_encoder_layers: {num_encoder_layers}")
logging.info(f"encoder_dims: {encoder_dims}")
logging.info(f"cnn_module_kernels: {cnn_module_kernels}")
logging.info(f"left_context_len: {left_context_len}")
logging.info(f"query_head_dims: {query_head_dims}")
logging.info(f"value_head_dims: {value_head_dims}")
logging.info(f"num_heads: {num_heads}")
num_encoders = len(num_encoder_layers)
self.states = []
for i in range(num_encoders):
num_layers = num_encoder_layers[i]
key_dim = query_head_dims[i] * num_heads[i]
embed_dim = encoder_dims[i]
nonlin_attn_head_dim = 3 * embed_dim // 4
value_dim = value_head_dims[i] * num_heads[i]
conv_left_pad = cnn_module_kernels[i] // 2
for layer in range(num_layers):
cached_key = torch.zeros(
left_context_len[i], batch_size, key_dim
).numpy()
cached_nonlin_attn = torch.zeros(
1, batch_size, left_context_len[i], nonlin_attn_head_dim
).numpy()
cached_val1 = torch.zeros(
left_context_len[i], batch_size, value_dim
).numpy()
cached_val2 = torch.zeros(
left_context_len[i], batch_size, value_dim
).numpy()
cached_conv1 = torch.zeros(batch_size, embed_dim, conv_left_pad).numpy()
cached_conv2 = torch.zeros(batch_size, embed_dim, conv_left_pad).numpy()
self.states += [
cached_key,
cached_nonlin_attn,
cached_val1,
cached_val2,
cached_conv1,
cached_conv2,
]
embed_states = torch.zeros(batch_size, 128, 3, 19).numpy()
self.states.append(embed_states)
processed_lens = torch.zeros(batch_size, dtype=torch.int64).numpy()
self.states.append(processed_lens)
self.num_encoders = num_encoders
self.segment = T
self.offset = decode_chunk_len
def _build_model_input_output(
self,
x: torch.Tensor,
) -> Tuple[Dict[str, np.ndarray], List[str]]:
model_input = {"x": x.numpy()}
model_output = ["log_probs"]
def build_inputs_outputs(tensors, i):
assert len(tensors) == 6, len(tensors)
# (downsample_left, batch_size, key_dim)
name = f"cached_key_{i}"
model_input[name] = tensors[0]
model_output.append(f"new_{name}")
# (1, batch_size, downsample_left, nonlin_attn_head_dim)
name = f"cached_nonlin_attn_{i}"
model_input[name] = tensors[1]
model_output.append(f"new_{name}")
# (downsample_left, batch_size, value_dim)
name = f"cached_val1_{i}"
model_input[name] = tensors[2]
model_output.append(f"new_{name}")
# (downsample_left, batch_size, value_dim)
name = f"cached_val2_{i}"
model_input[name] = tensors[3]
model_output.append(f"new_{name}")
# (batch_size, embed_dim, conv_left_pad)
name = f"cached_conv1_{i}"
model_input[name] = tensors[4]
model_output.append(f"new_{name}")
# (batch_size, embed_dim, conv_left_pad)
name = f"cached_conv2_{i}"
model_input[name] = tensors[5]
model_output.append(f"new_{name}")
for i in range(len(self.states[:-2]) // 6):
build_inputs_outputs(self.states[i * 6 : (i + 1) * 6], i)
# (batch_size, channels, left_pad, freq)
name = "embed_states"
embed_states = self.states[-2]
model_input[name] = embed_states
model_output.append(f"new_{name}")
# (batch_size,)
name = "processed_lens"
processed_lens = self.states[-1]
model_input[name] = processed_lens
model_output.append(f"new_{name}")
return model_input, model_output
def _update_states(self, states: List[np.ndarray]):
self.states = states
def __call__(self, x: torch.Tensor) -> torch.Tensor:
"""
Args:
x:
A 3-D tensor of shape (N, T, C)
Returns:
Return a 3-D tensor containing log_probs. Its shape is (N, T, vocab_size)
where T' is usually equal to ((T-7)//2 - 3)//2
"""
model_input, model_output_names = self._build_model_input_output(x)
out = self.model.run(model_output_names, model_input)
self._update_states(out[1:])
return torch.from_numpy(out[0])
def read_sound_files(
filenames: List[str], expected_sample_rate: float
) -> List[torch.Tensor]:
"""Read a list of sound files into a list 1-D float32 torch tensors.
Args:
filenames:
A list of sound filenames.
expected_sample_rate:
The expected sample rate of the sound files.
Returns:
Return a list of 1-D float32 torch tensors.
"""
ans = []
for f in filenames:
wave, sample_rate = torchaudio.load(f)
assert (
sample_rate == expected_sample_rate
), f"expected sample rate: {expected_sample_rate}. Given: {sample_rate}"
# We use only the first channel
ans.append(wave[0].contiguous())
return ans
def create_streaming_feature_extractor() -> OnlineFeature:
"""Create a CPU streaming feature extractor.
At present, we assume it returns a fbank feature extractor with
fixed options. In the future, we will support passing in the options
from outside.
Returns:
Return a CPU streaming feature extractor.
"""
opts = FbankOptions()
opts.device = "cpu"
opts.frame_opts.dither = 0
opts.frame_opts.snip_edges = False
opts.frame_opts.samp_freq = 16000
opts.mel_opts.num_bins = 80
opts.mel_opts.high_freq = -400
return OnlineFbank(opts)
def greedy_search(
log_probs: torch.Tensor,
) -> List[int]:
"""Greedy search for a single utterance.
Args:
log_probs:
A 3-D tensor of shape (1, T, vocab_size)
Returns:
Return the decoded result.
"""
assert log_probs.ndim == 3, log_probs.shape
assert log_probs.shape[0] == 1, log_probs.shape
max_indexes = log_probs[0].argmax(dim=1)
unique_indexes = torch.unique_consecutive(max_indexes)
blank_id = 0
unique_indexes = unique_indexes[unique_indexes != blank_id]
return unique_indexes.tolist()
@torch.no_grad()
def main():
parser = get_parser()
args = parser.parse_args()
logging.info(vars(args))
model = OnnxModel(model_filename=args.model_filename)
sample_rate = 16000
logging.info("Constructing Fbank computer")
online_fbank = create_streaming_feature_extractor()
logging.info(f"Reading sound files: {args.sound_file}")
waves = read_sound_files(
filenames=[args.sound_file],
expected_sample_rate=sample_rate,
)[0]
tail_padding = torch.zeros(int(0.3 * sample_rate), dtype=torch.float32)
wave_samples = torch.cat([waves, tail_padding])
num_processed_frames = 0
segment = model.segment
offset = model.offset
hyp = []
chunk = int(1 * sample_rate) # 1 second
start = 0
while start < wave_samples.numel():
end = min(start + chunk, wave_samples.numel())
samples = wave_samples[start:end]
start += chunk
online_fbank.accept_waveform(
sampling_rate=sample_rate,
waveform=samples,
)
while online_fbank.num_frames_ready - num_processed_frames >= segment:
frames = []
for i in range(segment):
frames.append(online_fbank.get_frame(num_processed_frames + i))
num_processed_frames += offset
frames = torch.cat(frames, dim=0)
frames = frames.unsqueeze(0)
log_probs = model(frames)
hyp += greedy_search(log_probs)
# To handle byte-level BPE, we convert string tokens to utf-8 encoded bytes
id2token = {}
with open(args.tokens, encoding="utf-8") as f:
for line in f:
token, idx = line.split()
if token[:3] == "<0x" and token[-1] == ">":
token = int(token[1:-1], base=16)
assert 0 <= token < 256, token
token = token.to_bytes(1, byteorder="little")
else:
token = token.encode(encoding="utf-8")
id2token[int(idx)] = token
text = b""
for i in hyp:
text += id2token[i]
text = text.decode(encoding="utf-8")
text = text.replace("", " ").strip()
logging.info(args.sound_file)
logging.info(text)
logging.info("Decoding Done")
if __name__ == "__main__":
formatter = "%(asctime)s %(levelname)s [%(filename)s:%(lineno)d] %(message)s"
logging.basicConfig(format=formatter, level=logging.INFO)
main()