From d55cec6b8741a6007eea53150f2ef4cdf82e19cb Mon Sep 17 00:00:00 2001
From: Fangjun Kuang <csukuangfj@gmail.com>
Date: Fri, 30 Sep 2022 16:54:11 +0800
Subject: [PATCH] Add lstm-transducer model for the wenetspeech dataset

---
 .../ASR/lstm_transducer_stateless/export.py   | 403 ++++++++++++++++++
 .../lstm_transducer_stateless/ncnn-decode.py  | 296 +++++++++++++
 .../ASR/lstm_transducer_stateless/train.py    |   3 +
 3 files changed, 702 insertions(+)
 create mode 100755 egs/wenetspeech/ASR/lstm_transducer_stateless/export.py
 create mode 100755 egs/wenetspeech/ASR/lstm_transducer_stateless/ncnn-decode.py

diff --git a/egs/wenetspeech/ASR/lstm_transducer_stateless/export.py b/egs/wenetspeech/ASR/lstm_transducer_stateless/export.py
new file mode 100755
index 000000000..3529cbfe4
--- /dev/null
+++ b/egs/wenetspeech/ASR/lstm_transducer_stateless/export.py
@@ -0,0 +1,403 @@
+#!/usr/bin/env python3
+#
+# Copyright 2021-2022 Xiaomi Corporation (Author: Fangjun Kuang, Zengwei Yao)
+#
+# 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.
+
+# This script converts several saved checkpoints
+# to a single one using model averaging.
+"""
+
+Usage:
+
+(1) Export to torchscript model using torch.jit.trace()
+
+./lstm_transducer_stateless/export.py \
+  --exp-dir ./lstm_transducer_stateless/exp \
+  --lang-dir data/lang_char \
+  --epoch 35 \
+  --avg 10 \
+  --jit-trace 1
+
+It will generate 3 files: `encoder_jit_trace.pt`,
+`decoder_jit_trace.pt`, and `joiner_jit_trace.pt`.
+
+(2) Export `model.state_dict()`
+
+./lstm_transducer_stateless/export.py \
+  --exp-dir ./lstm_transducer_stateless/exp \
+  --lang-dir data/lang_char \
+  --epoch 35 \
+  --avg 10
+
+It will generate a file `pretrained.pt` in the given `exp_dir`. You can later
+load it by `icefall.checkpoint.load_checkpoint()`.
+
+To use the generated file with `lstm_transducer_stateless/decode.py`,
+you can do:
+
+    cd /path/to/exp_dir
+    ln -s pretrained.pt epoch-9999.pt
+
+    cd /path/to/egs/librispeech/ASR
+    ./lstm_transducer_stateless/decode.py \
+        --exp-dir ./lstm_transducer_stateless/exp \
+        --epoch 9999 \
+        --avg 1 \
+        --max-duration 600 \
+        --decoding-method greedy_search \
+        --lang-dir data/lang_char \
+
+Check ./pretrained.py for its usage.
+"""
+
+import argparse
+import logging
+from pathlib import Path
+
+import torch
+import torch.nn as nn
+from scaling_converter import convert_scaled_to_non_scaled
+from train import add_model_arguments, get_params, get_transducer_model
+from icefall.lexicon import Lexicon
+
+from icefall.checkpoint import (
+    average_checkpoints,
+    average_checkpoints_with_averaged_model,
+    find_checkpoints,
+    load_checkpoint,
+)
+from icefall.utils import str2bool
+
+
+def get_parser():
+    parser = argparse.ArgumentParser(
+        formatter_class=argparse.ArgumentDefaultsHelpFormatter
+    )
+
+    parser.add_argument(
+        "--epoch",
+        type=int,
+        default=28,
+        help="""It specifies the checkpoint to use for averaging.
+        Note: Epoch counts from 0.
+        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=15,
+        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="pruned_transducer_stateless3/exp",
+        help="""It specifies the directory where all training related
+        files, e.g., checkpoints, log, etc, are saved
+        """,
+    )
+
+    parser.add_argument(
+        "--lang-dir",
+        type=str,
+        default="data/lang_char",
+        help="The lang dir",
+    )
+
+    parser.add_argument(
+        "--jit-trace",
+        type=str2bool,
+        default=False,
+        help="""True to save a model after applying torch.jit.trace.
+        It will generate 3 files:
+         - encoder_jit_trace.pt
+         - decoder_jit_trace.pt
+         - joiner_jit_trace.pt
+
+        Check ./jit_pretrained.py for how to use them.
+        """,
+    )
+
+    parser.add_argument(
+        "--pnnx",
+        type=str2bool,
+        default=False,
+        help="""True to save a model after applying torch.jit.trace for later
+        converting to PNNX. It will generate 3 files:
+         - encoder_jit_trace-pnnx.pt
+         - decoder_jit_trace-pnnx.pt
+         - joiner_jit_trace-pnnx.pt
+        """,
+    )
+
+    parser.add_argument(
+        "--context-size",
+        type=int,
+        default=2,
+        help="The context size in the decoder. 1 means bigram; "
+        "2 means tri-gram",
+    )
+
+    add_model_arguments(parser)
+
+    return parser
+
+
+def export_encoder_model_jit_trace(
+    encoder_model: nn.Module,
+    encoder_filename: str,
+) -> None:
+    """Export the given encoder model with torch.jit.trace()
+
+    Note: The warmup argument is fixed to 1.
+
+    Args:
+      encoder_model:
+        The input encoder model
+      encoder_filename:
+        The filename to save the exported model.
+    """
+    x = torch.zeros(1, 100, 80, dtype=torch.float32)
+    x_lens = torch.tensor([100], dtype=torch.int64)
+    states = encoder_model.get_init_states()
+
+    traced_model = torch.jit.trace(encoder_model, (x, x_lens, states))
+    traced_model.save(encoder_filename)
+    logging.info(f"Saved to {encoder_filename}")
+
+
+def export_decoder_model_jit_trace(
+    decoder_model: nn.Module,
+    decoder_filename: str,
+) -> None:
+    """Export the given decoder model with torch.jit.trace()
+
+    Note: The argument need_pad is fixed to False.
+
+    Args:
+      decoder_model:
+        The input decoder model
+      decoder_filename:
+        The filename to save the exported model.
+    """
+    y = torch.zeros(10, decoder_model.context_size, dtype=torch.int64)
+    need_pad = torch.tensor([False])
+
+    traced_model = torch.jit.trace(decoder_model, (y, need_pad))
+    traced_model.save(decoder_filename)
+    logging.info(f"Saved to {decoder_filename}")
+
+
+def export_joiner_model_jit_trace(
+    joiner_model: nn.Module,
+    joiner_filename: str,
+) -> None:
+    """Export the given joiner model with torch.jit.trace()
+
+    Note: The argument project_input is fixed to True. A user should not
+    project the encoder_out/decoder_out by himself/herself. The exported joiner
+    will do that for the user.
+
+    Args:
+      joiner_model:
+        The input joiner model
+      joiner_filename:
+        The filename to save the exported model.
+
+    """
+    encoder_out_dim = joiner_model.encoder_proj.weight.shape[1]
+    decoder_out_dim = joiner_model.decoder_proj.weight.shape[1]
+    encoder_out = torch.rand(1, encoder_out_dim, dtype=torch.float32)
+    decoder_out = torch.rand(1, decoder_out_dim, dtype=torch.float32)
+
+    traced_model = torch.jit.trace(joiner_model, (encoder_out, decoder_out))
+    traced_model.save(joiner_filename)
+    logging.info(f"Saved to {joiner_filename}")
+
+
+@torch.no_grad()
+def main():
+    args = get_parser().parse_args()
+    args.exp_dir = Path(args.exp_dir)
+
+    params = get_params()
+    params.update(vars(args))
+
+    device = torch.device("cpu")
+    if torch.cuda.is_available():
+        device = torch.device("cuda", 0)
+
+    logging.info(f"device: {device}")
+    lexicon = Lexicon(params.lang_dir)
+
+    params.blank_id = 0
+    params.vocab_size = max(lexicon.tokens) + 1
+
+    logging.info(params)
+
+    if params.pnnx:
+        params.is_pnnx = params.pnnx
+        logging.info("For PNNX")
+
+    logging.info("About to create model")
+    model = get_transducer_model(params)
+
+    num_param = sum([p.numel() for p in model.parameters()])
+    logging.info(f"Number of model parameters: {num_param}")
+
+    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 i >= 1:
+                    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("cpu")
+    model.eval()
+
+    if params.pnnx:
+        convert_scaled_to_non_scaled(model, inplace=True)
+        logging.info("Using torch.jit.trace()")
+        encoder_filename = params.exp_dir / "encoder_jit_trace-pnnx.pt"
+        export_encoder_model_jit_trace(model.encoder, encoder_filename)
+
+        decoder_filename = params.exp_dir / "decoder_jit_trace-pnnx.pt"
+        export_decoder_model_jit_trace(model.decoder, decoder_filename)
+
+        joiner_filename = params.exp_dir / "joiner_jit_trace-pnnx.pt"
+        export_joiner_model_jit_trace(model.joiner, joiner_filename)
+    elif params.jit_trace is True:
+        convert_scaled_to_non_scaled(model, inplace=True)
+        logging.info("Using torch.jit.trace()")
+        encoder_filename = params.exp_dir / "encoder_jit_trace.pt"
+        export_encoder_model_jit_trace(model.encoder, encoder_filename)
+
+        decoder_filename = params.exp_dir / "decoder_jit_trace.pt"
+        export_decoder_model_jit_trace(model.decoder, decoder_filename)
+
+        joiner_filename = params.exp_dir / "joiner_jit_trace.pt"
+        export_joiner_model_jit_trace(model.joiner, joiner_filename)
+    else:
+        logging.info("Not using torchscript")
+        # Save it using a format so that it can be loaded
+        # by :func:`load_checkpoint`
+        filename = params.exp_dir / "pretrained.pt"
+        torch.save({"model": model.state_dict()}, str(filename))
+        logging.info(f"Saved to {filename}")
+
+
+if __name__ == "__main__":
+    formatter = (
+        "%(asctime)s %(levelname)s [%(filename)s:%(lineno)d] %(message)s"
+    )
+
+    logging.basicConfig(format=formatter, level=logging.INFO)
+    main()
diff --git a/egs/wenetspeech/ASR/lstm_transducer_stateless/ncnn-decode.py b/egs/wenetspeech/ASR/lstm_transducer_stateless/ncnn-decode.py
new file mode 100755
index 000000000..50901e6da
--- /dev/null
+++ b/egs/wenetspeech/ASR/lstm_transducer_stateless/ncnn-decode.py
@@ -0,0 +1,296 @@
+#!/usr/bin/env python3
+# flake8: noqa
+#
+# Copyright      2022  Xiaomi Corp.        (authors: Fangjun Kuang, Zengwei Yao)
+#
+# 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:
+  ./lstm_transducer_stateless/ncnn-decode.py \
+   --token-filename ./data/lang_char/tokens.txt \
+   --encoder-param-filename ./lstm_transducer_stateless/exp-new/encoder_jit_trace-epoch-11-avg-2-pnnx.ncnn.param \
+   --encoder-bin-filename ./lstm_transducer_stateless/exp-new/encoder_jit_trace-epoch-11-avg-2-pnnx.ncnn.bin \
+   --decoder-param-filename ./lstm_transducer_stateless/exp-new/decoder_jit_trace-epoch-11-avg-2-pnnx.ncnn.param \
+   --decoder-bin-filename ./lstm_transducer_stateless/exp-new/decoder_jit_trace-epoch-11-avg-2-pnnx.ncnn.bin \
+   --joiner-param-filename ./lstm_transducer_stateless/exp-new/joiner_jit_trace-epoch-11-avg-2-pnnx.ncnn.param \
+   --joiner-bin-filename ./lstm_transducer_stateless/exp-new/joiner_jit_trace-epoch-11-avg-2-pnnx.ncnn.bin \
+   ./test_wavs/DEV_T0000000001.wav
+"""
+
+import argparse
+import logging
+from typing import List
+
+import k2
+import kaldifeat
+import ncnn
+import torch
+import torchaudio
+
+
+def get_args():
+    parser = argparse.ArgumentParser()
+
+    parser.add_argument(
+        "--token-filename",
+        type=str,
+        help="Path to tokens.txt",
+    )
+
+    parser.add_argument(
+        "--encoder-param-filename",
+        type=str,
+        help="Path to encoder.ncnn.param",
+    )
+
+    parser.add_argument(
+        "--encoder-bin-filename",
+        type=str,
+        help="Path to encoder.ncnn.bin",
+    )
+
+    parser.add_argument(
+        "--decoder-param-filename",
+        type=str,
+        help="Path to decoder.ncnn.param",
+    )
+
+    parser.add_argument(
+        "--decoder-bin-filename",
+        type=str,
+        help="Path to decoder.ncnn.bin",
+    )
+
+    parser.add_argument(
+        "--joiner-param-filename",
+        type=str,
+        help="Path to joiner.ncnn.param",
+    )
+
+    parser.add_argument(
+        "--joiner-bin-filename",
+        type=str,
+        help="Path to joiner.ncnn.bin",
+    )
+
+    parser.add_argument(
+        "sound_filename",
+        type=str,
+        help="Path to foo.wav",
+    )
+
+    return parser.parse_args()
+
+
+class Model:
+    def __init__(self, args):
+        self.init_encoder(args)
+        self.init_decoder(args)
+        self.init_joiner(args)
+
+    def init_encoder(self, args):
+        encoder_net = ncnn.Net()
+        encoder_net.opt.use_packing_layout = False
+        encoder_net.opt.use_fp16_storage = False
+        encoder_param = args.encoder_param_filename
+        encoder_model = args.encoder_bin_filename
+
+        encoder_net.load_param(encoder_param)
+        encoder_net.load_model(encoder_model)
+
+        self.encoder_net = encoder_net
+
+    def init_decoder(self, args):
+        decoder_param = args.decoder_param_filename
+        decoder_model = args.decoder_bin_filename
+
+        decoder_net = ncnn.Net()
+        decoder_net.opt.use_packing_layout = False
+
+        decoder_net.load_param(decoder_param)
+        decoder_net.load_model(decoder_model)
+
+        self.decoder_net = decoder_net
+
+    def init_joiner(self, args):
+        joiner_param = args.joiner_param_filename
+        joiner_model = args.joiner_bin_filename
+        joiner_net = ncnn.Net()
+        joiner_net.opt.use_packing_layout = False
+        joiner_net.load_param(joiner_param)
+        joiner_net.load_model(joiner_model)
+
+        self.joiner_net = joiner_net
+
+    def run_encoder(self, x, states):
+        with self.encoder_net.create_extractor() as ex:
+            ex.set_num_threads(10)
+            ex.input("in0", ncnn.Mat(x.numpy()).clone())
+            x_lens = torch.tensor([x.size(0)], dtype=torch.float32)
+            ex.input("in1", ncnn.Mat(x_lens.numpy()).clone())
+            ex.input("in2", ncnn.Mat(states[0].numpy()).clone())
+            ex.input("in3", ncnn.Mat(states[1].numpy()).clone())
+
+            ret, ncnn_out0 = ex.extract("out0")
+            assert ret == 0, ret
+
+            ret, ncnn_out1 = ex.extract("out1")
+            assert ret == 0, ret
+
+            ret, ncnn_out2 = ex.extract("out2")
+            assert ret == 0, ret
+
+            ret, ncnn_out3 = ex.extract("out3")
+            assert ret == 0, ret
+
+            encoder_out = torch.from_numpy(ncnn_out0.numpy()).clone()
+            encoder_out_lens = torch.from_numpy(ncnn_out1.numpy()).to(
+                torch.int32
+            )
+            hx = torch.from_numpy(ncnn_out2.numpy()).clone()
+            cx = torch.from_numpy(ncnn_out3.numpy()).clone()
+            return encoder_out, encoder_out_lens, hx, cx
+
+    def run_decoder(self, decoder_input):
+        assert decoder_input.dtype == torch.int32
+
+        with self.decoder_net.create_extractor() as ex:
+            ex.set_num_threads(10)
+            ex.input("in0", ncnn.Mat(decoder_input.numpy()).clone())
+            ret, ncnn_out0 = ex.extract("out0")
+            assert ret == 0, ret
+            decoder_out = torch.from_numpy(ncnn_out0.numpy()).clone()
+            return decoder_out
+
+    def run_joiner(self, encoder_out, decoder_out):
+        with self.joiner_net.create_extractor() as ex:
+            ex.set_num_threads(10)
+            ex.input("in0", ncnn.Mat(encoder_out.numpy()).clone())
+            ex.input("in1", ncnn.Mat(decoder_out.numpy()).clone())
+            ret, ncnn_out0 = ex.extract("out0")
+            assert ret == 0, ret
+            joiner_out = torch.from_numpy(ncnn_out0.numpy()).clone()
+            return joiner_out
+
+
+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}. "
+            f"Given: {sample_rate}"
+        )
+        # We use only the first channel
+        ans.append(wave[0])
+    return ans
+
+
+def greedy_search(model: Model, encoder_out: torch.Tensor):
+    assert encoder_out.ndim == 2
+    T = encoder_out.size(0)
+
+    context_size = 2
+    blank_id = 0  # hard-code to 0
+    hyp = [blank_id] * context_size
+
+    decoder_input = torch.tensor(hyp, dtype=torch.int32)  # (1, context_size)
+
+    decoder_out = model.run_decoder(decoder_input).squeeze(0)
+    #  print(decoder_out.shape)  # (512,)
+
+    for t in range(T):
+        encoder_out_t = encoder_out[t]
+        joiner_out = model.run_joiner(encoder_out_t, decoder_out)
+        #  print(joiner_out.shape) # [500]
+        y = joiner_out.argmax(dim=0).tolist()
+        if y != blank_id:
+            hyp.append(y)
+            decoder_input = hyp[-context_size:]
+            decoder_input = torch.tensor(decoder_input, dtype=torch.int32)
+            decoder_out = model.run_decoder(decoder_input).squeeze(0)
+    return hyp[context_size:]
+
+
+def main():
+    args = get_args()
+    logging.info(vars(args))
+
+    model = Model(args)
+
+    sound_file = args.sound_filename
+
+    sample_rate = 16000
+
+    logging.info("Constructing Fbank computer")
+    opts = kaldifeat.FbankOptions()
+    opts.device = "cpu"
+    opts.frame_opts.dither = 0
+    opts.frame_opts.snip_edges = False
+    opts.frame_opts.samp_freq = sample_rate
+    opts.mel_opts.num_bins = 80
+
+    fbank = kaldifeat.Fbank(opts)
+
+    logging.info(f"Reading sound files: {sound_file}")
+    wave_samples = read_sound_files(
+        filenames=[sound_file],
+        expected_sample_rate=sample_rate,
+    )[0]
+
+    logging.info("Decoding started")
+    features = fbank(wave_samples)
+
+    num_encoder_layers = 12
+    d_model = 512
+    rnn_hidden_size = 1024
+
+    states = (
+        torch.zeros(num_encoder_layers, d_model),
+        torch.zeros(
+            num_encoder_layers,
+            rnn_hidden_size,
+        ),
+    )
+
+    encoder_out, encoder_out_lens, hx, cx = model.run_encoder(features, states)
+    hyp = greedy_search(model, encoder_out)
+
+    logging.info(sound_file)
+
+    token_table = k2.SymbolTable.from_file(args.token_filename)
+    words = [token_table[i] for i in hyp]
+    logging.info("".join(words))
+
+
+if __name__ == "__main__":
+    formatter = (
+        "%(asctime)s %(levelname)s [%(filename)s:%(lineno)d] %(message)s"
+    )
+
+    logging.basicConfig(format=formatter, level=logging.INFO)
+
+    main()
diff --git a/egs/wenetspeech/ASR/lstm_transducer_stateless/train.py b/egs/wenetspeech/ASR/lstm_transducer_stateless/train.py
index 770833ef5..5b9712fda 100755
--- a/egs/wenetspeech/ASR/lstm_transducer_stateless/train.py
+++ b/egs/wenetspeech/ASR/lstm_transducer_stateless/train.py
@@ -405,6 +405,8 @@ def get_params() -> AttributeDict:
             "decoder_dim": 512,
             # parameters for joiner
             "joiner_dim": 512,
+            # True to generate a model that can be exported via PNNX
+            "is_pnnx": False,
             "env_info": get_env_info(),
         }
     )
@@ -421,6 +423,7 @@ def get_encoder_model(params: AttributeDict) -> nn.Module:
         dim_feedforward=params.dim_feedforward,
         num_encoder_layers=params.num_encoder_layers,
         aux_layer_period=params.aux_layer_period,
+        is_pnnx=params.is_pnnx,
     )
     return encoder