updates for the pruned_transducer_stateless recipes

.github/scripts/run-librispeech-pruned-transducer-stateless-2022-03-12.sh

@@ -28,7 +28,7 @@ for sym in 1 2 3; do
     --method greedy_search \
     --max-sym-per-frame $sym \
     --checkpoint $repo/exp/pretrained.pt \
-    --bpe-model $repo/data/lang_bpe_500/bpe.model \
+    --tokens $repo/data/lang_bpe_500/tokens.txt \
     $repo/test_wavs/1089-134686-0001.wav \
     $repo/test_wavs/1221-135766-0001.wav \
     $repo/test_wavs/1221-135766-0002.wav
@@ -41,7 +41,7 @@ for method in fast_beam_search modified_beam_search beam_search; do
     --method $method \
     --beam-size 4 \
     --checkpoint $repo/exp/pretrained.pt \
-    --bpe-model $repo/data/lang_bpe_500/bpe.model \
+    --tokens $repo/data/lang_bpe_500/tokens.txt \
     $repo/test_wavs/1089-134686-0001.wav \
     $repo/test_wavs/1221-135766-0001.wav \
     $repo/test_wavs/1221-135766-0002.wav

.github/scripts/run-librispeech-pruned-transducer-stateless2-2022-04-29.sh

@@ -36,7 +36,7 @@ for sym in 1 2 3; do
     --method greedy_search \
     --max-sym-per-frame $sym \
     --checkpoint $repo/exp/pretrained.pt \
-    --bpe-model $repo/data/lang_bpe_500/bpe.model \
+    --tokens $repo/data/lang_bpe_500/tokens.txt \
     $repo/test_wavs/1089-134686-0001.wav \
     $repo/test_wavs/1221-135766-0001.wav \
     $repo/test_wavs/1221-135766-0002.wav
@@ -49,7 +49,7 @@ for method in modified_beam_search beam_search fast_beam_search; do
     --method $method \
     --beam-size 4 \
     --checkpoint $repo/exp/pretrained.pt \
-    --bpe-model $repo/data/lang_bpe_500/bpe.model \
+    --tokens $repo/data/lang_bpe_500/tokens.txt \
     $repo/test_wavs/1089-134686-0001.wav \
     $repo/test_wavs/1221-135766-0001.wav \
     $repo/test_wavs/1221-135766-0002.wav

.github/scripts/run-librispeech-pruned-transducer-stateless3-2022-04-29.sh

@@ -35,7 +35,7 @@ for sym in 1 2 3; do
     --method greedy_search \
     --max-sym-per-frame $sym \
     --checkpoint $repo/exp/pretrained.pt \
-    --bpe-model $repo/data/lang_bpe_500/bpe.model \
+    --tokens $repo/data/lang_bpe_500/tokens.txt \
     $repo/test_wavs/1089-134686-0001.wav \
     $repo/test_wavs/1221-135766-0001.wav \
     $repo/test_wavs/1221-135766-0002.wav
@@ -48,7 +48,7 @@ for method in modified_beam_search beam_search fast_beam_search; do
     --method $method \
     --beam-size 4 \
     --checkpoint $repo/exp/pretrained.pt \
-    --bpe-model $repo/data/lang_bpe_500/bpe.model \
+    --tokens $repo/data/lang_bpe_500/tokens.txt \
     $repo/test_wavs/1089-134686-0001.wav \
     $repo/test_wavs/1221-135766-0001.wav \
     $repo/test_wavs/1221-135766-0002.wav

.github/scripts/run-librispeech-pruned-transducer-stateless3-2022-05-13.sh

@@ -30,14 +30,14 @@ popd
 log "Export to torchscript model"
 ./pruned_transducer_stateless3/export.py \
   --exp-dir $repo/exp \
-  --bpe-model $repo/data/lang_bpe_500/bpe.model \
+  --tokens $repo/data/lang_bpe_500/tokens.txt \
   --epoch 99 \
   --avg 1 \
   --jit 1
 
 ./pruned_transducer_stateless3/export.py \
   --exp-dir $repo/exp \
-  --bpe-model $repo/data/lang_bpe_500/bpe.model \
+  --tokens $repo/data/lang_bpe_500/tokens.txt \
   --epoch 99 \
   --avg 1 \
   --jit-trace 1
@@ -74,7 +74,7 @@ for sym in 1 2 3; do
     --method greedy_search \
     --max-sym-per-frame $sym \
     --checkpoint $repo/exp/pretrained.pt \
-    --bpe-model $repo/data/lang_bpe_500/bpe.model \
+    --tokens $repo/data/lang_bpe_500/tokens.txt \
     $repo/test_wavs/1089-134686-0001.wav \
     $repo/test_wavs/1221-135766-0001.wav \
     $repo/test_wavs/1221-135766-0002.wav
@@ -87,7 +87,7 @@ for method in modified_beam_search beam_search fast_beam_search; do
     --method $method \
     --beam-size 4 \
     --checkpoint $repo/exp/pretrained.pt \
-    --bpe-model $repo/data/lang_bpe_500/bpe.model \
+    --tokens $repo/data/lang_bpe_500/tokens.txt \
     $repo/test_wavs/1089-134686-0001.wav \
     $repo/test_wavs/1221-135766-0001.wav \
     $repo/test_wavs/1221-135766-0002.wav

.github/scripts/run-librispeech-pruned-transducer-stateless5-2022-05-13.sh

@@ -32,7 +32,7 @@ for sym in 1 2 3; do
     --method greedy_search \
     --max-sym-per-frame $sym \
     --checkpoint $repo/exp/pretrained.pt \
-    --bpe-model $repo/data/lang_bpe_500/bpe.model \
+    --tokens $repo/data/lang_bpe_500/tokens.txt \
     --num-encoder-layers 18 \
     --dim-feedforward 2048 \
     --nhead 8 \
@@ -51,7 +51,7 @@ for method in modified_beam_search beam_search fast_beam_search; do
     --method $method \
     --beam-size 4 \
     --checkpoint $repo/exp/pretrained.pt \
-    --bpe-model $repo/data/lang_bpe_500/bpe.model \
+    --tokens $repo/data/lang_bpe_500/tokens.txt \
     $repo/test_wavs/1089-134686-0001.wav \
     $repo/test_wavs/1221-135766-0001.wav \
     $repo/test_wavs/1221-135766-0002.wav \

.github/scripts/run-librispeech-pruned-transducer-stateless7-ctc-2022-12-01.sh

@@ -37,7 +37,7 @@ log "Export to torchscript model"
 ./pruned_transducer_stateless7_ctc/export.py \
   --exp-dir $repo/exp \
   --use-averaged-model false \
-  --bpe-model $repo/data/lang_bpe_500/bpe.model \
+  --tokens $repo/data/lang_bpe_500/tokens.txt \
   --epoch 99 \
   --avg 1 \
   --jit 1
@@ -74,7 +74,7 @@ for sym in 1 2 3; do
     --method greedy_search \
     --max-sym-per-frame $sym \
     --checkpoint $repo/exp/pretrained.pt \
-    --bpe-model $repo/data/lang_bpe_500/bpe.model \
+    --tokens $repo/data/lang_bpe_500/tokens.txt \
     $repo/test_wavs/1089-134686-0001.wav \
     $repo/test_wavs/1221-135766-0001.wav \
     $repo/test_wavs/1221-135766-0002.wav
@@ -87,7 +87,7 @@ for method in modified_beam_search beam_search fast_beam_search; do
     --method $method \
     --beam-size 4 \
     --checkpoint $repo/exp/pretrained.pt \
-    --bpe-model $repo/data/lang_bpe_500/bpe.model \
+    --tokens $repo/data/lang_bpe_500/tokens.txt \
     $repo/test_wavs/1089-134686-0001.wav \
     $repo/test_wavs/1221-135766-0001.wav \
     $repo/test_wavs/1221-135766-0002.wav

.github/scripts/run-librispeech-pruned-transducer-stateless7-ctc-bs-2022-12-15.sh

@@ -36,7 +36,7 @@ log "Export to torchscript model"
 ./pruned_transducer_stateless7_ctc_bs/export.py \
   --exp-dir $repo/exp \
   --use-averaged-model false \
-  --bpe-model $repo/data/lang_bpe_500/bpe.model \
+  --tokens $repo/data/lang_bpe_500/tokens.txt \
   --epoch 99 \
   --avg 1 \
   --jit 1
@@ -72,7 +72,7 @@ for sym in 1 2 3; do
     --method greedy_search \
     --max-sym-per-frame $sym \
     --checkpoint $repo/exp/pretrained.pt \
-    --bpe-model $repo/data/lang_bpe_500/bpe.model \
+    --tokens $repo/data/lang_bpe_500/tokens.txt \
     $repo/test_wavs/1089-134686-0001.wav \
     $repo/test_wavs/1221-135766-0001.wav \
     $repo/test_wavs/1221-135766-0002.wav
@@ -85,7 +85,7 @@ for method in modified_beam_search beam_search fast_beam_search; do
     --method $method \
     --beam-size 4 \
     --checkpoint $repo/exp/pretrained.pt \
-    --bpe-model $repo/data/lang_bpe_500/bpe.model \
+    --tokens $repo/data/lang_bpe_500/tokens.txt \
     $repo/test_wavs/1089-134686-0001.wav \
     $repo/test_wavs/1221-135766-0001.wav \
     $repo/test_wavs/1221-135766-0002.wav

.github/scripts/run-librispeech-pruned-transducer-stateless7-streaming-2022-12-29.sh

@@ -37,7 +37,7 @@ log "Export to torchscript model"
 ./pruned_transducer_stateless7_streaming/export.py \
   --exp-dir $repo/exp \
   --use-averaged-model false \
-  --bpe-model $repo/data/lang_bpe_500/bpe.model \
+  --tokens $repo/data/lang_bpe_500/tokens.txt \
   --decode-chunk-len 32 \
   --epoch 99 \
   --avg 1 \
@@ -81,7 +81,7 @@ for sym in 1 2 3; do
     --method greedy_search \
     --max-sym-per-frame $sym \
     --checkpoint $repo/exp/pretrained.pt \
-    --bpe-model $repo/data/lang_bpe_500/bpe.model \
+    --tokens $repo/data/lang_bpe_500/tokens.txt \
     --decode-chunk-len 32 \
     $repo/test_wavs/1089-134686-0001.wav \
     $repo/test_wavs/1221-135766-0001.wav \
@@ -95,7 +95,7 @@ for method in modified_beam_search beam_search fast_beam_search; do
     --method $method \
     --beam-size 4 \
     --checkpoint $repo/exp/pretrained.pt \
-    --bpe-model $repo/data/lang_bpe_500/bpe.model \
+    --tokens $repo/data/lang_bpe_500/tokens.txt \
     --decode-chunk-len 32 \
     $repo/test_wavs/1089-134686-0001.wav \
     $repo/test_wavs/1221-135766-0001.wav \

.github/scripts/run-librispeech-pruned-transducer-stateless8-2022-11-14.sh

@@ -41,7 +41,7 @@ log "Decode with models exported by torch.jit.script()"
 log "Export to torchscript model"
 ./pruned_transducer_stateless8/export.py \
   --exp-dir $repo/exp \
-  --bpe-model $repo/data/lang_bpe_500/bpe.model \
+  --tokens $repo/data/lang_bpe_500/tokens.txt \
   --use-averaged-model false \
   --epoch 99 \
   --avg 1 \
@@ -65,7 +65,7 @@ for sym in 1 2 3; do
     --method greedy_search \
     --max-sym-per-frame $sym \
     --checkpoint $repo/exp/pretrained.pt \
-    --bpe-model $repo/data/lang_bpe_500/bpe.model \
+    --tokens $repo/data/lang_bpe_500/tokens.txt \
     $repo/test_wavs/1089-134686-0001.wav \
     $repo/test_wavs/1221-135766-0001.wav \
     $repo/test_wavs/1221-135766-0002.wav
@@ -78,7 +78,7 @@ for method in modified_beam_search beam_search fast_beam_search; do
     --method $method \
     --beam-size 4 \
     --checkpoint $repo/exp/pretrained.pt \
-    --bpe-model $repo/data/lang_bpe_500/bpe.model \
+    --tokens $repo/data/lang_bpe_500/tokens.txt \
     $repo/test_wavs/1089-134686-0001.wav \
     $repo/test_wavs/1221-135766-0001.wav \
     $repo/test_wavs/1221-135766-0002.wav

.github/scripts/run-librispeech-streaming-pruned-transducer-stateless2-2022-06-26.sh

@@ -32,7 +32,7 @@ for sym in 1 2 3; do
     --method greedy_search \
     --max-sym-per-frame $sym \
     --checkpoint $repo/exp/pretrained.pt \
-    --bpe-model $repo/data/lang_bpe_500/bpe.model \
+    --tokens $repo/data/lang_bpe_500/tokens.txt \
     --simulate-streaming 1 \
     --causal-convolution 1 \
     $repo/test_wavs/1089-134686-0001.wav \
@@ -47,7 +47,7 @@ for method in modified_beam_search beam_search fast_beam_search; do
     --method $method \
     --beam-size 4 \
     --checkpoint $repo/exp/pretrained.pt \
-    --bpe-model $repo/data/lang_bpe_500/bpe.model \
+    --tokens $repo/data/lang_bpe_500/tokens.txt \
     --simulate-streaming 1 \
     --causal-convolution 1 \
     $repo/test_wavs/1089-134686-0001.wav \

egs/librispeech/ASR/pruned_transducer_stateless/export.py

@@ -22,7 +22,7 @@
 Usage:
 ./pruned_transducer_stateless/export.py \
   --exp-dir ./pruned_transducer_stateless/exp \
-  --bpe-model data/lang_bpe_500/bpe.model \
+  --tokens data/lang_bpe_500/tokens.txt \
   --epoch 20 \
   --avg 10
 
@@ -47,12 +47,12 @@ import argparse
 import logging
 from pathlib import Path
 
-import sentencepiece as spm
+import k2
 import torch
 from train import add_model_arguments, get_params, get_transducer_model
 
 from icefall.checkpoint import average_checkpoints, load_checkpoint
-from icefall.utils import str2bool
+from icefall.utils import num_tokens, str2bool
 
 
 def get_parser():
@@ -87,10 +87,10 @@ def get_parser():
     )
 
     parser.add_argument(
-        "--bpe-model",
+        "--tokens",
         type=str,
-        default="data/lang_bpe_500/bpe.model",
+        default="data/lang_bpe_500/tokens.txt",
-        help="Path to the BPE model",
+        help="Path to the tokens.txt.",
     )
 
     parser.add_argument(
@@ -135,13 +135,13 @@ def main():
 
     logging.info(f"device: {device}")
 
-    sp = spm.SentencePieceProcessor()
+    # Load tokens.txt here
-    sp.load(params.bpe_model)
+    token_table = k2.SymbolTable.from_file(params.tokens)
 
-    # <blk> is defined in local/train_bpe_model.py
+    # Load id of the <blk> token and the vocab size, <blk> is
-    params.blank_id = sp.piece_to_id("<blk>")
+    # defined in local/train_bpe_model.py
-    params.unk_id = sp.piece_to_id("<unk>")
+    params.blank_id = token_table["<blk>"]
-    params.vocab_size = sp.get_piece_size()
+    params.vocab_size = num_tokens(token_table) + 1  # +1 for <blk>
 
     if params.streaming_model:
         assert params.causal_convolution

egs/librispeech/ASR/pruned_transducer_stateless/pretrained.py

@@ -20,7 +20,7 @@ Usage:
 (1) greedy search
 ./pruned_transducer_stateless/pretrained.py \
     --checkpoint ./pruned_transducer_stateless/exp/pretrained.pt \
-    --bpe-model ./data/lang_bpe_500/bpe.model \
+    --tokens ./data/lang_bpe_500/tokens.txt \
     --method greedy_search \
     /path/to/foo.wav \
     /path/to/bar.wav
@@ -28,7 +28,7 @@ Usage:
 (2) beam search
 ./pruned_transducer_stateless/pretrained.py \
     --checkpoint ./pruned_transducer_stateless/exp/pretrained.pt \
-    --bpe-model ./data/lang_bpe_500/bpe.model \
+    --tokens ./data/lang_bpe_500/tokens.txt \
     --method beam_search \
     --beam-size 4 \
     /path/to/foo.wav \
@@ -37,7 +37,7 @@ Usage:
 (3) modified beam search
 ./pruned_transducer_stateless/pretrained.py \
     --checkpoint ./pruned_transducer_stateless/exp/pretrained.pt \
-    --bpe-model ./data/lang_bpe_500/bpe.model \
+    --tokens ./data/lang_bpe_500/tokens.txt \
     --method modified_beam_search \
     --beam-size 4 \
     /path/to/foo.wav \
@@ -46,7 +46,7 @@ Usage:
 (4) fast beam search
 ./pruned_transducer_stateless/pretrained.py \
     --checkpoint ./pruned_transducer_stateless/exp/pretrained.pt \
-    --bpe-model ./data/lang_bpe_500/bpe.model \
+    --tokens ./data/lang_bpe_500/tokens.txt \
     --method fast_beam_search \
     --beam-size 4 \
     /path/to/foo.wav \
@@ -66,7 +66,6 @@ from typing import List
 
 import k2
 import kaldifeat
-import sentencepiece as spm
 import torch
 import torchaudio
 from beam_search import (
@@ -79,7 +78,7 @@ from beam_search import (
 from torch.nn.utils.rnn import pad_sequence
 from train import add_model_arguments, get_params, get_transducer_model
 
-from icefall.utils import str2bool
+from icefall.utils import num_tokens, str2bool
 
 
 def get_parser():
@@ -97,9 +96,9 @@ def get_parser():
     )
 
     parser.add_argument(
-        "--bpe-model",
+        "--tokens",
         type=str,
-        help="""Path to bpe.model.""",
+        help="""Path to tokens.txt.""",
     )
 
     parser.add_argument(
@@ -237,13 +236,14 @@ def main():
 
     params.update(vars(args))
 
-    sp = spm.SentencePieceProcessor()
+    # Load tokens.txt here
-    sp.load(params.bpe_model)
+    token_table = k2.SymbolTable.from_file(params.tokens)
 
+    # Load id of the <blk> token and the vocab size
     # <blk> is defined in local/train_bpe_model.py
-    params.blank_id = sp.piece_to_id("<blk>")
+    params.blank_id = token_table["<blk>"]
-    params.unk_id = sp.piece_to_id("<unk>")
+    params.unk_id = token_table["<unk>"]
-    params.vocab_size = sp.get_piece_size()
+    params.vocab_size = num_tokens(token_table) + 1  # +1 for <blk>
 
     if params.simulate_streaming:
         assert (
@@ -314,6 +314,12 @@ def main():
         msg += f" with beam size {params.beam_size}"
     logging.info(msg)
 
+    def token_ids_to_words(token_ids: List[int]) -> str:
+        text = ""
+        for i in token_ids:
+            text += token_table[i]
+        return text.replace("▁", " ").strip()
+
     if params.method == "fast_beam_search":
         decoding_graph = k2.trivial_graph(params.vocab_size - 1, device=device)
         hyp_tokens = fast_beam_search_one_best(
@@ -325,8 +331,8 @@ def main():
             max_contexts=params.max_contexts,
             max_states=params.max_states,
         )
-        for hyp in sp.decode(hyp_tokens):
+        for hyp in hyp_tokens:
-            hyps.append(hyp.split())
+            hyps.append(token_ids_to_words(hyp))
     elif params.method == "modified_beam_search":
         hyp_tokens = modified_beam_search(
             model=model,
@@ -335,16 +341,16 @@ def main():
             beam=params.beam_size,
         )
 
-        for hyp in sp.decode(hyp_tokens):
+        for hyp in hyp_tokens:
-            hyps.append(hyp.split())
+            hyps.append(token_ids_to_words(hyp))
     elif params.method == "greedy_search" and params.max_sym_per_frame == 1:
         hyp_tokens = greedy_search_batch(
             model=model,
             encoder_out=encoder_out,
             encoder_out_lens=encoder_out_lens,
         )
-        for hyp in sp.decode(hyp_tokens):
+        for hyp in hyp_tokens:
-            hyps.append(hyp.split())
+            hyps.append(token_ids_to_words(hyp))
     else:
         for i in range(num_waves):
             # fmt: off
@@ -365,12 +371,11 @@ def main():
             else:
                 raise ValueError(f"Unsupported method: {params.method}")
 
-            hyps.append(sp.decode(hyp).split())
+            hyps.append(token_ids_to_words(hyp))
 
     s = "\n"
     for filename, hyp in zip(params.sound_files, hyps):
-        words = " ".join(hyp)
+        s += f"{filename}:\n{hyp}\n\n"
-        s += f"{filename}:\n{words}\n\n"
     logging.info(s)
 
     logging.info("Decoding Done")

egs/librispeech/ASR/pruned_transducer_stateless2/export.py

@@ -22,7 +22,7 @@
 Usage:
 ./pruned_transducer_stateless2/export.py \
   --exp-dir ./pruned_transducer_stateless2/exp \
-  --bpe-model data/lang_bpe_500/bpe.model \
+  --tokens ./data/lang_bpe_500/tokens.txt \
   --epoch 20 \
   --avg 10
 
@@ -47,12 +47,12 @@ import argparse
 import logging
 from pathlib import Path
 
-import sentencepiece as spm
+import k2
 import torch
 from train import add_model_arguments, get_params, get_transducer_model
 
 from icefall.checkpoint import average_checkpoints, find_checkpoints, load_checkpoint
-from icefall.utils import str2bool
+from icefall.utils import num_tokens, str2bool
 
 
 def get_parser():
@@ -98,10 +98,10 @@ def get_parser():
     )
 
     parser.add_argument(
-        "--bpe-model",
+        "--tokens",
         type=str,
-        default="data/lang_bpe_500/bpe.model",
+        default="data/lang_bpe_500/tokens.txt",
-        help="Path to the BPE model",
+        help="Path to the tokens.txt.",
     )
 
     parser.add_argument(
@@ -145,12 +145,14 @@ def main():
 
     logging.info(f"device: {device}")
 
-    sp = spm.SentencePieceProcessor()
+    # Load tokens.txt here
-    sp.load(params.bpe_model)
+    token_table = k2.SymbolTable.from_file(params.tokens)
 
+    # Load id of the <blk> token and the vocab size
     # <blk> is defined in local/train_bpe_model.py
-    params.blank_id = sp.piece_to_id("<blk>")
+    params.blank_id = token_table["<blk>"]
-    params.vocab_size = sp.get_piece_size()
+    params.unk_id = token_table["<unk>"]
+    params.vocab_size = num_tokens(token_table) + 1  # +1 for <blk>
 
     if params.streaming_model:
         assert params.causal_convolution

egs/librispeech/ASR/pruned_transducer_stateless2/pretrained.py

@@ -20,7 +20,7 @@ Usage:
 (1) greedy search
 ./pruned_transducer_stateless2/pretrained.py \
     --checkpoint ./pruned_transducer_stateless2/exp/pretrained.pt \
-    --bpe-model ./data/lang_bpe_500/bpe.model \
+    --tokens ./data/lang_bpe_500/tokens.txt \
     --method greedy_search \
     /path/to/foo.wav \
     /path/to/bar.wav
@@ -28,7 +28,7 @@ Usage:
 (2) beam search
 ./pruned_transducer_stateless2/pretrained.py \
     --checkpoint ./pruned_transducer_stateless2/exp/pretrained.pt \
-    --bpe-model ./data/lang_bpe_500/bpe.model \
+    --tokens ./data/lang_bpe_500/tokens.txt \
     --method beam_search \
     --beam-size 4 \
     /path/to/foo.wav \
@@ -37,7 +37,7 @@ Usage:
 (3) modified beam search
 ./pruned_transducer_stateless2/pretrained.py \
     --checkpoint ./pruned_transducer_stateless2/exp/pretrained.pt \
-    --bpe-model ./data/lang_bpe_500/bpe.model \
+    --tokens ./data/lang_bpe_500/tokens.txt \
     --method modified_beam_search \
     --beam-size 4 \
     /path/to/foo.wav \
@@ -46,7 +46,7 @@ Usage:
 (4) fast beam search
 ./pruned_transducer_stateless2/pretrained.py \
     --checkpoint ./pruned_transducer_stateless2/exp/pretrained.pt \
-    --bpe-model ./data/lang_bpe_500/bpe.model \
+    --tokens ./data/lang_bpe_500/tokens.txt \
     --method fast_beam_search \
     --beam-size 4 \
     /path/to/foo.wav \
@@ -66,7 +66,6 @@ from typing import List
 
 import k2
 import kaldifeat
-import sentencepiece as spm
 import torch
 import torchaudio
 from beam_search import (
@@ -79,7 +78,7 @@ from beam_search import (
 from torch.nn.utils.rnn import pad_sequence
 from train import add_model_arguments, get_params, get_transducer_model
 
-from icefall.utils import str2bool
+from icefall.utils import num_tokens, str2bool
 
 
 def get_parser():
@@ -97,9 +96,9 @@ def get_parser():
     )
 
     parser.add_argument(
-        "--bpe-model",
+        "--tokens",
         type=str,
-        help="""Path to bpe.model.""",
+        help="""Path to tokens.txt.""",
     )
 
     parser.add_argument(
@@ -238,13 +237,14 @@ def main():
 
     params.update(vars(args))
 
-    sp = spm.SentencePieceProcessor()
+    # Load tokens.txt here
-    sp.load(params.bpe_model)
+    token_table = k2.SymbolTable.from_file(params.tokens)
 
+    # Load id of the <blk> token and the vocab size
     # <blk> is defined in local/train_bpe_model.py
-    params.blank_id = sp.piece_to_id("<blk>")
+    params.blank_id = token_table["<blk>"]
-    params.unk_id = sp.piece_to_id("<unk>")
+    params.unk_id = token_table["<unk>"]
-    params.vocab_size = sp.get_piece_size()
+    params.vocab_size = num_tokens(token_table) + 1  # +1 for <blk>
 
     if params.simulate_streaming:
         assert (
@@ -315,6 +315,12 @@ def main():
         msg += f" with beam size {params.beam_size}"
     logging.info(msg)
 
+    def token_ids_to_words(token_ids: List[int]) -> str:
+        text = ""
+        for i in token_ids:
+            text += token_table[i]
+        return text.replace("▁", " ").strip()
+
     if params.method == "fast_beam_search":
         decoding_graph = k2.trivial_graph(params.vocab_size - 1, device=device)
         hyp_tokens = fast_beam_search_one_best(
@@ -326,8 +332,8 @@ def main():
             max_contexts=params.max_contexts,
             max_states=params.max_states,
         )
-        for hyp in sp.decode(hyp_tokens):
+        for hyp in hyp_tokens:
-            hyps.append(hyp.split())
+            hyps.append(token_ids_to_words(hyp))
     elif params.method == "modified_beam_search":
         hyp_tokens = modified_beam_search(
             model=model,
@@ -336,16 +342,16 @@ def main():
             beam=params.beam_size,
         )
 
-        for hyp in sp.decode(hyp_tokens):
+        for hyp in hyp_tokens:
-            hyps.append(hyp.split())
+            hyps.append(token_ids_to_words(hyp))
     elif params.method == "greedy_search" and params.max_sym_per_frame == 1:
         hyp_tokens = greedy_search_batch(
             model=model,
             encoder_out=encoder_out,
             encoder_out_lens=encoder_out_lens,
         )
-        for hyp in sp.decode(hyp_tokens):
+        for hyp in hyp_tokens:
-            hyps.append(hyp.split())
+            hyps.append(token_ids_to_words(hyp))
     else:
         for i in range(num_waves):
             # fmt: off
@@ -366,12 +372,11 @@ def main():
             else:
                 raise ValueError(f"Unsupported method: {params.method}")
 
-            hyps.append(sp.decode(hyp).split())
+            hyps.append(token_ids_to_words(hyp))
 
     s = "\n"
     for filename, hyp in zip(params.sound_files, hyps):
-        words = " ".join(hyp)
+        s += f"{filename}:\n{hyp}\n\n"
-        s += f"{filename}:\n{words}\n\n"
     logging.info(s)
 
     logging.info("Decoding Done")

egs/librispeech/ASR/pruned_transducer_stateless3/export-onnx.py

@@ -28,7 +28,7 @@ popd
 2. Export the model to ONNX
 
 ./pruned_transducer_stateless3/export-onnx.py \
-  --bpe-model $repo/data/lang_bpe_500/bpe.model \
+  --tokens $repo/data/lang_bpe_500/tokens.txt \
   --epoch 9999 \
   --avg 1 \
   --exp-dir $repo/exp/
@@ -48,8 +48,8 @@ import logging
 from pathlib import Path
 from typing import Dict, Tuple
 
+import k2
 import onnx
-import sentencepiece as spm
 import torch
 import torch.nn as nn
 from conformer import Conformer
@@ -59,7 +59,7 @@ from scaling_converter import convert_scaled_to_non_scaled
 from train import add_model_arguments, get_params, get_transducer_model
 
 from icefall.checkpoint import average_checkpoints, find_checkpoints, load_checkpoint
-from icefall.utils import setup_logger
+from icefall.utils import num_tokens, setup_logger
 
 
 def get_parser():
@@ -105,10 +105,10 @@ def get_parser():
     )
 
     parser.add_argument(
-        "--bpe-model",
+        "--tokens",
         type=str,
-        default="data/lang_bpe_500/bpe.model",
+        default="data/lang_bpe_500/tokens.txt",
-        help="Path to the BPE model",
+        help="Path to the tokens.txt.",
     )
 
     parser.add_argument(
@@ -393,12 +393,14 @@ def main():
 
     logging.info(f"device: {device}")
 
-    sp = spm.SentencePieceProcessor()
+    # Load tokens.txt here
-    sp.load(params.bpe_model)
+    token_table = k2.SymbolTable.from_file(params.tokens)
 
+    # Load id of the <blk> token and the vocab size
     # <blk> is defined in local/train_bpe_model.py
-    params.blank_id = sp.piece_to_id("<blk>")
+    params.blank_id = token_table["<blk>"]
-    params.vocab_size = sp.get_piece_size()
+    params.unk_id = token_table["<unk>"]
+    params.vocab_size = num_tokens(token_table) + 1  # +1 for <blk>
 
     logging.info(params)
 

egs/librispeech/ASR/pruned_transducer_stateless3/export.py

@@ -26,7 +26,7 @@ Usage:
 
 ./pruned_transducer_stateless3/export.py \
   --exp-dir ./pruned_transducer_stateless3/exp \
-  --bpe-model data/lang_bpe_500/bpe.model \
+  --tokens ./data/lang_bpe_500/tokens.txt \
   --epoch 20 \
   --avg 10 \
   --jit 1
@@ -44,7 +44,7 @@ It will also generate 3 other files: `encoder_jit_script.pt`,
 
 ./pruned_transducer_stateless3/export.py \
   --exp-dir ./pruned_transducer_stateless3/exp \
-  --bpe-model data/lang_bpe_500/bpe.model \
+  --tokens ./data/lang_bpe_500/tokens.txt \
   --epoch 20 \
   --avg 10 \
   --jit-trace 1
@@ -56,7 +56,7 @@ It will generates 3 files: `encoder_jit_trace.pt`,
 
 ./pruned_transducer_stateless3/export.py \
   --exp-dir ./pruned_transducer_stateless3/exp \
-  --bpe-model data/lang_bpe_500/bpe.model \
+  --tokens ./data/lang_bpe_500/tokens.txt \
   --epoch 20 \
   --avg 10
 
@@ -97,14 +97,14 @@ import argparse
 import logging
 from pathlib import Path
 
-import sentencepiece as spm
+import k2
 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.checkpoint import average_checkpoints, find_checkpoints, load_checkpoint
-from icefall.utils import str2bool
+from icefall.utils import num_tokens, str2bool
 
 
 def get_parser():
@@ -150,10 +150,10 @@ def get_parser():
     )
 
     parser.add_argument(
-        "--bpe-model",
+        "--tokens",
         type=str,
-        default="data/lang_bpe_500/bpe.model",
+        default="data/lang_bpe_500/tokens.txt",
-        help="Path to the BPE model",
+        help="Path to the tokens.txt",
     )
 
     parser.add_argument(
@@ -342,12 +342,14 @@ def main():
 
     logging.info(f"device: {device}")
 
-    sp = spm.SentencePieceProcessor()
+    # Load tokens.txt here
-    sp.load(params.bpe_model)
+    token_table = k2.SymbolTable.from_file(params.tokens)
 
+    # Load id of the <blk> token and the vocab size
     # <blk> is defined in local/train_bpe_model.py
-    params.blank_id = sp.piece_to_id("<blk>")
+    params.blank_id = token_table["<blk>"]
-    params.vocab_size = sp.get_piece_size()
+    params.unk_id = token_table["<unk>"]
+    params.vocab_size = num_tokens(token_table) + 1  # +1 for <blk>
 
     if params.streaming_model:
         assert params.causal_convolution

egs/librispeech/ASR/pruned_transducer_stateless3/pretrained.py

@@ -20,7 +20,7 @@ You can generate the checkpoint with the following command:
 
 ./pruned_transducer_stateless3/export.py \
   --exp-dir ./pruned_transducer_stateless3/exp \
-  --bpe-model data/lang_bpe_500/bpe.model \
+  --tokens ./data/lang_bpe_500/tokens.txt \
   --epoch 20 \
   --avg 10
 
@@ -29,7 +29,7 @@ Usage of this script:
 (1) greedy search
 ./pruned_transducer_stateless3/pretrained.py \
     --checkpoint ./pruned_transducer_stateless3/exp/pretrained.pt \
-    --bpe-model ./data/lang_bpe_500/bpe.model \
+    --tokens ./data/lang_bpe_500/tokens.txt \
     --method greedy_search \
     /path/to/foo.wav \
     /path/to/bar.wav
@@ -37,7 +37,7 @@ Usage of this script:
 (2) beam search
 ./pruned_transducer_stateless3/pretrained.py \
     --checkpoint ./pruned_transducer_stateless3/exp/pretrained.pt \
-    --bpe-model ./data/lang_bpe_500/bpe.model \
+    --tokens ./data/lang_bpe_500/tokens.txt \
     --method beam_search \
     --beam-size 4 \
     /path/to/foo.wav \
@@ -46,7 +46,7 @@ Usage of this script:
 (3) modified beam search
 ./pruned_transducer_stateless3/pretrained.py \
     --checkpoint ./pruned_transducer_stateless3/exp/pretrained.pt \
-    --bpe-model ./data/lang_bpe_500/bpe.model \
+    --tokens ./data/lang_bpe_500/tokens.txt \
     --method modified_beam_search \
     --beam-size 4 \
     /path/to/foo.wav \
@@ -55,7 +55,7 @@ Usage of this script:
 (4) fast beam search
 ./pruned_transducer_stateless3/pretrained.py \
     --checkpoint ./pruned_transducer_stateless3/exp/pretrained.pt \
-    --bpe-model ./data/lang_bpe_500/bpe.model \
+    --tokens ./data/lang_bpe_500/tokens.txt \
     --method fast_beam_search \
     --beam-size 4 \
     /path/to/foo.wav \
@@ -75,7 +75,6 @@ from typing import List
 
 import k2
 import kaldifeat
-import sentencepiece as spm
 import torch
 import torchaudio
 from beam_search import (
@@ -88,7 +87,7 @@ from beam_search import (
 from torch.nn.utils.rnn import pad_sequence
 from train import add_model_arguments, get_params, get_transducer_model
 
-from icefall.utils import str2bool
+from icefall.utils import num_tokens, str2bool
 
 
 def get_parser():
@@ -106,9 +105,9 @@ def get_parser():
     )
 
     parser.add_argument(
-        "--bpe-model",
+        "--tokens",
         type=str,
-        help="""Path to bpe.model.""",
+        help="""Path to tokens.txt.""",
     )
 
     parser.add_argument(
@@ -247,13 +246,14 @@ def main():
 
     params.update(vars(args))
 
-    sp = spm.SentencePieceProcessor()
+    # Load tokens.txt here
-    sp.load(params.bpe_model)
+    token_table = k2.SymbolTable.from_file(params.tokens)
 
+    # Load id of the <blk> token and the vocab size
     # <blk> is defined in local/train_bpe_model.py
-    params.blank_id = sp.piece_to_id("<blk>")
+    params.blank_id = token_table["<blk>"]
-    params.unk_id = sp.piece_to_id("<unk>")
+    params.unk_id = token_table["<unk>"]
-    params.vocab_size = sp.get_piece_size()
+    params.vocab_size = num_tokens(token_table) + 1  # +1 for <blk>
 
     if params.simulate_streaming:
         assert (
@@ -324,6 +324,12 @@ def main():
         msg += f" with beam size {params.beam_size}"
     logging.info(msg)
 
+    def token_ids_to_words(token_ids: List[int]) -> str:
+        text = ""
+        for i in token_ids:
+            text += token_table[i]
+        return text.replace("▁", " ").strip()
+
     if params.method == "fast_beam_search":
         decoding_graph = k2.trivial_graph(params.vocab_size - 1, device=device)
         hyp_tokens = fast_beam_search_one_best(
@@ -335,8 +341,8 @@ def main():
             max_contexts=params.max_contexts,
             max_states=params.max_states,
         )
-        for hyp in sp.decode(hyp_tokens):
+        for hyp in hyp_tokens:
-            hyps.append(hyp.split())
+            hyps.append(token_ids_to_words(hyp))
     elif params.method == "modified_beam_search":
         hyp_tokens = modified_beam_search(
             model=model,
@@ -345,16 +351,16 @@ def main():
             beam=params.beam_size,
         )
 
-        for hyp in sp.decode(hyp_tokens):
+        for hyp in hyp_tokens:
-            hyps.append(hyp.split())
+            hyps.append(token_ids_to_words(hyp))
     elif params.method == "greedy_search" and params.max_sym_per_frame == 1:
         hyp_tokens = greedy_search_batch(
             model=model,
             encoder_out=encoder_out,
             encoder_out_lens=encoder_out_lens,
         )
-        for hyp in sp.decode(hyp_tokens):
+        for hyp in hyp_tokens:
-            hyps.append(hyp.split())
+            hyps.append(token_ids_to_words(hyp))
     else:
         for i in range(num_waves):
             # fmt: off
@@ -375,12 +381,11 @@ def main():
             else:
                 raise ValueError(f"Unsupported method: {params.method}")
 
-            hyps.append(sp.decode(hyp).split())
+            hyps.append(token_ids_to_words(hyp))
 
     s = "\n"
     for filename, hyp in zip(params.sound_files, hyps):
-        words = " ".join(hyp)
+        s += f"{filename}:\n{hyp}\n\n"
-        s += f"{filename}:\n{words}\n\n"
     logging.info(s)
 
     logging.info("Decoding Done")

egs/librispeech/ASR/pruned_transducer_stateless4/export.py

@@ -22,7 +22,7 @@
 Usage:
 ./pruned_transducer_stateless4/export.py \
   --exp-dir ./pruned_transducer_stateless4/exp \
-  --bpe-model data/lang_bpe_500/bpe.model \
+  --tokens data/lang_bpe_500/tokens.txt \
   --epoch 20 \
   --avg 10
 
@@ -48,7 +48,7 @@ import argparse
 import logging
 from pathlib import Path
 
-import sentencepiece as spm
+import k2
 import torch
 from scaling_converter import convert_scaled_to_non_scaled
 from train import add_model_arguments, get_params, get_transducer_model
@@ -59,7 +59,7 @@ from icefall.checkpoint import (
     find_checkpoints,
     load_checkpoint,
 )
-from icefall.utils import str2bool
+from icefall.utils import num_tokens, str2bool
 
 
 def get_parser():
@@ -116,10 +116,10 @@ def get_parser():
     )
 
     parser.add_argument(
-        "--bpe-model",
+        "--tokens",
         type=str,
-        default="data/lang_bpe_500/bpe.model",
+        default="data/lang_bpe_500/tokens.txt",
-        help="Path to the BPE model",
+        help="Path to the tokens.txt.",
     )
 
     parser.add_argument(
@@ -164,12 +164,14 @@ def main():
 
     logging.info(f"device: {device}")
 
-    sp = spm.SentencePieceProcessor()
+    # Load tokens.txt here
-    sp.load(params.bpe_model)
+    token_table = k2.SymbolTable.from_file(params.tokens)
 
+    # Load id of the <blk> token and the vocab size
     # <blk> is defined in local/train_bpe_model.py
-    params.blank_id = sp.piece_to_id("<blk>")
+    params.blank_id = token_table["<blk>"]
-    params.vocab_size = sp.get_piece_size()
+    params.unk_id = token_table["<unk>"]
+    params.vocab_size = num_tokens(token_table) + 1  # +1 for <blk>
 
     if params.streaming_model:
         assert params.causal_convolution

egs/librispeech/ASR/pruned_transducer_stateless5/export-onnx-streaming.py

@@ -28,7 +28,7 @@ popd
 2. Export the model to ONNX
 
 ./pruned_transducer_stateless5/export-onnx-streaming.py \
-  --bpe-model $repo/data/lang_bpe_500/bpe.model \
+  --tokens $repo/data/lang_bpe_500/tokens.txt \
   --epoch 99 \
   --avg 1 \
   --use-averaged-model 0 \
@@ -58,8 +58,8 @@ import logging
 from pathlib import Path
 from typing import Dict, Tuple
 
+import k2
 import onnx
-import sentencepiece as spm
 import torch
 import torch.nn as nn
 from conformer import Conformer
@@ -74,7 +74,7 @@ from icefall.checkpoint import (
     find_checkpoints,
     load_checkpoint,
 )
-from icefall.utils import setup_logger, str2bool
+from icefall.utils import num_tokens, setup_logger, str2bool
 
 
 def get_parser():
@@ -131,10 +131,10 @@ def get_parser():
     )
 
     parser.add_argument(
-        "--bpe-model",
+        "--tokens",
         type=str,
-        default="data/lang_bpe_500/bpe.model",
+        default="data/lang_bpe_500/tokens.txt",
-        help="Path to the BPE model",
+        help="Path to the tokens.txt.",
     )
 
     parser.add_argument(
@@ -489,12 +489,14 @@ def main():
 
     logging.info(f"device: {device}")
 
-    sp = spm.SentencePieceProcessor()
+    # Load tokens.txt here
-    sp.load(params.bpe_model)
+    token_table = k2.SymbolTable.from_file(params.tokens)
 
+    # Load id of the <blk> token and the vocab size
     # <blk> is defined in local/train_bpe_model.py
-    params.blank_id = sp.piece_to_id("<blk>")
+    params.blank_id = token_table["<blk>"]
-    params.vocab_size = sp.get_piece_size()
+    params.unk_id = token_table["<unk>"]
+    params.vocab_size = num_tokens(token_table) + 1  # +1 for <blk>
 
     logging.info(params)
 

egs/librispeech/ASR/pruned_transducer_stateless5/export-onnx.py

@@ -28,7 +28,7 @@ popd
 2. Export the model to ONNX
 
 ./pruned_transducer_stateless5/export-onnx.py \
-  --bpe-model $repo/data/lang_bpe_500/bpe.model \
+  --tokens $repo/data/lang_bpe_500/tokens.txt \
   --epoch 99 \
   --avg 1 \
   --use-averaged-model 0 \
@@ -55,8 +55,8 @@ import logging
 from pathlib import Path
 from typing import Dict, Tuple
 
+import k2
 import onnx
-import sentencepiece as spm
 import torch
 import torch.nn as nn
 from conformer import Conformer
@@ -71,7 +71,7 @@ from icefall.checkpoint import (
     find_checkpoints,
     load_checkpoint,
 )
-from icefall.utils import setup_logger, str2bool
+from icefall.utils import num_tokens, setup_logger, str2bool
 
 
 def get_parser():
@@ -128,10 +128,10 @@ def get_parser():
     )
 
     parser.add_argument(
-        "--bpe-model",
+        "--tokens",
         type=str,
-        default="data/lang_bpe_500/bpe.model",
+        default="data/lang_bpe_500/tokens.txt",
-        help="Path to the BPE model",
+        help="Path to the tokens.txt.",
     )
 
     parser.add_argument(
@@ -416,12 +416,14 @@ def main():
 
     logging.info(f"device: {device}")
 
-    sp = spm.SentencePieceProcessor()
+    # Load tokens.txt here
-    sp.load(params.bpe_model)
+    token_table = k2.SymbolTable.from_file(params.tokens)
 
+    # Load id of the <blk> token and the vocab size
     # <blk> is defined in local/train_bpe_model.py
-    params.blank_id = sp.piece_to_id("<blk>")
+    params.blank_id = token_table["<blk>"]
-    params.vocab_size = sp.get_piece_size()
+    params.unk_id = token_table["<unk>"]
+    params.vocab_size = num_tokens(token_table) + 1  # +1 for <blk>
 
     logging.info(params)
 

egs/librispeech/ASR/pruned_transducer_stateless5/export.py

@@ -22,7 +22,7 @@
 Usage:
 ./pruned_transducer_stateless5/export.py \
   --exp-dir ./pruned_transducer_stateless5/exp \
-  --bpe-model data/lang_bpe_500/bpe.model \
+  --tokens data/lang_bpe_500/tokens.txt \
   --epoch 20 \
   --avg 10
 
@@ -48,7 +48,7 @@ import argparse
 import logging
 from pathlib import Path
 
-import sentencepiece as spm
+import k2
 import torch
 from scaling_converter import convert_scaled_to_non_scaled
 from train import add_model_arguments, get_params, get_transducer_model
@@ -59,7 +59,7 @@ from icefall.checkpoint import (
     find_checkpoints,
     load_checkpoint,
 )
-from icefall.utils import str2bool
+from icefall.utils import num_tokens, str2bool
 
 
 def get_parser():
@@ -116,10 +116,10 @@ def get_parser():
     )
 
     parser.add_argument(
-        "--bpe-model",
+        "--tokens",
         type=str,
-        default="data/lang_bpe_500/bpe.model",
+        default="data/lang_bpe_500/tokens.txt",
-        help="Path to the BPE model",
+        help="Path to the tokens.txt.",
     )
 
     parser.add_argument(
@@ -164,12 +164,14 @@ def main():
 
     logging.info(f"device: {device}")
 
-    sp = spm.SentencePieceProcessor()
+    # Load tokens.txt here
-    sp.load(params.bpe_model)
+    token_table = k2.SymbolTable.from_file(params.tokens)
 
+    # Load id of the <blk> token and the vocab size
     # <blk> is defined in local/train_bpe_model.py
-    params.blank_id = sp.piece_to_id("<blk>")
+    params.blank_id = token_table["<blk>"]
-    params.vocab_size = sp.get_piece_size()
+    params.unk_id = token_table["<unk>"]
+    params.vocab_size = num_tokens(token_table) + 1  # +1 for <blk>
 
     if params.streaming_model:
         assert params.causal_convolution

egs/librispeech/ASR/pruned_transducer_stateless5/pretrained.py

@@ -20,7 +20,7 @@ Usage:
 (1) greedy search
 ./pruned_transducer_stateless5/pretrained.py \
     --checkpoint ./pruned_transducer_stateless5/exp/pretrained.pt \
-    --bpe-model ./data/lang_bpe_500/bpe.model \
+    --tokens data/lang_bpe_500/tokens.txt \
     --method greedy_search \
     /path/to/foo.wav \
     /path/to/bar.wav
@@ -28,7 +28,7 @@ Usage:
 (2) beam search
 ./pruned_transducer_stateless5/pretrained.py \
     --checkpoint ./pruned_transducer_stateless5/exp/pretrained.pt \
-    --bpe-model ./data/lang_bpe_500/bpe.model \
+    --tokens data/lang_bpe_500/tokens.txt \
     --method beam_search \
     --beam-size 4 \
     /path/to/foo.wav \
@@ -37,7 +37,7 @@ Usage:
 (3) modified beam search
 ./pruned_transducer_stateless5/pretrained.py \
     --checkpoint ./pruned_transducer_stateless5/exp/pretrained.pt \
-    --bpe-model ./data/lang_bpe_500/bpe.model \
+    --tokens data/lang_bpe_500/tokens.txt \
     --method modified_beam_search \
     --beam-size 4 \
     /path/to/foo.wav \
@@ -46,7 +46,7 @@ Usage:
 (4) fast beam search
 ./pruned_transducer_stateless5/pretrained.py \
     --checkpoint ./pruned_transducer_stateless5/exp/pretrained.pt \
-    --bpe-model ./data/lang_bpe_500/bpe.model \
+    --tokens data/lang_bpe_500/tokens.txt \
     --method fast_beam_search \
     --beam-size 4 \
     /path/to/foo.wav \
@@ -66,7 +66,6 @@ from typing import List
 
 import k2
 import kaldifeat
-import sentencepiece as spm
 import torch
 import torchaudio
 from beam_search import (
@@ -79,6 +78,8 @@ from beam_search import (
 from torch.nn.utils.rnn import pad_sequence
 from train import add_model_arguments, get_params, get_transducer_model
 
+from icefall.utils import num_tokens
+
 
 def get_parser():
     parser = argparse.ArgumentParser(
@@ -95,9 +96,9 @@ def get_parser():
     )
 
     parser.add_argument(
-        "--bpe-model",
+        "--tokens",
         type=str,
-        help="""Path to bpe.model.""",
+        help="""Path to tokens.txt.""",
     )
 
     parser.add_argument(
@@ -214,13 +215,14 @@ def main():
 
     params.update(vars(args))
 
-    sp = spm.SentencePieceProcessor()
+    # Load tokens.txt here
-    sp.load(params.bpe_model)
+    token_table = k2.SymbolTable.from_file(params.tokens)
 
+    # Load id of the <blk> token and the vocab size
     # <blk> is defined in local/train_bpe_model.py
-    params.blank_id = sp.piece_to_id("<blk>")
+    params.blank_id = token_table["<blk>"]
-    params.unk_id = sp.piece_to_id("<unk>")
+    params.unk_id = token_table["<unk>"]
-    params.vocab_size = sp.get_piece_size()
+    params.vocab_size = num_tokens(token_table) + 1  # +1 for <blk>
 
     logging.info(f"{params}")
 
@@ -275,6 +277,12 @@ def main():
         msg += f" with beam size {params.beam_size}"
     logging.info(msg)
 
+    def token_ids_to_words(token_ids: List[int]) -> str:
+        text = ""
+        for i in token_ids:
+            text += token_table[i]
+        return text.replace("▁", " ").strip()
+
     if params.method == "fast_beam_search":
         decoding_graph = k2.trivial_graph(params.vocab_size - 1, device=device)
         hyp_tokens = fast_beam_search_one_best(
@@ -286,8 +294,8 @@ def main():
             max_contexts=params.max_contexts,
             max_states=params.max_states,
         )
-        for hyp in sp.decode(hyp_tokens):
+        for hyp in hyp_tokens:
-            hyps.append(hyp.split())
+            hyps.append(token_ids_to_words(hyp))
     elif params.method == "modified_beam_search":
         hyp_tokens = modified_beam_search(
             model=model,
@@ -296,16 +304,16 @@ def main():
             beam=params.beam_size,
         )
 
-        for hyp in sp.decode(hyp_tokens):
+        for hyp in hyp_tokens:
-            hyps.append(hyp.split())
+            hyps.append(token_ids_to_words(hyp))
     elif params.method == "greedy_search" and params.max_sym_per_frame == 1:
         hyp_tokens = greedy_search_batch(
             model=model,
             encoder_out=encoder_out,
             encoder_out_lens=encoder_out_lens,
         )
-        for hyp in sp.decode(hyp_tokens):
+        for hyp in hyp_tokens:
-            hyps.append(hyp.split())
+            hyps.append(token_ids_to_words(hyp))
     else:
         for i in range(num_waves):
             # fmt: off
@@ -326,12 +334,11 @@ def main():
             else:
                 raise ValueError(f"Unsupported method: {params.method}")
 
-            hyps.append(sp.decode(hyp).split())
+            hyps.append(token_ids_to_words(hyp))
 
     s = "\n"
     for filename, hyp in zip(params.sound_files, hyps):
-        words = " ".join(hyp)
+        s += f"{filename}:\n{hyp}\n\n"
-        s += f"{filename}:\n{words}\n\n"
     logging.info(s)
 
     logging.info("Decoding Done")

egs/librispeech/ASR/pruned_transducer_stateless6/export.py

@@ -22,7 +22,7 @@
 Usage:
 ./pruned_transducer_stateless6/export.py \
   --exp-dir ./pruned_transducer_stateless6/exp \
-  --bpe-model data/lang_bpe_500/bpe.model \
+  --tokens data/lang_bpe_500/tokens.txt \
   --epoch 20 \
   --avg 10
 
@@ -47,12 +47,12 @@ import argparse
 import logging
 from pathlib import Path
 
-import sentencepiece as spm
+import k2
 import torch
 from train import get_params, get_transducer_model
 
 from icefall.checkpoint import average_checkpoints, find_checkpoints, load_checkpoint
-from icefall.utils import str2bool
+from icefall.utils import num_tokens, str2bool
 
 
 def get_parser():
@@ -98,10 +98,10 @@ def get_parser():
     )
 
     parser.add_argument(
-        "--bpe-model",
+        "--tokens",
         type=str,
-        default="data/lang_bpe_500/bpe.model",
+        default="data/lang_bpe_500/tokens.txt",
-        help="Path to the BPE model",
+        help="Path to the tokens.txt.",
     )
 
     parser.add_argument(
@@ -135,12 +135,14 @@ def main():
 
     logging.info(f"device: {device}")
 
-    sp = spm.SentencePieceProcessor()
+    # Load tokens.txt here
-    sp.load(params.bpe_model)
+    token_table = k2.SymbolTable.from_file(params.tokens)
 
+    # Load id of the <blk> token and the vocab size
     # <blk> is defined in local/train_bpe_model.py
-    params.blank_id = sp.piece_to_id("<blk>")
+    params.blank_id = token_table["<blk>"]
-    params.vocab_size = sp.get_piece_size()
+    params.unk_id = token_table["<unk>"]
+    params.vocab_size = num_tokens(token_table) + 1  # +1 for <blk>
 
     logging.info(params)
 

egs/librispeech/ASR/pruned_transducer_stateless7_ctc/export.py

@@ -26,7 +26,7 @@ Usage:
 
 ./pruned_transducer_stateless7_ctc/export.py \
   --exp-dir ./pruned_transducer_stateless7_ctc/exp \
-  --bpe-model data/lang_bpe_500/bpe.model \
+  --tokens data/lang_bpe_500/tokens.txt \
   --epoch 30 \
   --avg 9 \
   --jit 1
@@ -45,7 +45,7 @@ for how to use the exported models outside of icefall.
 
 ./pruned_transducer_stateless7_ctc/export.py \
   --exp-dir ./pruned_transducer_stateless7_ctc/exp \
-  --bpe-model data/lang_bpe_500/bpe.model \
+  --tokens data/lang_bpe_500/tokens.txt \
   --epoch 20 \
   --avg 10
 
@@ -86,7 +86,7 @@ import argparse
 import logging
 from pathlib import Path
 
-import sentencepiece as spm
+import k2
 import torch
 from scaling_converter import convert_scaled_to_non_scaled
 from train import add_model_arguments, get_params, get_transducer_model
@@ -97,7 +97,7 @@ from icefall.checkpoint import (
     find_checkpoints,
     load_checkpoint,
 )
-from icefall.utils import str2bool
+from icefall.utils import num_tokens, str2bool
 
 
 def get_parser():
@@ -154,10 +154,10 @@ def get_parser():
     )
 
     parser.add_argument(
-        "--bpe-model",
+        "--tokens",
         type=str,
-        default="data/lang_bpe_500/bpe.model",
+        default="data/lang_bpe_500/tokens.txt",
-        help="Path to the BPE model",
+        help="Path to the tokens.txt.",
     )
 
     parser.add_argument(
@@ -197,12 +197,14 @@ def main():
 
     logging.info(f"device: {device}")
 
-    sp = spm.SentencePieceProcessor()
+    # Load tokens.txt here
-    sp.load(params.bpe_model)
+    token_table = k2.SymbolTable.from_file(params.tokens)
 
+    # Load id of the <blk> token and the vocab size
     # <blk> is defined in local/train_bpe_model.py
-    params.blank_id = sp.piece_to_id("<blk>")
+    params.blank_id = token_table["<blk>"]
-    params.vocab_size = sp.get_piece_size()
+    params.unk_id = token_table["<unk>"]
+    params.vocab_size = num_tokens(token_table) + 1  # +1 for <blk>
 
     logging.info(params)
 

egs/librispeech/ASR/pruned_transducer_stateless7_ctc/pretrained.py

@@ -20,7 +20,7 @@ You can generate the checkpoint with the following command:
 
 ./pruned_transducer_stateless7_ctc/export.py \
   --exp-dir ./pruned_transducer_stateless7_ctc/exp \
-  --bpe-model data/lang_bpe_500/bpe.model \
+  --tokens data/lang_bpe_500/tokens.txt \
   --epoch 20 \
   --avg 10
 
@@ -29,7 +29,7 @@ Usage of this script:
 (1) greedy search
 ./pruned_transducer_stateless7_ctc/pretrained.py \
     --checkpoint ./pruned_transducer_stateless7_ctc/exp/pretrained.pt \
-    --bpe-model ./data/lang_bpe_500/bpe.model \
+    --tokens data/lang_bpe_500/tokens.txt \
     --method greedy_search \
     /path/to/foo.wav \
     /path/to/bar.wav
@@ -37,7 +37,7 @@ Usage of this script:
 (2) beam search
 ./pruned_transducer_stateless7_ctc/pretrained.py \
     --checkpoint ./pruned_transducer_stateless7_ctc/exp/pretrained.pt \
-    --bpe-model ./data/lang_bpe_500/bpe.model \
+    --tokens data/lang_bpe_500/tokens.txt \
     --method beam_search \
     --beam-size 4 \
     /path/to/foo.wav \
@@ -46,7 +46,7 @@ Usage of this script:
 (3) modified beam search
 ./pruned_transducer_stateless7_ctc/pretrained.py \
     --checkpoint ./pruned_transducer_stateless7_ctc/exp/pretrained.pt \
-    --bpe-model ./data/lang_bpe_500/bpe.model \
+    --tokens data/lang_bpe_500/tokens.txt \
     --method modified_beam_search \
     --beam-size 4 \
     /path/to/foo.wav \
@@ -55,7 +55,7 @@ Usage of this script:
 (4) fast beam search
 ./pruned_transducer_stateless7_ctc/pretrained.py \
     --checkpoint ./pruned_transducer_stateless7_ctc/exp/pretrained.pt \
-    --bpe-model ./data/lang_bpe_500/bpe.model \
+    --tokens data/lang_bpe_500/tokens.txt \
     --method fast_beam_search \
     --beam-size 4 \
     /path/to/foo.wav \
@@ -75,7 +75,6 @@ from typing import List
 
 import k2
 import kaldifeat
-import sentencepiece as spm
 import torch
 import torchaudio
 from beam_search import (
@@ -88,6 +87,8 @@ from beam_search import (
 from torch.nn.utils.rnn import pad_sequence
 from train import add_model_arguments, get_params, get_transducer_model
 
+from icefall.utils import num_tokens
+
 
 def get_parser():
     parser = argparse.ArgumentParser(
@@ -104,9 +105,9 @@ def get_parser():
     )
 
     parser.add_argument(
-        "--bpe-model",
+        "--tokens",
         type=str,
-        help="""Path to bpe.model.""",
+        help="""Path to tokens.txt.""",
     )
 
     parser.add_argument(
@@ -223,13 +224,14 @@ def main():
 
     params.update(vars(args))
 
-    sp = spm.SentencePieceProcessor()
+    # Load tokens.txt here
-    sp.load(params.bpe_model)
+    token_table = k2.SymbolTable.from_file(params.tokens)
 
+    # Load id of the <blk> token and the vocab size
     # <blk> is defined in local/train_bpe_model.py
-    params.blank_id = sp.piece_to_id("<blk>")
+    params.blank_id = token_table["<blk>"]
-    params.unk_id = sp.piece_to_id("<unk>")
+    params.unk_id = token_table["<unk>"]
-    params.vocab_size = sp.get_piece_size()
+    params.vocab_size = num_tokens(token_table) + 1  # +1 for <blk>
 
     logging.info(f"{params}")
 
@@ -284,6 +286,12 @@ def main():
         msg += f" with beam size {params.beam_size}"
     logging.info(msg)
 
+    def token_ids_to_words(token_ids: List[int]) -> str:
+        text = ""
+        for i in token_ids:
+            text += token_table[i]
+        return text.replace("▁", " ").strip()
+
     if params.method == "fast_beam_search":
         decoding_graph = k2.trivial_graph(params.vocab_size - 1, device=device)
         hyp_tokens = fast_beam_search_one_best(
@@ -295,8 +303,8 @@ def main():
             max_contexts=params.max_contexts,
             max_states=params.max_states,
         )
-        for hyp in sp.decode(hyp_tokens):
+        for hyp in hyp_tokens:
-            hyps.append(hyp.split())
+            hyps.append(token_ids_to_words(hyp))
     elif params.method == "modified_beam_search":
         hyp_tokens = modified_beam_search(
             model=model,
@@ -305,16 +313,16 @@ def main():
             beam=params.beam_size,
         )
 
-        for hyp in sp.decode(hyp_tokens):
+        for hyp in hyp_tokens:
-            hyps.append(hyp.split())
+            hyps.append(token_ids_to_words(hyp))
     elif params.method == "greedy_search" and params.max_sym_per_frame == 1:
         hyp_tokens = greedy_search_batch(
             model=model,
             encoder_out=encoder_out,
             encoder_out_lens=encoder_out_lens,
         )
-        for hyp in sp.decode(hyp_tokens):
+        for hyp in hyp_tokens:
-            hyps.append(hyp.split())
+            hyps.append(token_ids_to_words(hyp))
     else:
         for i in range(num_waves):
             # fmt: off
@@ -335,12 +343,11 @@ def main():
             else:
                 raise ValueError(f"Unsupported method: {params.method}")
 
-            hyps.append(sp.decode(hyp).split())
+            hyps.append(token_ids_to_words(hyp))
 
     s = "\n"
     for filename, hyp in zip(params.sound_files, hyps):
-        words = " ".join(hyp)
+        s += f"{filename}:\n{hyp}\n\n"
-        s += f"{filename}:\n{words}\n\n"
     logging.info(s)
 
     logging.info("Decoding Done")

egs/librispeech/ASR/pruned_transducer_stateless7_ctc/pretrained_ctc.py

@@ -22,14 +22,14 @@ You can use the following command to get the exported models:
 
 ./pruned_transducer_stateless7_ctc/export.py \
   --exp-dir ./pruned_transducer_stateless7_ctc/exp \
-  --bpe-model data/lang_bpe_500/bpe.model \
+  --tokens data/lang_bpe_500/tokens.txt \
   --epoch 20 \
   --avg 10
 
 Usage of this script:
 
 (1) ctc-decoding
-./pruned_transducer_stateless7_ctc/jit_pretrained_ctc.py \
+./pruned_transducer_stateless7_ctc/pretrained_ctc.py \
   --checkpoint ./pruned_transducer_stateless7_ctc/exp/pretrained.pt \
   --bpe-model data/lang_bpe_500/bpe.model \
   --method ctc-decoding \
@@ -38,7 +38,7 @@ Usage of this script:
   /path/to/bar.wav
 
 (2) 1best
-./pruned_transducer_stateless7_ctc/jit_pretrained_ctc.py \
+./pruned_transducer_stateless7_ctc/pretrained_ctc.py \
   --checkpoint ./pruned_transducer_stateless7_ctc/exp/pretrained.pt \
   --HLG data/lang_bpe_500/HLG.pt \
   --words-file data/lang_bpe_500/words.txt  \
@@ -48,7 +48,7 @@ Usage of this script:
   /path/to/bar.wav
 
 (3) nbest-rescoring
-./bruned_transducer_stateless7_ctc/jit_pretrained_ctc.py \
+./bruned_transducer_stateless7_ctc/pretrained_ctc.py \
   --checkpoint ./pruned_transducer_stateless7_ctc/exp/pretrained.pt \
   --HLG data/lang_bpe_500/HLG.pt \
   --words-file data/lang_bpe_500/words.txt  \
@@ -60,7 +60,7 @@ Usage of this script:
 
 
 (4) whole-lattice-rescoring
-./pruned_transducer_stateless7_ctc/jit_pretrained_ctc.py \
+./pruned_transducer_stateless7_ctc/pretrained_ctc.py \
   --checkpoint ./pruned_transducer_stateless7_ctc/exp/pretrained.pt \
   --HLG data/lang_bpe_500/HLG.pt \
   --words-file data/lang_bpe_500/words.txt  \

egs/librispeech/ASR/pruned_transducer_stateless7_ctc_bs/export.py

@@ -26,7 +26,7 @@ Usage:
 
 ./pruned_transducer_stateless7_ctc_bs/export.py \
   --exp-dir ./pruned_transducer_stateless7_ctc_bs/exp \
-  --bpe-model data/lang_bpe_500/bpe.model \
+  --tokens data/lang_bpe_500/tokens.txt \
   --epoch 30 \
   --avg 13 \
   --jit 1
@@ -45,7 +45,7 @@ for how to use the exported models outside of icefall.
 
 ./pruned_transducer_stateless7_ctc_bs/export.py \
   --exp-dir ./pruned_transducer_stateless7_ctc_bs/exp \
-  --bpe-model data/lang_bpe_500/bpe.model \
+  --tokens data/lang_bpe_500/tokens.txt \
   --epoch 30 \
   --avg 13
 
@@ -86,7 +86,7 @@ import argparse
 import logging
 from pathlib import Path
 
-import sentencepiece as spm
+import k2
 import torch
 from scaling_converter import convert_scaled_to_non_scaled
 from train import add_model_arguments, get_params, get_transducer_model
@@ -97,7 +97,7 @@ from icefall.checkpoint import (
     find_checkpoints,
     load_checkpoint,
 )
-from icefall.utils import str2bool
+from icefall.utils import num_tokens, str2bool
 
 
 def get_parser():
@@ -154,10 +154,10 @@ def get_parser():
     )
 
     parser.add_argument(
-        "--bpe-model",
+        "--tokens",
         type=str,
-        default="data/lang_bpe_500/bpe.model",
+        default="data/lang_bpe_500/tokens.txt",
-        help="Path to the BPE model",
+        help="Path to the tokens.txt.",
     )
 
     parser.add_argument(
@@ -197,12 +197,14 @@ def main():
 
     logging.info(f"device: {device}")
 
-    sp = spm.SentencePieceProcessor()
+    # Load tokens.txt here
-    sp.load(params.bpe_model)
+    token_table = k2.SymbolTable.from_file(params.tokens)
 
+    # Load id of the <blk> token and the vocab size
     # <blk> is defined in local/train_bpe_model.py
-    params.blank_id = sp.piece_to_id("<blk>")
+    params.blank_id = token_table["<blk>"]
-    params.vocab_size = sp.get_piece_size()
+    params.unk_id = token_table["<unk>"]
+    params.vocab_size = num_tokens(token_table) + 1  # +1 for <blk>
 
     logging.info(params)
 

egs/librispeech/ASR/pruned_transducer_stateless7_ctc_bs/export_onnx.py

@@ -28,7 +28,7 @@ Usage:
 
 ./pruned_transducer_stateless7_ctc_bs/export_onnx.py \
   --exp-dir ./pruned_transducer_stateless7_ctc_bs/exp \
-  --bpe-model data/lang_bpe_500/bpe.model \
+  --tokens data/lang_bpe_500/tokens.txt \
   --epoch 30 \
   --avg 13 \
   --onnx 1
@@ -48,7 +48,7 @@ Check `onnx_check.py` for how to use them.
 (2) Export to ONNX format which can be used in Triton Server
 ./pruned_transducer_stateless7_ctc_bs/export_onnx.py \
   --exp-dir ./pruned_transducer_stateless7_ctc_bs/exp \
-  --bpe-model data/lang_bpe_500/bpe.model \
+  --tokens data/lang_bpe_500/tokens.txt \
   --epoch 30 \
   --avg 13 \
   --onnx-triton 1
@@ -86,9 +86,10 @@ import argparse
 import logging
 from pathlib import Path
 
-import sentencepiece as spm
+import k2
 import torch
 import torch.nn as nn
+from onnx_wrapper import TritonOnnxDecoder, TritonOnnxJoiner, TritonOnnxLconv
 from scaling_converter import convert_scaled_to_non_scaled
 from train import add_model_arguments, get_params, get_transducer_model
 
@@ -98,8 +99,7 @@ from icefall.checkpoint import (
     find_checkpoints,
     load_checkpoint,
 )
-from icefall.utils import str2bool
+from icefall.utils import num_tokens, str2bool
-from onnx_wrapper import TritonOnnxDecoder, TritonOnnxJoiner, TritonOnnxLconv
 
 
 def get_parser():
@@ -156,10 +156,10 @@ def get_parser():
     )
 
     parser.add_argument(
-        "--bpe-model",
+        "--tokens",
         type=str,
-        default="data/lang_bpe_500/bpe.model",
+        default="data/lang_bpe_500/tokens.txt",
-        help="Path to the BPE model",
+        help="Path to the tokens.txt.",
     )
 
     parser.add_argument(
@@ -728,12 +728,14 @@ def main():
 
     logging.info(f"device: {device}")
     
-    sp = spm.SentencePieceProcessor()
+    # Load tokens.txt here
-    sp.load(params.bpe_model)
+    token_table = k2.SymbolTable.from_file(params.tokens)
 
+    # Load id of the <blk> token and the vocab size
     # <blk> is defined in local/train_bpe_model.py
-    params.blank_id = sp.piece_to_id("<blk>")
+    params.blank_id = token_table["<blk>"]
-    params.vocab_size = sp.get_piece_size()
+    params.unk_id = token_table["<unk>"]
+    params.vocab_size = num_tokens(token_table) + 1  # +1 for <blk>
 
     logging.info(params)
 

egs/librispeech/ASR/pruned_transducer_stateless7_ctc_bs/pretrained.py

@@ -20,7 +20,7 @@ You can generate the checkpoint with the following command:
 
 ./pruned_transducer_stateless7_ctc_bs/export.py \
   --exp-dir ./pruned_transducer_stateless7_ctc_bs/exp \
-  --bpe-model data/lang_bpe_500/bpe.model \
+  --tokens data/lang_bpe_500/tokens.txt \
   --epoch 30 \
   --avg 13
 
@@ -29,7 +29,7 @@ Usage of this script:
 (1) greedy search
 ./pruned_transducer_stateless7_ctc_bs/pretrained.py \
     --checkpoint ./pruned_transducer_stateless7_ctc_bs/exp/pretrained.pt \
-    --bpe-model ./data/lang_bpe_500/bpe.model \
+    --tokens data/lang_bpe_500/tokens.txt \
     --method greedy_search \
     /path/to/foo.wav \
     /path/to/bar.wav
@@ -37,7 +37,7 @@ Usage of this script:
 (2) beam search
 ./pruned_transducer_stateless7_ctc_bs/pretrained.py \
     --checkpoint ./pruned_transducer_stateless7_ctc_bs/exp/pretrained.pt \
-    --bpe-model ./data/lang_bpe_500/bpe.model \
+    --tokens data/lang_bpe_500/tokens.txt \
     --method beam_search \
     --beam-size 4 \
     /path/to/foo.wav \
@@ -46,7 +46,7 @@ Usage of this script:
 (3) modified beam search
 ./pruned_transducer_stateless7_ctc_bs/pretrained.py \
     --checkpoint ./pruned_transducer_stateless7_ctc_bs/exp/pretrained.pt \
-    --bpe-model ./data/lang_bpe_500/bpe.model \
+    --tokens data/lang_bpe_500/tokens.txt \
     --method modified_beam_search \
     --beam-size 4 \
     /path/to/foo.wav \
@@ -55,7 +55,7 @@ Usage of this script:
 (4) fast beam search
 ./pruned_transducer_stateless7_ctc_bs/pretrained.py \
     --checkpoint ./pruned_transducer_stateless7_ctc_bs/exp/pretrained.pt \
-    --bpe-model ./data/lang_bpe_500/bpe.model \
+    --tokens data/lang_bpe_500/tokens.txt \
     --method fast_beam_search \
     --beam-size 4 \
     /path/to/foo.wav \
@@ -75,7 +75,6 @@ from typing import List
 
 import k2
 import kaldifeat
-import sentencepiece as spm
 import torch
 import torchaudio
 from beam_search import (
@@ -88,6 +87,8 @@ from beam_search import (
 from torch.nn.utils.rnn import pad_sequence
 from train import add_model_arguments, get_params, get_transducer_model
 
+from icefall.utils import num_tokens
+
 
 def get_parser():
     parser = argparse.ArgumentParser(
@@ -104,9 +105,9 @@ def get_parser():
     )
 
     parser.add_argument(
-        "--bpe-model",
+        "--tokens",
         type=str,
-        help="""Path to bpe.model.""",
+        help="""Path to tokens.txt.""",
     )
 
     parser.add_argument(
@@ -223,13 +224,14 @@ def main():
 
     params.update(vars(args))
 
-    sp = spm.SentencePieceProcessor()
+    # Load tokens.txt here
-    sp.load(params.bpe_model)
+    token_table = k2.SymbolTable.from_file(params.tokens)
 
+    # Load id of the <blk> token and the vocab size
     # <blk> is defined in local/train_bpe_model.py
-    params.blank_id = sp.piece_to_id("<blk>")
+    params.blank_id = token_table["<blk>"]
-    params.unk_id = sp.piece_to_id("<unk>")
+    params.unk_id = token_table["<unk>"]
-    params.vocab_size = sp.get_piece_size()
+    params.vocab_size = num_tokens(token_table) + 1  # +1 for <blk>
 
     logging.info(f"{params}")
 
@@ -284,6 +286,12 @@ def main():
         msg += f" with beam size {params.beam_size}"
     logging.info(msg)
 
+    def token_ids_to_words(token_ids: List[int]) -> str:
+        text = ""
+        for i in token_ids:
+            text += token_table[i]
+        return text.replace("▁", " ").strip()
+
     if params.method == "fast_beam_search":
         decoding_graph = k2.trivial_graph(params.vocab_size - 1, device=device)
         hyp_tokens = fast_beam_search_one_best(
@@ -295,8 +303,8 @@ def main():
             max_contexts=params.max_contexts,
             max_states=params.max_states,
         )
-        for hyp in sp.decode(hyp_tokens):
+        for hyp in hyp_tokens:
-            hyps.append(hyp.split())
+            hyps.append(token_ids_to_words(hyp))
     elif params.method == "modified_beam_search":
         hyp_tokens = modified_beam_search(
             model=model,
@@ -305,16 +313,16 @@ def main():
             beam=params.beam_size,
         )
 
-        for hyp in sp.decode(hyp_tokens):
+        for hyp in hyp_tokens:
-            hyps.append(hyp.split())
+            hyps.append(token_ids_to_words(hyp))
     elif params.method == "greedy_search" and params.max_sym_per_frame == 1:
         hyp_tokens = greedy_search_batch(
             model=model,
             encoder_out=encoder_out,
             encoder_out_lens=encoder_out_lens,
         )
-        for hyp in sp.decode(hyp_tokens):
+        for hyp in hyp_tokens:
-            hyps.append(hyp.split())
+            hyps.append(token_ids_to_words(hyp))
     else:
         for i in range(num_waves):
             # fmt: off
@@ -335,12 +343,11 @@ def main():
             else:
                 raise ValueError(f"Unsupported method: {params.method}")
 
-            hyps.append(sp.decode(hyp).split())
+            hyps.append(token_ids_to_words(hyp))
 
     s = "\n"
     for filename, hyp in zip(params.sound_files, hyps):
-        words = " ".join(hyp)
+        s += f"{filename}:\n{hyp}\n\n"
-        s += f"{filename}:\n{words}\n\n"
     logging.info(s)
 
     logging.info("Decoding Done")

egs/librispeech/ASR/pruned_transducer_stateless7_ctc_bs/pretrained_ctc.py

@@ -22,14 +22,14 @@ You can use the following command to get the exported models:
 
 ./pruned_transducer_stateless7_ctc_bs/export.py \
   --exp-dir ./pruned_transducer_stateless7_ctc_bs/exp \
-  --bpe-model data/lang_bpe_500/bpe.model \
+  --tokens data/lang_bpe_500/tokens.txt \
   --epoch 20 \
   --avg 10
 
 Usage of this script:
 
 (1) ctc-decoding
-./pruned_transducer_stateless7_ctc_bs/jit_pretrained_ctc.py \
+./pruned_transducer_stateless7_ctc_bs/pretrained_ctc.py \
   --checkpoint ./pruned_transducer_stateless7_ctc_bs/exp/pretrained.pt \
   --bpe-model data/lang_bpe_500/bpe.model \
   --method ctc-decoding \
@@ -38,7 +38,7 @@ Usage of this script:
   /path/to/bar.wav
 
 (2) 1best
-./pruned_transducer_stateless7_ctc_bs/jit_pretrained_ctc.py \
+./pruned_transducer_stateless7_ctc_bs/pretrained_ctc.py \
   --checkpoint ./pruned_transducer_stateless7_ctc_bs/exp/pretrained.pt \
   --HLG data/lang_bpe_500/HLG.pt \
   --words-file data/lang_bpe_500/words.txt  \
@@ -48,7 +48,7 @@ Usage of this script:
   /path/to/bar.wav
 
 (3) nbest-rescoring
-./bruned_transducer_stateless7_ctc/jit_pretrained_ctc.py \
+./bruned_transducer_stateless7_ctc/pretrained_ctc.py \
   --checkpoint ./pruned_transducer_stateless7_ctc_bs/exp/pretrained.pt \
   --HLG data/lang_bpe_500/HLG.pt \
   --words-file data/lang_bpe_500/words.txt  \
@@ -60,7 +60,7 @@ Usage of this script:
 
 
 (4) whole-lattice-rescoring
-./pruned_transducer_stateless7_ctc_bs/jit_pretrained_ctc.py \
+./pruned_transducer_stateless7_ctc_bs/pretrained_ctc.py \
   --checkpoint ./pruned_transducer_stateless7_ctc_bs/exp/pretrained.pt \
   --HLG data/lang_bpe_500/HLG.pt \
   --words-file data/lang_bpe_500/words.txt  \

egs/librispeech/ASR/pruned_transducer_stateless7_streaming/export-for-ncnn-zh.py

@@ -66,6 +66,7 @@ import argparse
 import logging
 from pathlib import Path
 
+import k2
 import torch
 from scaling_converter import convert_scaled_to_non_scaled
 from train2 import add_model_arguments, get_params, get_transducer_model
@@ -76,8 +77,7 @@ from icefall.checkpoint import (
     find_checkpoints,
     load_checkpoint,
 )
-from icefall.lexicon import Lexicon
+from icefall.utils import num_tokens, setup_logger, str2bool
-from icefall.utils import setup_logger, str2bool
 
 
 def get_parser():
@@ -123,10 +123,10 @@ def get_parser():
     )
 
     parser.add_argument(
-        "--lang-dir",
+        "--tokens",
         type=str,
-        default="data/lang_char",
+        default="data/lang_char/tokens.txt",
-        help="The lang dir",
+        help="The tokens.txt file",
     )
 
     parser.add_argument(
@@ -246,9 +246,14 @@ def main():
 
     logging.info(f"device: {device}")
 
-    lexicon = Lexicon(params.lang_dir)
+    # Load tokens.txt here
-    params.blank_id = 0
+    token_table = k2.SymbolTable.from_file(params.tokens)
-    params.vocab_size = max(lexicon.tokens) + 1
+
+    # Load id of the <blk> token and the vocab size
+    # <blk> is defined in local/train_bpe_model.py
+    params.blank_id = token_table["<blk>"]
+    params.unk_id = token_table["<unk>"]
+    params.vocab_size = num_tokens(token_table) + 1  # +1 for <blk>
 
     logging.info(params)
 

egs/librispeech/ASR/pruned_transducer_stateless7_streaming/export-for-ncnn.py

@@ -28,7 +28,7 @@ popd
 2. Export to ncnn
 
 ./pruned_transducer_stateless7_streaming/export-for-ncnn.py \
-  --bpe-model $repo/data/lang_bpe_500/bpe.model \
+  --tokens $repo/data/lang_bpe_500/tokens.txt \
   --exp-dir $repo/exp \
   --use-averaged-model 0 \
   --epoch 99 \
@@ -64,7 +64,7 @@ import argparse
 import logging
 from pathlib import Path
 
-import sentencepiece as spm
+import k2
 import torch
 from scaling_converter import convert_scaled_to_non_scaled
 from train2 import add_model_arguments, get_params, get_transducer_model
@@ -75,7 +75,7 @@ from icefall.checkpoint import (
     find_checkpoints,
     load_checkpoint,
 )
-from icefall.utils import setup_logger, str2bool
+from icefall.utils import num_tokens, setup_logger, str2bool
 
 
 def get_parser():
@@ -121,10 +121,10 @@ def get_parser():
     )
 
     parser.add_argument(
-        "--bpe-model",
+        "--tokens",
         type=str,
-        default="data/lang_bpe_500/bpe.model",
+        default="data/lang_bpe_500/tokens.txt",
-        help="Path to the BPE model",
+        help="Path to the tokens.txt.",
     )
 
     parser.add_argument(
@@ -244,12 +244,14 @@ def main():
 
     logging.info(f"device: {device}")
 
-    sp = spm.SentencePieceProcessor()
+    # Load tokens.txt here
-    sp.load(params.bpe_model)
+    token_table = k2.SymbolTable.from_file(params.tokens)
 
+    # Load id of the <blk> token and the vocab size
     # <blk> is defined in local/train_bpe_model.py
-    params.blank_id = sp.piece_to_id("<blk>")
+    params.blank_id = token_table["<blk>"]
-    params.vocab_size = sp.get_piece_size()
+    params.unk_id = token_table["<unk>"]
+    params.vocab_size = num_tokens(token_table) + 1  # +1 for <blk>
 
     logging.info(params)
 

egs/librispeech/ASR/pruned_transducer_stateless7_streaming/export-onnx-zh.py

@@ -29,7 +29,7 @@ popd
 2. Export the model to ONNX
 
 ./pruned_transducer_stateless7_streaming/export-onnx-zh.py \
-  --lang-dir $repo/data/lang_char_bpe \
+  --tokens $repo/data/lang_char_bpe/tokens.txt \
   --use-averaged-model 0 \
   --epoch 99 \
   --avg 1 \
@@ -60,6 +60,7 @@ import logging
 from pathlib import Path
 from typing import Dict, List, Tuple
 
+import k2
 import onnx
 import torch
 import torch.nn as nn
@@ -76,8 +77,7 @@ from icefall.checkpoint import (
     find_checkpoints,
     load_checkpoint,
 )
-from icefall.lexicon import Lexicon
+from icefall.utils import num_tokens, setup_logger, str2bool
-from icefall.utils import setup_logger, str2bool
 
 
 def get_parser():
@@ -134,10 +134,10 @@ def get_parser():
     )
 
     parser.add_argument(
-        "--lang-dir",
+        "--tokens",
         type=str,
-        default="data/lang_char",
+        default="data/lang_char/tokens.txt",
-        help="The lang dir",
+        help="The tokens.txt file",
     )
 
     parser.add_argument(
@@ -493,9 +493,14 @@ def main():
 
     logging.info(f"device: {device}")
 
-    lexicon = Lexicon(params.lang_dir)
+    # Load tokens.txt here
-    params.blank_id = 0
+    token_table = k2.SymbolTable.from_file(params.tokens)
-    params.vocab_size = max(lexicon.tokens) + 1
+
+    # Load id of the <blk> token and the vocab size
+    # <blk> is defined in local/train_bpe_model.py
+    params.blank_id = token_table["<blk>"]
+    params.unk_id = token_table["<unk>"]
+    params.vocab_size = num_tokens(token_table) + 1  # +1 for <blk>
 
     logging.info(params)
 

egs/librispeech/ASR/pruned_transducer_stateless7_streaming/export-onnx.py

@@ -27,7 +27,7 @@ popd
 2. Export the model to ONNX
 
 ./pruned_transducer_stateless7_streaming/export-onnx.py \
-  --bpe-model $repo/data/lang_bpe_500/bpe.model \
+  --tokens $repo/data/lang_bpe_500/tokens.txt \
   --use-averaged-model 0 \
   --epoch 99 \
   --avg 1 \
@@ -48,8 +48,8 @@ import logging
 from pathlib import Path
 from typing import Dict, List, Tuple
 
+import k2
 import onnx
-import sentencepiece as spm
 import torch
 import torch.nn as nn
 from decoder import Decoder
@@ -65,7 +65,7 @@ from icefall.checkpoint import (
     find_checkpoints,
     load_checkpoint,
 )
-from icefall.utils import setup_logger, str2bool
+from icefall.utils import num_tokens, setup_logger, str2bool
 
 
 def get_parser():
@@ -122,10 +122,10 @@ def get_parser():
     )
 
     parser.add_argument(
-        "--bpe-model",
+        "--tokens",
         type=str,
-        default="data/lang_bpe_500/bpe.model",
+        default="data/lang_bpe_500/tokens.txt",
-        help="Path to the BPE model",
+        help="Path to the tokens.txt.",
     )
 
     parser.add_argument(
@@ -481,12 +481,14 @@ def main():
 
     logging.info(f"device: {device}")
 
-    sp = spm.SentencePieceProcessor()
+    # Load tokens.txt here
-    sp.load(params.bpe_model)
+    token_table = k2.SymbolTable.from_file(params.tokens)
 
+    # Load id of the <blk> token and the vocab size
     # <blk> is defined in local/train_bpe_model.py
-    params.blank_id = sp.piece_to_id("<blk>")
+    params.blank_id = token_table["<blk>"]
-    params.vocab_size = sp.get_piece_size()
+    params.unk_id = token_table["<unk>"]
+    params.vocab_size = num_tokens(token_table) + 1  # +1 for <blk>
 
     logging.info(params)
 

egs/librispeech/ASR/pruned_transducer_stateless7_streaming/pretrained.py

@@ -20,7 +20,7 @@ You can generate the checkpoint with the following command:
 
 ./pruned_transducer_stateless7_streaming/export.py \
   --exp-dir ./pruned_transducer_stateless7_streaming/exp \
-  --bpe-model data/lang_bpe_500/bpe.model \
+  --tokens data/lang_bpe_500/tokens.txt \
   --epoch 20 \
   --avg 10
 
@@ -29,7 +29,7 @@ Usage of this script:
 (1) greedy search
 ./pruned_transducer_stateless7_streaming/pretrained.py \
     --checkpoint ./pruned_transducer_stateless7_streaming/exp/pretrained.pt \
-    --bpe-model ./data/lang_bpe_500/bpe.model \
+    --tokens data/lang_bpe_500/tokens.txt \
     --method greedy_search \
     /path/to/foo.wav \
     /path/to/bar.wav
@@ -37,7 +37,7 @@ Usage of this script:
 (2) beam search
 ./pruned_transducer_stateless7_streaming/pretrained.py \
     --checkpoint ./pruned_transducer_stateless7_streaming/exp/pretrained.pt \
-    --bpe-model ./data/lang_bpe_500/bpe.model \
+    --tokens data/lang_bpe_500/tokens.txt \
     --method beam_search \
     --beam-size 4 \
     /path/to/foo.wav \
@@ -46,7 +46,7 @@ Usage of this script:
 (3) modified beam search
 ./pruned_transducer_stateless7_streaming/pretrained.py \
     --checkpoint ./pruned_transducer_stateless7_streaming/exp/pretrained.pt \
-    --bpe-model ./data/lang_bpe_500/bpe.model \
+    --tokens data/lang_bpe_500/tokens.txt \
     --method modified_beam_search \
     --beam-size 4 \
     /path/to/foo.wav \
@@ -55,7 +55,7 @@ Usage of this script:
 (4) fast beam search
 ./pruned_transducer_stateless7_streaming/pretrained.py \
     --checkpoint ./pruned_transducer_stateless7_streaming/exp/pretrained.pt \
-    --bpe-model ./data/lang_bpe_500/bpe.model \
+    --tokens data/lang_bpe_500/tokens.txt \
     --method fast_beam_search \
     --beam-size 4 \
     /path/to/foo.wav \
@@ -75,7 +75,6 @@ from typing import List
 
 import k2
 import kaldifeat
-import sentencepiece as spm
 import torch
 import torchaudio
 from beam_search import (
@@ -88,7 +87,7 @@ from beam_search import (
 from torch.nn.utils.rnn import pad_sequence
 from train import add_model_arguments, get_params, get_transducer_model
 
-from icefall.utils import str2bool
+from icefall.utils import num_tokens, str2bool
 
 
 def get_parser():
@@ -106,9 +105,9 @@ def get_parser():
     )
 
     parser.add_argument(
-        "--bpe-model",
+        "--tokens",
         type=str,
-        help="""Path to bpe.model.""",
+        help="""Path to tokens.txt.""",
     )
 
     parser.add_argument(
@@ -225,13 +224,14 @@ def main():
 
     params.update(vars(args))
 
-    sp = spm.SentencePieceProcessor()
+    # Load tokens.txt here
-    sp.load(params.bpe_model)
+    token_table = k2.SymbolTable.from_file(params.tokens)
 
+    # Load id of the <blk> token and the vocab size
     # <blk> is defined in local/train_bpe_model.py
-    params.blank_id = sp.piece_to_id("<blk>")
+    params.blank_id = token_table["<blk>"]
-    params.unk_id = sp.piece_to_id("<unk>")
+    params.unk_id = token_table["<unk>"]
-    params.vocab_size = sp.get_piece_size()
+    params.vocab_size = num_tokens(token_table) + 1  # +1 for <blk>
 
     logging.info(f"{params}")
 
@@ -286,6 +286,12 @@ def main():
         msg += f" with beam size {params.beam_size}"
     logging.info(msg)
 
+    def token_ids_to_words(token_ids: List[int]) -> str:
+        text = ""
+        for i in token_ids:
+            text += token_table[i]
+        return text.replace("▁", " ").strip()
+
     if params.method == "fast_beam_search":
         decoding_graph = k2.trivial_graph(params.vocab_size - 1, device=device)
         hyp_tokens = fast_beam_search_one_best(
@@ -297,8 +303,8 @@ def main():
             max_contexts=params.max_contexts,
             max_states=params.max_states,
         )
-        for hyp in sp.decode(hyp_tokens):
+        for hyp in hyp_tokens:
-            hyps.append(hyp.split())
+            hyps.append(token_ids_to_words(hyp))
     elif params.method == "modified_beam_search":
         hyp_tokens = modified_beam_search(
             model=model,
@@ -307,16 +313,16 @@ def main():
             beam=params.beam_size,
         )
 
-        for hyp in sp.decode(hyp_tokens):
+        for hyp in hyp_tokens:
-            hyps.append(hyp.split())
+            hyps.append(token_ids_to_words(hyp))
     elif params.method == "greedy_search" and params.max_sym_per_frame == 1:
         hyp_tokens = greedy_search_batch(
             model=model,
             encoder_out=encoder_out,
             encoder_out_lens=encoder_out_lens,
         )
-        for hyp in sp.decode(hyp_tokens):
+        for hyp in hyp_tokens:
-            hyps.append(hyp.split())
+            hyps.append(token_ids_to_words(hyp))
     else:
         for i in range(num_waves):
             # fmt: off
@@ -337,12 +343,11 @@ def main():
             else:
                 raise ValueError(f"Unsupported method: {params.method}")
 
-            hyps.append(sp.decode(hyp).split())
+            hyps.append(token_ids_to_words(hyp))
 
     s = "\n"
     for filename, hyp in zip(params.sound_files, hyps):
-        words = " ".join(hyp)
+        s += f"{filename}:\n{hyp}\n\n"
-        s += f"{filename}:\n{words}\n\n"
     logging.info(s)
 
     logging.info("Decoding Done")

egs/librispeech/ASR/pruned_transducer_stateless7_streaming_multi/export-for-ncnn.py

@@ -28,7 +28,7 @@ popd
 2. Export to ncnn
 
 ./pruned_transducer_stateless7_streaming/export-for-ncnn.py \
-  --bpe-model $repo/data/lang_bpe_500/bpe.model \
+  --tokens $repo/data/lang_bpe_500/tokens.txt \
   --exp-dir $repo/exp \
   --use-averaged-model 0 \
   --epoch 99 \
@@ -64,7 +64,7 @@ import argparse
 import logging
 from pathlib import Path
 
-import sentencepiece as spm
+import k2
 import torch
 from scaling_converter import convert_scaled_to_non_scaled
 from train2 import add_model_arguments, get_params, get_transducer_model
@@ -75,7 +75,7 @@ from icefall.checkpoint import (
     find_checkpoints,
     load_checkpoint,
 )
-from icefall.utils import setup_logger, str2bool
+from icefall.utils import num_tokens, setup_logger, str2bool
 
 
 def get_parser():
@@ -121,10 +121,10 @@ def get_parser():
     )
 
     parser.add_argument(
-        "--bpe-model",
+        "--tokens",
         type=str,
-        default="data/lang_bpe_500/bpe.model",
+        default="data/lang_bpe_500/tokens.txt",
-        help="Path to the BPE model",
+        help="Path to the tokens.txt.",
     )
 
     parser.add_argument(
@@ -244,12 +244,14 @@ def main():
 
     logging.info(f"device: {device}")
 
-    sp = spm.SentencePieceProcessor()
+    # Load tokens.txt here
-    sp.load(params.bpe_model)
+    token_table = k2.SymbolTable.from_file(params.tokens)
 
+    # Load id of the <blk> token and the vocab size
     # <blk> is defined in local/train_bpe_model.py
-    params.blank_id = sp.piece_to_id("<blk>")
+    params.blank_id = token_table["<blk>"]
-    params.vocab_size = sp.get_piece_size()
+    params.unk_id = token_table["<unk>"]
+    params.vocab_size = num_tokens(token_table) + 1  # +1 for <blk>
 
     logging.info(params)
 

egs/librispeech/ASR/pruned_transducer_stateless8/export.py

@@ -26,7 +26,7 @@ Usage:
 
 ./pruned_transducer_stateless8/export.py \
   --exp-dir ./pruned_transducer_stateless8/exp \
-  --bpe-model data/lang_bpe_500/bpe.model \
+  --tokens data/lang_bpe_500/tokens.txt \
   --epoch 30 \
   --avg 9 \
   --jit 1
@@ -45,7 +45,7 @@ for how to use the exported models outside of icefall.
 
 ./pruned_transducer_stateless8/export.py \
   --exp-dir ./pruned_transducer_stateless8/exp \
-  --bpe-model data/lang_bpe_500/bpe.model \
+  --tokens data/lang_bpe_500/tokens.txt \
   --epoch 20 \
   --avg 10
 
@@ -86,7 +86,7 @@ import argparse
 import logging
 from pathlib import Path
 
-import sentencepiece as spm
+import k2
 import torch
 import torch.nn as nn
 from scaling_converter import convert_scaled_to_non_scaled
@@ -98,7 +98,7 @@ from icefall.checkpoint import (
     find_checkpoints,
     load_checkpoint,
 )
-from icefall.utils import str2bool
+from icefall.utils import num_tokens, str2bool
 
 
 def get_parser():
@@ -155,10 +155,10 @@ def get_parser():
     )
 
     parser.add_argument(
-        "--bpe-model",
+        "--tokens",
         type=str,
-        default="data/lang_bpe_500/bpe.model",
+        default="data/lang_bpe_500/tokens.txt",
-        help="Path to the BPE model",
+        help="Path to the tokens.txt.",
     )
 
     parser.add_argument(
@@ -198,12 +198,14 @@ def main():
 
     logging.info(f"device: {device}")
 
-    sp = spm.SentencePieceProcessor()
+    # Load tokens.txt here
-    sp.load(params.bpe_model)
+    token_table = k2.SymbolTable.from_file(params.tokens)
 
+    # Load id of the <blk> token and the vocab size
     # <blk> is defined in local/train_bpe_model.py
-    params.blank_id = sp.piece_to_id("<blk>")
+    params.blank_id = token_table["<blk>"]
-    params.vocab_size = sp.get_piece_size()
+    params.unk_id = token_table["<unk>"]
+    params.vocab_size = num_tokens(token_table) + 1  # +1 for <blk>
 
     logging.info(params)
 

egs/librispeech/ASR/pruned_transducer_stateless8/pretrained.py

@@ -20,7 +20,7 @@ You can generate the checkpoint with the following command:
 
 ./pruned_transducer_stateless8/export.py \
   --exp-dir ./pruned_transducer_stateless8/exp \
-  --bpe-model data/lang_bpe_500/bpe.model \
+  --tokens data/lang_bpe_500/tokens.txt \
   --epoch 20 \
   --avg 10
 
@@ -29,7 +29,7 @@ Usage of this script:
 (1) greedy search
 ./pruned_transducer_stateless8/pretrained.py \
     --checkpoint ./pruned_transducer_stateless8/exp/pretrained.pt \
-    --bpe-model ./data/lang_bpe_500/bpe.model \
+    --tokens data/lang_bpe_500/tokens.txt \
     --method greedy_search \
     /path/to/foo.wav \
     /path/to/bar.wav
@@ -37,7 +37,7 @@ Usage of this script:
 (2) beam search
 ./pruned_transducer_stateless8/pretrained.py \
     --checkpoint ./pruned_transducer_stateless8/exp/pretrained.pt \
-    --bpe-model ./data/lang_bpe_500/bpe.model \
+    --tokens data/lang_bpe_500/tokens.txt \
     --method beam_search \
     --beam-size 4 \
     /path/to/foo.wav \
@@ -46,7 +46,7 @@ Usage of this script:
 (3) modified beam search
 ./pruned_transducer_stateless8/pretrained.py \
     --checkpoint ./pruned_transducer_stateless8/exp/pretrained.pt \
-    --bpe-model ./data/lang_bpe_500/bpe.model \
+    --tokens data/lang_bpe_500/tokens.txt \
     --method modified_beam_search \
     --beam-size 4 \
     /path/to/foo.wav \
@@ -55,7 +55,7 @@ Usage of this script:
 (4) fast beam search
 ./pruned_transducer_stateless8/pretrained.py \
     --checkpoint ./pruned_transducer_stateless8/exp/pretrained.pt \
-    --bpe-model ./data/lang_bpe_500/bpe.model \
+    --tokens data/lang_bpe_500/tokens.txt \
     --method fast_beam_search \
     --beam-size 4 \
     /path/to/foo.wav \
@@ -75,7 +75,6 @@ from typing import List
 
 import k2
 import kaldifeat
-import sentencepiece as spm
 import torch
 import torchaudio
 from beam_search import (
@@ -88,7 +87,7 @@ from beam_search import (
 from torch.nn.utils.rnn import pad_sequence
 from train import add_model_arguments, get_params, get_transducer_model
 
-from icefall.utils import str2bool
+from icefall.utils import num_tokens, str2bool
 
 
 def get_parser():
@@ -106,9 +105,9 @@ def get_parser():
     )
 
     parser.add_argument(
-        "--bpe-model",
+        "--tokens",
         type=str,
-        help="""Path to bpe.model.""",
+        help="""Path to tokens.txt.""",
     )
 
     parser.add_argument(
@@ -225,13 +224,14 @@ def main():
 
     params.update(vars(args))
 
-    sp = spm.SentencePieceProcessor()
+    # Load tokens.txt here
-    sp.load(params.bpe_model)
+    token_table = k2.SymbolTable.from_file(params.tokens)
 
+    # Load id of the <blk> token and the vocab size
     # <blk> is defined in local/train_bpe_model.py
-    params.blank_id = sp.piece_to_id("<blk>")
+    params.blank_id = token_table["<blk>"]
-    params.unk_id = sp.piece_to_id("<unk>")
+    params.unk_id = token_table["<unk>"]
-    params.vocab_size = sp.get_piece_size()
+    params.vocab_size = num_tokens(token_table) + 1  # +1 for <blk>
 
     logging.info(f"{params}")
 
@@ -286,6 +286,12 @@ def main():
         msg += f" with beam size {params.beam_size}"
     logging.info(msg)
 
+    def token_ids_to_words(token_ids: List[int]) -> str:
+        text = ""
+        for i in token_ids:
+            text += token_table[i]
+        return text.replace("▁", " ").strip()
+
     if params.method == "fast_beam_search":
         decoding_graph = k2.trivial_graph(params.vocab_size - 1, device=device)
         hyp_tokens = fast_beam_search_one_best(
@@ -297,8 +303,8 @@ def main():
             max_contexts=params.max_contexts,
             max_states=params.max_states,
         )
-        for hyp in sp.decode(hyp_tokens):
+        for hyp in hyp_tokens:
-            hyps.append(hyp.split())
+            hyps.append(token_ids_to_words(hyp))
     elif params.method == "modified_beam_search":
         hyp_tokens = modified_beam_search(
             model=model,
@@ -307,16 +313,16 @@ def main():
             beam=params.beam_size,
         )
 
-        for hyp in sp.decode(hyp_tokens):
+        for hyp in hyp_tokens:
-            hyps.append(hyp.split())
+            hyps.append(token_ids_to_words(hyp))
     elif params.method == "greedy_search" and params.max_sym_per_frame == 1:
         hyp_tokens = greedy_search_batch(
             model=model,
             encoder_out=encoder_out,
             encoder_out_lens=encoder_out_lens,
         )
-        for hyp in sp.decode(hyp_tokens):
+        for hyp in hyp_tokens:
-            hyps.append(hyp.split())
+            hyps.append(token_ids_to_words(hyp))
     else:
         for i in range(num_waves):
             # fmt: off
@@ -337,12 +343,11 @@ def main():
             else:
                 raise ValueError(f"Unsupported method: {params.method}")
 
-            hyps.append(sp.decode(hyp).split())
+            hyps.append(token_ids_to_words(hyp))
 
     s = "\n"
     for filename, hyp in zip(params.sound_files, hyps):
-        words = " ".join(hyp)
+        s += f"{filename}:\n{hyp}\n\n"
-        s += f"{filename}:\n{words}\n\n"
     logging.info(s)
 
     logging.info("Decoding Done")