Add C++ runtime for non-streaming faster conformer transducer from NeMo.

.github/scripts/test-offline-transducer.sh

@@ -13,6 +13,105 @@ echo "PATH: $PATH"
 
 which $EXE
 
+log "------------------------------------------------------------------------"
+log "Run Nemo fast conformer hybrid transducer ctc models (transducer branch)"
+log "------------------------------------------------------------------------"
+
+url=https://github.com/k2-fsa/sherpa-onnx/releases/download/asr-models/sherpa-onnx-nemo-fast-conformer-transducer-be-de-en-es-fr-hr-it-pl-ru-uk-20k.tar.bz2
+name=$(basename $url)
+curl -SL -O $url
+tar xvf $name
+rm $name
+repo=$(basename -s .tar.bz2 $name)
+ls -lh $repo
+
+log "test $repo"
+test_wavs=(
+de-german.wav
+es-spanish.wav
+hr-croatian.wav
+po-polish.wav
+uk-ukrainian.wav
+en-english.wav
+fr-french.wav
+it-italian.wav
+ru-russian.wav
+)
+for w in ${test_wavs[@]}; do
+  time $EXE \
+    --tokens=$repo/tokens.txt \
+    --encoder=$repo/encoder.onnx \
+    --decoder=$repo/decoder.onnx \
+    --joiner=$repo/joiner.onnx \
+    --debug=1 \
+    $repo/test_wavs/$w
+done
+
+rm -rf $repo
+
+url=https://github.com/k2-fsa/sherpa-onnx/releases/download/asr-models/sherpa-onnx-nemo-fast-conformer-transducer-en-24500.tar.bz2
+name=$(basename $url)
+curl -SL -O $url
+tar xvf $name
+rm $name
+repo=$(basename -s .tar.bz2 $name)
+ls -lh $repo
+
+log "Test $repo"
+
+time $EXE \
+  --tokens=$repo/tokens.txt \
+  --encoder=$repo/encoder.onnx \
+  --decoder=$repo/decoder.onnx \
+  --joiner=$repo/joiner.onnx \
+  --debug=1 \
+  $repo/test_wavs/en-english.wav
+
+rm -rf $repo
+
+url=https://github.com/k2-fsa/sherpa-onnx/releases/download/asr-models/sherpa-onnx-nemo-fast-conformer-transducer-es-1424.tar.bz2
+name=$(basename $url)
+curl -SL -O $url
+tar xvf $name
+rm $name
+repo=$(basename -s .tar.bz2 $name)
+ls -lh $repo
+
+log "test $repo"
+
+time $EXE \
+  --tokens=$repo/tokens.txt \
+  --encoder=$repo/encoder.onnx \
+  --decoder=$repo/decoder.onnx \
+  --joiner=$repo/joiner.onnx \
+  --debug=1 \
+  $repo/test_wavs/es-spanish.wav
+
+rm -rf $repo
+
+url=https://github.com/k2-fsa/sherpa-onnx/releases/download/asr-models/sherpa-onnx-nemo-fast-conformer-transducer-en-de-es-fr-14288.tar.bz2
+name=$(basename $url)
+curl -SL -O $url
+tar xvf $name
+rm $name
+repo=$(basename -s .tar.bz2 $name)
+ls -lh $repo
+
+log "Test $repo"
+
+time $EXE \
+  --tokens=$repo/tokens.txt \
+  --encoder=$repo/encoder.onnx \
+  --decoder=$repo/decoder.onnx \
+  --joiner=$repo/joiner.onnx \
+  --debug=1 \
+  $repo/test_wavs/en-english.wav \
+  $repo/test_wavs/de-german.wav \
+  $repo/test_wavs/fr-french.wav \
+  $repo/test_wavs/es-spanish.wav
+
+rm -rf $repo
+
 log "------------------------------------------------------------"
 log "Run Conformer transducer (English)"
 log "------------------------------------------------------------"

.github/workflows/linux.yaml

@@ -128,6 +128,14 @@ jobs:
           name: release-${{ matrix.build_type }}-with-shared-lib-${{ matrix.shared_lib }}-with-tts-${{ matrix.with_tts }}
           path: install/*
 
+      - name: Test offline transducer
+        shell: bash
+        run: |
+          export PATH=$PWD/build/bin:$PATH
+          export EXE=sherpa-onnx-offline
+
+          .github/scripts/test-offline-transducer.sh
+
       - name: Test spoken language identification (C++ API)
         shell: bash
         run: |
@@ -215,14 +223,6 @@ jobs:
 
           .github/scripts/test-online-paraformer.sh
 
-      - name: Test offline transducer
-        shell: bash
-        run: |
-          export PATH=$PWD/build/bin:$PATH
-          export EXE=sherpa-onnx-offline
-
-          .github/scripts/test-offline-transducer.sh
-
       - name: Test online transducer
         shell: bash
         run: |

.github/workflows/macos.yaml

@@ -107,6 +107,14 @@ jobs:
           otool -L build/bin/sherpa-onnx
           otool -l build/bin/sherpa-onnx
 
+      - name: Test offline transducer
+        shell: bash
+        run: |
+          export PATH=$PWD/build/bin:$PATH
+          export EXE=sherpa-onnx-offline
+
+          .github/scripts/test-offline-transducer.sh
+
       - name: Test online CTC
         shell: bash
         run: |
@@ -192,14 +200,6 @@ jobs:
 
           .github/scripts/test-offline-ctc.sh
 
-      - name: Test offline transducer
-        shell: bash
-        run: |
-          export PATH=$PWD/build/bin:$PATH
-          export EXE=sherpa-onnx-offline
-
-          .github/scripts/test-offline-transducer.sh
-
       - name: Test online transducer
         shell: bash
         run: |

.gitignore

@@ -104,3 +104,4 @@ sherpa-onnx-kws-zipformer-wenetspeech-3.3M-2024-01-01
 sherpa-onnx-ced-*
 node_modules
 package-lock.json
+sherpa-onnx-nemo-*

python-api-examples/offline-nemo-ctc-decode-files.py

@@ -0,0 +1,68 @@
+#!/usr/bin/env python3
+
+"""
+This file shows how to use a non-streaming CTC model from NeMo
+to decode files.
+
+Please download model files from
+https://github.com/k2-fsa/sherpa-onnx/releases/tag/asr-models
+
+
+The example model supports 10 languages and it is converted from
+https://catalog.ngc.nvidia.com/orgs/nvidia/teams/nemo/models/stt_multilingual_fastconformer_hybrid_large_pc
+"""
+
+from pathlib import Path
+
+import sherpa_onnx
+import soundfile as sf
+
+
+def create_recognizer():
+    model = "./sherpa-onnx-nemo-fast-conformer-ctc-be-de-en-es-fr-hr-it-pl-ru-uk-20k/model.onnx"
+    tokens = "./sherpa-onnx-nemo-fast-conformer-ctc-be-de-en-es-fr-hr-it-pl-ru-uk-20k/tokens.txt"
+
+    test_wav = "./sherpa-onnx-nemo-fast-conformer-ctc-be-de-en-es-fr-hr-it-pl-ru-uk-20k/test_wavs/de-german.wav"
+    #  test_wav = "./sherpa-onnx-nemo-fast-conformer-ctc-be-de-en-es-fr-hr-it-pl-ru-uk-20k/test_wavs/en-english.wav"
+    #  test_wav = "./sherpa-onnx-nemo-fast-conformer-ctc-be-de-en-es-fr-hr-it-pl-ru-uk-20k/test_wavs/es-spanish.wav"
+    #  test_wav = "./sherpa-onnx-nemo-fast-conformer-ctc-be-de-en-es-fr-hr-it-pl-ru-uk-20k/test_wavs/fr-french.wav"
+    #  test_wav = "./sherpa-onnx-nemo-fast-conformer-ctc-be-de-en-es-fr-hr-it-pl-ru-uk-20k/test_wavs/hr-croatian.wav"
+    #  test_wav = "./sherpa-onnx-nemo-fast-conformer-ctc-be-de-en-es-fr-hr-it-pl-ru-uk-20k/test_wavs/it-italian.wav"
+    #  test_wav = "./sherpa-onnx-nemo-fast-conformer-ctc-be-de-en-es-fr-hr-it-pl-ru-uk-20k/test_wavs/po-polish.wav"
+    #  test_wav = "./sherpa-onnx-nemo-fast-conformer-ctc-be-de-en-es-fr-hr-it-pl-ru-uk-20k/test_wavs/ru-russian.wav"
+    #  test_wav = "./sherpa-onnx-nemo-fast-conformer-ctc-be-de-en-es-fr-hr-it-pl-ru-uk-20k/test_wavs/uk-ukrainian.wav"
+
+    if not Path(model).is_file() or not Path(test_wav).is_file():
+        raise ValueError(
+            """Please download model files from
+            https://github.com/k2-fsa/sherpa-onnx/releases/tag/asr-models
+            """
+        )
+    return (
+        sherpa_onnx.OfflineRecognizer.from_nemo_ctc(
+            model=model,
+            tokens=tokens,
+            debug=True,
+        ),
+        test_wav,
+    )
+
+
+def main():
+    recognizer, wave_filename = create_recognizer()
+
+    audio, sample_rate = sf.read(wave_filename, dtype="float32", always_2d=True)
+    audio = audio[:, 0]  # only use the first channel
+
+    # audio is a 1-D float32 numpy array normalized to the range [-1, 1]
+    # sample_rate does not need to be 16000 Hz
+
+    stream = recognizer.create_stream()
+    stream.accept_waveform(sample_rate, audio)
+    recognizer.decode_stream(stream)
+    print(wave_filename)
+    print(stream.result)
+
+
+if __name__ == "__main__":
+    main()

python-api-examples/offline-nemo-transducer-decode-files.py

@@ -0,0 +1,73 @@
+#!/usr/bin/env python3
+
+"""
+This file shows how to use a non-streaming transducer model from NeMo
+to decode files.
+
+Please download model files from
+https://github.com/k2-fsa/sherpa-onnx/releases/tag/asr-models
+
+
+The example model supports 10 languages and it is converted from
+https://catalog.ngc.nvidia.com/orgs/nvidia/teams/nemo/models/stt_multilingual_fastconformer_hybrid_large_pc
+"""
+
+from pathlib import Path
+
+import sherpa_onnx
+import soundfile as sf
+
+
+def create_recognizer():
+    encoder = "./sherpa-onnx-nemo-fast-conformer-transducer-be-de-en-es-fr-hr-it-pl-ru-uk-20k/encoder.onnx"
+    decoder = "./sherpa-onnx-nemo-fast-conformer-transducer-be-de-en-es-fr-hr-it-pl-ru-uk-20k/decoder.onnx"
+    joiner = "./sherpa-onnx-nemo-fast-conformer-transducer-be-de-en-es-fr-hr-it-pl-ru-uk-20k/joiner.onnx"
+    tokens = "./sherpa-onnx-nemo-fast-conformer-transducer-be-de-en-es-fr-hr-it-pl-ru-uk-20k/tokens.txt"
+
+    test_wav = "./sherpa-onnx-nemo-fast-conformer-transducer-be-de-en-es-fr-hr-it-pl-ru-uk-20k/test_wavs/de-german.wav"
+    #  test_wav = "./sherpa-onnx-nemo-fast-conformer-transducer-be-de-en-es-fr-hr-it-pl-ru-uk-20k/test_wavs/en-english.wav"
+    #  test_wav = "./sherpa-onnx-nemo-fast-conformer-transducer-be-de-en-es-fr-hr-it-pl-ru-uk-20k/test_wavs/es-spanish.wav"
+    #  test_wav = "./sherpa-onnx-nemo-fast-conformer-transducer-be-de-en-es-fr-hr-it-pl-ru-uk-20k/test_wavs/fr-french.wav"
+    #  test_wav = "./sherpa-onnx-nemo-fast-conformer-transducer-be-de-en-es-fr-hr-it-pl-ru-uk-20k/test_wavs/hr-croatian.wav"
+    #  test_wav = "./sherpa-onnx-nemo-fast-conformer-transducer-be-de-en-es-fr-hr-it-pl-ru-uk-20k/test_wavs/it-italian.wav"
+    #  test_wav = "./sherpa-onnx-nemo-fast-conformer-transducer-be-de-en-es-fr-hr-it-pl-ru-uk-20k/test_wavs/po-polish.wav"
+    #  test_wav = "./sherpa-onnx-nemo-fast-conformer-transducer-be-de-en-es-fr-hr-it-pl-ru-uk-20k/test_wavs/ru-russian.wav"
+    #  test_wav = "./sherpa-onnx-nemo-fast-conformer-transducer-be-de-en-es-fr-hr-it-pl-ru-uk-20k/test_wavs/uk-ukrainian.wav"
+
+    if not Path(encoder).is_file() or not Path(test_wav).is_file():
+        raise ValueError(
+            """Please download model files from
+            https://github.com/k2-fsa/sherpa-onnx/releases/tag/asr-models
+            """
+        )
+    return (
+        sherpa_onnx.OfflineRecognizer.from_transducer(
+            encoder=encoder,
+            decoder=decoder,
+            joiner=joiner,
+            tokens=tokens,
+            model_type="nemo_transducer",
+            debug=True,
+        ),
+        test_wav,
+    )
+
+
+def main():
+    recognizer, wave_filename = create_recognizer()
+
+    audio, sample_rate = sf.read(wave_filename, dtype="float32", always_2d=True)
+    audio = audio[:, 0]  # only use the first channel
+
+    # audio is a 1-D float32 numpy array normalized to the range [-1, 1]
+    # sample_rate does not need to be 16000 Hz
+
+    stream = recognizer.create_stream()
+    stream.accept_waveform(sample_rate, audio)
+    recognizer.decode_stream(stream)
+    print(wave_filename)
+    print(stream.result)
+
+
+if __name__ == "__main__":
+    main()

sherpa-onnx/csrc/CMakeLists.txt

@@ -40,9 +40,11 @@ set(sources
   offline-tdnn-ctc-model.cc
   offline-tdnn-model-config.cc
   offline-transducer-greedy-search-decoder.cc
+  offline-transducer-greedy-search-nemo-decoder.cc
   offline-transducer-model-config.cc
   offline-transducer-model.cc
   offline-transducer-modified-beam-search-decoder.cc
+  offline-transducer-nemo-model.cc
   offline-wenet-ctc-model-config.cc
   offline-wenet-ctc-model.cc
   offline-whisper-greedy-search-decoder.cc

sherpa-onnx/csrc/features.h

@@ -56,6 +56,19 @@ struct FeatureExtractorConfig {
   bool remove_dc_offset = true;       // Subtract mean of wave before FFT.
   std::string window_type = "povey";  // e.g. Hamming window
 
+  // For models from NeMo
+  // This option is not exposed and is set internally when loading models.
+  // Possible values:
+  // - per_feature
+  // - all_features (not implemented yet)
+  // - fixed_mean (not implemented)
+  // - fixed_std (not implemented)
+  // - or just leave it to empty
+  // See
+  // https://github.com/NVIDIA/NeMo/blob/main/nemo/collections/asr/parts/preprocessing/features.py#L59
+  // for details
+  std::string nemo_normalize_type;
+
   std::string ToString() const;
 
   void Register(ParseOptions *po);

sherpa-onnx/csrc/keyword-spotter-transducer-impl.h

@@ -68,7 +68,7 @@ class KeywordSpotterTransducerImpl : public KeywordSpotterImpl {
       : config_(config),
         model_(OnlineTransducerModel::Create(config.model_config)),
         sym_(config.model_config.tokens) {
-    if (sym_.contains("<unk>")) {
+    if (sym_.Contains("<unk>")) {
       unk_id_ = sym_["<unk>"];
     }
 
@@ -87,7 +87,7 @@ class KeywordSpotterTransducerImpl : public KeywordSpotterImpl {
       : config_(config),
         model_(OnlineTransducerModel::Create(mgr, config.model_config)),
         sym_(mgr, config.model_config.tokens) {
-    if (sym_.contains("<unk>")) {
+    if (sym_.Contains("<unk>")) {
       unk_id_ = sym_["<unk>"];
     }
 

sherpa-onnx/csrc/offline-nemo-enc-dec-ctc-model.cc

@@ -1,6 +1,6 @@
 // sherpa-onnx/csrc/offline-nemo-enc-dec-ctc-model.cc
 //
-// Copyright (c)  2023  Xiaomi Corporation
+// Copyright (c)  2023-2024  Xiaomi Corporation
 
 #include "sherpa-onnx/csrc/offline-nemo-enc-dec-ctc-model.h"