Streaming ASR

This page describes how to use the C++ API of sherpa for streaming/online ASR.

Warning

It supports only models from https://github.com/k2-fsa/icefall/tree/master/egs/librispeech/ASR/conv_emformer_transducer_stateless2 at present.

Please refer to Installation for installation.

After running make -j, you should find the following files:

• lib/libsherpa_online_recognizer.so

• include/sherpa/cpp_api/online_recognizer.h

• include/sherpa/cpp_api/online_stream.h

You can include the above two header files in your application and link libsherpa_online_recognizer.so with you executable to use the C++ APIs.

https://github.com/k2-fsa/sherpa/blob/master/sherpa/cpp_api/test_online_recognizer_microphone.cc shows how to use the C++ API for real-time speech recognition with a microphone. After running make -j, you can also find an executable bin/test_online_recognizer_microphone. The following shows how to use it:

cd /path/to/sherpa/build

git lfs install
git clone https://huggingface.co/Zengwei/icefall-asr-librispeech-conv-emformer-transducer-stateless2-2022-07-05

./bin/test_online_recognizer_microphone \
  ./icefall-asr-librispeech-conv-emformer-transducer-stateless2-2022-07-05/exp/cpu-jit-epoch-30-avg-10-torch-1.10.0.pt \
  ./icefall-asr-librispeech-conv-emformer-transducer-stateless2-2022-07-05/data/lang_bpe_500/tokens.txt

It will print something like below:

num devices: 4
Use default device: 2
  Name: MacBook Pro Microphone
  Max input channels: 1
Started

Say something and you will see the recognition result printed to the console in real-time.

You can find a demo below: