Go API

In this section, we describe how to use the Go API of sherpa-onnx.

The Go API of sherpa-onnx supports both streaming and non-streaming speech recognition.

The following table lists some Go API examples:

Description

URL

Decode a file with non-streaming models

https://github.com/k2-fsa/sherpa-onnx/tree/master/go-api-examples/non-streaming-decode-files

Decode a file with streaming models

https://github.com/k2-fsa/sherpa-onnx/tree/master/go-api-examples/streaming-decode-files

Real-time speech recognition from a microphone

https://github.com/k2-fsa/sherpa-onnx/tree/master/go-api-examples/real-time-speech-recognition-from-microphone

One thing to note is that we have provided pre-built libraries for Go so that you don’t need to build sherpa-onnx by yourself when using the Go API.

To make supporting multiple platforms easier, we split the Go API of sherpa-onnx into multiple packages, as listed in the following table:

OS

Package name

Supported Arch

Doc

Linux

sherpa-onnx-go-linux

x86_64, aarch64, arm

https://pkg.go.dev/github.com/k2-fsa/sherpa-onnx-go-linux

macOS

sherpa-onnx-go-macos

x86_64, aarch64

https://pkg.go.dev/github.com/k2-fsa/sherpa-onnx-go-macos

Windows

sherpa-onnx-go-windows

x86_64, x86

https://pkg.go.dev/github.com/k2-fsa/sherpa-onnx-go-windows

To simplify the usage, we have provided a single Go package for sherpa-onnx that supports multiple operating systems. It can be found at

Hint

Such a design is insipred by the following article:

You can use the following import to import sherpa-onnx-go into your Go project:

import (
  sherpa "github.com/k2-fsa/sherpa-onnx-go/sherpa_onnx"
)

In the following, we describe how to run our provided Go API examples.

Note

Before you continue, please make sure you have installed Go. If not, please follow https://go.dev/doc/install to install Go.

Hint

You need to enable cgo to build sherpa-onnx-go.

Decode files with non-streaming models

First, let us build the example:

git clone https://github.com/k2-fsa/sherpa-onnx
cd sherpa-onnx/go-api-examples/non-streaming-decode-files
go mod tidy
go build
./non-streaming-decode-files --help

You will find the following output:

Usage of ./non-streaming-decode-files:
      --debug int                Whether to show debug message
      --decoder string           Path to the decoder model
      --decoding-method string   Decoding method. Possible values: greedy_search, modified_beam_search (default "greedy_search")
      --encoder string           Path to the encoder model
      --joiner string            Path to the joiner model
      --lm-model string          Optional. Path to the LM model
      --lm-scale float32         Optional. Scale for the LM model (default 1)
      --max-active-paths int     Used only when --decoding-method is modified_beam_search (default 4)
      --model-type string        Optional. Used for loading the model in a faster way
      --nemo-ctc string          Path to the NeMo CTC model
      --num-threads int          Number of threads for computing (default 1)
      --paraformer string        Path to the paraformer model
      --provider string          Provider to use (default "cpu")
      --tokens string            Path to the tokens file
pflag: help requested

Congratulations! You have successfully built your first Go API example for speech recognition.

Note

If you are using Windows and don’t see any output after running ./non-streaming-decode-files --help, please copy *.dll from https://github.com/k2-fsa/sherpa-onnx-go-windows/tree/master/lib/x86_64-pc-windows-gnu (for Win64) or https://github.com/k2-fsa/sherpa-onnx-go-windows/tree/master/lib/i686-pc-windows-gnu (for Win32) to the directory sherpa-onnx/go-api-examples/non-streaming-decode-files.

Now let us refer to Pre-trained models to download a non-streaming model.

We give several examples below for demonstration.

Non-streaming transducer

We will use csukuangfj/sherpa-onnx-zipformer-en-2023-06-26 (English) as an example.

First, let us download it:

cd sherpa-onnx/go-api-examples/non-streaming-decode-files
wget https://github.com/k2-fsa/sherpa-onnx/releases/download/asr-models/sherpa-onnx-zipformer-en-2023-06-26.tar.bz2
tar xvf sherpa-onnx-zipformer-en-2023-06-26.tar.bz2
rm sherpa-onnx-zipformer-en-2023-06-26.tar.bz2

Now we can use:

./non-streaming-decode-files \
  --encoder ./sherpa-onnx-zipformer-en-2023-06-26/encoder-epoch-99-avg-1.onnx \
  --decoder ./sherpa-onnx-zipformer-en-2023-06-26/decoder-epoch-99-avg-1.onnx \
  --joiner ./sherpa-onnx-zipformer-en-2023-06-26/joiner-epoch-99-avg-1.onnx \
  --tokens ./sherpa-onnx-zipformer-en-2023-06-26/tokens.txt \
  --model-type transducer \
  ./sherpa-onnx-zipformer-en-2023-06-26/test_wavs/0.wav

It should give you the following output:

2023/08/10 14:52:48.723098 Reading ./sherpa-onnx-zipformer-en-2023-06-26/test_wavs/0.wav
2023/08/10 14:52:48.741042 Initializing recognizer (may take several seconds)
2023/08/10 14:52:51.998848 Recognizer created!
2023/08/10 14:52:51.998870 Start decoding!
2023/08/10 14:52:52.258818 Decoding done!
2023/08/10 14:52:52.258847  after early nightfall the yellow lamps would light up here and there the squalid quarter of the brothels
2023/08/10 14:52:52.258952 Wave duration: 6.625 seconds

Non-streaming paraformer

We will use csukuangfj/sherpa-onnx-paraformer-zh-2023-03-28 (Chinese + English) as an example.

First, let us download it:

cd sherpa-onnx/go-api-examples/non-streaming-decode-files
wget https://github.com/k2-fsa/sherpa-onnx/releases/download/asr-models/sherpa-onnx-paraformer-zh-2023-03-28.tar.bz2
tar xvf sherpa-onnx-paraformer-zh-2023-03-28.tar.bz2
rm sherpa-onnx-paraformer-zh-2023-03-28.tar.bz2

Now we can use:

./non-streaming-decode-files \
  --paraformer ./sherpa-onnx-paraformer-zh-2023-03-28/model.int8.onnx \
  --tokens ./sherpa-onnx-paraformer-zh-2023-03-28/tokens.txt \
  --model-type paraformer \
  ./sherpa-onnx-paraformer-zh-2023-03-28/test_wavs/0.wav

It should give you the following output:

2023/08/10 15:07:10.745412 Reading ./sherpa-onnx-paraformer-zh-2023-03-28/test_wavs/0.wav
2023/08/10 15:07:10.758414 Initializing recognizer (may take several seconds)
2023/08/10 15:07:13.992424 Recognizer created!
2023/08/10 15:07:13.992441 Start decoding!
2023/08/10 15:07:14.382157 Decoding done!
2023/08/10 15:07:14.382847 对我做了介绍啊那么我想说的是呢大家如果对我的研究感兴趣呢你
2023/08/10 15:07:14.382898 Wave duration: 5.614625 seconds

Non-streaming CTC model from NeMo

We will use stt_en_conformer_ctc_medium as an example.

First, let us download it:

cd sherpa-onnx/go-api-examples/non-streaming-decode-files
wget https://github.com/k2-fsa/sherpa-onnx/releases/download/asr-models/sherpa-onnx-nemo-ctc-en-conformer-medium.tar.bz2
tar xvf sherpa-onnx-nemo-ctc-en-conformer-medium.tar.bz2
rm sherpa-onnx-nemo-ctc-en-conformer-medium.tar.bz2

Now we can use:

./non-streaming-decode-files \
  --nemo-ctc ./sherpa-onnx-nemo-ctc-en-conformer-medium/model.onnx \
  --tokens ./sherpa-onnx-nemo-ctc-en-conformer-medium/tokens.txt \
  --model-type nemo_ctc \
  ./sherpa-onnx-nemo-ctc-en-conformer-medium/test_wavs/0.wav

It should give you the following output:

2023/08/10 15:11:48.667693 Reading ./sherpa-onnx-nemo-ctc-en-conformer-medium/test_wavs/0.wav
2023/08/10 15:11:48.680855 Initializing recognizer (may take several seconds)
2023/08/10 15:11:51.900852 Recognizer created!
2023/08/10 15:11:51.900869 Start decoding!
2023/08/10 15:11:52.125605 Decoding done!
2023/08/10 15:11:52.125630  after early nightfall the yellow lamps would light up here and there the squalid quarter of the brothels
2023/08/10 15:11:52.125645 Wave duration: 6.625 seconds

Decode files with streaming models

First, let us build the example:

git clone https://github.com/k2-fsa/sherpa-onnx
cd sherpa-onnx/go-api-examples/streaming-decode-files
go mod tidy
go build
./streaming-decode-files --help

You will find the following output:

Usage of ./streaming-decode-files:
      --debug int                Whether to show debug message
      --decoder string           Path to the decoder model
      --decoding-method string   Decoding method. Possible values: greedy_search, modified_beam_search (default "greedy_search")
      --encoder string           Path to the encoder model
      --joiner string            Path to the joiner model
      --max-active-paths int     Used only when --decoding-method is modified_beam_search (default 4)
      --model-type string        Optional. Used for loading the model in a faster way
      --num-threads int          Number of threads for computing (default 1)
      --provider string          Provider to use (default "cpu")
      --tokens string            Path to the tokens file
pflag: help requested

Note

If you are using Windows and don’t see any output after running ./streaming-decode-files --help, please copy *.dll from https://github.com/k2-fsa/sherpa-onnx-go-windows/tree/master/lib/x86_64-pc-windows-gnu (for Win64) or https://github.com/k2-fsa/sherpa-onnx-go-windows/tree/master/lib/i686-pc-windows-gnu (for Win32) to the directory sherpa-onnx/go-api-examples/streaming-decode-files.

Now let us refer to Pre-trained models to download a streaming model.

We give one example below for demonstration.

Streaming transducer

We will use csukuangfj/sherpa-onnx-streaming-zipformer-en-2023-06-26 (English) as an example.

First, let us download it:

cd sherpa-onnx/go-api-examples/streaming-decode-files
wget https://github.com/k2-fsa/sherpa-onnx/releases/download/asr-models/sherpa-onnx-streaming-zipformer-en-2023-06-26.tar.bz2
tar xvf sherpa-onnx-streaming-zipformer-en-2023-06-26.tar.bz2
rm sherpa-onnx-streaming-zipformer-en-2023-06-26.tar.bz2

Now we can use:

./streaming-decode-files \
  --encoder ./sherpa-onnx-streaming-zipformer-en-2023-06-26/encoder-epoch-99-avg-1-chunk-16-left-128.onnx \
  --decoder ./sherpa-onnx-streaming-zipformer-en-2023-06-26/decoder-epoch-99-avg-1-chunk-16-left-128.onnx \
  --joiner ./sherpa-onnx-streaming-zipformer-en-2023-06-26/joiner-epoch-99-avg-1-chunk-16-left-128.onnx \
  --tokens ./sherpa-onnx-streaming-zipformer-en-2023-06-26/tokens.txt \
  --model-type zipformer2 \
  ./sherpa-onnx-streaming-zipformer-en-2023-06-26/test_wavs/0.wav

It should give you the following output:

2023/08/10 15:17:00.226228 Reading ./sherpa-onnx-streaming-zipformer-en-2023-06-26/test_wavs/0.wav
2023/08/10 15:17:00.241024 Initializing recognizer (may take several seconds)
2023/08/10 15:17:03.352697 Recognizer created!
2023/08/10 15:17:03.352711 Start decoding!
2023/08/10 15:17:04.057130 Decoding done!
2023/08/10 15:17:04.057215  after early nightfall the yellow lamps would light up here and there the squalid quarter of the brothels
2023/08/10 15:17:04.057235 Wave duration: 6.625 seconds

Real-time speech recognition from microphone

Hint

You need to install portaudio for this example.

# for macOS
brew install portaudio
export PKG_CONFIG_PATH=/usr/local/Cellar/portaudio/19.7.0

# for Ubuntu
sudo apt-get install libasound-dev portaudio19-dev libportaudio2 libportaudiocpp0

To check that you have installed portaudio successfully, please run:

pkg-config --cflags --libs portaudio-2.0

It should give you something like below:

# for macOS
-I/usr/local/Cellar/portaudio/19.7.0/include -L/usr/local/Cellar/portaudio/19.7.0/lib -lportaudio -framework CoreAudio -framework AudioToolbox -framework AudioUnit -framework CoreFoundation -framework CoreServices

# for Ubuntu
-pthread -lportaudio -lasound -lm -lpthread

First, let us build the example:

git clone https://github.com/k2-fsa/sherpa-onnx
cd sherpa-onnx/go-api-examples/real-time-speech-recognition-from-microphone
go mod tidy
go build
./real-time-speech-recognition-from-microphone --help

You will find the following output:

Select default input device: MacBook Pro Microphone
Usage of ./real-time-speech-recognition-from-microphone:
      --debug int                            Whether to show debug message
      --decoder string                       Path to the decoder model
      --decoding-method string               Decoding method. Possible values: greedy_search, modified_beam_search (default "greedy_search")
      --enable-endpoint int                  Whether to enable endpoint (default 1)
      --encoder string                       Path to the encoder model
      --joiner string                        Path to the joiner model
      --max-active-paths int                 Used only when --decoding-method is modified_beam_search (default 4)
      --model-type string                    Optional. Used for loading the model in a faster way
      --num-threads int                      Number of threads for computing (default 1)
      --provider string                      Provider to use (default "cpu")
      --rule1-min-trailing-silence float32   Threshold for rule1 (default 2.4)
      --rule2-min-trailing-silence float32   Threshold for rule2 (default 1.2)
      --rule3-min-utterance-length float32   Threshold for rule3 (default 20)
      --tokens string                        Path to the tokens file
pflag: help requested

Now let us refer to Pre-trained models to download a streaming model.

We give one example below for demonstration.

Streaming transducer

We will use csukuangfj/sherpa-onnx-streaming-zipformer-en-2023-06-26 (English) as an example.

First, let us download it:

cd sherpa-onnx/go-api-examples/real-time-speech-recognition-from-microphone
wget https://github.com/k2-fsa/sherpa-onnx/releases/download/asr-models/sherpa-onnx-streaming-zipformer-en-2023-06-26.tar.bz2
tar xvf sherpa-onnx-streaming-zipformer-en-2023-06-26.tar.bz2
rm sherpa-onnx-streaming-zipformer-en-2023-06-26.tar.bz2

Now we can use:

./real-time-speech-recognition-from-microphone \
  --encoder ./sherpa-onnx-streaming-zipformer-en-2023-06-26/encoder-epoch-99-avg-1-chunk-16-left-128.onnx \
  --decoder ./sherpa-onnx-streaming-zipformer-en-2023-06-26/decoder-epoch-99-avg-1-chunk-16-left-128.onnx \
  --joiner ./sherpa-onnx-streaming-zipformer-en-2023-06-26/joiner-epoch-99-avg-1-chunk-16-left-128.onnx \
  --tokens ./sherpa-onnx-streaming-zipformer-en-2023-06-26/tokens.txt \
  --model-type zipformer2

It should give you the following output:

Select default input device: MacBook Pro Microphone
2023/08/10 15:22:00 Initializing recognizer (may take several seconds)
2023/08/10 15:22:03 Recognizer created!
Started! Please speak
0:  this is the first test
1:  this is the second

colab

We provide a colab notebook Sherpa-onnx go api example colab notebook for you to try the Go API examples of sherpa-onnx.