Google Cloud Speech API Samples

These examples demo accessing the Google Cloud Speech API in streaming mode (via its gRPC API) and in non-streaming mode (via its REST API).

Prerequisites

Enable the Speech API

If you have not already done so, enable the Google Cloud Speech API for your project. You must be whitelisted to do this.

Set Up to Authenticate With Your Project's Credentials

The example uses a service account for OAuth2 authentication. So next, set up to authenticate with the Speech API using your project's service account credentials.

Visit the Cloud Console, and navigate to: API Manager > Credentials > Create credentials > Service account key > New service account. Create a new service account, and download the json credentials file.

Then, set the GOOGLE_APPLICATION_CREDENTIALS environment variable to point to your downloaded service account credentials before running this example:

export GOOGLE_APPLICATION_CREDENTIALS=/path/to/your/credentials-key.json

If you do not do this, the REST api will return a 403. The streaming sample will just sort of hang silently.

See the Cloud Platform Auth Guide for more information.

Setup

Before running these samples perform the steps:

• Clone this repo

  git clone https://github.com/GoogleCloudPlatform/python-docs-samples.git
  cd python-docs-samples/speech/api
  

• Create a virtualenv

  virtualenv env
  source env/bin/activate
  

Install the dependencies

The sample uses the PyAudio library to stream audio from your computer's microphone. PyAudio depends on PortAudio, which may need to be installed separately, depending on your platform:

• Install the pyAudio dependencies.

• If you're running the speech_rest.py sample:

  $ pip install -r requirements-speech_rest.txt

• If you're running the speech_streaming.py sample:

  $ pip install -r requirements-speech_grpc.txt

Troubleshooting

PortAudio on OS X

If you see the error

fatal error: 'portaudio.h' file not found

Try adding the following to your ~/.pydistutils.cfg file, substituting in your appropriate brew Cellar directory:

include_dirs=/usr/local/Cellar/portaudio/19.20140130/include/
library_dirs=/usr/local/YourUsername/homebrew/Cellar/portaudio/19.20140130/lib/

Run the example

• To run the speech_rest.py sample:

  $ python speech_rest.py resources/audio.raw

  You should see a response with the transcription result.

• To run the speech_async_rest.py sample:

  $ python speech_async_rest.py resources/audio.raw

  You should see a response with the transcription result.

• To run the speech_streaming.py sample:

  $ python speech_streaming.py

  The sample will run in a continuous loop, printing the data and metadata it receives from the Speech API, which includes alternative transcriptions of what it hears, and a confidence score. Say "exit" to exit the loop.

  Note that the speech_streaming.py sample does not yet support python 3, as the upstream grpcio library's support is not yet complete.

Deactivate virtualenv

deactivate