Google Cloud TTS Service uses the non-free Google Cloud Text-to-Speech API to convert text or Speech Synthesis Markup Language (SSML) input into audio data of natural human speech.
It provides multiple voices, available in different languages and variants and applies DeepMind’s groundbreaking research in WaveNet and Google’s powerful neural networks.
The Google Cloud TTS service uses the openHAB TTS cache to cache audio files produced from the most recent queries in order to reduce traffic, improve performance and reduce number of requests.
1. Select or create a Google Cloud project ([link](https://console.cloud.google.com/cloud-resource-manager))
2. Make sure that billing is enabled for your project ([link](https://cloud.google.com/billing/docs/how-to/modify-project))
3. Enable the `Text-to-Speech API` ([link](https://console.cloud.google.com/apis/dashboard))
* Don't mistake with the `Speech-to-Text API`
4. Set up authentication:
1. Go to the `APIs & Services` -> `Credentials` page in the GCP Console and your project ([link](https://console.cloud.google.com/apis/credentials))
2. From the `Create credentials` drop-down list, select `OAuth client ID`.
3. Select application type `Web application` and enter a name into the `Name` (e.g. `OpenHAB TTS`) field.
4. Add `https://www.google.com` to the `Authorized redirect URIs`.
* Watch out for trailing spaces in the URL! E.g. when using the copy url feature in the context menu of Google Chrome it appends a slash (`https://www.google.com` becomes `https://www.google.com`) and the steps afterwards fail.
5. Click Create. A pop-up appears, showing your "client ID" and "client secret".
1. Go to `OAuth consent screen` ([link](https://console.cloud.google.com/apis/credentials/consent)) and set the `publishing status` to `production` to activate the created project.
2. Wait a few minutes. The step before takes some time to go live. Sometimes it is necessary to wait a few hours, so you can try after some minutes, if it doesn't work, try again the next day.
3. Go to your browser and access the following URL to generate an authorization code
[https://accounts.google.com/o/oauth2/v2/auth?scope=https://www.googleapis.com/auth/cloud-platform&access_type=offline&prompt=consent&include_granted_scopes=true&response_type=code&redirect_uri=https://www.google.com&client_id=<clientId>](https://accounts.google.com/o/oauth2/v2/auth?scope=https://www.googleapis.com/auth/cloud-platform&access_type=offline&prompt=consent&include_granted_scopes=true&response_type=code&redirect_uri=https://www.google.com&client_id=CLIENTID) (replace `CLIENTID` at the end by your Client Id)
4. After your browser has been redirected to https://www.google.com, the authorization code will be set in the browser URL as value of the "code" URL query parameter (e.g. `https://www.google.com/?code=XXXXXXXXXX&scope=https://www.googleapis.com/auth/cloud-platform` --> `XXXXXXXXXX`)
5. After initial authorization, this code is not needed anymore. It is recommended to clear this configuration parameter afterwards.
In case you would like to setup these settings via a text file, you can edit the file `runtime.cfg` in `$OPENHAB_ROOT/conf/services` and set the following entries:
