# Orca Streaming Text-to-Speech Demos

Made in Vancouver, Canada by [Picovoice](https://picovoice.ai)

## Orca

Orca is an on-device streaming text-to-speech engine that is designed for use with LLMs, enabling zero-latency
voice assistants. Orca is:

- Private; All speech synthesis runs locally.
- Cross-Platform:
    - Linux (x86_64), macOS (x86_64, arm64), Windows (x86_64, arm64)
    - Android and iOS
    - Chrome, Safari, Firefox, and Edge
    - Raspberry Pi (3, 4, 5)

## Compatibility

- Node.js 18+
- Runs on Linux (x86_64), macOS (x86_64, arm64), Windows (x86_64, arm64), and Raspberry Pi (3, 4, 5).

## Installation

```console
npm install -g @picovoice/orca-node-demo
```

## AccessKey

Orca requires a valid Picovoice `AccessKey` at initialization. `AccessKey` acts as your credentials when using Orca
SDKs. You can get your `AccessKey` for free. Make sure to keep your `AccessKey` secret.
Signup or Login to [Picovoice Console](https://console.picovoice.ai/) to get your `AccessKey`.

## Usage

Orca supports two modes of operation: streaming and single synthesis.

In the streaming synthesis mode, Orca processes an incoming text stream in real-time and generates audio in parallel.
This is demonstrated in the Orca streaming demo.

In the single synthesis mode, the text is synthesized in a single call to the Orca engine.

### Streaming synthesis demo

In this demo, we simulate a response from a language model by creating a text stream from a user-defined text.
We stream that text to Orca and play the synthesized audio as soon as it gets generated.

[@picovoice/pvspeaker-node](https://www.npmjs.com/package/@picovoice/pvspeaker-node) is used to play pcm audio generated
by Orca to your device's speakers.

Execute the following:

```console
orca-streaming-demo --access_key ${ACCESS_KEY} --model_file_path ${MODEL_FILE_PATH} --text_to_stream ${TEXT}
```

Replace `${ACCESS_KEY}` with your `AccessKey` obtained from Picovoice Console, `${MODEL_FILE_PATH}` with a path to any of the model files available under [lib/common](https://github.com/Picovoice/orca/tree/main/lib/common), and `${TEXT}` with your text to be streamed to Orca.

### Single synthesis demo

To synthesize speech in a single call to Orca and without audio playback, run the following:

```console
orca-file-demo --access_key ${ACCESS_KEY} --model_file_path ${MODEL_FILE_PATH} --text ${TEXT} --output_path ${WAV_OUTPUT_PATH}
```

Replace `${ACCESS_KEY}` with yours obtained from Picovoice Console, `${MODEL_FILE_PATH}` with a path to any of the model files available under [lib/common](https://github.com/Picovoice/orca/tree/main/lib/common), `${TEXT}` with your text to be synthesized, and `${WAV_OUTPUT_PATH}` with a path to a `.wav` file where the generated audio will be stored as a single-channel, 16-bit PCM `.wav` file.