Google

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Overview

GoogleTTSService provides high-quality text-to-speech synthesis using Google Cloud’s Text-to-Speech API. It supports SSML for advanced voice control and multiple languages.

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Installation

To use GoogleTTSService, install the required dependencies:

pip install pipecat-ai[google]

You’ll also need to set up Google Cloud credentials through either:

• Environment variable: GOOGLE_APPLICATION_CREDENTIALS
• Direct credentials JSON
• Credentials file path

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Configuration

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Constructor Parameters

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Input Parameters

class InputParams(BaseModel):
    pitch: Optional[str]
    rate: Optional[str]
    volume: Optional[str]
    emphasis: Optional[Literal["strong", "moderate", "reduced", "none"]]
    language: Optional[Language] = Language.EN
    gender: Optional[Literal["male", "female", "neutral"]]
    google_style: Optional[Literal["apologetic", "calm", "empathetic", "firm", "lively"]]

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Output Frames

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Control Frames

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Audio Frames

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Error Frames

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Usage Examples

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Basic Usage

# Configure service
tts_service = GoogleTTSService(
    credentials_path="path/to/credentials.json",
    voice_id="en-US-Neural2-A",
    params=GoogleTTSService.InputParams(
        language=Language.EN,
        gender="female",
        google_style="empathetic"
    )
)

# Use in pipeline
pipeline = Pipeline([
    text_input,
    tts_service,
    audio_output
])

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With SSML Controls

# Configure with voice controls
service = GoogleTTSService(
    credentials=credentials_json,
    params=GoogleTTSService.InputParams(
        pitch="+2st",
        rate="1.2",
        volume="loud",
        emphasis="moderate"
    )
)

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Methods

See the TTS base class methods for additional functionality.

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Language Support

Google Cloud Text-to-Speech supports the following languages and regional variants:

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Usage Example

# Configure service with specific language and region
service = GoogleTTSService(
    credentials_path="path/to/credentials.json",
    voice_id="en-US-Neural2-A",
    params=GoogleTTSService.InputParams(
        language=Language.EN_GB,  # British English
        gender="female"
    )
)

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Regional Considerations

• Each language code includes both language and region (e.g., fr-FR for French in France)
• Some languages have multiple regional variants (e.g., English has US, UK, Australian, and Indian variants)
• Voice availability may vary by region
• Neural voices may not be available for all language/region combinations

Note: Voice selection should match the specified language code for optimal results.

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Frame Flow

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Notes

• Supports SSML markup
• Multiple voice styles
• Gender selection
• Prosody control
• Emphasis levels
• Regional language variants
• Metrics collection
• Chunked audio output
• Thread-safe processing