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Audio Control

TTS Wrapper provides comprehensive audio playback control features, allowing you to manage speech synthesis playback in real-time.

Basic Playback Controls​

Starting Playback​

# Basic playback
tts.speak("Hello, world!")

# Playback with streaming
tts.speak_streamed("Hello, world!")

Pause and Resume​

# Start speaking
tts.speak("This is a long sentence that we will pause in the middle.")

# Pause after 1 second
time.sleep(1)
tts.pause()

# Resume after another second
time.sleep(1)
tts.resume()

Stop Playback​

# Stop playback immediately
tts.stop()

Audio Properties​

Volume Control​

# Set volume (0-100)
tts.set_property("volume", "75")

# Get current volume
current_volume = tts.get_property("volume")

Speech Rate​

# Set speech rate
tts.set_property("rate", "fast")  # x-slow, slow, medium, fast, x-fast
tts.set_property("rate", "150")   # Percentage (100 is normal)

Pitch Control​

# Set pitch
tts.set_property("pitch", "high")  # x-low, low, medium, high, x-high

Audio Device Selection​

# List available audio devices
import sounddevice as sd
devices = sd.query_devices()
print(devices)

# Set output device by ID
tts.set_output_device(device_id=1)

File Output​

Saving to File​

# Save as WAV file
tts.synth_to_file("Hello world", "output.wav")

# Save as MP3
tts.synth_to_file("Hello world", "output.mp3", "mp3")

Streaming with File Output​

# Stream audio and save to file simultaneously
tts.speak_streamed("Hello world", save_to_file_path="output.wav")

Advanced Audio Control​

Timed Playback​

# Play for specific duration
tts.play(duration=2.0)  # Play for 2 seconds

# Pause for specific duration
tts.pause(duration=1.0)  # Pause for 1 second

Audio Buffer Management​

# Load audio into buffer without playing
audio_bytes = tts.synth_to_bytes("Hello world")
tts.load_audio(audio_bytes)

# Play when ready
tts.play()

Stream Setup​

# Configure audio stream
tts.setup_stream(
    samplerate=44100,
    channels=1,
    dtype="int16"
)

Event Handling​

Playback Events​

def on_start():
    print("Audio started playing")

def on_end():
    print("Audio finished playing")

# Connect event handlers
tts.connect("onStart", on_start)
tts.connect("onEnd", on_end)

Cleanup​

# Clean up resources when done
tts.cleanup()

Best Practices​

  1. Resource Management

    • Always call cleanup() when done
    • Use context managers where possible
    • Release audio resources explicitly

  2. Error Handling

    try:
        tts.speak("Hello world")
    except Exception as e:
        print(f"Playback error: {e}")
    finally:
        tts.cleanup()

  3. Performance

    • Use streaming for long text
    • Pre-synthesize repeated phrases
    • Monitor memory usage with large audio files

  4. Device Compatibility

    • Check device availability before setting
    • Handle device errors gracefully
    • Test across different platforms

Example: Complete Audio Control​

Here's a comprehensive example combining various audio control features:

from tts_wrapper import PollyClient, PollyTTS
import time

# Initialize TTS
client = PollyClient(credentials=('region', 'key_id', 'access_key'))
tts = PollyTTS(client)

# Set up event handlers
def on_start():
    print("Started speaking")

def on_end():
    print("Finished speaking")

tts.connect("onStart", on_start)
tts.connect("onEnd", on_end)

try:
    # Configure audio properties
    tts.set_property("volume", "80")
    tts.set_property("rate", "medium")
    tts.set_property("pitch", "high")

    # Start speaking
    text = "This is a demonstration of audio control features."
    tts.speak_streamed(text)

    # Wait a moment
    time.sleep(1)

    # Pause playback
    tts.pause()
    print("Paused for 2 seconds...")
    time.sleep(2)

    # Resume playback
    tts.resume()
    print("Resumed playback")

    # Wait for completion
    while tts.isplaying:
        time.sleep(0.1)

except Exception as e:
    print(f"Error during playback: {e}")
finally:
    tts.cleanup()

Next Steps​