ship-controller/speech_to_text.py

"""
Speech-to-Text module for MIDI-to-Hue application.
Handles audio recording and cloud-based speech recognition.
"""
import os
import time
import threading
import requests
import io
import wave
import pyaudio
import numpy as np
from typing import Optional, Dict, Any, Callable


class SpeechToText:
    """Manages audio recording and speech-to-text processing."""
    
    def __init__(self, config: Dict[str, Any]):
        """
        Initialize the Speech-to-Text controller.
        
        Args:
            config: Configuration dictionary with STT settings
        """
        self.config = config
        self.recording = False
        self.stream = None
        self.frames = []
        self.p = None
        self.recording_thread = None
        self.callback = None
        
        # Audio settings from config or defaults
        self.format = pyaudio.paInt16
        self.channels = 1
        self.rate = 16000
        self.chunk = 4096
        self.device_index = config.get("audio_device_index", 1)
        self.language = config.get("language", "de")
        self.api_key = config.get("api_key", "")
        self.api_endpoint = config.get("api_endpoint", "https://api.openai.com/v1/audio/transcriptions")
        
    def initialize(self) -> bool:
        """Initialize PyAudio and check if the device is available."""
        try:
            self.p = pyaudio.PyAudio()
            device_count = self.p.get_device_count()
            
            if self.device_index >= device_count:
                print(f"Error: Audio device index {self.device_index} out of range.")
                print(f"Available devices: {device_count}")
                return False
                
            # Get device info to display
            device_info = self.p.get_device_info_by_index(self.device_index)
            print(f"Using audio device: {device_info['name']}")
            return True
            
        except Exception as e:
            print(f"Error initializing audio: {e}")
            return False
            
    def set_callback(self, callback: Callable[[str], None]) -> None:
        """Set callback function to receive transcription results."""
        self.callback = callback

    def start_recording(self) -> bool:
        """Start recording audio when MIDI button is pressed."""
        if self.recording:
            return False  # Already recording
            
        try:
            print("Starting audio recording...")
            self.recording = True
            self.frames = []
            
            # Open audio stream
            self.stream = self.p.open(
                format=self.format,
                channels=self.channels,
                rate=self.rate,
                input=True,
                input_device_index=self.device_index,
                frames_per_buffer=self.chunk
            )
            
            # Start recording thread
            self.recording_thread = threading.Thread(target=self._record_audio)
            self.recording_thread.daemon = True
            self.recording_thread.start()
            
            return True
            
        except Exception as e:
            print(f"Error starting recording: {e}")
            self.recording = False
            return False

    def _record_audio(self) -> None:
        """Record audio in a separate thread while recording flag is True."""
        try:
            while self.recording:
                data = self.stream.read(self.chunk, exception_on_overflow=False)
                self.frames.append(data)
                
        except Exception as e:
            print(f"Error during recording: {e}")
            self.recording = False
            
    def stop_recording(self) -> None:
        """Stop recording and process the audio."""
        if not self.recording:
            return  # Not recording
            
        print("Stopping recording and processing audio...")
        self.recording = False
        
        # Wait for recording thread to finish
        if self.recording_thread:
            self.recording_thread.join(timeout=1.0)
            
        # Close the stream
        if self.stream:
            self.stream.stop_stream()
            self.stream.close()
            self.stream = None
            
        # Process the recorded audio
        if self.frames:
            threading.Thread(target=self._process_audio).start()

    def _process_audio(self) -> None:
        """Process recorded audio and send to the cloud STT service."""
        try:
            if not self.frames:
                print("No audio frames recorded.")
                return
                
            # Prepare WAV file in memory
            wav_buffer = io.BytesIO()
            with wave.open(wav_buffer, 'wb') as wf:
                wf.setnchannels(self.channels)
                wf.setsampwidth(self.p.get_sample_size(self.format))
                wf.setframerate(self.rate)
                wf.writeframes(b''.join(self.frames))
                
            # Reset buffer position
            wav_buffer.seek(0)
            
            # Check if we have API key
            if not self.api_key:
                print("Error: No API key provided for STT service.")
                return
                
            # Send to API
            headers = {"Authorization": f"Bearer {self.api_key}"}
            
            files = {
                "file": ("audio.wav", wav_buffer, "audio/wav")
            }
            
            data = {
                "model": "whisper-1",
                "language": self.language
            }
            
            print("Sending audio to STT service...")
            response = requests.post(
                self.api_endpoint,
                headers=headers,
                files=files,
                data=data
            )
            
            if response.status_code == 200:
                result = response.json()
                text = result.get("text", "")
                
                print(f"Recognized: {text}")
                
                # Call callback with result if provided
                if self.callback and text:
                    self.callback(text)
            else:
                print(f"Error: {response.status_code}, {response.text}")
                
        except Exception as e:
            print(f"Error processing audio: {e}")
            
    def cleanup(self) -> None:
        """Clean up resources."""
        if self.recording:
            self.recording = False
            
        if self.stream:
            self.stream.stop_stream()
            self.stream.close()
            
        if self.p:
            self.p.terminate()