Translate Streaming STT Transcripts with LLM Gateway

1
import pyaudio
2
import websocket
3
import json
4
import threading
5
import time
6
import requests
7
from urllib.parse import urlencode
8
from datetime import datetime
9
10
# --- Configuration ---
11
YOUR_API_KEY = "YOUR_API_KEY"  # Replace with your actual API key
12
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CONNECTION_PARAMS = {
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    "sample_rate": 16000,
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    "format_turns": True,  # Request formatted final transcripts
16
}
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API_ENDPOINT_BASE_URL = "wss://streaming.assemblyai.com/v3/ws"
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API_ENDPOINT = f"{API_ENDPOINT_BASE_URL}?{urlencode(CONNECTION_PARAMS)}"
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# Audio Configuration
21
FRAMES_PER_BUFFER = 800  # 50ms of audio (0.05s * 16000Hz)
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SAMPLE_RATE = CONNECTION_PARAMS["sample_rate"]
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CHANNELS = 1
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FORMAT = pyaudio.paInt16
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# Global variables for audio stream and websocket
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audio = None
28
stream = None
29
ws_app = None
30
audio_thread = None
31
stop_event = threading.Event()  # To signal the audio thread to stop
32
33
# WAV recording variables
34
recorded_frames = []  # Store audio frames for WAV file
35
recording_lock = threading.Lock()  # Thread-safe access to recorded_frames
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# --- Function to Translate Text with LLM Gateway ---
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def translate_text(text):
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    """Called when translating final transcripts."""
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    headers = {
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        "authorization": YOUR_API_KEY
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    }
44
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    llm_gateway_data = {
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        "model": "gemini-2.5-flash-lite",
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        "prompt": f"Translate the following text into Spanish. Do not write a preamble. Just return the translated text.\n\nText: {text}",
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        "max_tokens": 1000
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    }
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    result = requests.post(
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        "https://llm-gateway.assemblyai.com/v1/chat/completions",
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        headers=headers,
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        json=llm_gateway_data
55
    )
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    return result.json()["choices"][0]["message"]["content"]
57
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# --- WebSocket Event Handlers ---
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def on_open(ws):
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    """Called when the WebSocket connection is established."""
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    print("WebSocket connection opened.")
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    print(f"Connected to: {API_ENDPOINT}")
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    # Start sending audio data in a separate thread
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    def stream_audio():
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        global stream
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        print("Starting audio streaming...")
69
        while not stop_event.is_set():
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            try:
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                audio_data = stream.read(FRAMES_PER_BUFFER, exception_on_overflow=False)
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                # Store audio data for WAV recording
74
                with recording_lock:
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                    recorded_frames.append(audio_data)
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                # Send audio data as binary message
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                ws.send(audio_data, websocket.ABNF.OPCODE_BINARY)
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            except Exception as e:
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                print(f"Error streaming audio: {e}")
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                # If stream read fails, likely means it's closed, stop the loop
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                break
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        print("Audio streaming stopped.")
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    global audio_thread
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    audio_thread = threading.Thread(target=stream_audio)
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    audio_thread.daemon = (
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        True  # Allow main thread to exit even if this thread is running
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    )
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    audio_thread.start()
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def on_message(ws, message):
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    try:
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        data = json.loads(message)
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        msg_type = data.get('type')
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        if msg_type == "Begin":
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            session_id = data.get('id')
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            expires_at = data.get('expires_at')
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            print(f"\nSession began: ID={session_id}, ExpiresAt={datetime.fromtimestamp(expires_at)}")
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        elif msg_type == "Turn":
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            transcript = data.get('transcript', '')
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            if data.get('end_of_turn'):
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                print('\r' + ' ' * 80 + '\r', end='')
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                print(translate_text(transcript))
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        elif msg_type == "Termination":
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            audio_duration = data.get('audio_duration_seconds', 0)
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            session_duration = data.get('session_duration_seconds', 0)
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            print(f"\nSession Terminated: Audio Duration={audio_duration}s, Session Duration={session_duration}s")
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    except json.JSONDecodeError as e:
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        print(f"Error decoding message: {e}")
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    except Exception as e:
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        print(f"Error handling message: {e}")
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def on_error(ws, error):
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    """Called when a WebSocket error occurs."""
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    print(f"\nWebSocket Error: {error}")
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    # Attempt to signal stop on error
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    stop_event.set()
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def on_close(ws, close_status_code, close_msg):
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    """Called when the WebSocket connection is closed."""
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    print(f"\nWebSocket Disconnected: Status={close_status_code}, Msg={close_msg}")
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    # Ensure audio resources are released
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    global stream, audio
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    stop_event.set()  # Signal audio thread just in case it's still running
130
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    if stream:
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        if stream.is_active():
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            stream.stop_stream()
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        stream.close()
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        stream = None
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    if audio:
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        audio.terminate()
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        audio = None
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    # Try to join the audio thread to ensure clean exit
140
    if audio_thread and audio_thread.is_alive():
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        audio_thread.join(timeout=1.0)
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# --- Main Execution ---
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def run():
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    global audio, stream, ws_app
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    # Initialize PyAudio
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    audio = pyaudio.PyAudio()
150
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    # Open microphone stream
152
    try:
153
        stream = audio.open(
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            input=True,
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            frames_per_buffer=FRAMES_PER_BUFFER,
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            channels=CHANNELS,
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            format=FORMAT,
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            rate=SAMPLE_RATE,
159
        )
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        print("Microphone stream opened successfully.")
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        print("Speak into your microphone. Press Ctrl+C to stop.")
162
        print("Audio will be saved to a WAV file when the session ends.")
163
    except Exception as e:
164
        print(f"Error opening microphone stream: {e}")
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        if audio:
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            audio.terminate()
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        return  # Exit if microphone cannot be opened
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    # Create WebSocketApp
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    ws_app = websocket.WebSocketApp(
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        API_ENDPOINT,
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        header={"Authorization": YOUR_API_KEY},
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        on_open=on_open,
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        on_message=on_message,
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        on_error=on_error,
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        on_close=on_close,
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    )
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    # Run WebSocketApp in a separate thread to allow main thread to catch KeyboardInterrupt
180
    ws_thread = threading.Thread(target=ws_app.run_forever)
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    ws_thread.daemon = True
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    ws_thread.start()
183
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    try:
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        # Keep main thread alive until interrupted
186
        while ws_thread.is_alive():
187
            time.sleep(0.1)
188
    except KeyboardInterrupt:
189
        print("\nCtrl+C received. Stopping...")
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        stop_event.set()  # Signal audio thread to stop
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        # Send termination message to the server
193
        if ws_app and ws_app.sock and ws_app.sock.connected:
194
            try:
195
                terminate_message = {"type": "Terminate"}
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                print(f"Sending termination message: {json.dumps(terminate_message)}")
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                ws_app.send(json.dumps(terminate_message))
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                # Give a moment for messages to process before forceful close
199
                time.sleep(5)
200
            except Exception as e:
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                print(f"Error sending termination message: {e}")
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        # Close the WebSocket connection (will trigger on_close)
204
        if ws_app:
205
            ws_app.close()
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        # Wait for WebSocket thread to finish
208
        ws_thread.join(timeout=2.0)
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210
    except Exception as e:
211
        print(f"\nAn unexpected error occurred: {e}")
212
        stop_event.set()
213
        if ws_app:
214
            ws_app.close()
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        ws_thread.join(timeout=2.0)
216
217
    finally:
218
        # Final cleanup (already handled in on_close, but good as a fallback)
219
        if stream and stream.is_active():
220
            stream.stop_stream()
221
        if stream:
222
            stream.close()
223
        if audio:
224
            audio.terminate()
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        print("Cleanup complete. Exiting.")
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if __name__ == "__main__":
228
    run()

1
import pyaudio
2
import websocket
3
import json
4
import threading
5
import time
6
import requests
7
from urllib.parse import urlencode
8
from datetime import datetime
9
10
YOUR_API_KEY = "YOUR_API_KEY"  # Replace with your actual API key

1
CONNECTION_PARAMS = {
2
    "sample_rate": 16000,
3
    "format_turns": True,  # Request formatted final transcripts
4
}
5
API_ENDPOINT_BASE_URL = "wss://streaming.assemblyai.com/v3/ws"
6
API_ENDPOINT = f"{API_ENDPOINT_BASE_URL}?{urlencode(CONNECTION_PARAMS)}"
7
8
# Audio Configuration
9
FRAMES_PER_BUFFER = 800  # 50ms of audio (0.05s * 16000Hz)
10
SAMPLE_RATE = CONNECTION_PARAMS["sample_rate"]
11
CHANNELS = 1
12
FORMAT = pyaudio.paInt16
13
14
# Global variables for audio stream and websocket
15
audio = None
16
stream = None
17
ws_app = None
18
audio_thread = None
19
stop_event = threading.Event()  # To signal the audio thread to stop
20
21
# WAV recording variables
22
recorded_frames = []  # Store audio frames for WAV file
23
recording_lock = threading.Lock()  # Thread-safe access to recorded_frames

1
def translate_text(text):
2
    """Called when translating final transcripts."""
3
    headers = {
4
        "authorization": YOUR_API_KEY
5
    }
6
7
    llm_gateway_data = {
8
        "model": "claude-sonnet-4-20250514",
9
        "prompt": f"Translate the following text into Spanish. Do not write a preamble. Just return the translated text.\n\nText: {text}",
10
        "max_tokens": 1000
11
    }
12
13
    result = requests.post(
14
        "https://llm-gateway.assemblyai.com/v1/chat/completions",
15
        headers=headers,
16
        json=llm_gateway_data
17
    )
18
    return result.json()["choices"][0]["message"]["content"]

1
def on_open(ws):
2
    """Called when the WebSocket connection is established."""
3
    print("WebSocket connection opened.")
4
    print(f"Connected to: {API_ENDPOINT}")
5
6
    # Start sending audio data in a separate thread
7
    def stream_audio():
8
        global stream
9
        print("Starting audio streaming...")
10
        while not stop_event.is_set():
11
            try:
12
                audio_data = stream.read(FRAMES_PER_BUFFER, exception_on_overflow=False)
13
14
                # Store audio data for WAV recording
15
                with recording_lock:
16
                    recorded_frames.append(audio_data)
17
18
                # Send audio data as binary message
19
                ws.send(audio_data, websocket.ABNF.OPCODE_BINARY)
20
            except Exception as e:
21
                print(f"Error streaming audio: {e}")
22
                # If stream read fails, likely means it's closed, stop the loop
23
                break
24
        print("Audio streaming stopped.")
25
26
    global audio_thread
27
    audio_thread = threading.Thread(target=stream_audio)
28
    audio_thread.daemon = (
29
        True  # Allow main thread to exit even if this thread is running
30
    )
31
    audio_thread.start()

1
def on_message(ws, message):
2
    try:
3
        data = json.loads(message)
4
        msg_type = data.get('type')
5
6
        if msg_type == "Begin":
7
            session_id = data.get('id')
8
            expires_at = data.get('expires_at')
9
            print(f"\nSession began: ID={session_id}, ExpiresAt={datetime.fromtimestamp(expires_at)}")
10
        elif msg_type == "Turn":
11
            transcript = data.get('transcript', '')
12
            if data.get('end_of_turn'):
13
                print('\r' + ' ' * 80 + '\r', end='')
14
                print(translate_text(transcript))
15
16
        elif msg_type == "Termination":
17
            audio_duration = data.get('audio_duration_seconds', 0)
18
            session_duration = data.get('session_duration_seconds', 0)
19
            print(f"\nSession Terminated: Audio Duration={audio_duration}s, Session Duration={session_duration}s")
20
21
    except json.JSONDecodeError as e:
22
        print(f"Error decoding message: {e}")
23
    except Exception as e:
24
        print(f"Error handling message: {e}")

1
def on_close(ws, close_status_code, close_msg):
2
    """Called when the WebSocket connection is closed."""
3
    print(f"\nWebSocket Disconnected: Status={close_status_code}, Msg={close_msg}")
4
5
    # Ensure audio resources are released
6
    global stream, audio
7
    stop_event.set()  # Signal audio thread just in case it's still running
8
9
    if stream:
10
        if stream.is_active():
11
            stream.stop_stream()
12
        stream.close()
13
        stream = None
14
    if audio:
15
        audio.terminate()
16
        audio = None
17
    # Try to join the audio thread to ensure clean exit
18
    if audio_thread and audio_thread.is_alive():
19
        audio_thread.join(timeout=1.0)

1
def on_error(ws, error):
2
    """Called when a WebSocket error occurs."""
3
    print(f"\nWebSocket Error: {error}")
4
    # Attempt to signal stop on error
5
    stop_event.set()

1
def run():
2
    global audio, stream, ws_app
3
4
    # Initialize PyAudio
5
    audio = pyaudio.PyAudio()
6
7
    # Open microphone stream
8
    try:
9
        stream = audio.open(
10
            input=True,
11
            frames_per_buffer=FRAMES_PER_BUFFER,
12
            channels=CHANNELS,
13
            format=FORMAT,
14
            rate=SAMPLE_RATE,
15
        )
16
        print("Microphone stream opened successfully.")
17
        print("Speak into your microphone. Press Ctrl+C to stop.")
18
        print("Audio will be saved to a WAV file when the session ends.")
19
    except Exception as e:
20
        print(f"Error opening microphone stream: {e}")
21
        if audio:
22
            audio.terminate()
23
        return  # Exit if microphone cannot be opened
24
25
    # Create WebSocketApp
26
    ws_app = websocket.WebSocketApp(
27
        API_ENDPOINT,
28
        header={"Authorization": YOUR_API_KEY},
29
        on_open=on_open,
30
        on_message=on_message,
31
        on_error=on_error,
32
        on_close=on_close,
33
    )
34
35
    # Run WebSocketApp in a separate thread to allow main thread to catch KeyboardInterrupt
36
    ws_thread = threading.Thread(target=ws_app.run_forever)
37
    ws_thread.daemon = True
38
    ws_thread.start()
39
40
    try:
41
        # Keep main thread alive until interrupted
42
        while ws_thread.is_alive():
43
            time.sleep(0.1)
44
    except KeyboardInterrupt:
45
        print("\nCtrl+C received. Stopping...")
46
        stop_event.set()  # Signal audio thread to stop
47
48
        # Send termination message to the server
49
        if ws_app and ws_app.sock and ws_app.sock.connected:
50
            try:
51
                terminate_message = {"type": "Terminate"}
52
                print(f"Sending termination message: {json.dumps(terminate_message)}")
53
                ws_app.send(json.dumps(terminate_message))
54
                # Give a moment for messages to process before forceful close
55
                time.sleep(5)
56
            except Exception as e:
57
                print(f"Error sending termination message: {e}")
58
59
        # Close the WebSocket connection (will trigger on_close)
60
        if ws_app:
61
            ws_app.close()
62
63
        # Wait for WebSocket thread to finish
64
        ws_thread.join(timeout=2.0)
65
66
    except Exception as e:
67
        print(f"\nAn unexpected error occurred: {e}")
68
        stop_event.set()
69
        if ws_app:
70
            ws_app.close()
71
        ws_thread.join(timeout=2.0)
72
73
    finally:
74
        # Final cleanup (already handled in on_close, but good as a fallback)
75
        if stream and stream.is_active():
76
            stream.stop_stream()
77
        if stream:
78
            stream.close()
79
        if audio:
80
            audio.terminate()
81
        print("Cleanup complete. Exiting.")
82
83
if __name__ == "__main__":
84
    run()