feat(audio): add PyAudio initialization check and error handling (#355)

This commit introduces proper initialization checks for PyAudio in both realtime transcription examples. It adds:

1. A new utility function `load_pyaudio()` to handle PyAudio initialization
2. Error handling for cases where PyAudio cannot be initialized
3. Early termination with error message when PyAudio is not available
4. Consistent error handling across both microphone examples

The changes ensure the applications fail gracefully when PyAudio is not available or cannot be initialized, providing better user feedback.

Author: jean-malo

examples/mistral/audio/async_realtime_transcription_dual_delay_microphone.py

@@ -35,6 +35,8 @@
     TranscriptionStreamTextDelta,
 )
 
+from pyaudio_utils import load_pyaudio
+
 console = Console()
 
 
@@ -188,7 +190,7 @@ async def iter_microphone(
     Yield microphone PCM chunks using PyAudio (16-bit mono).
     Encoding is always pcm_s16le.
     """
-    import pyaudio
+    pyaudio = load_pyaudio()
 
     p = pyaudio.PyAudio()
     chunk_samples = int(sample_rate * chunk_duration_ms / 1000)
@@ -373,6 +375,12 @@ async def main() -> int:
     args = parse_args()
     api_key = args.api_key or os.environ["MISTRAL_API_KEY"]
 
+    try:
+        load_pyaudio()
+    except RuntimeError as exc:
+        console.print(str(exc), style="red")
+        return 1
+
     state = DualTranscriptState()
     display = DualTranscriptDisplay(
         model=args.model,
@@ -431,6 +439,16 @@ async def main() -> int:
     try:
         while True:
             await asyncio.sleep(0.1)
+            for task in (broadcaster, fast_task, slow_task):
+                if not task.done():
+                    continue
+                exc = task.exception()
+                if exc:
+                    state.set_error(str(exc))
+                    if update_queue.empty():
+                        update_queue.put_nowait(None)
+                    stop_event.set()
+                    break
             if state.error:
                 stop_event.set()
                 break

examples/mistral/audio/async_realtime_transcription_microphone.py

@@ -33,6 +33,8 @@
     TranscriptionStreamTextDelta,
 )
 
+from pyaudio_utils import load_pyaudio
+
 console = Console()
 
 
@@ -131,7 +133,7 @@ async def iter_microphone(
     Yield microphone PCM chunks using PyAudio (16-bit mono).
     Encoding is always pcm_s16le.
     """
-    import pyaudio
+    pyaudio = load_pyaudio()
 
     p = pyaudio.PyAudio()
     chunk_samples = int(sample_rate * chunk_duration_ms / 1000)
@@ -189,6 +191,12 @@ async def main() -> int:
     args = parse_args()
     api_key = args.api_key or os.environ["MISTRAL_API_KEY"]
 
+    try:
+        load_pyaudio()
+    except RuntimeError as exc:
+        console.print(str(exc), style="red")
+        return 1
+
     client = Mistral(api_key=api_key, server_url=args.base_url)
 
     # microphone is always pcm_s16le here
@@ -231,6 +239,10 @@ async def main() -> int:
         except KeyboardInterrupt:
             display.status = "⏹️ Stopped"
             live.update(display.render())
+        except Exception as exc:
+            display.set_error(str(exc))
+            live.update(display.render())
+            return 1
 
     return 0