示例#1
0
class RhasspySilenceTestCase(unittest.TestCase):
    """Tests for rhasspysilence."""
    def __init__(self, *args):
        super().__init__(*args)

        self.recorder = None
        self.chunk_size = 2048

    def setUp(self):
        self.recorder = WebRtcVadRecorder()
        self.recorder.start()

    def test_command(self):
        """Verify voice command sample WAV file."""
        command = None

        # Check test WAV file
        with wave.open("etc/turn_on_living_room_lamp.wav", "r") as wav_file:
            audio_data = wav_file.readframes(wav_file.getnframes())
            while audio_data:
                chunk = audio_data[:self.chunk_size]
                audio_data = audio_data[self.chunk_size:]

                command = self.recorder.process_chunk(chunk)
                if command:
                    break

            self.assertTrue(command)
            self.assertEqual(command.result, VoiceCommandResult.SUCCESS)
            self.assertGreater(len(command.audio_data), 0)

    def test_noise(self):
        """Verify no command in noise WAV file."""
        command = None

        # Check test WAV file
        with wave.open("etc/noise.wav", "r") as wav_file:
            audio_data = wav_file.readframes(wav_file.getnframes())
            while audio_data:
                chunk = audio_data[:self.chunk_size]
                audio_data = audio_data[self.chunk_size:]

                command = self.recorder.process_chunk(chunk)
                if command:
                    break

            self.assertFalse(command)
示例#2
0
def record_templates(
    record_dir: Path,
    name_format: str,
    recorder: WebRtcVadRecorder,
    args: argparse.Namespace,
):
    """Record audio templates."""
    print("Reading 16-bit 16Khz mono audio from stdin...", file=sys.stderr)

    num_templates = 0

    try:
        print(
            f"Recording template {num_templates}. Please speak your wake word. Press CTRL+C to exit."
        )
        recorder.start()

        while True:
            # Read raw audio chunk
            chunk = sys.stdin.buffer.read(recorder.chunk_size)
            if not chunk:
                # Empty chunk
                break

            result = recorder.process_chunk(chunk)
            if result:
                audio_bytes = recorder.stop()
                audio_bytes = trim_silence(audio_bytes)

                template_path = record_dir / name_format.format(
                    n=num_templates)
                template_path.parent.mkdir(parents=True, exist_ok=True)

                wav_bytes = buffer_to_wav(audio_bytes)
                template_path.write_bytes(wav_bytes)
                _LOGGER.debug("Wrote %s byte(s) of WAV audio to %s",
                              len(wav_bytes), template_path)

                num_templates += 1
                print(
                    f"Recording template {num_templates}. Please speak your wake word. Press CTRL+C to exit."
                )
                recorder.start()
    except KeyboardInterrupt:
        print("Done")
def test_noise():
    """Verify no command in noise WAV file."""
    command = None
    recorder = WebRtcVadRecorder()
    recorder.start()

    # Check test WAV file
    with wave.open("etc/noise.wav", "r") as wav_file:
        audio_data = wav_file.readframes(wav_file.getnframes())
        while audio_data:
            chunk = audio_data[:CHUNK_SIZE]
            audio_data = audio_data[CHUNK_SIZE:]

            command = recorder.process_chunk(chunk)
            if command:
                break

        assert not command
def test_command():
    """Verify voice command sample WAV file."""
    command = None
    recorder = WebRtcVadRecorder()
    recorder.start()

    # Check test WAV file
    with wave.open("etc/turn_on_living_room_lamp.wav", "r") as wav_file:
        audio_data = wav_file.readframes(wav_file.getnframes())
        while audio_data:
            chunk = audio_data[:CHUNK_SIZE]
            audio_data = audio_data[CHUNK_SIZE:]

            command = recorder.process_chunk(chunk)
            if command:
                break

        assert command
        assert command.result == VoiceCommandResult.SUCCESS
        assert command.audio_data
class WakeHermesMqtt(HermesClient):
    """Hermes MQTT server for Rhasspy wakeword with Raven."""
    def __init__(
        self,
        client,
        ravens: typing.List[Raven],
        examples_dir: typing.Optional[Path] = None,
        examples_format: str = "{keyword}/examples/%Y%m%d-%H%M%S.wav",
        wakeword_id: str = "",
        site_ids: typing.Optional[typing.List[str]] = None,
        enabled: bool = True,
        sample_rate: int = 16000,
        sample_width: int = 2,
        channels: int = 1,
        chunk_size: int = 1920,
        udp_audio: typing.Optional[typing.List[typing.Tuple[str, int,
                                                            str]]] = None,
        udp_chunk_size: int = 2048,
        log_predictions: bool = False,
        lang: typing.Optional[str] = None,
    ):
        super().__init__(
            "rhasspywake_raven_hermes",
            client,
            sample_rate=sample_rate,
            sample_width=sample_width,
            channels=channels,
            site_ids=site_ids,
        )

        self.subscribe(
            AudioFrame,
            HotwordToggleOn,
            HotwordToggleOff,
            GetHotwords,
            RecordHotwordExample,
        )

        self.ravens = ravens
        self.wakeword_id = wakeword_id

        self.examples_dir = examples_dir
        self.examples_format = examples_format

        self.enabled = enabled
        self.disabled_reasons: typing.Set[str] = set()

        # Required audio format
        self.sample_rate = sample_rate
        self.sample_width = sample_width
        self.channels = channels

        self.chunk_size = chunk_size

        # Queue of WAV audio chunks to process (plus site_id)
        self.wav_queue: queue.Queue = queue.Queue()

        self.first_audio: bool = True

        self.last_audio_site_id: str = "default"

        self.lang = lang

        # Fields for recording examples
        self.recording_example = False
        self.example_recorder = WebRtcVadRecorder(max_seconds=10)
        self.example_future: typing.Optional[asyncio.Future] = None

        # Raw audio chunk queues for Raven threads
        self.chunk_queues: typing.List[queue.Queue] = [
            queue.Queue() for raven in ravens
        ]

        # Start main thread to convert audio from MQTT/UDP
        self.audio_thread = threading.Thread(target=self.audio_thread_proc,
                                             daemon=True)
        self.audio_thread.start()

        # Start a thread per Raven instance (per-keyword)
        self.detection_threads = [
            threading.Thread(
                target=self.detection_thread_proc,
                args=(self.chunk_queues[i], self.ravens[i]),
                daemon=True,
            ) for i in range(len(self.ravens))
        ]

        for thread in self.detection_threads:
            thread.start()

        # Listen for raw audio on UDP too
        self.udp_chunk_size = udp_chunk_size

        if udp_audio:
            for udp_host, udp_port, udp_site_id in udp_audio:
                threading.Thread(
                    target=self.udp_thread_proc,
                    args=(udp_host, udp_port, udp_site_id),
                    daemon=True,
                ).start()

    # -------------------------------------------------------------------------

    async def handle_audio_frame(self,
                                 wav_bytes: bytes,
                                 site_id: str = "default") -> None:
        """Process a single audio frame"""
        self.wav_queue.put((wav_bytes, site_id))

    async def handle_detection(
        self, matching_indexes: typing.List[int], raven: Raven
    ) -> typing.AsyncIterable[typing.Union[typing.Tuple[
            HotwordDetected, TopicArgs], HotwordError]]:
        """Handle a successful hotword detection"""
        try:
            template = raven.templates[matching_indexes[0]]

            wakeword_id = raven.keyword_name or template.name
            if not wakeword_id:
                wakeword_id = "default"

            yield (
                HotwordDetected(
                    site_id=self.last_audio_site_id,
                    model_id=template.name,
                    current_sensitivity=raven.probability_threshold,
                    model_version="",
                    model_type="personal",
                    lang=self.lang,
                ),
                {
                    "wakeword_id": wakeword_id
                },
            )
        except Exception as e:
            _LOGGER.exception("handle_detection")
            yield HotwordError(
                error=str(e),
                context=f"{raven.keyword_name}: {template.name}",
                site_id=self.last_audio_site_id,
            )

    async def handle_get_hotwords(
        self, get_hotwords: GetHotwords
    ) -> typing.AsyncIterable[typing.Union[Hotwords, HotwordError]]:
        """Report available hotwords"""
        try:
            models: typing.List[Hotword] = []

            # Each keyword is in a separate Raven instance
            for raven in self.ravens:
                # Assume that the directory name is something like
                # "okay-rhasspy" for the keyword "okay rhasspy".
                models.append(
                    Hotword(
                        model_id=raven.keyword_name,
                        model_words=re.sub(r"[_-]+", " ", raven.keyword_name),
                    ))

            yield Hotwords(models=models,
                           id=get_hotwords.id,
                           site_id=get_hotwords.site_id)

        except Exception as e:
            _LOGGER.exception("handle_get_hotwords")
            yield HotwordError(error=str(e),
                               context=str(get_hotwords),
                               site_id=get_hotwords.site_id)

    async def handle_record_example(
        self, record_example: RecordHotwordExample
    ) -> typing.AsyncIterable[typing.Union[typing.Tuple[
            HotwordExampleRecorded, TopicArgs], HotwordError]]:
        """Record an example of a hotword."""
        try:
            if self.recording_example:
                _LOGGER.warning("Cancelling previous recording")
                self.example_recorder.stop()

            # Start recording
            assert self.loop, "No loop"
            self.example_future = self.loop.create_future()
            self.example_recorder.start()
            self.recording_example = True

            # Wait for result
            _LOGGER.debug("Recording example (id=%s)", record_example.id)
            example_audio = await self.example_future
            assert isinstance(example_audio, bytes)

            # Trim silence
            _LOGGER.debug("Trimming silence from example")
            example_audio = trim_silence(example_audio)

            # Convert to WAV format
            wav_data = self.to_wav_bytes(example_audio)

            yield (
                HotwordExampleRecorded(wav_bytes=wav_data),
                {
                    "site_id": record_example.site_id,
                    "request_id": record_example.id
                },
            )

        except Exception as e:
            _LOGGER.exception("handle_record_example")
            yield HotwordError(
                error=str(e),
                context=str(record_example),
                site_id=record_example.site_id,
            )

    def add_example_audio(self, audio_data: bytes):
        """Add an audio frame to the currently recording example."""
        result = self.example_recorder.process_chunk(audio_data)
        if result:
            self.recording_example = False
            assert self.example_future is not None, "No future"
            example_audio = self.example_recorder.stop()
            _LOGGER.debug("Recorded %s byte(s) for audio for example",
                          len(example_audio))

            # Signal waiting coroutine with audio
            assert self.loop, "No loop"
            self.loop.call_soon_threadsafe(self.example_future.set_result,
                                           example_audio)

    # -------------------------------------------------------------------------

    def audio_thread_proc(self):
        """Handle WAV audio chunks."""
        try:
            while True:
                wav_bytes, site_id = self.wav_queue.get()
                if wav_bytes is None:
                    # Shutdown signal
                    for chunk_queue in self.chunk_queues:
                        chunk_queue.put(None)

                    # Wait for detection threads to exit
                    for thread in self.detection_threads:
                        thread.join()

                    break

                self.last_audio_site_id = site_id

                # Handle audio frames
                if self.first_audio:
                    _LOGGER.debug("Receiving audio")
                    self.first_audio = False

                # Extract/convert audio data
                audio_data = self.maybe_convert_wav(wav_bytes)

                if self.recording_example:
                    # Add to currently recording example
                    self.add_example_audio(audio_data)

                    # Don't process audio for wake word while recording
                    continue

                # Add to queues for detection threads
                for chunk_queue in self.chunk_queues:
                    chunk_queue.put(audio_data)
        except Exception:
            _LOGGER.exception("audio_thread_proc")

    def detection_thread_proc(self, chunk_queue: queue.Queue, raven: Raven):
        """Run Raven detection on audio chunks."""
        try:
            _LOGGER.debug(
                "Listening for keyword %s (probability_threshold=%s, minimum_matches=%s, num_templates=%s)",
                raven.keyword_name,
                raven.probability_threshold,
                raven.minimum_matches,
                len(raven.templates),
            )

            while True:
                audio_data = chunk_queue.get()
                if audio_data is None:
                    # Shutdown signal
                    break

                if audio_data:
                    try:
                        keep_audio = bool(self.examples_dir)
                        matching_indexes = raven.process_chunk(
                            audio_data, keep_audio=keep_audio)
                        if len(matching_indexes) >= raven.minimum_matches:
                            # Report detection
                            assert self.loop is not None, "No loop"
                            asyncio.run_coroutine_threadsafe(
                                self.publish_all(
                                    self.handle_detection(
                                        matching_indexes, raven)),
                                self.loop,
                            )

                            if keep_audio:
                                # Save positive example
                                assert self.examples_dir is not None
                                example_path = self.examples_dir / time.strftime(
                                    self.examples_format).format(
                                        keyword=raven.keyword_name)

                                example_path.parent.mkdir(parents=True,
                                                          exist_ok=True)

                                with open(example_path, "wb") as example_file:
                                    example_wav_bytes = self.to_wav_bytes(
                                        raven.example_audio_buffer)
                                    example_file.write(example_wav_bytes)

                                _LOGGER.debug("Wrote example to %s",
                                              example_path)
                    except Exception:
                        _LOGGER.exception("process_chunk")
        except Exception:
            _LOGGER.exception("detection_thread_proc")

    # -------------------------------------------------------------------------

    def stop(self):
        """Stop audio and detection threads."""
        self.wav_queue.put((None, ""))

        _LOGGER.debug("Waiting for detection threads to stop...")
        self.audio_thread.join()

    # -------------------------------------------------------------------------

    def udp_thread_proc(self, host: str, port: int, site_id: str):
        """Handle WAV chunks from UDP socket."""
        try:
            udp_socket = socket.socket(socket.AF_INET, socket.SOCK_DGRAM)
            udp_socket.bind((host, port))
            _LOGGER.debug("Listening for audio on UDP %s:%s", host, port)

            while True:
                wav_bytes, _ = udp_socket.recvfrom(self.udp_chunk_size +
                                                   WAV_HEADER_BYTES)

                if self.enabled:
                    self.wav_queue.put((wav_bytes, site_id))
        except Exception:
            _LOGGER.exception("udp_thread_proc")

    # -------------------------------------------------------------------------

    async def on_message_blocking(
        self,
        message: Message,
        site_id: typing.Optional[str] = None,
        session_id: typing.Optional[str] = None,
        topic: typing.Optional[str] = None,
    ) -> GeneratorType:
        """Received message from MQTT broker."""
        # Check enable/disable messages
        if isinstance(message, HotwordToggleOn):
            if message.reason == HotwordToggleReason.UNKNOWN:
                # Always enable on unknown
                self.disabled_reasons.clear()
            else:
                self.disabled_reasons.discard(message.reason)

            if self.disabled_reasons:
                _LOGGER.debug("Still disabled: %s", self.disabled_reasons)
            else:
                self.enabled = True
                self.first_audio = True
                _LOGGER.debug("Enabled")
        elif isinstance(message, HotwordToggleOff):
            self.enabled = False
            self.disabled_reasons.add(message.reason)
            _LOGGER.debug("Disabled")
        elif isinstance(message, AudioFrame):
            if self.enabled:
                assert site_id, "Missing site_id"
                await self.handle_audio_frame(message.wav_bytes,
                                              site_id=site_id)
        elif isinstance(message, GetHotwords):
            async for hotword_result in self.handle_get_hotwords(message):
                yield hotword_result
        elif isinstance(message, RecordHotwordExample):
            # Handled in on_message
            pass
        else:
            _LOGGER.warning("Unexpected message: %s", message)

    async def on_message(
        self,
        message: Message,
        site_id: typing.Optional[str] = None,
        session_id: typing.Optional[str] = None,
        topic: typing.Optional[str] = None,
    ) -> GeneratorType:
        """Received message from MQTT broker (non-blocking)."""
        if isinstance(message, RecordHotwordExample):
            async for example_result in self.handle_record_example(message):
                yield example_result
示例#6
0
class WakeHermesMqtt(HermesClient):
    """Hermes MQTT server for Rhasspy wakeword with Raven."""

    def __init__(
        self,
        client,
        raven: Raven,
        minimum_matches: int = 1,
        wakeword_id: str = "",
        site_ids: typing.Optional[typing.List[str]] = None,
        enabled: bool = True,
        sample_rate: int = 16000,
        sample_width: int = 2,
        channels: int = 1,
        chunk_size: int = 960,
        udp_audio: typing.Optional[typing.List[typing.Tuple[str, int, str]]] = None,
        udp_chunk_size: int = 2048,
        log_predictions: bool = False,
    ):
        super().__init__(
            "rhasspywake_raven_hermes",
            client,
            sample_rate=sample_rate,
            sample_width=sample_width,
            channels=channels,
            site_ids=site_ids,
        )

        self.subscribe(
            AudioFrame,
            HotwordToggleOn,
            HotwordToggleOff,
            GetHotwords,
            RecordHotwordExample,
        )

        self.raven = raven
        self.minimum_matches = minimum_matches
        self.wakeword_id = wakeword_id

        self.enabled = enabled
        self.disabled_reasons: typing.Set[str] = set()

        # Required audio format
        self.sample_rate = sample_rate
        self.sample_width = sample_width
        self.channels = channels

        self.chunk_size = chunk_size

        # Queue of WAV audio chunks to process (plus site_id)
        self.wav_queue: queue.Queue = queue.Queue()

        self.first_audio: bool = True
        self.audio_buffer = bytes()

        self.last_audio_site_id: str = "default"

        # Fields for recording examples
        self.recording_example = False
        self.example_recorder = WebRtcVadRecorder(max_seconds=10)
        self.example_future: typing.Optional[asyncio.Future] = None

        # Start threads
        self.detection_thread = threading.Thread(
            target=self.detection_thread_proc, daemon=True
        )
        self.detection_thread.start()

        # Listen for raw audio on UDP too
        self.udp_chunk_size = udp_chunk_size

        if udp_audio:
            for udp_host, udp_port, udp_site_id in udp_audio:
                threading.Thread(
                    target=self.udp_thread_proc,
                    args=(udp_host, udp_port, udp_site_id),
                    daemon=True,
                ).start()

    # -------------------------------------------------------------------------

    async def handle_audio_frame(
        self, wav_bytes: bytes, site_id: str = "default"
    ) -> None:
        """Process a single audio frame"""
        self.wav_queue.put((wav_bytes, site_id))

    async def handle_detection(
        self, matching_indexes: typing.List[int]
    ) -> typing.AsyncIterable[
        typing.Union[typing.Tuple[HotwordDetected, TopicArgs], HotwordError]
    ]:
        """Handle a successful hotword detection"""
        try:
            template = self.raven.templates[matching_indexes[0]]
            wakeword_id = self.wakeword_id
            if not wakeword_id:
                wakeword_id = template.name

            yield (
                HotwordDetected(
                    site_id=self.last_audio_site_id,
                    model_id=template.name,
                    current_sensitivity=self.raven.distance_threshold,
                    model_version="",
                    model_type="personal",
                ),
                {"wakeword_id": wakeword_id},
            )
        except Exception as e:
            _LOGGER.exception("handle_detection")
            yield HotwordError(
                error=str(e),
                context=str(matching_indexes),
                site_id=self.last_audio_site_id,
            )

    async def handle_get_hotwords(
        self, get_hotwords: GetHotwords
    ) -> typing.AsyncIterable[typing.Union[Hotwords, HotwordError]]:
        """Report available hotwords"""
        try:
            yield Hotwords(models=[], id=get_hotwords.id, site_id=get_hotwords.site_id)

        except Exception as e:
            _LOGGER.exception("handle_get_hotwords")
            yield HotwordError(
                error=str(e), context=str(get_hotwords), site_id=get_hotwords.site_id
            )

    async def handle_record_example(
        self, record_example: RecordHotwordExample
    ) -> typing.AsyncIterable[
        typing.Union[typing.Tuple[HotwordExampleRecorded, TopicArgs], HotwordError]
    ]:
        """Record an example of a hotword."""
        try:
            assert (
                not self.recording_example
            ), "Only one example can be recorded at a time"

            # Start recording
            assert self.loop, "No loop"
            self.example_future = self.loop.create_future()
            self.example_recorder.start()
            self.recording_example = True

            # Wait for result
            _LOGGER.debug("Recording example (id=%s)", record_example.id)
            example_audio = await self.example_future
            assert isinstance(example_audio, bytes)

            # Trim silence
            _LOGGER.debug("Trimming silence from example")
            example_audio = trim_silence(example_audio)

            # Convert to WAV format
            wav_data = self.to_wav_bytes(example_audio)

            yield (
                HotwordExampleRecorded(wav_bytes=wav_data),
                {"site_id": record_example.site_id, "request_id": record_example.id},
            )

        except Exception as e:
            _LOGGER.exception("handle_record_example")
            yield HotwordError(
                error=str(e),
                context=str(record_example),
                site_id=record_example.site_id,
            )

    def add_example_audio(self, audio_data: bytes):
        """Add an audio frame to the currently recording example."""
        result = self.example_recorder.process_chunk(audio_data)
        if result:
            self.recording_example = False
            assert self.example_future is not None, "No future"
            example_audio = self.example_recorder.stop()
            _LOGGER.debug(
                "Recorded %s byte(s) for audio for example", len(example_audio)
            )

            # Signal waiting coroutine with audio
            assert self.loop, "No loop"
            self.loop.call_soon_threadsafe(
                self.example_future.set_result, example_audio
            )

    # -------------------------------------------------------------------------

    def detection_thread_proc(self):
        """Handle WAV audio chunks."""
        try:
            while True:
                wav_bytes, site_id = self.wav_queue.get()
                if wav_bytes is None:
                    # Shutdown signal
                    break

                self.last_audio_site_id = site_id

                # Handle audio frames
                if self.first_audio:
                    _LOGGER.debug("Receiving audio")
                    self.first_audio = False

                # Extract/convert audio data
                audio_data = self.maybe_convert_wav(wav_bytes)

                if self.recording_example:
                    # Add to currently recording example
                    self.add_example_audio(audio_data)

                    # Don't process audio for wake word while recording
                    self.audio_buffer = bytes()
                    continue

                # Add to persistent buffer
                self.audio_buffer += audio_data

                # Process in chunks.
                # Any remaining audio data will be kept in buffer.
                while len(self.audio_buffer) >= self.chunk_size:
                    chunk = self.audio_buffer[: self.chunk_size]
                    self.audio_buffer = self.audio_buffer[self.chunk_size :]

                    if chunk:
                        try:
                            matching_indexes = self.raven.process_chunk(chunk)
                            if len(matching_indexes) >= self.minimum_matches:
                                asyncio.run_coroutine_threadsafe(
                                    self.publish_all(
                                        self.handle_detection(matching_indexes)
                                    ),
                                    self.loop,
                                )
                        except Exception:
                            _LOGGER.exception("process_chunk")
        except Exception:
            _LOGGER.exception("detection_thread_proc")

    # -------------------------------------------------------------------------

    def udp_thread_proc(self, host: str, port: int, site_id: str):
        """Handle WAV chunks from UDP socket."""
        try:
            udp_socket = socket.socket(socket.AF_INET, socket.SOCK_DGRAM)
            udp_socket.bind((host, port))
            _LOGGER.debug("Listening for audio on UDP %s:%s", host, port)

            while True:
                wav_bytes, _ = udp_socket.recvfrom(
                    self.udp_chunk_size + WAV_HEADER_BYTES
                )

                if self.enabled:
                    self.wav_queue.put((wav_bytes, site_id))
        except Exception:
            _LOGGER.exception("udp_thread_proc")

    # -------------------------------------------------------------------------

    async def on_message_blocking(
        self,
        message: Message,
        site_id: typing.Optional[str] = None,
        session_id: typing.Optional[str] = None,
        topic: typing.Optional[str] = None,
    ) -> GeneratorType:
        """Received message from MQTT broker."""
        # Check enable/disable messages
        if isinstance(message, HotwordToggleOn):
            if message.reason == HotwordToggleReason.UNKNOWN:
                # Always enable on unknown
                self.disabled_reasons.clear()
            else:
                self.disabled_reasons.discard(message.reason)

            if self.disabled_reasons:
                _LOGGER.debug("Still disabled: %s", self.disabled_reasons)
            else:
                self.enabled = True
                self.first_audio = True
                _LOGGER.debug("Enabled")
        elif isinstance(message, HotwordToggleOff):
            self.enabled = False
            self.disabled_reasons.add(message.reason)
            _LOGGER.debug("Disabled")
        elif isinstance(message, AudioFrame):
            if self.enabled:
                assert site_id, "Missing site_id"
                await self.handle_audio_frame(message.wav_bytes, site_id=site_id)
        elif isinstance(message, GetHotwords):
            async for hotword_result in self.handle_get_hotwords(message):
                yield hotword_result
        elif isinstance(message, RecordHotwordExample):
            # Handled in on_message
            pass
        else:
            _LOGGER.warning("Unexpected message: %s", message)

    async def on_message(
        self,
        message: Message,
        site_id: typing.Optional[str] = None,
        session_id: typing.Optional[str] = None,
        topic: typing.Optional[str] = None,
    ) -> GeneratorType:
        """Received message from MQTT broker (non-blocking)."""
        if isinstance(message, RecordHotwordExample):
            async for example_result in self.handle_record_example(message):
                yield example_result