platypush/platypush/plugins/stt/__init__.py

311 lines
12 KiB
Python

import queue
import threading
from abc import ABC, abstractmethod
from typing import Optional, Union, List
import sounddevice as sd
from platypush.context import get_bus
from platypush.message.event.stt import SpeechDetectionStartedEvent, SpeechDetectionStoppedEvent, SpeechStartedEvent, \
SpeechDetectedEvent, HotwordDetectedEvent, ConversationDetectedEvent
from platypush.message.response.stt import SpeechDetectedResponse
from platypush.plugins import Plugin, action
class SttPlugin(ABC, Plugin):
"""
Abstract class for speech-to-text plugins.
Triggers:
* :class:`platypush.message.event.stt.SpeechStartedEvent` when speech starts being detected.
* :class:`platypush.message.event.stt.SpeechDetectedEvent` when speech is detected.
* :class:`platypush.message.event.stt.SpeechDetectionStartedEvent` when speech detection starts.
* :class:`platypush.message.event.stt.SpeechDetectionStoppedEvent` when speech detection stops.
* :class:`platypush.message.event.stt.HotwordDetectedEvent` when a user-defined hotword is detected.
* :class:`platypush.message.event.stt.ConversationDetectedEvent` when speech is detected after a hotword.
"""
_thread_stop_timeout = 10.0
rate = 16000
channels = 1
def __init__(self,
input_device: Optional[Union[int, str]] = None,
hotword: Optional[str] = None,
hotwords: Optional[List[str]] = None,
conversation_timeout: Optional[float] = 10.0,
block_duration: float = 1.0):
"""
:param input_device: PortAudio device index or name that will be used for recording speech (default: default
system audio input device).
:param hotword: When this word is detected, the plugin will trigger a
:class:`platypush.message.event.stt.HotwordDetectedEvent` instead of a
:class:`platypush.message.event.stt.SpeechDetectedEvent` event. You can use these events for hooking other
assistants.
:param hotwords: Use a list of hotwords instead of a single one.
:param conversation_timeout: If ``hotword`` or ``hotwords`` are set and ``conversation_timeout`` is set,
the next speech detected event will trigger a :class:`platypush.message.event.stt.ConversationDetectedEvent`
instead of a :class:`platypush.message.event.stt.SpeechDetectedEvent` event. You can hook custom hooks
here to run any logic depending on the detected speech - it can emulate a kind of
"OK, Google. Turn on the lights" interaction without using an external assistant (default: 10 seconds).
:param block_duration: Duration of the acquired audio blocks (default: 1 second).
"""
super().__init__()
self.input_device = input_device
self.conversation_timeout = conversation_timeout
self.block_duration = block_duration
self.hotwords = set(hotwords or [])
if hotword:
self.hotwords = {hotword}
self._conversation_event = threading.Event()
self._input_stream: Optional[sd.InputStream] = None
self._recording_thread: Optional[threading.Thread] = None
self._detection_thread: Optional[threading.Thread] = None
self._audio_queue: Optional[queue.Queue] = None
self._current_text = ''
def _get_input_device(self, device: Optional[Union[int, str]] = None) -> int:
"""
Get the index of the input device by index or name.
:param device: Device index or name. If None is set then the function will return the index of the
default audio input device.
:return: Index of the audio input device.
"""
if not device:
device = self.input_device
if not device:
return sd.query_hostapis()[0].get('default_input_device')
if isinstance(device, int):
assert device <= len(sd.query_devices())
return device
for i, dev in enumerate(sd.query_devices()):
if dev['name'] == device:
return i
raise AssertionError('Device {} not found'.format(device))
def on_speech_detected(self, speech: str) -> None:
"""
Hook called when speech is detected. Triggers the right event depending on the current context.
:param speech: Detected speech.
"""
speech = speech.strip()
if speech in self.hotwords:
event = HotwordDetectedEvent(hotword=speech)
if self.conversation_timeout:
self._conversation_event.set()
threading.Timer(self.conversation_timeout, lambda: self._conversation_event.clear()).start()
elif self._conversation_event.is_set():
event = ConversationDetectedEvent(speech=speech)
else:
event = SpeechDetectedEvent(speech=speech)
get_bus().post(event)
@staticmethod
def convert_frames(frames: bytes) -> bytes:
"""
Conversion method for raw audio frames. It just returns the input frames as bytes. Override it if required
by your logic.
:param frames: Input audio frames, as bytes.
:return: The audio frames as passed on the input. Override if required.
"""
return frames
def on_detection_started(self) -> None:
"""
Method called when the ``detection_thread`` starts. Initialize your context variables and models here if
required.
"""
pass
def on_detection_ended(self) -> None:
"""
Method called when the ``detection_thread`` stops. Clean up your context variables and models here.
"""
pass
def before_recording(self) -> None:
"""
Method called when the ``recording_thread`` starts. Put here any logic that you may want to run before the
recording thread starts.
"""
pass
def on_recording_started(self) -> None:
"""
Method called after the ``recording_thread`` opens the audio device. Put here any logic that you may want to
run after the recording starts.
"""
pass
def on_recording_ended(self) -> None:
"""
Method called when the ``recording_thread`` stops. Put here any logic that you want to run after the audio
device is closed.
"""
pass
@abstractmethod
def detect_speech(self, frames) -> str:
"""
Method called within the ``detection_thread`` when new audio frames have been captured. Must be implemented
by the derived classes.
:param frames: Audio frames, as returned by ``convert_frames``.
:return: Detected text, as a string. Returns an empty string if no text has been detected.
"""
raise NotImplementedError
def process_text(self, text: str) -> None:
if (not text and self._current_text) or (text and text == self._current_text):
self.on_speech_detected(self._current_text)
self._current_text = ''
else:
if text:
if not self._current_text:
get_bus().post(SpeechStartedEvent())
self.logger.info('Intermediate speech results: [{}]'.format(text))
self._current_text = text
def detection_thread(self) -> None:
"""
This thread reads frames from ``_audio_queue``, performs the speech-to-text detection and calls
"""
self._current_text = ''
self.logger.debug('Detection thread started')
self.on_detection_started()
while self._audio_queue:
try:
frames = self._audio_queue.get()
frames = self.convert_frames(frames)
except Exception as e:
self.logger.warning('Error while feeding audio to the model: {}'.format(str(e)))
continue
text = self.detect_speech(frames).strip()
self.process_text(text)
self.on_detection_ended()
self.logger.debug('Detection thread terminated')
def recording_thread(self, block_duration: Optional[float] = None, block_size: Optional[int] = None,
input_device: Optional[str] = None) -> None:
"""
Recording thread. It reads raw frames from the audio device and dispatches them to ``detection_thread``.
:param block_duration: Audio blocks duration. Specify either ``block_duration`` or ``block_size``.
:param block_size: Size of the audio blocks. Specify either ``block_duration`` or ``block_size``.
:param input_device: Input device
"""
assert (block_duration or block_size) and not (block_duration and block_size), \
'Please specify either block_duration or block_size'
if not block_size:
block_size = int(self.rate * self.channels * block_duration)
self.before_recording()
self.logger.debug('Recording thread started')
device = self._get_input_device(input_device)
self._input_stream = sd.InputStream(samplerate=self.rate, device=device,
channels=self.channels, dtype='int16', latency=0,
blocksize=block_size)
self._input_stream.start()
self.on_recording_started()
get_bus().post(SpeechDetectionStartedEvent())
while self._input_stream:
try:
frames = self._input_stream.read(block_size)[0]
except Exception as e:
self.logger.warning('Error while reading from the audio input: {}'.format(str(e)))
continue
self._audio_queue.put(frames)
get_bus().post(SpeechDetectionStoppedEvent())
self.on_recording_ended()
self.logger.debug('Recording thread terminated')
@abstractmethod
@action
def detect(self, audio_file: str) -> SpeechDetectedResponse:
"""
Perform speech-to-text analysis on an audio file. Must be implemented by the derived classes.
:param audio_file: Path to the audio file.
"""
raise NotImplementedError
def __enter__(self):
"""
Context manager enter. Starts detection and returns self.
"""
self.start_detection()
return self
def __exit__(self, exc_type, exc_val, exc_tb):
"""
Context manager exit. Stops detection.
"""
self.stop_detection()
@action
def start_detection(self, input_device: Optional[str] = None, seconds: Optional[float] = None,
block_duration: Optional[float] = None) -> None:
"""
Start the speech detection engine.
:param input_device: Audio input device name/index override
:param seconds: If set, then the detection engine will stop after this many seconds, otherwise it'll
start running until ``stop_detection`` is called or application stop.
:param block_duration: ``block_duration`` override.
"""
assert not self._input_stream and not self._recording_thread, 'Speech detection is already running'
block_duration = block_duration or self.block_duration
input_device = input_device if input_device is not None else self.input_device
self._audio_queue = queue.Queue()
self._recording_thread = threading.Thread(
target=lambda: self.recording_thread(block_duration=block_duration, input_device=input_device))
self._recording_thread.start()
self._detection_thread = threading.Thread(target=lambda: self.detection_thread())
self._detection_thread.start()
if seconds:
threading.Timer(seconds, lambda: self.stop_detection()).start()
@action
def stop_detection(self) -> None:
"""
Stop the speech detection engine.
"""
assert self._input_stream, 'Speech detection is not running'
self._input_stream.stop(ignore_errors=True)
self._input_stream.close(ignore_errors=True)
self._input_stream = None
if self._recording_thread:
self._recording_thread.join(timeout=self._thread_stop_timeout)
self._recording_thread = None
self._audio_queue = None
if self._detection_thread:
self._detection_thread.join(timeout=self._thread_stop_timeout)
self._detection_thread = None
# vim:sw=4:ts=4:et: