docs: add docs to CB

Pretty much every class and method should have documentation now.

ref: N25B-295
This commit is contained in:
2025-11-24 21:58:22 +01:00
parent 54502e441c
commit 129d3c4420
26 changed files with 757 additions and 80 deletions

View File

@@ -14,15 +14,28 @@ from control_backend.core.config import settings
class SpeechRecognizer(abc.ABC):
"""
Abstract base class for speech recognition backends.
Provides a common interface for loading models and transcribing audio,
as well as heuristics for estimating token counts to optimize decoding.
:ivar limit_output_length: If True, limits the generated text length based on audio duration.
"""
def __init__(self, limit_output_length=True):
"""
:param limit_output_length: When `True`, the length of the generated speech will be limited
by the length of the input audio and some heuristics.
:param limit_output_length: When ``True``, the length of the generated speech will be
limited by the length of the input audio and some heuristics.
"""
self.limit_output_length = limit_output_length
@abc.abstractmethod
def load_model(self): ...
def load_model(self):
"""
Load the speech recognition model into memory.
"""
...
@abc.abstractmethod
def recognize_speech(self, audio: np.ndarray) -> str:
@@ -30,15 +43,17 @@ class SpeechRecognizer(abc.ABC):
Recognize speech from the given audio sample.
:param audio: A full utterance sample. Audio must be 16 kHz, mono, np.float32, values in the
range [-1.0, 1.0].
:return: Recognized speech.
range [-1.0, 1.0].
:return: The recognized speech text.
"""
@staticmethod
def _estimate_max_tokens(audio: np.ndarray) -> int:
"""
Estimate the maximum length of a given audio sample in tokens. Assumes a maximum speaking
rate of 450 words per minute (3x average), and assumes that 3 words is 4 tokens.
Estimate the maximum length of a given audio sample in tokens.
Assumes a maximum speaking rate of 450 words per minute (3x average), and assumes that
3 words is approx. 4 tokens.
:param audio: The audio sample (16 kHz) to use for length estimation.
:return: The estimated length of the transcribed audio in tokens.
@@ -51,8 +66,10 @@ class SpeechRecognizer(abc.ABC):
def _get_decode_options(self, audio: np.ndarray) -> dict:
"""
Construct decoding options for the Whisper model.
:param audio: The audio sample (16 kHz) to use to determine options like max decode length.
:return: A dict that can be used to construct `whisper.DecodingOptions`.
:return: A dict that can be used to construct ``whisper.DecodingOptions`` (or equivalent).
"""
options = {}
if self.limit_output_length:
@@ -61,7 +78,12 @@ class SpeechRecognizer(abc.ABC):
@staticmethod
def best_type():
"""Get the best type of SpeechRecognizer based on system capabilities."""
"""
Factory method to get the best available `SpeechRecognizer`.
:return: An instance of :class:`MLXWhisperSpeechRecognizer` if on macOS with Apple Silicon,
otherwise :class:`OpenAIWhisperSpeechRecognizer`.
"""
if torch.mps.is_available():
print("Choosing MLX Whisper model.")
return MLXWhisperSpeechRecognizer()
@@ -71,12 +93,20 @@ class SpeechRecognizer(abc.ABC):
class MLXWhisperSpeechRecognizer(SpeechRecognizer):
"""
Speech recognizer using the MLX framework (optimized for Apple Silicon).
"""
def __init__(self, limit_output_length=True):
super().__init__(limit_output_length)
self.was_loaded = False
self.model_name = settings.speech_model_settings.mlx_model_name
def load_model(self):
"""
Ensures the model is downloaded and cached. MLX loads dynamically, so this
pre-fetches the model.
"""
if self.was_loaded:
return
# There appears to be no dedicated mechanism to preload a model, but this `get_model` does
@@ -94,11 +124,18 @@ class MLXWhisperSpeechRecognizer(SpeechRecognizer):
class OpenAIWhisperSpeechRecognizer(SpeechRecognizer):
"""
Speech recognizer using the standard OpenAI Whisper library (PyTorch).
"""
def __init__(self, limit_output_length=True):
super().__init__(limit_output_length)
self.model = None
def load_model(self):
"""
Loads the OpenAI Whisper model onto the available device (CUDA or CPU).
"""
if self.model is not None:
return
device = torch.device("cuda:0" if torch.cuda.is_available() else "cpu")

View File

@@ -13,11 +13,26 @@ from .speech_recognizer import SpeechRecognizer
class TranscriptionAgent(BaseAgent):
"""
An agent which listens to audio fragments with voice, transcribes them, and sends the
transcription to other agents.
Transcription Agent.
This agent listens to audio fragments (containing speech) on a ZMQ SUB socket,
transcribes them using the configured :class:`SpeechRecognizer`, and sends the
resulting text to other agents (e.g., the Text Belief Extractor).
It uses an internal semaphore to limit the number of concurrent transcription tasks.
:ivar audio_in_address: The ZMQ address to receive audio from (usually from VAD Agent).
:ivar audio_in_socket: The ZMQ SUB socket instance.
:ivar speech_recognizer: The speech recognition engine instance.
:ivar _concurrency: Semaphore to limit concurrent transcriptions.
"""
def __init__(self, audio_in_address: str):
"""
Initialize the Transcription Agent.
:param audio_in_address: The ZMQ address of the audio source (e.g., VAD output).
"""
super().__init__(settings.agent_settings.transcription_name)
self.audio_in_address = audio_in_address
@@ -26,6 +41,13 @@ class TranscriptionAgent(BaseAgent):
self._concurrency = None
async def setup(self):
"""
Initialize the agent resources.
1. Connects to the audio input ZMQ socket.
2. Initializes the :class:`SpeechRecognizer` (choosing the best available backend).
3. Starts the background transcription loop.
"""
self.logger.info("Setting up %s", self.name)
self._connect_audio_in_socket()
@@ -42,23 +64,45 @@ class TranscriptionAgent(BaseAgent):
self.logger.info("Finished setting up %s", self.name)
async def stop(self):
"""
Stop the agent and close sockets.
"""
assert self.audio_in_socket is not None
self.audio_in_socket.close()
self.audio_in_socket = None
return await super().stop()
def _connect_audio_in_socket(self):
"""
Helper to connect the ZMQ SUB socket for audio input.
"""
self.audio_in_socket = azmq.Context.instance().socket(zmq.SUB)
self.audio_in_socket.setsockopt_string(zmq.SUBSCRIBE, "")
self.audio_in_socket.connect(self.audio_in_address)
async def _transcribe(self, audio: np.ndarray) -> str:
"""
Run the speech recognition on the audio data.
This runs in a separate thread (via `asyncio.to_thread`) to avoid blocking the event loop,
constrained by the concurrency semaphore.
:param audio: The audio data as a numpy array.
:return: The transcribed text string.
"""
assert self._concurrency is not None and self.speech_recognizer is not None
async with self._concurrency:
return await asyncio.to_thread(self.speech_recognizer.recognize_speech, audio)
async def _share_transcription(self, transcription: str):
"""Share a transcription to the other agents that depend on it."""
"""
Share a transcription to the other agents that depend on it.
Currently sends to:
- :attr:`settings.agent_settings.text_belief_extractor_name`
:param transcription: The transcribed text.
"""
receiver_names = [
settings.agent_settings.text_belief_extractor_name,
]
@@ -72,6 +116,12 @@ class TranscriptionAgent(BaseAgent):
await self.send(message)
async def _transcribing_loop(self) -> None:
"""
The main loop for receiving audio and triggering transcription.
Receives audio chunks from ZMQ, decodes them to float32, and calls :meth:`_transcribe`.
If speech is found, it calls :meth:`_share_transcription`.
"""
while self._running:
try:
assert self.audio_in_socket is not None