espnet2/train/preprocessor.py

from abc import ABC
from abc import abstractmethod
from pathlib import Path
from typing import Collection
from typing import Dict
from typing import Iterable
from typing import Union

import numpy as np
import scipy.signal
import soundfile
from typeguard import check_argument_types
from typeguard import check_return_type

from espnet2.text.build_tokenizer import build_tokenizer
from espnet2.text.cleaner import TextCleaner
from espnet2.text.token_id_converter import TokenIDConverter


class AbsPreprocessor(ABC):
    def __init__(self, train: bool):
        self.train = train

    @abstractmethod
    def __call__(
        self, uid: str, data: Dict[str, Union[str, np.ndarray]]
    ) -> Dict[str, np.ndarray]:
        raise NotImplementedError


def framing(
    x,
    frame_length: int = 512,
    frame_shift: int = 256,
    centered: bool = True,
    padded: bool = True,
):
    if x.size == 0:
        raise ValueError("Input array size is zero")
    if frame_length < 1:
        raise ValueError("frame_length must be a positive integer")
    if frame_length > x.shape[-1]:
        raise ValueError("frame_length is greater than input length")
    if 0 >= frame_shift:
        raise ValueError("frame_shift must be greater than 0")

    if centered:
        pad_shape = [(0, 0) for _ in range(x.ndim - 1)] + [
            (frame_length // 2, frame_length // 2)
        ]
        x = np.pad(x, pad_shape, mode="constant", constant_values=0)

    if padded:
        # Pad to integer number of windowed segments
        # I.e make x.shape[-1] = frame_length + (nseg-1)*nstep,
        #  with integer nseg
        nadd = (-(x.shape[-1] - frame_length) % frame_shift) % frame_length
        pad_shape = [(0, 0) for _ in range(x.ndim - 1)] + [(0, nadd)]
        x = np.pad(x, pad_shape, mode="constant", constant_values=0)

    # Created strided array of data segments
    if frame_length == 1 and frame_length == frame_shift:
        result = x[..., None]
    else:
        shape = x.shape[:-1] + (
            (x.shape[-1] - frame_length) // frame_shift + 1,
            frame_length,
        )
        strides = x.strides[:-1] + (frame_shift * x.strides[-1], x.strides[-1])
        result = np.lib.stride_tricks.as_strided(x, shape=shape, strides=strides)
    return result


def detect_non_silence(
    x: np.ndarray,
    threshold: float = 0.01,
    frame_length: int = 1024,
    frame_shift: int = 512,
    window: str = "boxcar",
) -> np.ndarray:
    """Power based voice activity detection.

    Args:
        x: (Channel, Time)
    >>> x = np.random.randn(1000)
    >>> detect = detect_non_silence(x)
    >>> assert x.shape == detect.shape
    >>> assert detect.dtype == np.bool
    """
    if x.shape[-1] < frame_length:
        return np.full(x.shape, fill_value=True, dtype=np.bool)

    if x.dtype.kind == "i":
        x = x.astype(np.float64)
    # framed_w: (C, T, F)
    framed_w = framing(
        x,
        frame_length=frame_length,
        frame_shift=frame_shift,
        centered=False,
        padded=True,
    )
    framed_w *= scipy.signal.get_window(window, frame_length).astype(framed_w.dtype)
    # power: (C, T)
    power = (framed_w ** 2).mean(axis=-1)
    # mean_power: (C,)
    mean_power = power.mean(axis=-1)
    if np.all(mean_power == 0):
        return np.full(x.shape, fill_value=True, dtype=np.bool)
    # detect_frames: (C, T)
    detect_frames = power / mean_power > threshold
    # detects: (C, T, F)
    detects = np.broadcast_to(
        detect_frames[..., None], detect_frames.shape + (frame_shift,)
    )
    # detects: (C, TF)
    detects = detects.reshape(*detect_frames.shape[:-1], -1)
    # detects: (C, TF)
    return np.pad(
        detects,
        [(0, 0)] * (x.ndim - 1) + [(0, x.shape[-1] - detects.shape[-1])],
        mode="edge",
    )


class CommonPreprocessor(AbsPreprocessor):
    def __init__(
        self,
        train: bool,
        token_type: str = None,
        token_list: Union[Path, str, Iterable[str]] = None,
        bpemodel: Union[Path, str, Iterable[str]] = None,
        text_cleaner: Collection[str] = None,
        g2p_type: str = None,
        unk_symbol: str = "<unk>",
        space_symbol: str = "<space>",
        non_linguistic_symbols: Union[Path, str, Iterable[str]] = None,
        delimiter: str = None,
        rir_scp: str = None,
        rir_apply_prob: float = 1.0,
        noise_scp: str = None,
        noise_apply_prob: float = 1.0,
        noise_db_range: str = "3_10",
        speech_volume_normalize: float = None,
        speech_name: str = "speech",
        text_name: str = "text",
    ):
        super().__init__(train)
        self.train = train
        self.speech_name = speech_name
        self.text_name = text_name
        self.speech_volume_normalize = speech_volume_normalize
        self.rir_apply_prob = rir_apply_prob
        self.noise_apply_prob = noise_apply_prob

        if token_type is not None:
            if token_list is None:
                raise ValueError("token_list is required if token_type is not None")
            self.text_cleaner = TextCleaner(text_cleaner)

            self.tokenizer = build_tokenizer(
                token_type=token_type,
                bpemodel=bpemodel,
                delimiter=delimiter,
                space_symbol=space_symbol,
                non_linguistic_symbols=non_linguistic_symbols,
                g2p_type=g2p_type,
            )
            self.token_id_converter = TokenIDConverter(
                token_list=token_list,
                unk_symbol=unk_symbol,
            )
        else:
            self.text_cleaner = None
            self.tokenizer = None
            self.token_id_converter = None

        if train and rir_scp is not None:
            self.rirs = []
            with open(rir_scp, "r", encoding="utf-8") as f:
                for line in f:
                    sps = line.strip().split(None, 1)
                    if len(sps) == 1:
                        self.rirs.append(sps[0])
                    else:
                        self.rirs.append(sps[1])
        else:
            self.rirs = None

        if train and noise_scp is not None:
            self.noises = []
            with open(noise_scp, "r", encoding="utf-8") as f:
                for line in f:
                    sps = line.strip().split(None, 1)
                    if len(sps) == 1:
                        self.noises.append(sps[0])
                    else:
                        self.noises.append(sps[1])
            sps = noise_db_range.split("_")
            if len(sps) == 1:
                self.noise_db_low, self.noise_db_high = float(sps[0])
            elif len(sps) == 2:
                self.noise_db_low, self.noise_db_high = float(sps[0]), float(sps[1])
            else:
                raise ValueError(
                    "Format error: '{noise_db_range}' e.g. -3_4 -> [-3db,4db]"
                )
        else:
            self.noises = None

    def __call__(
        self, uid: str, data: Dict[str, Union[str, np.ndarray]]
    ) -> Dict[str, np.ndarray]:
        assert check_argument_types()

        if self.speech_name in data:
            if self.train and self.rirs is not None and self.noises is not None:
                speech = data[self.speech_name]
                nsamples = len(speech)

                # speech: (Nmic, Time)
                if speech.ndim == 1:
                    speech = speech[None, :]
                else:
                    speech = speech.T
                # Calc power on non shlence region
                power = (speech[detect_non_silence(speech)] ** 2).mean()

                # 1. Convolve RIR
                if self.rirs is not None and self.rir_apply_prob >= np.random.random():
                    rir_path = np.random.choice(self.rirs)
                    if rir_path is not None:
                        rir, _ = soundfile.read(
                            rir_path, dtype=np.float64, always_2d=True
                        )

                        # rir: (Nmic, Time)
                        rir = rir.T

                        # speech: (Nmic, Time)
                        # Note that this operation doesn't change the signal length
                        speech = scipy.signal.convolve(speech, rir, mode="full")[
                            :, : speech.shape[1]
                        ]
                        # Reverse mean power to the original power
                        power2 = (speech[detect_non_silence(speech)] ** 2).mean()
                        speech = np.sqrt(power / max(power2, 1e-10)) * speech

                # 2. Add Noise
                if (
                    self.noises is not None
                    and self.rir_apply_prob >= np.random.random()
                ):
                    noise_path = np.random.choice(self.noises)
                    if noise_path is not None:
                        noise_db = np.random.uniform(
                            self.noise_db_low, self.noise_db_high
                        )
                        with soundfile.SoundFile(noise_path) as f:
                            if f.frames == nsamples:
                                noise = f.read(dtype=np.float64, always_2d=True)
                            elif f.frames < nsamples:
                                offset = np.random.randint(0, nsamples - f.frames)
                                # noise: (Time, Nmic)
                                noise = f.read(dtype=np.float64, always_2d=True)
                                # Repeat noise
                                noise = np.pad(
                                    noise,
                                    [(offset, nsamples - f.frames - offset), (0, 0)],
                                    mode="wrap",
                                )
                            else:
                                offset = np.random.randint(0, f.frames - nsamples)
                                f.seek(offset)
                                # noise: (Time, Nmic)
                                noise = f.read(
                                    nsamples, dtype=np.float64, always_2d=True
                                )
                                if len(noise) != nsamples:
                                    raise RuntimeError(f"Something wrong: {noise_path}")
                        # noise: (Nmic, Time)
                        noise = noise.T

                        noise_power = (noise ** 2).mean()
                        scale = (
                            10 ** (-noise_db / 20)
                            * np.sqrt(power)
                            / np.sqrt(max(noise_power, 1e-10))
                        )
                        speech = speech + scale * noise

                speech = speech.T
                ma = np.max(np.abs(speech))
                if ma > 1.0:
                    speech /= ma
                data[self.speech_name] = speech

            if self.speech_volume_normalize is not None:
                speech = data[self.speech_name]
                ma = np.max(np.abs(speech))
                data[self.speech_name] = speech * self.speech_volume_normalize / ma

        if self.text_name in data and self.tokenizer is not None:
            text = data[self.text_name]
            text = self.text_cleaner(text)
            tokens = self.tokenizer.text2tokens(text)
            text_ints = self.token_id_converter.tokens2ids(tokens)
            data[self.text_name] = np.array(text_ints, dtype=np.int64)
        assert check_return_type(data)
        return data


class CommonPreprocessor_multi(AbsPreprocessor):
    def __init__(
        self,
        train: bool,
        token_type: str = None,
        token_list: Union[Path, str, Iterable[str]] = None,
        bpemodel: Union[Path, str, Iterable[str]] = None,
        text_cleaner: Collection[str] = None,
        g2p_type: str = None,
        unk_symbol: str = "<unk>",
        space_symbol: str = "<space>",
        non_linguistic_symbols: Union[Path, str, Iterable[str]] = None,
        delimiter: str = None,
        speech_name: str = "speech",
        text_name: list = ["text"],
    ):
        super().__init__(train)
        self.train = train
        self.speech_name = speech_name
        self.text_name = text_name

        if token_type is not None:
            if token_list is None:
                raise ValueError("token_list is required if token_type is not None")
            self.text_cleaner = TextCleaner(text_cleaner)

            self.tokenizer = build_tokenizer(
                token_type=token_type,
                bpemodel=bpemodel,
                delimiter=delimiter,
                space_symbol=space_symbol,
                non_linguistic_symbols=non_linguistic_symbols,
                g2p_type=g2p_type,
            )
            self.token_id_converter = TokenIDConverter(
                token_list=token_list,
                unk_symbol=unk_symbol,
            )
        else:
            self.text_cleaner = None
            self.tokenizer = None
            self.token_id_converter = None

    def __call__(
        self, uid: str, data: Dict[str, Union[str, np.ndarray]]
    ) -> Dict[str, np.ndarray]:
        assert check_argument_types()

        if self.speech_name in data:
            # Nothing now: candidates:
            # - STFT
            # - Fbank
            # - CMVN
            # - Data augmentation
            pass

        for text_n in self.text_name:
            if text_n in data and self.tokenizer is not None:
                text = data[text_n]
                text = self.text_cleaner(text)
                tokens = self.tokenizer.text2tokens(text)
                text_ints = self.token_id_converter.tokens2ids(tokens)
                data[text_n] = np.array(text_ints, dtype=np.int64)
        assert check_return_type(data)
        return data