Source code for audinterface.core.segment

import errno
import os
import typing

import numpy as np
import pandas as pd

import audeer
import audformat

from audinterface.core import utils
from audinterface.core.typing import Timestamp
from audinterface.core.typing import Timestamps


def signal_index(signal, sampling_rate, **kwargs) -> pd.MultiIndex:
    r"""Default segment process function.

    This function is used,
    when ``Segment`` is instantiated
    with ``process_func=None``.
    It returns an empty multi-index,
    with levels ``start`` and ``end``.

    Args:
        signal: signal
        sampling_rate: sampling rate in Hz
        **kwargs: additional keyword arguments of the processing function

    Returns:
        index with segments

    """
    return utils.signal_index()


def inverted_process_func(
    signal,
    sampling_rate,
    *,
    __process_func,
    **kwargs,
) -> pd.MultiIndex:
    r"""Inverted segment process function.

    This function is used,
    when ``Segment`` is instantiated
    with ``invert=True``.

    Args:
        signal: signal
        sampling_rate: sampling rate in Hz
        __process_func: process func to invert.
            Note, ``__process_func`` needs to be added to ``process_func_args``
            before calling this function.
            This means, a user cannot use ``__process_func``
            as argument name
            in ``process_func``
        **kwargs: additional keyword arguments of the processing function

    Returns:
        index with segments

    """
    index = __process_func(signal, sampling_rate, **kwargs)
    duration = pd.to_timedelta(signal.shape[-1] / sampling_rate, unit="s")
    index = index.sortlevel("start")[0]
    index = merge_index(index)
    index = invert_index(index, duration)
    return index


def invert_index(
    index: pd.MultiIndex,
    dur: pd.Timedelta,
) -> pd.MultiIndex:
    r"""Invert index.

    Assumes that index is sorted by 'start' level.

    """
    if index.empty:
        return utils.signal_index(0, dur)

    starts = index.get_level_values("start")
    ends = index.get_level_values("end")
    new_starts = ends[:-1]
    new_ends = starts[1:]
    if starts[0] != pd.to_timedelta(0):
        new_starts = new_starts.insert(0, pd.to_timedelta(0))
        new_ends = new_ends.insert(0, starts[0])
    if ends[-1] != dur:
        new_starts = new_starts.insert(len(new_starts), ends[-1])
        new_ends = new_ends.insert(len(new_ends), dur)
    return utils.signal_index(new_starts, new_ends)


def merge_index(
    index: pd.MultiIndex,
) -> pd.MultiIndex:
    r"""Merge overlapping segments.

    Assumes that index is sorted by 'start' level.

    """
    if index.empty:
        return index

    starts = index.get_level_values("start")
    ends = index.get_level_values("end")
    new_starts = []
    new_ends = []
    new_start = starts[0]
    new_end = ends[0]
    for start, end in zip(starts[1:], ends[1:]):
        if start > new_end:
            new_starts.append(new_start)
            new_ends.append(new_end)
            new_start = start
            new_end = end
        elif end > new_end:
            new_end = end
    new_starts.append(new_start)
    new_ends.append(new_end)

    return utils.signal_index(new_starts, new_ends)


[docs]class Segment: r"""Segmentation interface. Interface for models that apply a segmentation to the input signal, e.g. a voice activity model that detects speech regions. Args: process_func: segmentation function, which expects the two positional arguments ``signal`` and ``sampling_rate`` and any number of additional keyword arguments (see ``process_func_args``). There are the following special arguments: ``'idx'``, ``'file'``, ``'root'``. If expected by the function, but not specified in ``process_func_args``, they will be replaced with: a running index, the currently processed file, the root folder. Must return a :class:`pandas.MultiIndex` with two levels named `start` and `end` that hold start and end positions as :class:`pandas.Timedelta` objects process_func_args: (keyword) arguments passed on to the processing function invert: Invert the segmentation sampling_rate: sampling rate in Hz If ``None`` it will call ``process_func`` with the actual sampling rate of the signal resample: if ``True`` enforces given sampling rate by resampling channels: channel selection, see :func:`audresample.remix` mixdown: apply mono mix-down on selection min_signal_dur: minimum signal length required by ``process_func``. If value is a float or integer it is treated as seconds. See :func:`audinterface.utils.to_timedelta` for further options. If provided signal is shorter, it will be zero padded at the end max_signal_dur: maximum signal length required by ``process_func``. If value is a float or integer it is treated as seconds. See :func:`audinterface.utils.to_timedelta` for further options. If provided signal is longer, it will be cut at the end keep_nat: if the end of segment is set to ``NaT`` do not replace with file duration in the result num_workers: number of parallel jobs or 1 for sequential processing. If ``None`` will be set to the number of processors on the machine multiplied by 5 in case of multithreading and number of processors in case of multiprocessing multiprocessing: use multiprocessing instead of multithreading verbose: show debug messages Raises: ValueError: if ``resample = True``, but ``sampling_rate = None`` Examples: >>> def segment(signal, sampling_rate, *, win_size=0.2, hop_size=0.1): ... size = signal.shape[1] / sampling_rate ... starts = pd.to_timedelta(np.arange(0, size - win_size, hop_size), unit="s") ... ends = pd.to_timedelta(np.arange(win_size, size, hop_size), unit="s") ... return pd.MultiIndex.from_tuples(zip(starts, ends), names=["start", "end"]) >>> interface = Segment(process_func=segment) >>> signal = np.array([1.0, 2.0, 3.0]) >>> interface(signal, sampling_rate=3) MultiIndex([( '0 days 00:00:00', '0 days 00:00:00.200000'), ('0 days 00:00:00.100000', '0 days 00:00:00.300000'), ('0 days 00:00:00.200000', '0 days 00:00:00.400000'), ('0 days 00:00:00.300000', '0 days 00:00:00.500000'), ('0 days 00:00:00.400000', '0 days 00:00:00.600000'), ('0 days 00:00:00.500000', '0 days 00:00:00.700000'), ('0 days 00:00:00.600000', '0 days 00:00:00.800000'), ('0 days 00:00:00.700000', '0 days 00:00:00.900000')], names=['start', 'end']) >>> # Apply interface on an audformat conform index of a dataframe >>> import audb >>> db = audb.load( ... "emodb", ... version="1.3.0", ... media="wav/03a01Fa.wav", ... full_path=False, ... verbose=False, ... ) >>> interface = Segment( ... process_func=segment, ... process_func_args={"win_size": 0.5, "hop_size": 0.25}, ... ) >>> interface.process_index(db["emotion"].index, root=db.root) MultiIndex([('wav/03a01Fa.wav', '0 days 00:00:00', ...), ('wav/03a01Fa.wav', '0 days 00:00:00.250000', ...), ('wav/03a01Fa.wav', '0 days 00:00:00.500000', ...), ('wav/03a01Fa.wav', '0 days 00:00:00.750000', ...), ('wav/03a01Fa.wav', '0 days 00:00:01', ...), ('wav/03a01Fa.wav', '0 days 00:00:01.250000', ...)], names=['file', 'start', 'end']) """ # noqa: E501 def __init__( self, *, process_func: typing.Callable[..., pd.MultiIndex] = None, process_func_args: typing.Dict[str, typing.Any] = None, invert: bool = False, sampling_rate: int = None, resample: bool = False, channels: typing.Union[int, typing.Sequence[int]] = None, mixdown: bool = False, min_signal_dur: Timestamp = None, max_signal_dur: Timestamp = None, keep_nat: bool = False, num_workers: typing.Optional[int] = 1, multiprocessing: bool = False, verbose: bool = False, ): # avoid cycling imports from audinterface.core.process import Process if process_func is None: process_func = signal_index if invert: process_func_args = process_func_args or {} process_func_args["__process_func"] = process_func process_func = inverted_process_func process = Process( process_func=process_func, process_func_args=process_func_args, sampling_rate=sampling_rate, resample=resample, channels=channels, mixdown=mixdown, min_signal_dur=min_signal_dur, max_signal_dur=max_signal_dur, keep_nat=keep_nat, num_workers=num_workers, multiprocessing=multiprocessing, verbose=verbose, ) self.process = process r"""Processing object.""" self.invert = invert r"""Invert segmentation."""
[docs] def process_file( self, file: str, *, start: Timestamp = None, end: Timestamp = None, root: str = None, process_func_args: typing.Dict[str, typing.Any] = None, ) -> pd.Index: r"""Segment the content of an audio file. Args: file: file path start: start processing at this position. If value is a float or integer it is treated as seconds. See :func:`audinterface.utils.to_timedelta` for further options end: end processing at this position. If value is a float or integer it is treated as seconds. See :func:`audinterface.utils.to_timedelta` for further options root: root folder to expand relative file path process_func_args: (keyword) arguments passed on to the processing function. They will temporarily overwrite the ones stored in :attr:`audinterface.Segment.process.process_func_args` Returns: Segmented index conform to audformat_ Raises: RuntimeError: if sampling rates do not match RuntimeError: if channel selection is invalid .. _audformat: https://audeering.github.io/audformat/data-format.html """ if start is None or pd.isna(start): start = pd.to_timedelta(0) index = self.process.process_file( file, start=start, end=end, root=root, process_func_args=process_func_args, ).values[0] return audformat.segmented_index( files=[file] * len(index), starts=index.get_level_values("start") + start, ends=index.get_level_values("end") + start, )
[docs] def process_files( self, files: typing.Sequence[str], *, starts: Timestamps = None, ends: Timestamps = None, root: str = None, process_func_args: typing.Dict[str, typing.Any] = None, ) -> pd.Index: r"""Segment a list of files. Args: files: list of file paths starts: segment start positions. Time values given as float or integers are treated as seconds. See :func:`audinterface.utils.to_timedelta` for further options. If a scalar is given, it is applied to all files ends: segment end positions. Time values given as float or integers are treated as seconds See :func:`audinterface.utils.to_timedelta` for further options. If a scalar is given, it is applied to all files root: root folder to expand relative file paths process_func_args: (keyword) arguments passed on to the processing function. They will temporarily overwrite the ones stored in :attr:`audinterface.Segment.process.process_func_args` Returns: Segmented index conform to audformat_ Raises: RuntimeError: if sampling rates do not match RuntimeError: if channel selection is invalid .. _audformat: https://audeering.github.io/audformat/data-format.html """ y = self.process.process_files( files, starts=starts, ends=ends, root=root, process_func_args=process_func_args, ) if len(y) == 0: return audformat.filewise_index() files = [] starts = [] ends = [] for (file, start, _), index in y.items(): files.extend([file] * len(index)) starts.extend(index.get_level_values("start") + start) ends.extend(index.get_level_values("end") + start) return audformat.segmented_index(files, starts, ends)
[docs] def process_folder( self, root: str, *, filetype: str = "wav", include_root: bool = True, process_func_args: typing.Dict[str, typing.Any] = None, ) -> pd.Index: r"""Segment files in a folder. .. note:: At the moment does not scan in sub-folders! Args: root: root folder filetype: file extension include_root: if ``True`` the file paths are absolute in the index of the returned result process_func_args: (keyword) arguments passed on to the processing function. They will temporarily overwrite the ones stored in :attr:`audinterface.Segment.process.process_func_args` Returns: Segmented index conform to audformat_ Raises: FileNotFoundError: if folder does not exist RuntimeError: if sampling rates do not match RuntimeError: if channel selection is invalid .. _audformat: https://audeering.github.io/audformat/data-format.html """ root = audeer.path(root) if not os.path.exists(root): raise FileNotFoundError( errno.ENOENT, os.strerror(errno.ENOENT), root, ) files = audeer.list_file_names( root, filetype=filetype, basenames=not include_root, ) return self.process_files( files, root=root, process_func_args=process_func_args, )
[docs] def process_index( self, index: pd.Index, *, root: str = None, cache_root: str = None, process_func_args: typing.Dict[str, typing.Any] = None, ) -> pd.Index: r"""Segment files or segments from an index. If ``cache_root`` is not ``None``, a hash value is created from the index using :func:`audformat.utils.hash` and the result is stored as ``<cache_root>/<hash>.pkl``. When called again with the same index, results will be read from the cached file. Args: index: index conform to audformat_ root: root folder to expand relative file paths cache_root: cache folder (see description) process_func_args: (keyword) arguments passed on to the processing function. They will temporarily overwrite the ones stored in :attr:`audinterface.Segment.process.process_func_args` Returns: Segmented index conform to audformat_ Raises: RuntimeError: if sampling rates do not match RuntimeError: if channel selection is invalid .. _audformat: https://audeering.github.io/audformat/data-format.html """ index = audformat.utils.to_segmented_index(index) utils.assert_index(index) if index.empty: return index y = self.process.process_index( index, preserve_index=False, root=root, cache_root=cache_root, process_func_args=process_func_args, ) files = [] starts = [] ends = [] for (file, start, _), index in y.items(): files.extend([file] * len(index)) starts.extend(index.get_level_values("start") + start) ends.extend(index.get_level_values("end") + start) return audformat.segmented_index(files, starts, ends)
[docs] def process_table( self, table: typing.Union[pd.Series, pd.DataFrame], *, root: str = None, cache_root: str = None, process_func_args: typing.Dict[str, typing.Any] = None, ) -> typing.Union[pd.Series, pd.DataFrame]: r"""Segment files or segments from a table. The labels of the table are reassigned to the new segments. If ``cache_root`` is not ``None``, a hash value is created from the index using :func:`audformat.utils.hash` and the result is stored as ``<cache_root>/<hash>.pkl``. When called again with the same index, results will be read from the cached file. Args: table: :class:`pandas.Series` or :class:`pandas.DataFrame` with an index conform to audformat_ root: root folder to expand relative file paths cache_root: cache folder (see description) process_func_args: (keyword) arguments passed on to the processing function. They will temporarily overwrite the ones stored in :attr:`audinterface.Segment.process.process_func_args` Returns: Segmented table with an index conform to audformat_ Raises: ValueError: if table is not a :class:`pandas.Series` or a :class:`pandas.DataFrame` RuntimeError: if sampling rates do not match RuntimeError: if channel selection is invalid .. _audformat: https://audeering.github.io/audformat/data-format.html """ if not isinstance(table, pd.Series) and not isinstance(table, pd.DataFrame): raise ValueError("table has to be pd.Series or pd.DataFrame") index = audformat.utils.to_segmented_index(table.index) utils.assert_index(index) if index.empty: return table y = self.process.process_index( index, preserve_index=False, root=root, cache_root=cache_root, process_func_args=process_func_args, ) # Assign labels from the original table # to the newly created segments files = [] starts = [] ends = [] labels = [] if isinstance(table, pd.Series): for n, ((file, start, _), index) in enumerate(y.items()): files.extend([file] * len(index)) starts.extend(index.get_level_values("start") + start) ends.extend(index.get_level_values("end") + start) labels.extend([[table.iloc[n]] * len(index)]) labels = np.hstack(labels) else: for n, ((file, start, _), index) in enumerate(y.items()): files.extend([file] * len(index)) starts.extend(index.get_level_values("start") + start) ends.extend(index.get_level_values("end") + start) if len(index) > 0: # avoid issues when stacking 0-length dataframes labels.extend([[table.iloc[n].values] * len(index)]) if len(labels) > 0: labels = np.vstack(labels) else: labels = np.empty((0, table.shape[1])) # avoid issue below index = audformat.segmented_index(files, starts, ends) if isinstance(table, pd.Series): dtype = table.dtype table = pd.Series(labels, index, name=table.name, dtype=dtype) else: dtypes = [table[col].dtype for col in table.columns] labels = { col: pd.Series( labels[:, ncol], index=index, dtype=dtypes[ncol] ) # supports also category for ncol, col in enumerate(table.columns) } table = pd.DataFrame(labels, index) return table
[docs] def process_signal( self, signal: np.ndarray, sampling_rate: int, *, file: str = None, start: Timestamp = None, end: Timestamp = None, process_func_args: typing.Dict[str, typing.Any] = None, ) -> pd.Index: r"""Segment audio signal. .. note:: If a ``file`` is given, the index of the returned frame has levels ``file``, ``start`` and ``end``. Otherwise, it consists only of ``start`` and ``end``. Args: signal: signal values sampling_rate: sampling rate in Hz file: file path start: start processing at this position. If value is a float or integer it is treated as seconds. See :func:`audinterface.utils.to_timedelta` for further options end: end processing at this position. If value is a float or integer it is treated as seconds. See :func:`audinterface.utils.to_timedelta` for further options process_func_args: (keyword) arguments passed on to the processing function. They will temporarily overwrite the ones stored in :attr:`audinterface.Segment.process.process_func_args` Returns: Segmented index conform to audformat_ Raises: RuntimeError: if sampling rates do not match RuntimeError: if channel selection is invalid .. _audformat: https://audeering.github.io/audformat/data-format.html """ index = self.process.process_signal( signal, sampling_rate, file=file, start=start, end=end, process_func_args=process_func_args, ).values[0] utils.assert_index(index) if start is not None: start = utils.to_timedelta(start) # Here we change directly the levels, # so we need to use # `index.levels[0]` # instead of # `index.get_level_values('start')` index = index.set_levels( [ index.levels[0] + start, index.levels[1] + start, ], level=[0, 1], ) if file is not None: index = audformat.segmented_index( files=[file] * len(index), starts=index.get_level_values("start"), ends=index.get_level_values("end"), ) return index
[docs] def process_signal_from_index( self, signal: np.ndarray, sampling_rate: int, index: pd.Index, process_func_args: typing.Dict[str, typing.Any] = None, ) -> pd.Index: r"""Segment parts of a signal. Args: signal: signal values sampling_rate: sampling rate in Hz index: a segmented index conform to audformat_ or a :class:`pandas.MultiIndex` with two levels named `start` and `end` that hold start and end positions as :class:`pandas.Timedelta` objects. See also :func:`audinterface.utils.signal_index` process_func_args: (keyword) arguments passed on to the processing function. They will temporarily overwrite the ones stored in :attr:`audinterface.Segment.process.process_func_args` Returns: Segmented index conform to audformat_ Raises: RuntimeError: if sampling rates do not match RuntimeError: if channel selection is invalid ValueError: if index contains duplicates .. _audformat: https://audeering.github.io/audformat/data-format.html """ utils.assert_index(index) if index.empty: return index if isinstance(index, pd.MultiIndex) and len(index.levels) == 2: has_file_level = False params = [ ( (signal, sampling_rate), {"start": start, "end": end}, ) for start, end in index ] else: has_file_level = True index = audformat.utils.to_segmented_index(index) params = [ ( (signal, sampling_rate), { "file": file, "start": start, "end": end, "process_func_args": process_func_args, }, ) for file, start, end in index ] y = audeer.run_tasks( self.process_signal, params, num_workers=self.process.num_workers, multiprocessing=self.process.multiprocessing, progress_bar=self.process.verbose, task_description=f"Process {len(index)} segments", ) files = [] starts = [] ends = [] for idx in y: if has_file_level: files.extend(idx.get_level_values("file")) starts.extend(idx.get_level_values("start")) ends.extend(idx.get_level_values("end")) if has_file_level: index = audformat.segmented_index(files, starts, ends) else: index = utils.signal_index(starts, ends) return index
[docs] def __call__( self, signal: np.ndarray, sampling_rate: int, ) -> pd.Index: r"""Apply processing to signal. This function processes the signal **without** transforming the output into a :class:`pd.MultiIndex`. Instead, it will return the raw processed signal. However, if channel selection, mixdown and/or resampling is enabled, the signal will be first remixed and resampled if the input sampling rate does not fit the expected sampling rate. Args: signal: signal values sampling_rate: sampling rate in Hz Returns: Processed signal Raises: RuntimeError: if sampling rates do not match RuntimeError: if channel selection is invalid """ return self.process( signal, sampling_rate, )