Module `audioio.audioloader`

Loading data, metadata, and markers from audio files.

load_audio(): load a whole audio file at once.
metadata(): read metadata of an audio file.
markers(): read markers of an audio file.
class AudioLoader: read data from audio files in chunks.

The read in data are always numpy arrays of floats ranging between -1 and 1. The arrays are 2-D ndarrays with first axis time and second axis channel, even for single channel data.

If an audio file cannot be loaded, you might need to install additional packages. See installation for further instructions.

For a demo run the module as:

python -m src.audioio.audioloader audiofile.wav

Global variables

var audio_loader_funcs: List of implemented load() functions.

Each element of the list is a tuple with the module's name and its load() function.

Functions

def main(*args)

Call demo with command line arguments.

Parameters

args : list of str: Command line arguments as provided by sys.argv[1:]

def load_wave(filepath)

Load wav file using the wave module from pythons standard libray.

Documentation

https://docs.python.org/3.8/library/wave.html

Parameters

filepath : str: The full path and name of the file to load.

Returns

data : ndarray: All data traces as an 2-D ndarray, first dimension is time, second is channel
rate : float: The sampling rate of the data in Hertz.

Raises

ImportError: The wave module is not installed

* Loading of the data failed

def load_ewave(filepath)

Load wav file using ewave module.

Documentation

https://github.com/melizalab/py-ewave

Parameters

filepath : str: The full path and name of the file to load.

Returns

data : ndarray: All data traces as an 2-D ndarray, first dimension is time, second is channel.
rate : float: The sampling rate of the data in Hertz.

Raises

ImportError: The ewave module is not installed

* Loading of the data failed

def load_wavfile(filepath)

Load wav file using scipy.io.wavfile.

Documentation

http://docs.scipy.org/doc/scipy/reference/io.html Does not support blocked read.

Parameters

filepath : str: The full path and name of the file to load.

Returns

data : ndarray: All data traces as an 2-D ndarray, first dimension is time, second is channel.
rate : float: The sampling rate of the data in Hertz.

Raises

ImportError: The scipy.io module is not installed

* Loading of the data failed

def load_soundfile(filepath)

Load audio file using SoundFile (based on libsndfile).

Documentation

http://pysoundfile.readthedocs.org http://www.mega-nerd.com/libsndfile

Parameters

filepath : str: The full path and name of the file to load.

Returns

data : ndarray: All data traces as an 2-D ndarray, first dimension is time, second is channel.
rate : float: The sampling rate of the data in Hertz.

Raises

ImportError: The soundfile module is not installed.

* Loading of the data failed.

def load_wavefile(filepath)

Load audio file using wavefile (based on libsndfile).

Documentation

https://github.com/vokimon/python-wavefile

Parameters

filepath : str: The full path and name of the file to load.

Returns

data : ndarray: All data traces as an 2-D ndarray, first dimension is time, second is channel.
rate : float: The sampling rate of the data in Hertz.

Raises

ImportError: The wavefile module is not installed.

* Loading of the data failed.

def load_audioread(filepath)

Load audio file using audioread.

Documentation

https://github.com/beetbox/audioread

Parameters

filepath : str: The full path and name of the file to load.

Returns

data : ndarray: All data traces as an 2-D ndarray, first dimension is time, second is channel.
rate : float: The sampling rate of the data in Hertz.

Raises

ImportError: The audioread module is not installed.

* Loading of the data failed.

def load_audio(filepath, verbose=0)

Call this function to load all channels of audio data from a file.

This function tries different python modules to load the audio file.

Parameters

filepath : str: The full path and name of the file to load.
verbose : int: If larger than zero show detailed error/warning messages.

Returns

data : ndarray: All data traces as an 2-D ndarray, even for single channel data. First dimension is time, second is channel. Data values range maximally between -1 and 1.
rate : float: The sampling rate of the data in Hertz.

Raises

ValueError: Empty filepath.
FileNotFoundError: filepath is not an existing file.
EOFError: File size of filepath is zero.
IOError: Failed to load data.

Examples

import matplotlib.pyplot as plt
from audioio import load_audio

data, rate = load_audio('some/audio.wav')
plt.plot(np.arange(len(data))/rate, data[:,0])
plt.show()

def metadata(filepath, store_empty=False)

Read metadata of an audio file.

Parameters

filepath : str or file handle: The audio file from which to read metadata.
store_empty : bool: If False do not return meta data with empty values.

Returns

meta_data : nested dict: Meta data contained in the audio file. Keys of the nested dictionaries are always strings. If the corresponding values are dictionaries, then the key is the section name of the metadata contained in the dictionary. All other types of values are values for the respective key. In particular they are strings. But other types like for example ints or floats are also allowed. See audioio.audiometadata module for available functions to work with such metadata.

Examples

from audioio import metadata, print_metadata
md = metadata('data.wav')
print_metadata(md)

def markers(filepath)

Read markers of an audio file.

See audioio.audiomarkers module for available functions to work with markers.

Parameters

filepath : str or file handle: The audio file.

Returns

locs : 2-D ndarray of int: Marker positions (first column) and spans (second column) for each marker (rows).
labels : 2-D ndarray of string objects: Labels (first column) and texts (second column) for each marker (rows).

Examples

from audioio import markers, print_markers
locs, labels = markers('data.wav')
print_markers(locs, labels)

def demo(file_path, plot)

Demo of the audioloader functions.

Parameters

file_path : str: File path of an audio file.
plot : bool: If True also plot the loaded data.

Classes

class AudioLoader (filepath=None, buffersize=10.0, backsize=0.0, verbose=0, **meta_kwargs)

Buffered reading of audio data for random access of the data in the file.

The class allows for reading very large audio files that do not fit into memory. An AudioLoader instance can be used like a huge read-only numpy array, i.e.

data = AudioLoader('path/to/audio/file.wav')
x = data[10000:20000,0]

The first index specifies the frame, the second one the channel.

Behind the scenes, AudioLoader tries to open the audio file with all available audio modules until it succeeds (first line). It then reads data from the file as necessary for the requested data (second line). Accesing the content of the audio files via a buffer that holds only a part of the data is managed by the BufferedArray class.

Reading sequentially through the file is always possible. Some modules, however, (e.g. audioread, needed for mp3 files) can only read forward. If previous data are requested, then the file is read from the beginning again. This slows down access to previous data considerably. Use the backsize argument of the open function to make sure some data are loaded into the buffer before the requested frame. Then a subsequent access to the data within backsize seconds before that frame can still be handled without the need to reread the file from the beginning.

Usage

With context management:

import audioio as aio
with aio.AudioLoader(filepath, 60.0, 10.0) as data:
    # do something with the content of the file:
    x = data[0:10000]
    y = data[10000:20000]
    z = x + y

For using a specific audio module, here the audioread module:

data = aio.AudioLoader()
with data.open_audioread(filepath, 60.0, 10.0):
    # do something ...

Use blocks() for sequential, blockwise reading and processing:

from scipy.signal import spectrogram
nfft = 2048
with aio.AudioLoader('some/audio.wav') as data:
    for x in data.blocks(100*nfft, nfft//2):
        f, t, Sxx = spectrogram(x, fs=data.rate,
                                nperseg=nfft, noverlap=nfft//2)

For loop iterates over single frames (1-D arrays containing samples for each channel):

with aio.AudioLoader('some/audio.wav') as data:
    for x in data:
        print(x)

Traditional open and close:

data = aio.AudioLoader(filepath, 60.0)
x = data[:,:]  # read the whole file
data.close()

this is the same as:

data = aio.AudioLoader()
data.open(filepath, 60.0)
...

Classes inheriting AudioLoader just need to implement

self.load_audio_buffer(offset, nsamples, pbuffer)

This function needs to load the supplied pbuffer with nframes frames of data starting at frame offset.

In the constructor or some kind of opening function, you need to set some member variables, as described for BufferedArray.

Parameters

filepath : str: Name of the file.
buffersize : float: Size of internal buffer in seconds.
backsize : float: Part of the buffer to be loaded before the requested start index in seconds.
verbose : int: If larger than zero show detailed error/warning messages.
store_empty : bool: If False do not return meta data with empty values.

Attributes

filepath : str: Path and name of the file.
rate : float: The sampling rate of the data in seconds.
channels : int: The number of channels.
frames : int: The number of frames in the file. Same as len().
format : str or None: Format of the audio file.
encoding : str or None: Encoding/subtype of the audio file.
shape : tuple: Frames and channels of the data.
ndim : int: Number of dimensions: always 2 (frames and channels).
offset : int: Index of first frame in the current buffer.
buffer : ndarray of floats: The curently available data from the file.
ampl_min : float: Minimum amplitude the file format supports. Always -1.0 for audio data.
ampl_max : float: Maximum amplitude the file format supports. Always +1.0 for audio data.

Methods

len(): Number of frames.
open(): Open an audio file by trying available audio modules.
open_*(): Open an audio file with the respective audio module.
__getitem__: Access data of the audio file.
update_buffer(): Update the internal buffer for a range of frames.
blocks(): Generator for blockwise processing of AudioLoader data.
format_dict(): technical infos about how the data are stored.
metadata(): Metadata stored along with the audio data.
markers(): Markers stored along with the audio data.
set_unwrap(): Set parameters for unwrapping clipped data.
close(): Close the file.

Notes

Access via __getitem__ or __next__ is slow! Even worse, using numpy functions on this class first converts it to a numpy array - that is something we actually do not want! We should subclass directly from numpy.ndarray . For details see http://docs.scipy.org/doc/numpy/user/basics.subclassing.html When subclassing, there is an offset argument, that might help to speed up __getitem__ .

Construtor for initializing 2D arrays (times x channels).

Expand source code

class AudioLoader(BufferedArray):
    """Buffered reading of audio data for random access of the data in the file.
    
    The class allows for reading very large audio files that do not
    fit into memory.
    An AudioLoader instance can be used like a huge read-only numpy array, i.e.
    ```
    data = AudioLoader('path/to/audio/file.wav')
    x = data[10000:20000,0]
    ```
    The first index specifies the frame, the second one the channel.

    Behind the scenes, `AudioLoader` tries to open the audio file with
    all available audio modules until it succeeds (first line). It
    then reads data from the file as necessary for the requested data
    (second line). Accesing the content of the audio files via a
    buffer that holds only a part of the data is managed by the
    `BufferedArray` class.

    Reading sequentially through the file is always possible. Some
    modules, however, (e.g. audioread, needed for mp3 files) can only
    read forward. If previous data are requested, then the file is read
    from the beginning again. This slows down access to previous data
    considerably. Use the `backsize` argument of the open function to
    make sure some data are loaded into the buffer before the requested
    frame. Then a subsequent access to the data within `backsize` seconds
    before that frame can still be handled without the need to reread
    the file from the beginning.

    Usage
    -----
    With context management:
    ```
    import audioio as aio
    with aio.AudioLoader(filepath, 60.0, 10.0) as data:
        # do something with the content of the file:
        x = data[0:10000]
        y = data[10000:20000]
        z = x + y
    ```

    For using a specific audio module, here the audioread module:
    ```
    data = aio.AudioLoader()
    with data.open_audioread(filepath, 60.0, 10.0):
        # do something ...
    ```

    Use `blocks()` for sequential, blockwise reading and processing:
    ```
    from scipy.signal import spectrogram
    nfft = 2048
    with aio.AudioLoader('some/audio.wav') as data:
        for x in data.blocks(100*nfft, nfft//2):
            f, t, Sxx = spectrogram(x, fs=data.rate,
                                    nperseg=nfft, noverlap=nfft//2)
    ```

    For loop iterates over single frames (1-D arrays containing samples for each channel):
    ```
    with aio.AudioLoader('some/audio.wav') as data:
        for x in data:
            print(x)
    ```
    
    Traditional open and close:
    ```
    data = aio.AudioLoader(filepath, 60.0)
    x = data[:,:]  # read the whole file
    data.close()
    ```
        
    this is the same as:
    ```
    data = aio.AudioLoader()
    data.open(filepath, 60.0)
    ...
    ```

    Classes inheriting AudioLoader just need to implement
    ```
    self.load_audio_buffer(offset, nsamples, pbuffer)
    ```
    This function needs to load the supplied `pbuffer` with
    `nframes` frames of data starting at frame `offset`.

    In the constructor or some kind of opening function, you need to
    set some member variables, as described for `BufferedArray`.
    
    Parameters
    ----------
    filepath: str
        Name of the file.
    buffersize: float
        Size of internal buffer in seconds.
    backsize: float
        Part of the buffer to be loaded before the requested start index in seconds.
    verbose: int
        If larger than zero show detailed error/warning messages.
    store_empty: bool
        If `False` do not return meta data with empty values.

    Attributes
    ----------
    filepath: str
        Path and name of the file.
    rate: float
        The sampling rate of the data in seconds.
    channels: int
        The number of channels.
    frames: int
        The number of frames in the file. Same as `len()`.
    format: str or None
        Format of the audio file.
    encoding: str or None
        Encoding/subtype of the audio file.
    shape: tuple
        Frames and channels of the data.
    ndim: int
        Number of dimensions: always 2 (frames and channels).
    offset: int
        Index of first frame in the current buffer.
    buffer: ndarray of floats
        The curently available data from the file.
    ampl_min: float
        Minimum amplitude the file format supports.
        Always -1.0 for audio data.
    ampl_max: float
        Maximum amplitude the file format supports.
        Always +1.0 for audio data.

    Methods
    -------
    - `len()`: Number of frames.
    - `open()`: Open an audio file by trying available audio modules.
    - `open_*()`: Open an audio file with the respective audio module.
    - `__getitem__`: Access data of the audio file.
    - `update_buffer()`: Update the internal buffer for a range of frames.
    - `blocks()`: Generator for blockwise processing of AudioLoader data.
    - `format_dict()`: technical infos about how the data are stored.
    - `metadata()`: Metadata stored along with the audio data.
    - `markers()`: Markers stored along with the audio data.
    - `set_unwrap()`: Set parameters for unwrapping clipped data.
    - `close()`: Close the file.

    Notes
    -----
    Access via `__getitem__` or `__next__` is slow!
    Even worse, using numpy functions on this class first converts
    it to a numpy array - that is something we actually do not want!
    We should subclass directly from numpy.ndarray .
    For details see http://docs.scipy.org/doc/numpy/user/basics.subclassing.html
    When subclassing, there is an offset argument, that might help to
    speed up `__getitem__` .

    """
    
    def __init__(self, filepath=None, buffersize=10.0, backsize=0.0,
                 verbose=0, **meta_kwargs):
        super().__init__(verbose=verbose)
        self.format = None
        self.encoding = None
        self._metadata = None
        self._locs = None
        self._labels = None
        self._load_metadata = metadata
        self._load_markers = markers
        self._metadata_kwargs = meta_kwargs
        self.filepath = None
        self.sf = None
        self.close = self._close
        self.load_buffer = self._load_buffer_unwrap
        self.ampl_min = -1.0
        self.ampl_max = +1.0
        self.unwrap = False
        self.unwrap_thresh = 0.0
        self.unwrap_clips = False
        self.unwrap_ampl = 1.0
        self.unwrap_downscale = True
        if filepath is not None:
            self.open(filepath, buffersize, backsize, verbose)
            
    numpy_encodings = {np.dtype(np.int64): 'PCM_64',
                       np.dtype(np.int32): 'PCM_32',
                       np.dtype(np.int16): 'PCM_16',
                       np.dtype(np.single): 'FLOAT',
                       np.dtype(np.double): 'DOUBLE',
                       np.dtype('>f4'): 'FLOAT',
                       np.dtype('>f8'): 'DOUBLE'}
    """ Map numpy dtypes to encodings.
    """

    def _close(self):
        pass

    def __del__(self):
        self.close()

    def format_dict(self):
        """ Technical infos about how the data are stored in the file.

        Returns
        -------
        fmt: dict
            Dictionary with filepath, format, encoding, samplingrate,
            channels, frames, and duration of the audio file as strings.

        """
        fmt = dict(filepath=self.filepath)
        if self.format is not None:
            fmt['format'] = self.format
        if self.encoding is not None:
            fmt['encoding'] = self.encoding
        fmt.update(dict(samplingrate=f'{self.rate:.0f}Hz',
                        channels=self.channels,
                        frames=self.frames,
                        duration=f'{self.frames/self.rate:.3f}s'))
        return fmt
        
    def metadata(self):
        """Metadata of the audio file.

        Parameters
        ----------
        store_empty: bool
            If `False` do not add meta data with empty values.

        Returns
        -------
        meta_data: nested dict

            Meta data contained in the audio file.  Keys of the nested
            dictionaries are always strings.  If the corresponding
            values are dictionaries, then the key is the section name
            of the metadata contained in the dictionary. All other
            types of values are values for the respective key. In
            particular they are strings. But other types like for
            example ints or floats are also allowed.  See
            `audioio.audiometadata` module for available functions to
            work with such metadata.

        """
        if self._metadata is None:
            if self._load_metadata is None:
                self._metadata = {}
            else:
                self._metadata = self._load_metadata(self.filepath,
                                                     **self._metadata_kwargs)
        return self._metadata

    def markers(self):
        """Read markers of the audio file.

        See `audioio.audiomarkers` module for available functions
        to work with markers.

        Returns
        -------
        locs: 2-D ndarray of int
            Marker positions (first column) and spans (second column)
            for each marker (rows).
        labels: 2-D ndarray of str objects
            Labels (first column) and texts (second column)
            for each marker (rows).
        """
        if self._locs is None:
            if self._load_markers is None:
                self._locs = np.zeros((0, 2), dtype=int)
                self._labels = np.zeros((0, 2), dtype=object)
            else:
                self._locs, self._labels = self._load_markers(self.filepath)
        return self._locs, self._labels 

    def set_unwrap(self, thresh, clips=False, down_scale=True, unit=''):
        """Set parameters for unwrapping clipped data.

        See unwrap() function from the audioio package.

        Parameters
        ----------
        thresh: float
            Threshold for detecting wrapped data relative to self.unwrap_ampl
            which is initially set to self.ampl_max.
            If zero, do not unwrap.
        clips: bool
            If True, then clip the unwrapped data properly.
            Otherwise, unwrap the data and double the
            minimum and maximum data range
            (self.ampl_min and self.ampl_max).
        down_scale: bool
            If not `clip`, then downscale the signal by a factor of two,
            in order to keep the range between -1 and 1.
        unit: str
            Unit of the data.
        """
        self.unwrap_ampl = self.ampl_max
        self.unwrap_thresh = thresh
        self.unwrap_clips = clips
        self.unwrap_down_scale = down_scale
        self.unwrap = thresh > 1e-3
        if self.unwrap:
            if self.unwrap_clips:
                add_unwrap(self.metadata(),
                           self.unwrap_thresh*self.unwrap_ampl,
                           self.unwrap_ampl, unit)
            elif down_scale:
                update_gain(self.metadata(), 0.5)
                add_unwrap(self.metadata(),
                           0.5*self.unwrap_thresh*self.unwrap_ampl,
                           0.0, unit)
            else:
                self.ampl_min *= 2
                self.ampl_max *= 2
                add_unwrap(self.metadata(),
                           self.unwrap_thresh*self.unwrap_ampl,
                           0.0, unit)

    def _load_buffer_unwrap(self, r_offset, r_size, pbuffer):
        """Load new data and unwrap it.

        Parameters
        ----------
        r_offset: int
           First frame to be read from file.
        r_size: int
           Number of frames to be read from file.
        pbuffer: ndarray
           Buffer where to store the loaded data.
        """
        self.load_audio_buffer(r_offset, r_size, pbuffer)
        if self.unwrap:
            # TODO: handle edge effects!
            unwrap(pbuffer, self.unwrap_thresh, self.unwrap_ampl)
            if self.unwrap_clips:
                pbuffer[pbuffer > self.ampl_max] = self.ampl_max
                pbuffer[pbuffer < self.ampl_min] = self.ampl_min
            elif self.unwrap_down_scale:
                pbuffer *= 0.5
                
                
    # wave interface:        
    def open_wave(self, filepath, buffersize=10.0, backsize=0.0,
                  verbose=0):
        """Open audio file for reading using the wave module.

        Note: we assume that setpos() and tell() use integer numbers!

        Parameters
        ----------
        filepath: str
            Name of the file.
        buffersize: float
            Size of internal buffer in seconds.
        backsize: float
            Part of the buffer to be loaded before the requested start index in seconds.
        verbose: int
            If larger than zero show detailed error/warning messages.

        Raises
        ------
        ImportError
            The wave module is not installed
        """
        self.verbose = verbose
        if self.verbose > 0:
            print(f'open_wave(filepath) with filepath={filepath}')
        if not audio_modules['wave']:
            self.rate = 0.0
            self.channels = 0
            self.frames = 0
            self.size = 0
            self.shape = (0, 0)
            self.offset = 0
            raise ImportError
        if self.sf is not None:
            self._close_wave()
        self.sf = wave.open(filepath, 'r')
        self.filepath = filepath
        self.rate = float(self.sf.getframerate())
        self.format = 'WAV'
        sampwidth = self.sf.getsampwidth()
        if sampwidth == 1:
            self.dtype = 'u1'
            self.encoding = 'PCM_U8'
        else:
            self.dtype = f'i{sampwidth}' 
            self.encoding = f'PCM_{sampwidth*8}'
        self.factor = 1.0/(2.0**(sampwidth*8-1))
        self.channels = self.sf.getnchannels()
        self.frames = self.sf.getnframes()
        self.shape = (self.frames, self.channels)
        self.size = self.frames * self.channels
        self.bufferframes = int(buffersize*self.rate)
        self.backframes = int(backsize*self.rate)
        self.init_buffer()
        self.close = self._close_wave
        self.load_audio_buffer = self._load_buffer_wave
        # read 1 frame to determine the unit of the position values:
        self.p0 = self.sf.tell()
        self.sf.readframes(1)
        self.pfac = self.sf.tell() - self.p0
        self.sf.setpos(self.p0)
        return self

    def _close_wave(self):
        """Close the audio file using the wave module. """
        if self.sf is not None:
            self.sf.close()
            self.sf = None

    def _load_buffer_wave(self, r_offset, r_size, buffer):
        """Load new data from file using the wave module.

        Parameters
        ----------
        r_offset: int
           First frame to be read from file.
        r_size: int
           Number of frames to be read from file.
        buffer: ndarray
           Buffer where to store the loaded data.
        """
        self.sf.setpos(r_offset*self.pfac + self.p0)
        fbuffer = self.sf.readframes(r_size)
        fbuffer = np.frombuffer(fbuffer, dtype=self.dtype).reshape((-1, self.channels))
        if self.dtype[0] == 'u':
            buffer[:, :] = fbuffer * self.factor - 1.0
        else:
            buffer[:, :] = fbuffer * self.factor


    # ewave interface:        
    def open_ewave(self, filepath, buffersize=10.0, backsize=0.0,
                   verbose=0):
        """Open audio file for reading using the ewave module.

        Parameters
        ----------
        filepath: str
            Name of the file.
        buffersize: float
            Size of internal buffer in seconds.
        backsize: float
            Part of the buffer to be loaded before the requested start index in seconds.
        verbose: int
            If larger than zero show detailed error/warning messages.

        Raises
        ------
        ImportError
            The ewave module is not installed.
        """
        self.verbose = verbose
        if self.verbose > 0:
            print(f'open_ewave(filepath) with filepath={filepath}')
        if not audio_modules['ewave']:
            self.rate = 0.0
            self.channels = 0
            self.frames = 0
            self.shape = (0, 0)
            self.size = 0
            self.offset = 0
            raise ImportError
        if self.sf is not None:
            self._close_ewave()
        self.sf = ewave.open(filepath, 'r')
        self.filepath = filepath
        self.rate = float(self.sf.sampling_rate)
        self.channels = self.sf.nchannels
        self.frames = self.sf.nframes
        self.shape = (self.frames, self.channels)
        self.size = self.frames * self.channels
        self.format = 'WAV' # or WAVEX?
        self.encoding = self.numpy_encodings[self.sf.dtype]
        self.bufferframes = int(buffersize*self.rate)
        self.backframes = int(backsize*self.rate)
        self.init_buffer()
        self.close = self._close_ewave
        self.load_audio_buffer = self._load_buffer_ewave
        return self

    def _close_ewave(self):
        """Close the audio file using the ewave module. """
        if self.sf is not None:
            del self.sf
            self.sf = None

    def _load_buffer_ewave(self, r_offset, r_size, buffer):
        """Load new data from file using the ewave module.

        Parameters
        ----------
        r_offset: int
           First frame to be read from file.
        r_size: int
           Number of frames to be read from file.
        buffer: ndarray
           Buffer where to store the loaded data.
        """
        fbuffer = self.sf.read(frames=r_size, offset=r_offset, memmap='r')
        fbuffer = ewave.rescale(fbuffer, 'float')
        if len(fbuffer.shape) == 1:
            fbuffer = np.reshape(fbuffer,(-1, 1))
        buffer[:,:] = fbuffer

        
    # soundfile interface:        
    def open_soundfile(self, filepath, buffersize=10.0, backsize=0.0,
                       verbose=0):
        """Open audio file for reading using the SoundFile module.

        Parameters
        ----------
        filepath: str
            Name of the file.
        bufferframes: float
            Size of internal buffer in seconds.
        backsize: float
            Part of the buffer to be loaded before the requested start index in seconds.
        verbose: int
            If larger than zero show detailed error/warning messages.

        Raises
        ------
        ImportError
            The SoundFile module is not installed
        """
        self.verbose = verbose
        if self.verbose > 0:
            print(f'open_soundfile(filepath) with filepath={filepath}')
        if not audio_modules['soundfile']:
            self.rate = 0.0
            self.channels = 0
            self.frames = 0
            self.shape = (0, 0)
            self.size = 0
            self.offset = 0
            raise ImportError
        if self.sf is not None:
            self._close_soundfile()
        self.sf = soundfile.SoundFile(filepath, 'r')
        self.filepath = filepath
        self.rate = float(self.sf.samplerate)
        self.channels = self.sf.channels
        self.frames = 0
        self.size = 0
        if self.sf.seekable():
            self.frames = self.sf.seek(0, soundfile.SEEK_END)
            self.sf.seek(0, soundfile.SEEK_SET)
        # TODO: if not seekable, we cannot handle that file!
        self.shape = (self.frames, self.channels)
        self.size = self.frames * self.channels
        self.format = self.sf.format
        self.encoding = self.sf.subtype
        self.bufferframes = int(buffersize*self.rate)
        self.backframes = int(backsize*self.rate)
        self.init_buffer()
        self.close = self._close_soundfile
        self.load_audio_buffer = self._load_buffer_soundfile
        return self

    def _close_soundfile(self):
        """Close the audio file using the SoundFile module. """
        if self.sf is not None:
            self.sf.close()
            self.sf = None

    def _load_buffer_soundfile(self, r_offset, r_size, buffer):
        """Load new data from file using the SoundFile module.

        Parameters
        ----------
        r_offset: int
           First frame to be read from file.
        r_size: int
           Number of frames to be read from file.
        buffer: ndarray
           Buffer where to store the loaded data.
        """
        self.sf.seek(r_offset, soundfile.SEEK_SET)
        buffer[:, :] = self.sf.read(r_size, always_2d=True)

        
    # wavefile interface:        
    def open_wavefile(self, filepath, buffersize=10.0, backsize=0.0,
                      verbose=0):
        """Open audio file for reading using the wavefile module.

        Parameters
        ----------
        filepath: str
            Name of the file.
        bufferframes: float
            Size of internal buffer in seconds.
        backsize: float
            Part of the buffer to be loaded before the requested start index in seconds.
        verbose: int
            If larger than zero show detailed error/warning messages.

        Raises
        ------
        ImportError
            The wavefile module is not installed
        """
        self.verbose = verbose
        if self.verbose > 0:
            print(f'open_wavefile(filepath) with filepath={filepath}')
        if not audio_modules['wavefile']:
            self.rate = 0.0
            self.channels = 0
            self.frames = 0
            self.shape = (0, 0)
            self.size = 0
            self.offset = 0
            raise ImportError
        if self.sf is not None:
            self._close_wavefile()
        self.sf = wavefile.WaveReader(filepath)
        self.filepath = filepath
        self.rate = float(self.sf.samplerate)
        self.channels = self.sf.channels
        self.frames = self.sf.frames
        self.shape = (self.frames, self.channels)
        self.size = self.frames * self.channels
        # get format and encoding:
        for attr in dir(wavefile.Format):
            v = getattr(wavefile.Format, attr)
            if isinstance(v, int):
                if v & wavefile.Format.TYPEMASK > 0 and \
                   (self.sf.format & wavefile.Format.TYPEMASK) == v:
                    self.format = attr
                if v & wavefile.Format.SUBMASK > 0 and \
                   (self.sf.format & wavefile.Format.SUBMASK) == v:
                    self.encoding = attr
        # init buffer:
        self.bufferframes = int(buffersize*self.rate)
        self.backframes = int(backsize*self.rate)
        self.init_buffer()
        self.close = self._close_wavefile
        self.load_audio_buffer = self._load_buffer_wavefile
        return self

    def _close_wavefile(self):
        """Close the audio file using the wavefile module. """
        if self.sf is not None:
            self.sf.close()
            self.sf = None

    def _load_buffer_wavefile(self, r_offset, r_size, buffer):
        """Load new data from file using the wavefile module.

        Parameters
        ----------
        r_offset: int
           First frame to be read from file.
        r_size: int
           Number of frames to be read from file.
        buffer: ndarray
           Buffer where to store the loaded data.
        """
        self.sf.seek(r_offset, wavefile.Seek.SET)
        fbuffer = self.sf.buffer(r_size, dtype=self.buffer.dtype)
        self.sf.read(fbuffer)
        buffer[:,:] = fbuffer.T

            
    # audioread interface:        
    def open_audioread(self, filepath, buffersize=10.0, backsize=0.0,
                       verbose=0):
        """Open audio file for reading using the audioread module.

        Note, that audioread can only read forward, therefore random and
        backward access is really slow.

        Parameters
        ----------
        filepath: str
            Name of the file.
        bufferframes: float
            Size of internal buffer in seconds.
        backsize: float
            Part of the buffer to be loaded before the requested start index in seconds.
        verbose: int
            If larger than zero show detailed error/warning messages.

        Raises
        ------
        ImportError
            The audioread module is not installed
        """
        self.verbose = verbose
        if self.verbose > 0:
            print(f'open_audioread(filepath) with filepath={filepath}')
        if not audio_modules['audioread']:
            self.rate = 0.0
            self.channels = 0
            self.frames = 0
            self.shape = (0, 0)
            self.size = 0
            self.offset = 0
            raise ImportError
        if self.sf is not None:
            self._close_audioread()
        self.sf = audioread.audio_open(filepath)
        self.filepath = filepath
        self.rate = float(self.sf.samplerate)
        self.channels = self.sf.channels
        self.frames = int(np.ceil(self.rate*self.sf.duration))
        self.shape = (self.frames, self.channels)
        self.size = self.frames * self.channels
        self.bufferframes = int(buffersize*self.rate)
        self.backframes = int(backsize*self.rate)
        self.init_buffer()
        self.read_buffer = np.zeros((0,0))
        self.read_offset = 0
        self.close = self._close_audioread
        self.load_audio_buffer = self._load_buffer_audioread
        self.filepath = filepath
        self.sf_iter = self.sf.__iter__()
        return self

    def _close_audioread(self):
        """Close the audio file using the audioread module. """
        if self.sf is not None:
            self.sf.__exit__(None, None, None)
            self.sf = None

    def _load_buffer_audioread(self, r_offset, r_size, buffer):
        """Load new data from file using the audioread module.

        audioread can only iterate through a file once and in blocksizes that are
        given by audioread. Therefore we keep yet another buffer: `self.read_buffer`
        at file offset `self.read_offset` containing whatever audioread returned.

        Parameters
        ----------
        r_offset: int
           First frame to be read from file.
        r_size: int
           Number of frames to be read from file.
        buffer: ndarray
           Buffer where to store the loaded data.
        """
        b_offset = 0
        if ( self.read_offset + self.read_buffer.shape[0] >= r_offset + r_size
             and self.read_offset < r_offset + r_size ):
            # read_buffer overlaps at the end of the requested interval:
            i = 0
            n = r_offset + r_size - self.read_offset
            if n > r_size:
                i += n - r_size
                n = r_size
            buffer[self.read_offset+i-r_offset:self.read_offset+i+n-r_offset,:] = self.read_buffer[i:i+n,:] / (2.0**15-1.0)
            if self.verbose > 2:
                print(f'  recycle {n:6d} frames from the front of the read buffer at {self.read_offset}-{self.read_offset+n} ({self.read_offset-self.offset}-{self.read_offset-self.offset+n} in buffer)')
            r_size -= n
            if r_size <= 0:
                return
        # go back to beginning of file:
        if r_offset < self.read_offset:
            if self.verbose > 2:
                print('  rewind')
            self._close_audioread()
            self.sf = audioread.audio_open(self.filepath)
            self.sf_iter = self.sf.__iter__()
            self.read_buffer = np.zeros((0,0))
            self.read_offset = 0
        # read to position:
        while self.read_offset + self.read_buffer.shape[0] < r_offset:
            self.read_offset += self.read_buffer.shape[0]
            try:
                if hasattr(self.sf_iter, 'next'):
                    fbuffer = self.sf_iter.next()
                else:
                    fbuffer = next(self.sf_iter)
            except StopIteration:
                self.read_buffer = np.zeros((0,0))
                buffer[:,:] = 0.0
                if self.verbose > 1:
                    print(f'  caught StopIteration, padded buffer with {r_size} zeros')
                break
            self.read_buffer = np.frombuffer(fbuffer, dtype='<i2').reshape(-1, self.channels)
            if self.verbose > 2:
                print(f'  read forward by {self.read_buffer.shape[0]} frames')
        # recycle file data:
        if ( self.read_offset + self.read_buffer.shape[0] > r_offset
             and self.read_offset <= r_offset ):
            i = r_offset - self.read_offset
            n = self.read_offset + self.read_buffer.shape[0] - r_offset
            if n > r_size:
                n = r_size
            buffer[:n,:] = self.read_buffer[i:i+n,:] / (2.0**15-1.0)
            if self.verbose > 2:
                print(f'  recycle {n:6d} frames from the end of the read buffer at {self.read_offset}-{self.read_offset + self.read_buffer.shape[0]} to {r_offset}-{r_offset+n} ({r_offset-self.offset}-{r_offset+n-self.offset} in buffer)')
            b_offset += n
            r_offset += n
            r_size -= n
        # read data:
        if self.verbose > 2 and r_size > 0:
            print(f'  read    {r_size:6d} frames at {r_offset}-{r_offset+r_size} ({r_offset-self.offset}-{r_offset+r_size-self.offset} in buffer)')
        while r_size > 0:
            self.read_offset += self.read_buffer.shape[0]
            try:
                if hasattr(self.sf_iter, 'next'):
                    fbuffer = self.sf_iter.next()
                else:
                    fbuffer = next(self.sf_iter)
            except StopIteration:
                self.read_buffer = np.zeros((0,0))
                buffer[b_offset:,:] = 0.0
                if self.verbose > 1:
                    print(f'  caught StopIteration, padded buffer with {r_size} zeros')
                break
            self.read_buffer = np.frombuffer(fbuffer, dtype='<i2').reshape(-1, self.channels)
            n = self.read_buffer.shape[0]
            if n > r_size:
                n = r_size
            if n > 0:
                buffer[b_offset:b_offset+n,:] = self.read_buffer[:n,:] / (2.0**15-1.0)
                if self.verbose > 2:
                    print(f'    read  {n:6d} frames to {r_offset}-{r_offset+n} ({r_offset-self.offset}-{r_offset+n-self.offset} in buffer)')
                b_offset += n
                r_offset += n
                r_size -= n

                                
    def open(self, filepath, buffersize=10.0, backsize=0.0, verbose=0):
        """Open audio file for reading.

        Parameters
        ----------
        filepath: str
            Name of the file.
        buffersize: float
            Size of internal buffer in seconds.
        backsize: float
            Part of the buffer to be loaded before the requested start index in seconds.
        verbose: int
            If larger than zero show detailed error/warning messages.

        Raises
        ------
        ValueError
            Empty `filepath`.
        FileNotFoundError
            `filepath` is not an existing file.
        EOFError
            File size of `filepath` is zero.
        IOError
            Failed to load data.
        """
        self.buffer = np.array([])
        self.rate = 0.0
        if not filepath:
            raise ValueError('input argument filepath is empty string!')
        if not os.path.isfile(filepath):
            raise FileNotFoundError(f'file "{filepath}" not found')
        if os.path.getsize(filepath) <= 0:
            raise EOFError(f'file "{filepath}" is empty (size=0)!')
        # list of implemented open functions:
        audio_open_funcs = (
            ('soundfile', self.open_soundfile),
            ('wave', self.open_wave),
            ('wavefile', self.open_wavefile),
            ('ewave', self.open_ewave),
            ('audioread', self.open_audioread),
            )
        # open an audio file by trying various modules:
        not_installed = []
        errors = [f'failed to load data from file "{filepath}":']
        for lib, open_file in audio_open_funcs:
            if not audio_modules[lib]:
                if verbose > 1:
                    print(f'unable to load data from file "{filepath}" using {lib} module: module not available')
                not_installed.append(lib)
                continue
            try:
                open_file(filepath, buffersize, backsize, verbose-1)
                if self.frames > 0:
                    if verbose > 0:
                        print(f'opened audio file "{filepath}" using {lib}')
                        if verbose > 1:
                            if self.format is not None:
                                print(f'  format       : {self.format}')
                            if self.encoding is not None:
                                print(f'  encoding     : {self.encoding}')
                            print(f'  sampling rate: {self.rate} Hz')
                            print(f'  channels     : {self.channels}')
                            print(f'  frames       : {self.frames}')
                    return self
            except Exception as e:
                errors.append(f'  {lib} failed: {str(e)}')
                if verbose > 1:
                    print(errors[-1])
        if len(not_installed) > 0:
            errors.append('\n  You may need to install one of the ' + \
              ', '.join(not_installed) + ' packages.')
        raise IOError('\n'.join(errors))
        return self

Ancestors

BufferedArray

Class variables

var numpy_encodings: Map numpy dtypes to encodings.

Methods

def format_dict(self)

Technical infos about how the data are stored in the file.

Returns

fmt : dict: Dictionary with filepath, format, encoding, samplingrate, channels, frames, and duration of the audio file as strings.

def metadata(self)

Metadata of the audio file.

Parameters

store_empty : bool: If False do not add meta data with empty values.

Returns

meta_data : nested dict: Meta data contained in the audio file. Keys of the nested dictionaries are always strings. If the corresponding values are dictionaries, then the key is the section name of the metadata contained in the dictionary. All other types of values are values for the respective key. In particular they are strings. But other types like for example ints or floats are also allowed. See audioio.audiometadata module for available functions to work with such metadata.

def markers(self)

Read markers of the audio file.

See audioio.audiomarkers module for available functions to work with markers.

Returns

locs : 2-D ndarray of int: Marker positions (first column) and spans (second column) for each marker (rows).
labels : 2-D ndarray of str objects: Labels (first column) and texts (second column) for each marker (rows).

def set_unwrap(self, thresh, clips=False, down_scale=True, unit='')

Set parameters for unwrapping clipped data.

See unwrap() function from the audioio package.

Parameters

thresh : float: Threshold for detecting wrapped data relative to self.unwrap_ampl which is initially set to self.ampl_max. If zero, do not unwrap.
clips : bool: If True, then clip the unwrapped data properly. Otherwise, unwrap the data and double the minimum and maximum data range (self.ampl_min and self.ampl_max).
down_scale : bool: If not clip, then downscale the signal by a factor of two, in order to keep the range between -1 and 1.
unit : str: Unit of the data.

def open_wave(self, filepath, buffersize=10.0, backsize=0.0, verbose=0)

Open audio file for reading using the wave module.

Note: we assume that setpos() and tell() use integer numbers!

Parameters

filepath : str: Name of the file.
buffersize : float: Size of internal buffer in seconds.
backsize : float: Part of the buffer to be loaded before the requested start index in seconds.
verbose : int: If larger than zero show detailed error/warning messages.

Raises

ImportError: The wave module is not installed

def open_ewave(self, filepath, buffersize=10.0, backsize=0.0, verbose=0)

Open audio file for reading using the ewave module.

Parameters

filepath : str: Name of the file.
buffersize : float: Size of internal buffer in seconds.
backsize : float: Part of the buffer to be loaded before the requested start index in seconds.
verbose : int: If larger than zero show detailed error/warning messages.

Raises

ImportError: The ewave module is not installed.

def open_soundfile(self, filepath, buffersize=10.0, backsize=0.0, verbose=0)

Open audio file for reading using the SoundFile module.

Parameters

filepath : str: Name of the file.
bufferframes : float: Size of internal buffer in seconds.
backsize : float: Part of the buffer to be loaded before the requested start index in seconds.
verbose : int: If larger than zero show detailed error/warning messages.

Raises

ImportError: The SoundFile module is not installed

def open_wavefile(self, filepath, buffersize=10.0, backsize=0.0, verbose=0)

Open audio file for reading using the wavefile module.

Parameters

filepath : str: Name of the file.
bufferframes : float: Size of internal buffer in seconds.
backsize : float: Part of the buffer to be loaded before the requested start index in seconds.
verbose : int: If larger than zero show detailed error/warning messages.

Raises

ImportError: The wavefile module is not installed

def open_audioread(self, filepath, buffersize=10.0, backsize=0.0, verbose=0)

Open audio file for reading using the audioread module.

Note, that audioread can only read forward, therefore random and backward access is really slow.

Parameters

filepath : str: Name of the file.
bufferframes : float: Size of internal buffer in seconds.
backsize : float: Part of the buffer to be loaded before the requested start index in seconds.
verbose : int: If larger than zero show detailed error/warning messages.

Raises

ImportError: The audioread module is not installed

def open(self, filepath, buffersize=10.0, backsize=0.0, verbose=0)

Open audio file for reading.

Parameters

filepath : str: Name of the file.
buffersize : float: Size of internal buffer in seconds.
backsize : float: Part of the buffer to be loaded before the requested start index in seconds.
verbose : int: If larger than zero show detailed error/warning messages.

Raises

ValueError: Empty filepath.
FileNotFoundError: filepath is not an existing file.
EOFError: File size of filepath is zero.
IOError: Failed to load data.

Inherited members

BufferedArray:
- allocate_buffer
- blocks
- buffer_position
- init_buffer
- move_buffer
- recycle_buffer
- reload_buffer
- update_buffer
- update_time