import numpy as np
from . import container
SAMPLING_RATE_ATTR = 'sampling-rate'
MAX_INT16_VALUE = np.iinfo(np.int16).max
[docs]class AudioContainer(container.Container):
"""
Container to store raw audio samples.
Notes:
The samples are stored as 16-Bit Integers.
But all methods expect or return the samples as 32-Bit Floats,
in the range of -1.0 to 1.0.
"""
[docs] def get(self, key, mem_map=True):
"""
Return the samples for the given key and the sampling-rate.
Args:
key (str): The key to read the data from.
mem_map (bool): If ``True`` returns the data as
memory-mapped array, otherwise a copy is returned.
Note:
The container has to be opened in advance.
Returns:
tuple: A tuple containing the samples as numpy array
with ``np.float32`` [-1.0,1.0] and the sampling-rate.
"""
self.raise_error_if_not_open()
if key in self._file:
data = self._file[key]
sampling_rate = data.attrs[SAMPLING_RATE_ATTR]
if not mem_map:
data = data[()]
data = np.float32(data) / MAX_INT16_VALUE
return data, sampling_rate
return None
# skipcq: PYL-W0221
[docs] def set(self, key, samples, sampling_rate):
"""
Set the samples and sampling-rate for the given key.
Existing data will be overwritten.
The samples have to have ``np.float32`` datatype and values in
the range of -1.0 and 1.0.
Args:
key (str): A key to store the data for.
samples (numpy.ndarray): 1-D array of audio samples (np.float32).
sampling_rate (int): The sampling-rate of the audio samples.
Note:
The container has to be opened in advance.
"""
if not np.issubdtype(samples.dtype, np.floating):
raise ValueError('Samples are required as np.float32!')
if len(samples.shape) > 1:
raise ValueError('Only single channel supported!')
self.raise_error_if_not_open()
if key in self._file:
del self._file[key]
samples = (samples * MAX_INT16_VALUE).astype(np.int16)
dset = self._file.create_dataset(key, data=samples)
dset.attrs[SAMPLING_RATE_ATTR] = sampling_rate
# skipcq: PYL-W0221
[docs] def append(self, key, samples, sampling_rate):
"""
Append the given samples to the data that already exists
in the container for the given key.
Args:
key (str): A key to store the data for.
samples (numpy.ndarray): 1-D array of audio samples (int-16).
sampling_rate (int): The sampling-rate of the audio samples.
Note:
The container has to be opened in advance.
For appending to existing data the HDF5-Dataset has to be chunked,
so it is not allowed to first add data via ``set``.
"""
if not np.issubdtype(samples.dtype, np.floating):
raise ValueError('Samples are required as np.float32!')
if len(samples.shape) > 1:
raise ValueError('Only single channel supported!')
existing = self.get(key, mem_map=True)
samples = (samples * MAX_INT16_VALUE).astype(np.int16)
if existing is not None:
existing_samples, existing_sr = existing
if existing_sr != sampling_rate:
raise ValueError('Different sampling-rate than existing data!')
num_existing = existing_samples.shape[0]
self._file[key].resize(num_existing + samples.shape[0], 0)
self._file[key][num_existing:] = samples
else:
dset = self._file.create_dataset(key, data=samples,
chunks=True, maxshape=(None,))
dset.attrs[SAMPLING_RATE_ATTR] = sampling_rate