Scroll to navigation

PYTHON-SAMPLERATE(1) python-samplerate PYTHON-SAMPLERATE(1)

NAME

python-samplerate - python-samplerate Documentation [image]
<https://pypi.python.org/pypi/samplerate>[image]
<https://pypi.python.org/pypi/samplerate>[image]
<https://pypi.python.org/pypi/samplerate>[image]
<https://pypi.python.org/pypi/samplerate>[image: Documentation Status] [image]
<http://python-samplerate.readthedocs.io/en/latest/?badge=latest>

This is a wrapper around Erik de Castro Lopo's libsamplerate <http://www.mega-nerd.com/libsamplerate/> (aka Secret Rabbit Code) for high-quality sample rate conversion.

It implements all three APIs <http://www.mega-nerd.com/libsamplerate/api.html> available in libsamplerate <http://www.mega-nerd.com/libsamplerate/>:

  • Simple API: for resampling a large chunk of data with a single library call
  • Full API: for obtaining the resampled signal from successive chunks of data
  • Callback API: like Full API, but input samples are provided by a callback function

The libsamplerate <http://www.mega-nerd.com/libsamplerate/> library is statically built together with the python bindings using pybind11 <https://github.com/pybind/pybind11/>.

INSTALLATION

$ pip install samplerate


Binary wheels of libsamplerate <http://www.mega-nerd.com/libsamplerate/> for macOS and Windows (64 bit) are available. For other systems, a C++ 14 or above compiler is required to build the package.

USAGE

import numpy as np
import samplerate
# Synthesize data
fs = 1000.
t = np.arange(fs * 2) / fs
input_data = np.sin(2 * np.pi * 5 * t)
# Simple API
ratio = 1.5
converter = 'sinc_best'  # or 'sinc_fastest', ...
output_data_simple = samplerate.resample(input_data, ratio, converter)
# Full API
resampler = samplerate.Resampler(converter, channels=1)
output_data_full = resampler.process(input_data, ratio, end_of_input=True)
# The result is the same for both APIs.
assert np.allclose(output_data_simple, output_data_full)
# See `samplerate.CallbackResampler` for the Callback API, or
# `examples/play_modulation.py` for an example.


See samplerate.resample, samplerate.Resampler, and samplerate.CallbackResampler in the API documentation for details.

SEE ALSO


LICENSE

This project is licensed under the MIT license <https://opensource.org/licenses/MIT>.

As of version 0.1.9, libsamplerate <http://www.mega-nerd.com/libsamplerate/> is licensed under the 2-clause BSD license <https://opensource.org/licenses/BSD-2-Clause>.

API DOCUMENTATION

samplerate module documentation

samplerate -- Python bindings for libsamplerate based on CFFI and NumPy

Simple API

See samplerate.converters.resample() <#samplerate.converters.resample>.

Full API

See samplerate.converters.Resampler() <#samplerate.converters.Resampler>.

Callback API

See samplerate.converters.CallbackResampler() <#samplerate.converters.CallbackResampler>.

Exceptions

See samplerate.converters.CallbackResampler() <#samplerate.converters.CallbackResampler>.

samplerate.converters -- Sample rate converters

Converter types

Enum of samplerate converter types.

Pass any of the members, or their string or value representation, as converter_type in the resamplers.



Members:

sinc_best

sinc_medium

sinc_fastest

zero_order_hold

linear











Sample rate converters

Simple

Resample the signal in input_data at once.
  • input_data (ndarray) -- Input data. Input data with one or more channels is represented as a 2D array of shape (num_frames, num_channels). A single channel can be provided as a 1D array of num_frames length. For use with libsamplerate, input_data is converted to 32-bit float and C (row-major) memory order.
  • ratio (float) -- Conversion ratio = output sample rate / input sample rate.
  • converter_type (ConverterType <#samplerate.converters.ConverterType>, str, or int) -- Sample rate converter (default: sinc_best).
  • verbose (bool) -- If True, print additional information about the conversion.

output_data -- Resampled input data.
ndarray

Note:

If samples are to be processed in chunks, Resampler and CallbackResampler will provide better results and allow for variable conversion ratios.



Full API

Resampler.
  • converter_type (ConverterType <#samplerate.converters.ConverterType>, str, or int) -- Sample rate converter (default: sinc_best).
  • num_channels (int) -- Number of channels.


Number of channels.

Creates a copy of the resampler object with the same internal state.

Converter type.

Resample the signal in input_data.
  • input_data (ndarray) -- Input data. Input data with one or more channels is represented as a 2D array of shape (num_frames, num_channels). A single channel can be provided as a 1D array of num_frames length. For use with libsamplerate, input_data is converted to 32-bit float and C (row-major) memory order.
  • ratio (float) -- Conversion ratio = output sample rate / input sample rate.
  • end_of_input (int) -- Set to True if no more data is available, or to False otherwise.
  • verbose (bool) -- If True, print additional information about the conversion.

output_data -- Resampled input data.
ndarray


Reset internal state.

Set a new conversion ratio immediately.


Callback API

CallbackResampler.
  • callback (function) -- Function that returns new frames on each call, or None otherwise. Input data with one or more channels is represented as a 2D array of shape (num_frames, num_channels). A single channel can be provided as a 1D array of num_frames length. For use with libsamplerate, input_data is converted to 32-bit float and C (row-major) memory order.
  • ratio (float) -- Conversion ratio = output sample rate / input sample rate.
  • converter_type (ConverterType <#samplerate.converters.ConverterType>, str, or int) -- Sample rate converter.
  • channels (int) -- Number of channels.


Number of channels.

Create a copy of the resampler object.

Converter type.

Conversion ratio = output sample rate / input sample rate.

Read a number of frames from the resampler.
num_frames (int) -- Number of frames to read.
output_data -- Resampled frames as a (num_output_frames, num_channels) or (num_output_frames,) array. Note that this may return fewer frames than requested, for example when no more input is available.
ndarray


Reset state.

Set the starting conversion ratio for the next read call.


samplerate.exceptions -- Sample rate exceptions


CHANGE LOG

Change Log

0.1.0

•
Initial release.

INDICES AND TABLES

  • Index <>
  • Module Index <>
  • Search Page <>

Author

Tino Wagner

Copyright

2017, Tino Wagner

March 8, 2026 0.0.0