G711 A-Law / u-Law audio-coding library

The library is written as an extension for python3 and allows to work simply with G711 encoded audio.

Requirements

1. Python 3.5+
2. Numpy (will be installed anyway before the building procedure)
3. Tools for building C/C++ applications (GCC/Clang/VS build tools)

Implementation details

The library is written in pure C and relies exclusively on a python build system. I tried to minimize the use of any platform-dependend functions to provide a truly cross-platform and fast library.

Installation

Source distribution is uploaded to PyPI, so just invoke pip install g711. Equivalently, you can clone code from https://github.com/stolpa4/g711 and then run pip install <path to cloned repo>.

Functions

• load_alaw(path: Union[str, os.PathLike]) -> numpy.ndarray(dtype=numpy.float32) - Opens a file, loads its contents and decodes it from A-Law to float32 numpy array.
• load_ulaw(path: Union[str, os.PathLike]) -> numpy.ndarray(dtype=numpy.float32) - Same for u-Law.
• save_alaw(path: Union[str, os.PathLike], audio_data: numpy.ndarray(dtype=numpy.float32)) -> bool - Encodes an array to A-Law and writes bytes to a specified file. audio_data can be anything convertible to numpy.ndarray(dtype=numpy.float32).
• save_ulaw(path: Union[str, os.PathLike], audio_data: numpy.ndarray(dtype=numpy.float32)) -> bool - Same for u-Law.
• decode_alaw(encoded_bts: bytes) -> numpy.ndarray(dtype=numpy.float32) - Decodes raw A-Law bytes to float32 audio.
• decode_ulaw(encoded_bts: bytes) -> numpy.ndarray(dtype=numpy.float32) - Same for u-Law.
• encode_alaw(audio_data: numpy.ndarray(dtype=numpy.float32)) -> bytes - Encodes an array to A-Law and returns bytes object. audio_data can be anything convertible to numpy.ndarray(dtype=numpy.float32).
• encode_ulaw(audio_data: numpy.ndarray(dtype=numpy.float32)) -> bytes - Same for u-Law.