Mu-law companding (encode): linear amplitude to companded.
Parameters:
x (Union[_Buffer, _SupportsArray[dtype[Any]], _NestedSequence[_SupportsArray[dtype[Any]]], complex, bytes, str, _NestedSequence[complex | bytes | str]]) – Input signal. If input is in [-1, 1], the output will be in [-1, 1].
mu (float) – Compression parameter (default 255, as in G.711).
