audioop.ulaw2lin(fragment, width) Convert sound fragments in u-LAW encoding to linearly encoded sound fragments. u-LAW encoding always uses 8 bits samples, so width refers only to the sample width of the output fragment here.

audioop.tostereo(fragment, width, lfactor, rfactor) Generate a stereo fragment from a mono fragment. Each pair of samples in the stereo fragment are computed from the mono sample, whereby left channel samples are multiplied by lfactor and right channel samples by rfactor.

base64.a85decode(b, *, foldspaces=False, adobe=False, ignorechars=b' \t\n\r\v') Decode the Ascii85 encoded bytes-like object or ASCII string b and return the decoded bytes. foldspaces is a flag that specifies whether the ‘y’ short sequence should be accepted as shorthand for 4 consecutive spaces (ASCII 0x20). This feature is not supported by the “standard” Ascii85 encoding. adobe controls whether the input sequence is in Adobe Ascii85 format (i.e. is framed with <~ and ~>). ignorechars

audioop.mul(fragment, width, factor) Return a fragment that has all samples in the original fragment multiplied by the floating-point value factor. Samples are truncated in case of overflow.

audioop.ratecv(fragment, width, nchannels, inrate, outrate, state[, weightA[, weightB]]) Convert the frame rate of the input fragment. state is a tuple containing the state of the converter. The converter returns a tuple (newfragment, newstate), and newstate should be passed to the next call of ratecv(). The initial call should pass None as the state. The weightA and weightB arguments are parameters for a simple digital filter and default to 1 and 0 respectively.

audioop.reverse(fragment, width) Reverse the samples in a fragment and returns the modified fragment.

audioop.rms(fragment, width) Return the root-mean-square of the fragment, i.e. sqrt(sum(S_i^2)/n). This is a measure of the power in an audio signal.

audioop.tomono(fragment, width, lfactor, rfactor) Convert a stereo fragment to a mono fragment. The left channel is multiplied by lfactor and the right channel by rfactor before adding the two channels to give a mono signal.

audioop.minmax(fragment, width) Return a tuple consisting of the minimum and maximum values of all samples in the sound fragment.

audioop.lin2adpcm(fragment, width, state) Convert samples to 4 bit Intel/DVI ADPCM encoding. ADPCM coding is an adaptive coding scheme, whereby each 4 bit number is the difference between one sample and the next, divided by a (varying) step. The Intel/DVI ADPCM algorithm has been selected for use by the IMA, so it may well become a standard. state is a tuple containing the state of the coder. The coder returns a tuple (adpcmfrag, newstate), and the newstate should be passed to the next call