This is a Renoise tool (XRNX) that allows you to change the bit depth of all samples in the currently selected instrument.
Currently, Renoise does not expose converting bit depth or sample rate in the Lua API. So it requires creating a new sample buffer inside Renoise and copying over the data manually. Therefore, existing samples using non-standard sample rates are unsupported.
Ideally, go to the Renoise tools page.
Or, you can turn these sources into a tool by zipping the files and changing the file extension to .xrnx.
Public Domain