Hi,

Two I know of are CWGet and CWDecoder. They work by interpreting data from sound card input. They are generally meant to work with CW received from a ham radio, that is, feeding ham radio output into the computer sound card input.

Not sure if this will work with audio coming "out" of the sound card.

If you don't have a physical SW Receiver, what probably will work is if you have two PCs/Laptops and fed the output from the SDR receiver machine (line-out) into the computer sound card (line in) with the CW software.

Note, these software packages are often volume sensitive. You usually have to fiddle around to get the volume going into the machine with the CW software just right (usually volume going in need to be very low – as in the just barely audible range). Also, it may not work well if you would try to use the Microphone in as opposed to the line-in. Some sound cards may only have one or the other. Others may only have one sound input port, but the sound card driver may have a software setting that allow it to be used as either a Microphone-In or a Line-In, at any one time

Edited to make a clarification

buckeye