Combine local microhone audio with RTSP stream audio

[bleathe]

I am currently working on a project which requires me to record audio both coming from the user speaking into the microphone, and audio coming from a remote location via an RTSP stream. I have been digging through some old forum posts and I'm starting to wonder if this is even possible using VLC due to differences in time stamps between the two streams, or failure to combine dshow captures with other sources. Am I correct in thinking this? Ideally all I want to do is capture live audio from both streams and have them be combined into a single audio file.

I have been trying to make use of the "Play another media synchronously" checkbox located in the VLC GUI, but haven't had any luck combining my RTSP stream with the dshow audio capture, and only seem to be able to save one at a time.

I have also been trying a solution where I save both streams to separate files, and then use VLC to mux the two files together after everything has been recorded. This produces similar results however I was noticing that while playing the video in VLC I have two seperate audio tracks to choose from, however one of them is always silent.

Is there some solution to this problem that I have been overlooking?