Download on Github: https://github.com/downthecrop/audio-remuxer/releases/

Features:
- Automatically selects the most recent stream recording to remux
- Drag any recordings onto the .exe to remux them into the output directory
- Fast. a 2 hour stream can be muxed in 10 seconds.
- Batch directory support
- Output file prefixing
- Free and Open Source

With Twitch DMCA muting vods lots of people are going to be multitrack recoding locally. This tool can remux multritrack recodings into a new mp4 with a single audiotrack selected. Useful specifically if you record a track with only game audio and microphone selected for archival on Twitch or YouTube.

If you utilize multitrack recording with OBS you might already be using a script to use FFMPEG to remux the video. This program makes remuxing after a stream really easy.