StemMaker

StemMaker turns MP3 files into Traktor stem files (.stem.mp4): the original track plus four separate parts, drums, bass, other (melody) and vocals. DJs can then mute or boost single parts live, for acapellas, instrumentals or mashups.

• No Traktor software needed: convert whole MP3 collections and listen to every converted file in the built-in StemPlayer, all without Traktor installed.
• Nothing to set up: the separation (Demucs, via demucs.cpp) runs as C++ code on the processor. No Python, no PyTorch, no CUDA driver.
• Real .stem.mp4 files with master, four stems and Traktor metadata. They work in Traktor Pro 3 and 4 and on Kontrol hardware with stem decks.
• Batch queue for whole folders, with a time estimate, overnight runs and resume after a crash or power cut. The folder structure is rebuilt in the output folder.
• Tags and cover art are copied (title, artist, album, genre, BPM, key, label, ISRC).
• Built-in StemPlayer to check the result: mute, solo and a fader per stem, level meters, A/B against the original.
• Club level and bass fix as optional post-processing.
• Runs offline, no account, no cloud. Free and open source (MIT).

Traktor Pro 4 can separate stems itself and is faster per track. StemMaker is for people who want standalone, portable stem files next to their music, convert whole folders at once, or use Traktor 3. On a current PC one song takes about twice its length.