Elospeed StemPacker 0.3

by Elospeed

🇩🇪 Deutsche Anleitung: LIESMICH.md · 🌐 Project page: elospeed.github.io/StemPacker

Turns finished single tracks into Traktor stem files (*.stem.mp4), without AI and in batches. Each song needs a master and up to four stems, for example from your DAW, from 5.1 DVDs or from another separation tool. Every song becomes one file <song>.stem.mp4 that loads straight into Traktor Pro 4.

StemPacker is part of the Elospeed StemMaker family. StemMaker separates your music into stems with AI; StemPacker packs stems you already have.

Status: version 0.3, version 0.1 tested with 178 songs in Traktor Pro 4. Please work with copies of your files.

Features

• Simple mode: drop one folder onto the window. StemPacker detects the naming by itself (Song_drums, Song - Bass, Song (Vocals), Song (A) … (D), Song_1 … _4 and more) and finds master and stems, even in separate subfolders. Without a master file, the master is mixed from the stems.
• Or set it yourself — folder + name pattern per track: the star * stands for the song name. Example 5.1 DVD: master * (DOWNMIX #1) in folder 1, stems * (A) … * (D) in folder 2. Example DAW export: master *, stems *_drums, *_bass, *_other, *_vocals in one folder.
• Presets: 5.1 DVD, DAW export, numbers, custom. Subfolders optional.
• Your own stem names and colours, shown directly in Traktor.
• Tags and cover from the master (title, artist, album, BPM, key, label, ISRC …). No title? The song name is used. Cover from the folder if the master has none.
• Formats: AAC 320 kbit/s (like Traktor), ALAC lossless 16 bit / 44.1 kHz, ALAC 24 bit at the original sample rate (test).
• Mix the master from the stems, fill missing stems with silence, overwrite or skip finished songs.
• Helpful checks: if a stem is missing, the list shows the file name it looked for and a similarly named file, if there is one. A track that is shorter or longer than the master gets a warning.
• Your source files are only read, never changed. Log file logs\StemPacker.log.
• Nine languages: English, German, Spanish, French, Portuguese (Brazil), Italian, Japanese, Dutch and Polish. Works at 100 % to 200 % Windows scaling.

Download

Get StemPacker-<version>.zip from the releases page, unzip it and start StemPacker.exe. Nothing is installed. The ZIP contains:

• StemPacker-User-Guide.pdf: full guide with pictures (English)
• Example\: three short test songs to try it
• StemPlayer.exe: listen to finished stem files without Traktor (mute/solo per stem)
• tools\ffmpeg.exe: FFmpeg (LGPL), does the actual audio work

Windows SmartScreen may warn because the exe is not signed: "More info" → "Run anyway".

FAQ

My stem file does not load into a Traktor track deck. That is how Traktor works: stem files only load into stem decks, also those made by Native Instruments' own Stem Creator. Switch the deck to a stem deck.

A song shows "missing". The list names the file it looked for, e.g. Stem 2 "Hello (B)", and a similarly named file if it finds one. Rename the file or adjust the pattern.

"Warning: Stem 2 is 1.3 s shorter than the master". The song was packed anyway. Listen in Traktor whether all stems are in sync.

Building

Lazarus 3.8 (Free Pascal 3.2.2), no extra packages:

lazbuild -B --os=win64 --cpu=x86_64 --ws=win32 src/StemPacker.lpi

The exe lands in bin\. Language files: python lang-tools/i18n.py src src/lang (translations in lang-tools/en.json and es.json). Download ZIP: tools/release-zip.sh bin/StemPacker.exe ausgabe. Every push and pull request is built automatically by GitHub Actions (.github/workflows/build.yml).

Developer documents (in German): CHANGELOG, ROADMAP, TODO, development rules, development log, test builds, ideas.

Support

StemPacker is a one-person hobby project. If it saves you some time, you can buy me a coffee on Ko-fi ☕. Entirely optional, the tool stays free either way.

Thanks

To Cuiusquemodi for the idea, the test with 178 songs and lots of feedback.

License

MIT, see LICENSE. The download ZIP contains FFmpeg (LGPL, runs as a separate program; licence and source info in tools\). FFmpeg is a trademark of Fabrice Bellard. Traktor is a trademark of Native Instruments; StemPacker is not affiliated with Native Instruments.