EmotionalMagenta

Emotional Magenta is the accessibility award winning project from the Music Hackspace Hackathon at Berklee College of Music on June 6-7, 2026. It connects live facial emotion analysis to Magenta Realtime music generation application Collider. Some modifications have been made since.

Music Hackspace Page: https://musichackspace.org/events/hackathon-boston-june-2026/projects/67

Alternate video: https://vimeo.com/1204253845?fl=ip&fe=ec

The current main flow:

• Reads webcam frames and performs periodic emotion analysis.
• Aggregates emotion signals over a time window for stability.
• Launches and updates the revised Collider app with a special emotion prompt node with the latest detected emotion.

Repository Layout

• main.py: Primary runtime entrypoint (camera + emotion + Collider bridge).
• src/core/analyzer.py: Emotion analysis and aggregation helpers.
• magenta-realtime/: Local Magenta Realtime source and Collider example project.
• scripts/rebuild_all.sh: One-command rebuild/bootstrap script.
• REBUILD.md: Detailed rebuild notes and options.

Requirements

• macOS
• Python 3.12+
• Webcam access (for live emotion detection)
• Network access for model downloads (mrt models ...)

Quick Start

No local build is required for normal use. The repo includes a prebuilt collider_em.app.

1. Create and activate a virtual environment:

python3.12 -m venv .venv
source .venv/bin/activate

2. Install project dependencies:

pip install -e .

3. Run the app.

python main.py

• The first time main.py is run, there is a delay while the analyzer model is downloaded.
• If the collider app crashes, send a keyboard interrupt to stop main.py. Then rerun python main.py and you should be good to go.

Build Scripts

If you need to build from source or refresh the checked-in prebuilt app, use these scripts:

Useful environment overrides:

• MODEL_NAME (default mrt2_base)
• DOWNLOAD_MODELS (1 or 0)
• AUTO_INSTALL_CMAKE (1 or 0)
• MAGENTA_REALTIME_BUILD_DIR (default magenta-realtime/build)
• JOBS (default 10)

./scripts/rebuild_all.sh

Optional overrides for rebuild_all.sh:

• MODEL_NAME (default mrt2_base)
• DOWNLOAD_MODELS (1 or 0)
• AUTO_INSTALL_CMAKE (1 or 0)
• MAGENTA_REALTIME_BUILD_DIR (default magenta-realtime/build)
• JOBS (default 10)

Collider App Discovery

main.py looks for the Collider app in this order:

1. COLLIDER_APP_PATH (environment variable)
2. prebuilt/collider/collider_em.app (checked-in prebuilt app)
3. magenta-realtime/build/examples/collider/collider_em.app
4. ~/Applications/collider_em.app

If the app is missing, run ./scripts/rebuild_all.sh or set COLLIDER_APP_PATH explicitly.

Shipping Prebuilt Collider In Git

Yes. You can include a built Collider app so users can run immediately without building first.

Recommended approach:

1. Build Collider once on a trusted macOS machine using 'scripts/rebuild_all.sh'. This also runs stage_prebuilt_Collider.sh, which moves the newly bulit binary to 'prebuilt/collider/collider_em.app'.
2. Commit with Git LFS enabled for prebuilt/collider/**.

Optional overrides:

• SOURCE_APP_PATH=/absolute/path/to/collider_em.app
• AUTO_STAGE=0 (copy only, do not run git add)

Notes:

Troubleshooting

Camera not opening

Symptoms:

• Unable to open camera device 0.

Checks:

• Confirm macOS camera permission is enabled for your terminal app and/or IDE.
• Close other apps that may be holding the camera.
• Re-run from an activated virtual environment.

Models missing or not found

Symptoms:

• Missing model bundle/state messages.
• Prompt like: Run mrt models download.

Fix:

mrt models init
mrt models download mrt2_base

Also verify that these files exist:

• models/mrt2_base/mrt2_base.mlxfn
• models/mrt2_base/mrt2_base_state.safetensors

Collider app not found

Symptoms:

• Collider app not found in expected locations.

Fix:

./scripts/rebuild_all.sh

Or set an explicit app path:

export COLLIDER_APP_PATH="/absolute/path/to/collider_em.app"
python main.py

Python environment issues

Symptoms:

• Import errors for magenta_rt, opencv-python, or deepface.

Fix:

source .venv/bin/activate
pip install -e .

If needed, recreate the environment with Python 3.12.

Build tool issues (CMake missing)

Symptoms:

• cmake: command not found.

Fix:

• Install CMake and verify it is on PATH.
• Or run the helper script with auto-install enabled:

AUTO_INSTALL_CMAKE=1 ./scripts/rebuild_all.sh

Runtime exits or interrupted run

Symptoms:

• Process exits with code 130.

Explanation:

• Exit code 130 usually means the process was interrupted (for example, Ctrl+C).

If this was unintentional, restart with:

python main.py

License

This project's own code is licensed under the Apache License 2.0 — see LICENSE for details.

Third-party components have their own licenses (Apache 2.0):

• magenta-realtime: Apache 2.0 — see third_party/licenses/magenta-realtime-LICENSE
• sequence-layers: Apache 2.0 — see third_party/licenses/sequence-layers-LICENSE

For full attribution details, see THIRD_PARTY_NOTICES.md.