NepTune - A social network for samples

NepTune is an Android app and backend that makes capturing, editing, and sharing short audio samples simple and social. It combines a lightweight sound-design toolset (resampling without pitch distortion, filters, reverb, fades) with social features (sharing, subscriptions, favorites, stats).

This project has been done for the CS-311 course at EPFL given by George Candea

Install the app

You can download the last apk release here

Project overview

NepTune helps creators capture real-world sound, apply basic audio processing, and share results with a community. The Android app (in app/) includes audio capture and editing features and integrates with Firebase for auth, storage and server-side processing. Cloud functions (in functions/) perform heavier tasks such as server-side preview generation and FFmpeg-based processing.

Key features

• Record audio from the device microphone
• Basic sound design: resampling (without pitch shift), filters, reverb, fade in/out
• Export as WAV or as a portable project file
• Social features: share samples, follow users, favorites, stats
• Server-side sample processing & preview generation (Firebase Functions + FFmpeg)

UI/UX

Link to our Figma design

Structure and data diagram

Build the project

Setup

1. Install JDK 11 and Android Studio.
2. Configure local Android SDK in Android Studio and set local.properties if needed (Android Studio usually writes this automatically):
   • local.properties (example):

     sdk.dir=/path/to/Android/Sdk
     

3. Open the project in Android Studio by selecting the repository root or settings.gradle.kts.
4. Gradle will sync dependencies. If Android Studio asks to upgrade Gradle plugin or Kotlin plugin, prefer the versions defined by the project unless you have a specific reason.
5. Ensure app/google-services.json is present. If you need to use a different Firebase project, replace that file with one from the Firebase console.
6. Native libraries: app/libs/ contains TarsosDSPKit-release.aar which is included by the Gradle build. No extra steps required unless you replace the AAR.

Firebase emulator

1. Ensure you have Node.js 22 installed (the functions package.json sets engines.node to 22).
2. Install Firebase CLI (npm install -g firebase-tools) and log in: firebase login.
3. Navigate to the functions folder and install dependencies:

   cd functions
   npm install
   

4. Run the emulator: firebase emulators:start

Build, run and test commands (quick reference)

Android (from repo root):

• Build debug APK: ./gradlew :app:assembleDebug

• Build release APK (ensure signing config / keystore is available): ./gradlew :app:assembleRelease

• Run unit tests (JVM/Robolectric): ./gradlew :app:testDebugUnitTest

• Run connected instrumentation tests (device/emulator required): ./gradlew :app:connectedDebugAndroidTest

• Generate combined JaCoCo report (unit + android tests; configured in app/build.gradle.kts): ./gradlew :app:jacocoTestReport

CI and release notes

• Keep secrets out of the repository. Configure CI secrets for:
  • Firebase token (FIREBASE_TOKEN) or use service account auth
  • Keystore file and passwords (or upload the keystore as a protected CI artifact)
• Example automated steps for CI (GitHub Actions):
  1. Checkout
  2. Set up JDK 11 and Android SDK
  3. Cache Gradle & Node modules
  4. Build ./gradlew assembleDebug and run :app:testDebugUnitTest
  5. Optionally run npm --prefix functions ci && npm --prefix functions run build to validate functions
  6. Deploy functions only from protected branches or tags using firebase deploy --only functions with a FIREBASE_TOKEN stored in secrets

Contributing & PR process

• We use pull_request_template.md in the repository root to standardize PRs. Please follow it when opening PRs.
• Branching model: create feature branches from main (or your current default branch), open a PR and request reviews.

Creators

Name	GitHub
Adrien Jangal	@Ryukriss-f
Angéline Bignens	@AngeB21
Arianna Baur	@abaur3
Gregory Blanc	@xgby
Timéo Golaz	@Timeo21
Tony Andriamampianina	@touunyy
Uri Jaquet	@uri-j