An Android radio streaming app with UPnP/DLNA and Google Cast support.

Or get the latest APK from the Releases section.

• Stream internet radio stations to your Android device
• Cast audio to UPnP/DLNA renderers on your local network
• Cast audio to Google Cast devices (Chromecast, etc.)
• Sleep timer, alarm, playlist history
• Import/export radio lists (JSON, CSV)
• Google Assistant voice commands support
• Android Auto support

Most UPnP/DLNA radio apps simply forward the radio stream URL directly to the renderer. RadioUpnp takes a different approach: the audio is fully decoded on the Android device and re-streamed as PCM/WAV to the renderer.

This brings two key advantages:

• Any radio format supported by ExoPlayer (HLS, AAC, MP3, etc.) works on any renderer, regardless of its codec support
• ICY metadata (track titles) is captured locally and displayed in the app in real time

Internet radio stream
        │
        ▼
   ExoPlayer (Media3)
        │
        ▼
  CapturingAudioSink        ← custom AudioSink intercepting raw PCM
        │
        ▼
     Pacer thread           ← paces PCM output to match real-time bitrate
        │
        ▼
  UpnpStreamServer          ← local HTTP server (NanoHTTPD) serving WAV stream
        │
        ▼
  UPnP/DLNA renderer  ──or──  Google Cast device

CapturingAudioSink wraps ExoPlayer's DefaultAudioSink and intercepts the decoded PCM data before it reaches the audio hardware. A Pacer thread paces the output to match the real-time audio bitrate, preventing buffer overruns on the renderer side. The WAV header is built dynamically from the format reported by ExoPlayer (sampleRate, channelCount, bitsPerSample).

For Google Cast, the same local WAV stream is served to the Cast device, keeping a unified streaming pipeline for both protocols.

Most Android UPnP apps historically relied on Cling, a library that has been unmaintained for years and carries significant technical debt. RadioUpnp takes a different path: the entire UPnP stack was rewritten from scratch over 6 months, resulting in a lightweight and modern implementation with no legacy dependency.

The custom stack covers:

• SSDP discovery — via AndroidSsdpClient, a purpose-built library
• Device description parsing — XML UPnP device and service descriptors
• SOAP action control — UPnP action invocation over HTTP via OkHttp
• AVTransport / RenderingControl / ConnectionManager — the three core UPnP services for audio rendering

This makes RadioUpnp one of the very few modern Android open source apps with a fully self-contained UPnP implementation.

• Media3 / ExoPlayer — radio decoding and PCM capture via custom AudioSink
• NanoHTTPD — embedded HTTP server for WAV streaming
• AndroidSsdpClient — lightweight SSDP discovery (custom library)
• OkHttp — UPnP/DLNA SOAP action control
• Google Cast SDK — Chromecast support
• MediaBrowserServiceCompat — background playback and Android Auto

Contributions are welcome, especially around:

• UPnP/DLNA compatibility with specific renderers
• Audio format handling edge cases
• Google Assistant / App Actions integration

Please open an issue before submitting a pull request.