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Stream Relaying, Multi-DJ Hub & Backstage Green Room

CASTIUM provides a comprehensive suite of collaboration tools designed for multi-DJ broadcasts, guest co-hosts, back-to-back (B2B) DJ sets, and off-air performer coordination.

Stream Relaying, Multi-DJ Hub & Backstage Green Room

CASTIUM provides a comprehensive suite of collaboration tools designed for multi-DJ broadcasts, guest co-hosts, back-to-back (B2B) DJ sets, and off-air performer coordination.

1. Stream Relaying & Multi-DJ Party Hub (card-stream-relay)

The Stream Relaying & Multi-DJ Party Hub enables broadcasters to ingest live external audio streams from remote guest DJs, sister radio stations, or co-hosts directly into the studio console.

Key Capabilities

  • Generic & CASTIUM-to-CASTIUM Ingest:
    • Ingest standard MP3, AAC, Ogg, or FLAC HTTP streams via FFmpeg auto-reconnecting background decoders (-reconnect 1 -reconnect_streamed 1 -reconnect_delay_max 5).
    • Auto-Detection for CASTIUM Sources: If the remote source is another CASTIUM station, CASTIUM automatically detects the peer via /api/branding and stream HTTP headers (X-Powered-By: CASTIUM, X-CASTIUM-Host, X-CASTIUM-Avatar).
  • Remote DJ Name, Bio & Avatar Passthrough:
    • In CASTIUM-to-CASTIUM mode, remote DJ names, bios, and avatars are dynamically displayed in the studio console.
    • With Web Passthrough enabled, remote DJ branding flows seamlessly into the web player via real-time Server-Sent Events (SSE), displaying the guest DJ's name and avatar to listeners while they are on air.
  • Pre-Fade Listen (PFL) Headphone Cueing:
    • Dedicated CUE button on each ingested stream card.
    • Allows broadcasters to preview, monitor, and beatmatch guest DJ audio in headphones over a dedicated WASAPI monitor audio device before bringing the guest on-air.
  • Stream Latency & Health Diagnostics:
    • Real-time telemetry indicators calculate buffer depth and ping health (EXCELLENT, GOOD, BUFFERING, UNSTABLE).
    • Displays remote buffer latency in seconds (e.g., (1.2s buffer)).
  • Remote Track Metadata Passthrough:
    • Queries remote /api/metadata to detect the song title and artist currently playing on the guest DJ's decks.
    • Broadcasters can toggle Track Passthrough to seamlessly publish the guest DJ's track titles to web listeners and song history logs.
  • Automated B2B DJ Crossfader:
    • Quick action buttons Hand-Off to Guest (8s) and Take Back Decks (8s).
    • Executes smooth S-curve crossfades between host audio and guest relay streams over configurable durations (default: 8s), preventing abrupt cuts.
  • Fail-Safe Auto-Fallback on Stream Drop:
    • If a guest DJ's connection drops unexpectedly, CASTIUM triggers ActiveRelayDisconnected, instantly restoring host deck audio volume to 100% and alerting the broadcaster in the studio console.

Dual Processing Modes

  1. Re-encoded Mix Deck: Routes incoming relay audio directly into the native Pro DJ channel strip. The relay stream is smoothly ducked under local microphone announcements, shaped by the DJ 10-band EQ, blended with soundboard effects, and processed by the master limiter.
  2. Raw Passthrough: Routes raw audio stream directly for low-CPU relaying.

2. Backstage DJ & Green Room Private Chat (card-green-room)

In addition to broadcast audio relaying, CASTIUM includes a dedicated Backstage DJ & Green Room for off-air coordination with performers across local and wide-area networks (WAN).

Private Talkback Intercom

  • TALKBACK (GREEN ROOM) toggle button in the studio console.
  • When active, the host microphone is isolated from the master on-air broadcast sum (TalkbackActive = true), allowing private spoken coordination with guest performers off-air without leaking into the public stream.

Security & Passcode Protection

  • Customizable Owner Passcode:
    • The station owner can set a custom Green Room passcode/PIN in the studio console (Profile.GreenRoomPasscode, default: party4242).
    • Broadcasters can generate a secure random PIN at any time.
    • Endpoints /api/greenroom/chat and /api/greenroom/auth reject unauthorized requests with 401 Unauthorized.
  • Passcode Authentication Methods:
    • Supports X-GreenRoom-Passcode HTTP header.
    • Supports ?pin= or ?passcode= query parameter.
    • Supports JSON payload {"passcode": "..."}.

Mobile-Friendly Web Backstage Portal (/greenroom)

  • Dedicated Performer Intercom:
    • Guest DJs and performers can access the Green Room from any smartphone, tablet, or laptop via http://host:port/greenroom.
    • Click Copy DJ Invite Link in the console to copy a pre-authenticated invite link (http://host:port/greenroom?pin=...).
  • Interactive Backstage Features:
    • Live Chat Stream: Real-time SSE updates and smooth auto-scrolling.
    • Quick Performance Cues: Tap-to-send shortcut chips (Ready in 30s, Beatmatching, Key & BPM, Fade me in!, Taking decks, Great set!).
    • Broadcast Audio Monitor: In-browser audio player allows off-air performers to listen to the live master broadcast stream.
    • Live Track & Station Status: Displays current station title, host name, and real-time playing track information.
    • Remembered Credentials: Performer handles and PINs are saved locally in the browser for instant one-tap reconnection.

CASTIUM-to-CASTIUM Console Interconnect (Cross-Network / WAN)

  • Broadcasters running CASTIUM consoles across different networks or locations can connect directly to each other using the host's public URL and Green Room passcode.
  • Providing the remote stream URL and Green Room passcode in the Add Remote Stream / Co-Host form links both consoles together.
  • Ingested streams connected with a passcode display a GREEN ROOM badge, and chat messages sent from either studio console automatically synchronize across connected consoles in real time.

3. Stream Profile Manager for Venue Re-Use

Broadcasters frequently transition between different venues, clubs, or broadcast formats. CASTIUM provides complete profile lifecycle management:

  • Topbar Profile Switcher: Select between saved venue profiles instantly with the dropdown selector in the navigation bar.
  • Quick Save: Save all current settings, cards, layouts, EQ gains, and branding to the active profile with one click.
  • Save As New Venue: Clone current settings into a new venue profile (e.g., "Club Horizon", "Home Studio", "Festival Stage B").
  • Import & Export:
    • Export profiles to .json files to share setups with other DJs or create offsite backups.
    • Import external .json profiles safely with automatic deduplication and validation.
  • Profile Deletion & Reset: Delete obsolete profiles while protecting the default active profile from accidental deletion.

4. Web Player Experience & DJ Hand-Offs

When guest streams and B2B transitions occur, listeners on the web player experience seamless broadcast continuity:

  • Now on the Decks / B2B Stage Presence Badge: Visual dual-avatar cluster with glowing neon pulsing rings indicating which DJ is actively playing.
  • DJ Hand-off Toast Banner: Animated slide-in notification alerting listeners whenever the decks change hands.
  • Guest DJ Profile Modal: Popover dialog displaying the guest DJ's avatar, bio, and social links (Twitch, Discord, X/Twitter).
  • Party Celebration Reactions: Interactive PARTY button triggering floating celebratory confetti and pyro emoji bursts across listener screens via real-time SSE.