feat: broadcast mode — stream playlist as HTTP radio station

[gitcoder89431]

Overview

Add a tuitube serve (or tuitube broadcast) command that streams the currently playing audio as a continuous HTTP audio stream — like a personal internet radio station. Any device on the LAN (phone, laptop, TV browser) can tune in by opening a single URL. No frontend, no app, no playback controls required.

How It Works

tuitube playing a playlist (TUI works as normal)
  └── mpv audio output → ffmpeg pipe → Go HTTP chunked response
      └── http://<LAN-IP>:8080/stream
          ├── phone browser  → <audio src="..."> just plays
          ├── VLC / mpv      → open URL, plays immediately
          └── any browser    → works out of the box

mpv continues playing normally in the TUI. The broadcast layer taps into the audio output (via ffmpeg pipe or mpv's --audio-device stdout) and fans it out to all connected HTTP listeners simultaneously.

Startup Output

On tuitube serve, print the resolved URLs so the user can just copy-paste:

tuitube is broadcasting on:
  → http://192.168.1.42:8080/stream   (LAN)
  → http://localhost:8080/stream      (this machine)

Open in any browser, VLC, or mpv to listen.

LAN IP is auto-detected via net.InterfaceAddrs() — no config needed for basic use.

ICY Metadata (Now Playing)

Use the Icecast ICY metadata protocol so the current track title shows up in VLC, mpv, and browser media sessions automatically:

icy-name: tuitube
icy-metaint: 8192

Every 8192 bytes, inject a metadata frame with the current track title + artist. This means listeners see "Now Playing: Track Name" in their player with zero extra work.

Now Playing Page

GET / serves a minimal HTML page (no JS framework, pure HTML):

• Current track title + artist
• Album art (if available)
• The stream URL to copy
• Auto-refreshes on track change via SSE or a simple meta-refresh

Implementation Notes

• Audio pipe: ffmpeg -i pipe:0 -f mp3 - reading from mpv's stdout, or use mpv's --audio-device=pcm + ffmpeg stdin
• Fan-out: a broadcaster goroutine reads mp3 frames and writes to all connected http.ResponseWriter clients via channels
• mp3 frame boundaries: only start new listeners on a clean mp3 frame boundary to avoid glitches (see mp3frame pattern from cliamp-server)
• LAN ACL: --lan flag required to accept non-loopback connections (safe default = localhost only)
• mDNS announce (optional stretch): register tuitube.local via mDNS so devices can use http://tuitube.local:8080/stream instead of IP

CLI

tuitube serve [--port 8080] [--lan] [--no-mdns]

Flag	Default	Description
--port	8080	Port to listen on
--lan	false	Accept connections from LAN (non-loopback)
--no-mdns	false	Disable mDNS tuitube.local announcement

Dependencies

• net/http — stdlib, already present
• ffmpeg — already a soft dependency via yt-dlp workflows; document as required for broadcast mode
• No new Go deps for core broadcast; optional hashicorp/mdns for mDNS announce

Non-Goals (v1)

• Playback control from the browser (skip, pause) — that's a separate web UI feature
• Authentication / passwords
• External internet exposure (that's the user's job via Tailscale etc.)
• HLS / DASH streaming

References

• cliamp-server — Go radio server with icy, mp3frame, broadcast, transcode packages worth studying
• Icecast ICY metadata spec