Security Cameras (RTSP & ONVIF)

homectl provides discovery and streaming capabilities for local security cameras (including Hikvision, Dahua, Axis, Amcrest, Alarm.com, and generic RTSP IP cameras).

Discovery Pipeline

Security cameras often suppress broadcast announcements or use proprietary discovery protocols. homectl uses a dual-engine approach in pkg/camera/discovery.go:

1. mDNS & WS-Discovery Probing: Scans for _rtsp._tcp, _axis-video._tcp, _http._tcp, and ONVIF WS-Discovery probe messages (239.255.255.250:3702).
2. Throttled RTSP Port Probing: Iterates through private subnet hosts (10.x.x.x, 172.16-31.x.x, 192.168.x.x) with a 50-worker concurrency semaphore testing TCP port 554.

./homectl discover

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Authentication Configuration

RTSP camera streams typically require authentication. You can set global camera credentials in ~/.config/homectl/config.json:

{
  "camera_auth": "admin:MySecurePassword123"
}

When configured, RTSP URLs are constructed with embedded authentication:

rtsp://admin:MySecurePassword123@192.168.1.200:554

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On-Demand Transcoding & Streaming

Web browsers cannot render raw RTSP H.264 streams directly without plugins or WebRTC gateways. homectl provides an on-demand transcoding proxy via FFmpeg.

Stream Endpoint

GET /api/security/stream?ip=192.168.1.200

When a browser connects:

1. The Go server spawns a context-bounded ffmpeg process:

   ffmpeg -rtsp_transport tcp -i rtsp://user:pass@192.168.1.200:554 \
     -f mpjpeg -q:v 3 -vcodec mjpeg pipe:1

2. The output stream is piped to HTTP response headers:

   Content-Type: multipart/x-mixed-replace; boundary=ffserver

3. When the browser tab closes or the user stops streaming in the Web UI, the request context is cancelled, automatically terminating the ffmpeg subprocess to avoid CPU leaks.

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Web UI Camera Card

In the Web UI, each camera renders as an isolated <camera-card>:

• Stream Offline by default: Prevents unnecessary network bandwidth consumption.
• Enable Live Stream: Dynamically injects the /api/security/stream?ip=... endpoint into an <img> tag.
• Direct RTSP Link: Provides a one-click rtsp://<ip>:554 link to open the full-resolution stream in VLC or external media players.