VTX Link - Edge Media Gateway

Tailored for Extreme Environments: A lightweight HLS forwarding and on-demand streaming solution specifically designed for 32MB/64MB RAM edge devices.

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Core Philosophy

As a pivotal component of the vtx-core ecosystem, VTX Link empowers low-resource edge nodes (e.g., OpenWrt routers, legacy gateways) with robust media orchestration capabilities.

• Resource Awareness: Real-time monitoring of system memory (RSS/Available RAM). It proactively rejects new tasks before physical memory exhaustion to maintain OS stability.
• Hardware Longevity: Native support for RAMDisk-based HLS segment storage (e.g., /dev/shm), eliminating high-frequency Flash write cycles and preserving hardware lifespan.
• Industrial Resilience: Built-in Exponential Backoff strategy for crash recovery, ensuring autonomous restoration during source-side failures.

Features

• On-Demand Activation: Spawn FFmpeg processes only upon .m3u8 request; supports configurable idle timeouts for automatic resource reclamation.
• Ultra-Lightweight: Written in Rust with a ~5MB binary footprint; features a zero-dependency embedded Single Page Application (SPA) for management.
• Deep Integration: Optimized for use with VTX FFmpeg Release tailored binaries.
• Observability: Integrated dashboard to monitor real-time uptime, idle duration, and crash history.

Quick Start

1. Requirements

• OS: Linux (static musl recommended) or Windows.
• Dependency: FFmpeg binary (optimized profiles like vtx-ffmpeg-stream are recommended).

2. Configuration (vtx-link.yaml)

server:
  listen: "0.0.0.0:8080"
  ffmpeg_binary: "/usr/local/bin/ffmpeg"
  hls_root: "/dev/shm/vtx-hls" # Highly recommended to point to RAMDisk

streams:
  - name: "lobby_cam"
    source: "rtsp://admin:password@192.168.1.10"
    auto_start: true
    idle_timeout: 30
    output_args:
      - "-c"
      - "copy"
      - "-f"
      - "hls"
      - "{output_dir}/index.m3u8"
    retry:
      max_attempts: 5
      initial_backoff_sec: 2

3. Execution

./vtx-link --config vtx-link.yaml

Performance Specs (32MB RAM Device)

Metric	Performance
Idle Memory Footprint	~4.5 MB
Single HLS Relayer (Copy Mode)	+2.0 MB ~ 4.0 MB
Max Concurrent Streams	3 - 5 (Depending on FFmpeg buffer settings)

Architecture

The project follows a modular domain-driven design:

• Engine: Manages process lifecycle, RAMDisk mounting, and directory sanitation.
• Supervisor: Orchestrates crash recovery and idle stream recycling.
• Web: Provides RESTful APIs and the embedded management SPA.

License

Licensed under the Apache License, Version 2.0. See the LICENSE file for details.