DarkDM — Video Download Manager for Linux

DarkDM is a video download manager for Linux inspired by IDM. It detects HLS streams automatically from any streaming site and downloads them via ffmpeg — no DRM bypassing, just intercepting the stream URLs the page requests.

Architecture

Vivaldi/Chrome (MV3 Extension)
  ↓ webRequest.onSendHeaders detects .m3u8 URLs
  ↓ Popup shows detected streams
  ↓ fetch('http://localhost:8765/download')
Native Host (Rust HTTP Server)
  ↓ Downloads manifest with curl
  ↓ Filters ad URLs injected by the site
  ↓ Resolves relative segment URLs to absolute
  ↓ ffmpeg -c copy (no re-encode, multiplexed stream)
  ↓
~/Descargas/DarkDM/video.mp4

Why HTTP server instead of native messaging?

Chrome MV3 service workers go to sleep after ~30s of inactivity. When the user clicks download, the worker wakes up but chrome.runtime.sendNativeMessage fails silently — the host never launches. Video DownloadHelper solved this with chrome.offscreen API, but that only works for browser-native downloads. Since DarkDM needs to run ffmpeg (an external binary), it uses an HTTP server on localhost:8765 instead. fetch() works reliably even when the service worker is dormant.

Quick Start

1. Build and install native host

cd native-host/
cargo build --release
cp target/release/darkdm-host ~/.local/bin/

# Install as systemd user service (auto-start on login)
cp ../systemd/darkdm-host.service ~/.config/systemd/user/
systemctl --user daemon-reload
systemctl --user enable --now darkdm-host

# Verify
curl http://localhost:8765/health
# → {"status":"ok","version":"1.0.0"}

2. Load extension in Vivaldi/Chrome

vivaldi://extensions → Enable developer mode → Load unpacked → select extension/

3. Download a video

1. Open any streaming site (pelisjuanita.com, etc.)
2. Navigate to the movie/episode page — no need to press play
3. Click the DarkDM extension icon — detected streams appear automatically
4. Click ⬇️ Descargar
5. Check ~/Descargas/DarkDM/

The extension intercepts .m3u8 requests via webRequest.onSendHeaders as soon as the page loads them — before any video plays.

Dependencies

sudo pacman -S ffmpeg curl

Project Structure

extension/        — Chrome/Vivaldi MV3 extension
  background.js   — webRequest stream detection
  popup/          — Stream list + download button
native-host/      — Rust HTTP server (localhost:8765)
  src/server.rs   — HTTP endpoints + ffmpeg launcher
  src/downloader.rs — HLS/DASH download utilities
openspec/         — Spec-driven change tracking
scripts/          — Helper scripts

HTTP API

The native host exposes a simple REST API:

GET  /health          → {"status":"ok","version":"1.0.0"}
POST /download        → Launch ffmpeg in background
OPTIONS /download     → CORS preflight

POST /download

{
  "manifest_url": "https://cdn.example.com/stream.m3u8",
  "title": "Movie Title",
  "page_url": "https://pelisjuanita.com/...",
  "headers": {
    "user-agent": "Mozilla/5.0 ...",
    "referer": "https://pelisjuanita.com/..."
  }
}

Response:

{"success": true, "message": "Download started", "output_path": "/home/dark/Descargas/DarkDM/Movie Title.mp4"}

Known Limitations

• Sites that inject TikTok/ad URLs into HLS manifests may fail (the host tries to filter them but not all cases are covered)
• DRM-protected streams (Netflix, Disney+, Prime) are not supported — DarkDM only downloads streams the browser can play without DRM
• The native host must be running before clicking download (systemctl --user status darkdm-host)

Status

Feature	Status
Auto-detect HLS streams via webRequest	✅ Works
HTTP server (replaces native messaging)	✅ Works
ffmpeg download (-c copy, no re-encode)	✅ Works
Ad URL filtering in manifests	🔧 Partial (known sites)
Multi-stream popup (per tab)	✅ Works
Stream dedup on page reload	✅ Works
Systemd auto-start	✅ Works
DASH streams	🔜 TODO
Download progress in popup	🔜 TODO