Streaming Tool Dev

Control Method: DCS vs. ICS

How Do Plugins Communicate with the Outside World?

Two systems:

DCS = Direct Control System (HTTP-based, browser source in OBS) ICS = Interface Control System (GUI window with pywebview, window capture in OBS)

# config.yaml
control_method: DCS    # Or: ICS

DCS: Direct Control (Standard)

Plugin                    Streaming Software (OBS)
  ↓                           ↓
Flask HTTP Server    →    Browser Source (http://localhost:PORT)
  → HTML/CSS is rendered directly in the browser
  → Live updates via Server-Sent Events (SSE)

How it works:

• Plugin starts a Flask server on localhost:PORT
• OBS loads the URL as a browser source
• Data is rendered directly in the browser (live updates via SSE)

Advantages:

• ✓ Fast and direct (no screen capture artifacts)
• ✓ Reliable
• ✓ Transparent background possible (for overlays)

Disadvantages:

• ✗ Streaming software must support browser source

ICS: Interface Control (Fallback)

Plugin                    Streaming Software (OBS)
  ↓ (pywebview window)       ↓
 GUI is displayed
  ↓ (Window Capture in OBS)
Overlay in stream

How it works:

• Plugin opens a pywebview window with the GUI
• User uses Window Capture in OBS to capture the window
• Result: Visual integration into the stream

Advantages:

• ✓ Works with any streaming software (including TikTok Live Studio)
• ✓ No browser source required

Disadvantages:

• ✗ Overhead due to screen capture
• ✗ Higher latency
• ✗ Loss of quality possible

When to Use Which System?

DCS vs. ICS in the Registry

When registering, each plugin defines whether it supports ICS:

register_plugin(AppConfig(
    name="Timer",
    path=MAIN_FILE,
    enable=True,
    level=4,
    ics=True     # Supports ICS (has pywebview GUI)
))

register_plugin(AppConfig(
    name="App",
    path=APP_EXE_PATH,
    enable=True,
    level=2,
    ics=False    # DCS only (no GUI window)
))

ics=True = Plugin has a pywebview GUI and supports window capture ics=False = Plugin only runs as an HTTP server (DCS)

[!NOTE] All built-in plugins (Timer, DeathCounter, WinCounter, LikeGoal, OverlayTxt) have ics=True.

At Runtime (start.py)

start.py checks the control_method from the config and the ics value of each plugin:

if app.ics and CONTROL_METHOD == "DCS" and app.enable:
    # Plugin has GUI, but DCS is desired:
    # → Start with --gui-hidden (Flask server only, no window)
    start_exe(path=app.path, name=app.name,
              hidden=get_visibility(app.level), gui_hidden=True)
elif app.enable:
    # Normal start (with GUI if ics=True, without if ics=False)
    start_exe(path=app.path, name=app.name,
              hidden=get_visibility(app.level))

This means:

• With control_method: DCS, GUI plugins are started with --gui-hidden → Flask is running, but no window opens
• With control_method: ICS, GUI plugins are started normally → pywebview opens a window

Key Points

• DCS = HTTP server, browser source in OBS
• ICS = pywebview window, window capture in OBS
• DCS is the default (faster, more reliable)
• ICS is the fallback (if no browser source available)
• All built-in plugins support ICS (ics=True)

→ Next: PLUGIN_REGISTRY