Parrot — Record and Replay X Application Interactions

Parrot lets you record mouse clicks, keyboard input, and navigation paths through any X11 GUI application, then replay those interactions automatically. It is designed for benchmarking and testing desktop applications in a reproducible, sandboxed environment.

Everything runs inside Docker, so there are no security implications for the host system and results are fully reproducible across machines.

How It Works

1. Record — Interact with any X application through a browser-based VNC viewer. Parrot captures every mouse movement, click, and keystroke. It also takes care of setting the screen and application size correctly.
2. Replay — Play back the recorded session against the same application. Parrot finds the correct window, replays each action with correct timing, and optionally asserts on screenshots.
3. Benchmark — Plug the replay into the Green Metrics Tool via a usage_scenario.yml to measure energy and performance.

Example Applications

Application	Path
Firefox	applications/firefox/
LibreOffice Calc	applications/calc/
VLC	applications/vlc/
Okular (PDF viewer)	applications/pdf_viewers/okular/

Each application directory contains the recorded .🦜 macro file and a usage_scenario.yml for use with the Green Metrics Tool.

Quick Start

1. Start the Window Container

Every application ships with a Docker Compose file (or uses the shared ribalba/xwindow-server image). To bring up Firefox:

docker compose -f applications/firefox/usage_scenario.yml up --build

Open the GUI in your browser at http://localhost:6080/vnc.html.

2. Record a Macro

./record-macro.py applications/firefox/usage_scenario.yml

• Interact with the application in the browser-based VNC viewer.
• Press Pause to stop recording.
• Press Scroll Lock at any point to capture a reference screenshot (inserts a Check assertion into the macro).
• Pass --script path/to/script.md to attach one note per checkpoint; trimmed blank lines and lines starting with # are ignored.
• When a script is provided, recording shows a live checklist and highlights the next pending item in green.

Override the hotkeys if your browser intercepts them:

STOP_KEYSYM=F9 CHECK_KEYSYM=F3 ./record-macro.py applications/firefox/usage_scenario.yml

Output files are written to recordings/<app-name>/:

recordings/firefox/firefox.🦜
recordings/firefox/firefox-check-001.png

3. Replay a Macro

./replay.py applications/firefox/usage_scenario.yml

Optional speed multiplier:

REPLAY_SPEED=2.0 ./replay.py applications/firefox/usage_scenario.yml   # faster
REPLAY_SPEED=0.5 ./replay.py applications/firefox/usage_scenario.yml   # slower

Replay finds the application window by class/title metadata embedded in the macro, focuses it, and plays back every action. Any Check line triggers a screenshot comparison against the saved reference image. A failed check exits non-zero.

Recording Any X Application

Parrot is not limited to the bundled applications. You can record interactions with any X11 GUI application by supplying the relevant metadata at record time:

APP_STARTCOMMAND='xterm' \
APP_WINDOW_TITLE='xterm' \
APP_WINDOW_CLASS='xterm' \
./record-macro.py <your-compose-file.yml>

Metadata is embedded into the .🦜 macro file and used by replay to locate and focus the correct window.

Macro File Format

Recorded macros (.🦜 files) contain:

• #APP metadata lines — window class, title, and optional start command
• Timed xmacro events — MotionNotify, ButtonPress, KeyStrPress, etc.
• #WAIT_SEC <seconds> — timing gaps between events
• Check <path>.png — screenshot assertion lines
• log <text> — note lines emitted to stdout during replay as <timestamp_microseconds> <text>

Example header:

#APP startcommand='firefox https://browserbench.org/Speedometer3.1/'
#APP windowtitle=Firefox
#APP windowclass=firefox

Screenshot Assertions

Press Scroll Lock during recording to insert a checkpoint. During replay, Parrot compares the current window screenshot to the saved reference using RMSE.

Tune the comparison:

# Loosen the threshold
CHECK_MAX_RMSE=0.02 ./replay.py applications/firefox/usage_scenario.yml

# Ignore dynamic regions (e.g. toolbars, clocks) — format: x,y,width,height
CHECK_IGNORE_RECT=0,0,420,40 ./replay.py applications/firefox/usage_scenario.yml

# Multiple regions (semicolon-separated)
CHECK_IGNORE_RECT="0,0,420,40;300,580,120,30" ./replay.py applications/firefox/usage_scenario.yml

Green Metrics Tool Integration

Parrot has native support for the Green Metrics Tool. Each application includes a usage_scenario.yml that defines the container setup and the replay command:

name: Parrot Firefox
author: Didi <didi@green-coding.io>
description: Benchmarks Firefox using Parrot

services:
  window-container:
    image: ribalba/xwindow-server
    environment:
      DEBUG: 0
    setup-commands:
      - command: bash /tmp/repo/applications/firefox/install.sh
      - command: bash /usr/local/bin/entrypoint.sh

flow:
  - name: Run Benchmark
    container: window-container
    commands:
      - type: console
        command: python3 /usr/local/bin/replay.py /tmp/repo/applications/firefox/firefox.🦜

Point the Green Metrics Tool at the repository and it will set up the container, run the replay, and collect energy and performance metrics automatically.

Deterministic Window Layout

To keep click coordinates and screenshots stable across runs, configure fixed window geometry in the compose environment:

Variable	Description
AUTO_POSITION	1 to enable, 0 to disable
WINDOW_X / WINDOW_Y	Window position
WINDOW_WIDTH / WINDOW_HEIGHT	Window size
APP_WINDOW_CLASS	xdotool window class matcher
APP_WINDOW_TITLE	xdotool window title matcher

Troubleshooting

• Stop key not working in browser — set STOP_KEYSYM to another key, e.g. F9.
• Check hotkey affects the app — Scroll Lock is the default; if your keyboard or environment handles it poorly, choose another key via CHECK_KEYSYM.
• Screenshot checks fail due to minor UI variation — increase CHECK_MAX_RMSE slightly or mask dynamic regions with CHECK_IGNORE_RECT.
• Click coordinates are off — rebuild/restart the container and re-record; window geometry may have shifted.