Helper script for recording Pebble watch emulator GIFs on Linux (tested on Ubuntu 24)

record_pebble.sh

#!/bin/bash

# =============================================================================
# record_pebble.sh
#
# DESCRIPTION:
#   Records the selected Pebble emulator window and converts the captured
#   output to a minimal, pixel perfect animated GIF.
#
# USAGE:
#   ./record_pebble.sh [output.gif]
#
# DEPENDENCIES:
#   sudo apt install xdotool ffmpeg xwininfo
#
# TIPS:
#   - Call 'light_enable(true)' in your app's startup handler to keep the
#     backlight at full brightness throughout the recording.
#   - Disable vibrations, if your app has them, to prevent the emulator screen
#     from shaking and interfering with the recording.
# =============================================================================

set -euo pipefail

# Variables
OUTPUT="${1:-output.gif}"
TMP_DIR=$(mktemp -d)
MP4="$TMP_DIR/recording.mp4"
DECIMATED="$TMP_DIR/decimated.mp4"
PALETTE="$TMP_DIR/palette.png"
FPS=15

# Error handling
trap 'echo "Error on line $LINENO" >&2; rm -rf "$TMP_DIR"' ERR
trap 'rm -rf "$TMP_DIR"' EXIT

# Get targeted window information
echo "Click the emulator window to record..."
WIN_INFO=$(xwininfo)
WIN_ID=$(echo "$WIN_INFO" | grep "Window id:"            | awk '{print $4}')
X=$(echo "$WIN_INFO"      | grep "Absolute upper-left X" | awk '{print $NF}')
Y=$(echo "$WIN_INFO"      | grep "Absolute upper-left Y" | awk '{print $NF}')
W=$(echo "$WIN_INFO"      | grep "Width:"                | awk '{print $NF}')
H=$(echo "$WIN_INFO"      | grep "Height:"               | awk '{print $NF}')
# Remove padding from basalt emulator (better way to do this?)
if [[ "$W" -eq 148 && "$H" -eq 172 ]]; then
  X=$((X + 2))
  Y=$((Y + 2))
  W=$((W - 4))
  H=$((H - 4))
fi
# Transfer focus from the terminal to the selected window
xdotool windowactivate --sync "$WIN_ID"

# Capture the screen as a lossless video to the temp directory
echo "Capturing window. Press Ctrl+C to stop recording..."
ffmpeg -f x11grab -draw_mouse 0 -framerate $FPS -i "$DISPLAY" \
  -vf "crop=${W}:${H}:${X}:${Y}" -c:v libx264rgb -crf 0 "$MP4" -v error || true
# Strip out unused frames, maintaining the lossless quality
echo "Processing recording..."
ffmpeg -i "$MP4" -vf "mpdecimate,fps=$FPS" -c:v libx264rgb -crf 0 \
  "$DECIMATED" -v error
# Generate a minimal color pallet
ffmpeg -i "$DECIMATED" -vf "palettegen=max_colors=64:reserve_transparent=0" \
  "$PALETTE" -v error
# Encode the video as a gif
ffmpeg -i "$DECIMATED" -i "$PALETTE" \
  -filter_complex "[0:v][1:v]paletteuse=dither=none" -y "$OUTPUT" -v error

echo "GIF saved to: $OUTPUT"

Thanks, I just pushed a fix!