video-capture

name

video-capture

description

Record an mp4 video of the headless debug runtime by capturing periodic screenshots and stitching them with ffmpeg. Deterministic fixed-timestep: the sim runs at 60Hz, so capturing a frame every 4 sim-frames yields real-time 15fps. Drive movement (turn/walk via /v1/control/input) while capturing for smooth footage - a pan of a scene, a walk down a corridor, or a record of a playtest session. Local artifact (not hosted), so file size is fine. Used standalone to grab a clip, or by the `playtest` / `play-through` skills to record a session.

video-capture — record an mp4 from the debug runtime

Turn the deterministic step+screenshot loop into a video. The sim is fixed 60Hz, so capture every 4 sim-frames → real-time 15fps (every 6 → 10fps). Screenshots are deterministic (each captures the fully-rendered frame), so no sleeps/retries.

Capture loop

Against a running runtime (launch it, or reuse a playtest session). Make a subdir under /tmp/claude/ (where the runtime writes shots) and capture sequential frames while something is moving:

BASE=http://127.0.0.1:8080   # the runtime's port
mkdir -p /tmp/claude/rec
# optional: drive smooth motion (a slow turn-in-place pan)
curl -s -X POST $BASE/v1/control/input -d '{"left_hand.thumbstick":[0.35,0.0]}'
for n in $(seq -w 1 60); do
  curl -s -X POST $BASE/v1/step -d '{"frames":4}'                              # 4 -> 15fps
  curl -s -X POST $BASE/v1/screenshot -d "{\"filename\":\"rec/frame-${n}.png\"}"
done
curl -s -X POST $BASE/v1/control/input -d '{"left_hand.thumbstick":[0.0,0.0]}'  # stop

Motion options via /v1/control/input (set channel, then step): left_hand.thumbstick:[turn,0] to look around, right_hand.thumbstick:[strafe,forward] to walk. A discrete teleport-and-poke session records as a choppier slideshow; continuous motion is smooth.

Assemble

node .agents/skills/video-capture/record-video.mjs /tmp/claude/rec        # -> rec/video.mp4 @ 15fps
node .agents/skills/video-capture/record-video.mjs /tmp/claude/rec out.mp4 15

record-video.mjs globs frame-*.png and runs ffmpeg (libx264, yuv420p, even-dimension scale). Requires ffmpeg on PATH.

Notes

• Delegate a long capture when the host supports subagents; otherwise run it inline. Keep the image traffic out of the manager context and return the mp4 path.
• Frame count / fps: N frames at F fps = N/F seconds. 60 frames @ 15fps = 4s.
• Local-only artifact; embed/host separately only if a PR needs it (see pr-visuals for GIF+gist hosting).