demoreel

Changed

• A recording still blank halfway through -d now fails there. (DEMO-0008) The blank check used to look only at the end, so an app that drew something in the last moments passed with a mostly empty video. It now also looks halfway through the countdown. -d 0 runs have no halfway point and keep the end check only. A run that used to succeed can now fail.

• -d now gives a clip of about the length asked for, and runs start faster. (DEMO-0012) -d 3 used to produce about 4.2 seconds of video. It now produces about 3.2. Each run also finishes about 1.4 seconds sooner, because demoreel waits for things to actually happen instead of sleeping for a fixed time.

• demoreel stop works straight after the run is launched. (DEMO-0034) A run used to be unreachable until it was already recording, so a stop issued too early said no such recording existed. stop now finds a starting run, waits for it to record, and stops it. The retry loop the README showed is gone. A stop for a name that is not running now takes a second to say so.

Fixed

• Apps that title their window only the modern way, such as vkcube, are now found. (DEMO-0043) demoreel looked only at a window's older title property, so these windows were never found. Every such run waited the full 20 second startup timeout and recorded the window at its own size, not filling the frame. A --gpu -- vkcube run now takes about 4 seconds instead of

• Two runs started together under one name no longer both record. (DEMO-0011) The later one's state file used to hide the earlier one from demoreel stop. The duplicate-name check is now a lock, so exactly one records and the other exits with an error.

• The blank check no longer passes a video it could not look at. (DEMO-0033) When its sample of the screen failed, the check used to report "not blank", so the run succeeded. That now fails the run with the reason, and --settle stops instead of waiting blind. A run that used to succeed can now fail, which is why this is in a MINOR.

[0.1.1] - 2026-09-08

Added

• demoreel records a GUI app on a private virtual display. One command takes the app to run and gives back a video file: it starts the display, launches the app on it, sizes the window to the frame, records with ffmpeg, optionally replays scripted actions, and tears everything down. Nothing of the user's real desktop is in frame, because the app never runs there. Two display backends: Xvfb by default, and --gpu for an app that needs the graphics card. Everything in this block is the first release; nothing has been tagged yet.

• The pre-push gate ships with the repository. (DEMO-0027) git config core.hooksPath .githooks turns it on after cloning. The gate previously reached this project through settings on one machine, so a fresh clone had ci.sh and nothing that ran it.

Fixed

• An app that exits without a window is no longer told it is a single-instance app. (DEMO-0026) That was one possible cause stated as the established one. A command that simply finished without needing a window got the same message. It now says what happened, offers the hand-over as the likely cause, and names the other case.

Security

• The private display is behind an auth cookie on both backends. (DEMO-0017) Every client is handed an MIT-MAGIC-COOKIE-1 credential through an Xauthority file at mode 0600. Measured before the guard existed: a local process with no credential read the display's geometry and grabbed a frame of whatever was on screen. Socket permissions were no substitute, because Xvfb also listens on an abstract socket, which has none.

• Text passed to -a type no longer appears in the system process list. (DEMO-0018) It reaches xdotool on stdin instead of as an argument. It is still on demoreel's own command line, because the caller wrote it there, and SECURITY.md keeps that as a stated boundary rather than implying it is closed.

• The run-state directory is checked before it is used. (DEMO-0019) Without XDG_RUNTIME_DIR the fallback path is predictable, so on a shared machine another user can create it first. demoreel now refuses anything that is not a directory it owns, and looks with lstat so a planted symlink is seen rather than followed.

• demoreel stop no longer signals a process it did not start. (DEMO-0036) A run killed abruptly leaves its state file behind, and the system reuses process numbers -- so stop could send a terminating signal to whatever inherited the number. Reproduced against an unrelated sleep, which died. The run's start time is now recorded beside its process number and checked first.

• The CI workflow keeps its token off disk and its values out of shell. (DEMO-0037) Checkout no longer persists the job's credentials, where every later step could read them, and step values are passed through the environment rather than pasted into the script before the shell sees them. With DEMO-0038.