Screen capture

Ferrocast takes screenshots from the launcher or from a hotkey you choose. Each capture is saved as a PNG and opens in a small Capture window where you can copy it, annotate it, copy the text in it or pin it above your other windows.

It also records your screen. A recording is saved as a project folder with the video and a log of what you did with the mouse. You can then edit it in Ferrocast, with automatic zooms on your clicks, and export it as an MP4 or a GIF.

The four screenshot commands

Type any of these in the launcher. Each one has the subtitle “Capture”.

Command	What it does
Capture Area	Dims every display and shows a crosshair and the size in pixels (`W × H`). Drag to choose the area. `Space` switches to window mode, `Esc` cancels without saving anything.
Capture Window	The same overlay, already in window mode: click the window you want.
Capture Screen	Captures the whole display.
Capture Scrolling	Choose an area, then Ferrocast scrolls it and stitches the pieces into one tall image. See below.

None of them has a default shortcut. Set one in Settings → Capture → Shortcuts.

Captures are saved at the display’s native pixel size (twice the points on a Retina screen) as Capture YYYY-MM-DD at HH.MM.SS.png. If that name exists, 2 is added. The default folder is ~/Pictures/Ferrocast Captures.

Requirements

These apply to both screenshots and recordings.

macOS 14 or later. On macOS 13 the commands are hidden. If you have a shortcut set, pressing it shows, once per session: Screen capture needs macOS 14. This Mac runs macOS 13. If Ferrocast was built without its capture helper, the message is Screen capture is not available in this build.
Screen Recording permission. Without it you get this message and System Settings opens; no half-written file is left:

Screen Recording is off for Ferrocast. Turn it on in System Settings → Privacy & Security → Screen & System Audio Recording, then try again.

Capture Scrolling also needs Accessibility, because Ferrocast sends the scroll events. If it is off, the message is Scrolling capture needs Accessibility. Turn Ferrocast on in System Settings → Privacy & Security → Accessibility, then try again.

Recording also needs Screen Recording. Without it you get the same message, System Settings opens and the half-made project folder is removed.

The Capture window

After a capture, Settings → Capture → After capture decides what happens: Show opens the Capture window, Copy only copies the image, Save only saves the file. The window has six buttons. Every one of them works on the saved file.

Button	Shortcut
Copy (copies the image and closes)	`↵`
Save	`⌘` `S`
Annotate… (opens the annotation editor)	`⌘` `⇧` `A`
Background… (opens the add-background editor)	`⌘` `⇧` `B`
Copy Text	`⌘` `T`
Pin	`⌘` `P`

Copy Text

Copy Text reads the text in the image with the macOS Vision framework, on your Mac, and puts it on the clipboard in reading order. A toast says Copied N characters, or No text found. The image is not sent anywhere.

Pin opens the image in a borderless window that stays above your other windows, at its captured size in points. Drag it by its background. Zoom from 25 % to 400 % with the scroll wheel, a pinch, + and -; 0 goes back to the captured size. Esc closes it. You can have several pins at once.

Scrolling capture

Choose the area that scrolls, and Ferrocast scrolls it for you, takes a strip after each step and joins the strips into one image.

It stops when the content stops moving (two identical strips) or after 60 screens, with the toast Scrolling capture stopped at 60 screens.
If it loses track of the overlap, it saves the screens captured before that point and says so.
Esc cancels it. Clicking does not.
The mouse pointer is never drawn in the strips.

Screen recording

The commands

Command	What it does
Record Screen	Records a whole display.
Record Area	Choose an area, as in Capture Area, then record it.
Record Window	Choose a window, as in Capture Window, then record it.
Open Last Recording	Opens your newest recording in the editor.
Recordings	Lists your recordings, newest first.

Each one has the subtitle “Capture” and no default shortcut. Set shortcuts in Settings → Capture → Shortcuts.

Starting and stopping

After you choose the target, a countdown runs (3 s by default; Settings → Capture → Recording countdown offers Off, 3 s and 5 s). Running the command again during the countdown cancels it. Then a small recording panel appears with the elapsed time, Pause (it becomes Resume) and Stop. The panel is not in the video.

While recording, the menu bar icon shows ● mm:ss and the tray menu starts with Stop Recording. Stop from the panel or from that menu item. While one recording runs, you cannot start another. A toast tells you the file is saved, with its name and length.

The frame rate is 60 fps by default; Settings → Capture → Recording frame rate also offers 30 fps. The recording is as long as the wall-clock time between the end of the countdown and Stop, even if the screen does not change.

What is saved

Each recording is a folder named Recording YYYY-MM-DD at HH.MM.SS.ferrocast in ~/Movies/Ferrocast Recordings. To use another folder, set capture.recordings_folder in settings.json. There is no Settings row for it yet. Inside:

File	What it holds
`screen.mov`	The video. The mouse pointer is not drawn into it: the editor draws it from `events.json`.
`events.json`	A log of the cursor position (about 60 times a second), clicks, scrolling, and the position of the windows. For keys it stores only shortcuts (a key pressed with a modifier other than `⇧`) so they can be shown. Plain typing is never stored beyond the time of each key press, so a recording cannot contain a password.
`project.json`	The recording’s settings and its duration.
`thumb.png`	A still picture of the recording, used in the Recordings list.

Everything stays on your Mac.

Input Monitoring

Input Monitoring is needed only to log shortcut keys. Without it, recording still works and you see this message when it starts: Keyboard shortcuts will not be shown: Input Monitoring is off. Clicks, scrolling and the cursor do not need it.

Low disk space

Below 2 GB free, a warning shows Low disk space: N GB left. Below 200 MB, the recording stops by itself, cleanly, and keeps the file. The toast says Recording stopped: low disk space. followed by the project name and length.

Recordings and Open Last Recording

Recordings lists the projects in the recordings folder, newest first, with their length and size.

Key	Action
`↵`	Open in the editor
`⌘` `↵`	Show in Finder
`⌘` `⌫`	Move to Trash (asks to confirm)
`Esc`	Go back

Open Last Recording opens the newest recording in the editor. If there is none, it says No recordings yet.

Editing a recording

The editor shows the preview on the left and a panel with four tabs on the right. Under the preview there is a timeline (a ruler, a row for trims and speed changes, a row for zooms) with the playhead, and a row with Play/Pause, Undo, Redo, Export… and the time. The time reads output time / output length · source time, so you see the length after your edits. At the right end of that row you see the number of zooms and the save state. Esc closes the editor and writes anything not yet saved.

The cursor you see is drawn by the editor from the recorded events in events.json. It is not in screen.mov, which is why you can resize it, smooth it or remove it.

Playback and keys

Key	Action
`Space`	Play or pause
`←` / `→`	One frame back or forward
`⇧` `←` / `⇧` `→`	One second back or forward
`Home` / `End`	Jump to the start or the end
`⌘` `Z` / `⇧` `⌘` `Z`	Undo / Redo
`⌘` `E`	Export…

Click or drag on the timeline to move the playhead. While you type in a number field of the panel, only ⌘ E keeps working. The one-frame step uses the frame rate of Settings → Capture → Recording frame rate.

Auto zoom

Auto zoom zooms toward your clicks. Clicks that are close in time and place form one group. A zoom starts 0.4 s before the first click of a group and returns to the whole screen after 1.2 s without clicks or cursor movement. The default level is 2×.

When you open a recording that has no zooms, Ferrocast works them out and applies them in memory only. Nothing is written to project.json until you change something. Exporting a recording you have not touched saves its project.json first, with those zooms.

Auto zoom is on by default. capture.auto_zoom and capture.zoom_scale in settings.json turn it off or set the level (1× to 6×); there is no Settings row for them yet. The Auto zoom button of the Zoom tab uses the same level.

The panel

Every change can be undone and redone (⌘ Z, ⇧ ⌘ Z, or the Undo and Redo buttons). Changes of the same kind made within one second, such as dragging a slider, are one step. A change that would make the project invalid is refused and the reason shows in red above the controls.

Zoom

Add at playhead adds a manual zoom of 2 s, shorter if the next zoom is close. If the playhead is inside a zoom you get There is already a zoom at the playhead.
Auto zoom replaces the automatic zooms with new ones. Manual zooms stay and win any overlap.
Click a zoom in the list to edit it: Start, End, Scale (1× to 6×), Focus (X and Y, in %), Ease in and Ease out (0 to 3 s). Editing a zoom makes it manual, so Auto zoom keeps it.
Pick on preview sets the focus where you click the preview. Follow cursor makes the zoom follow the pointer again. Delete zoom removes it.

Cursor

Default, None and Hidden: the pointer, or no pointer (None and Hidden do the same).
Size (0.5× to 4×), Smoothing (0 to 100 %), Click ring (a ring where you clicked) and Motion blur (0 to 200 %).

Style

Aspect: 16:9, 4:3, 1:1, 9:16 or Source.
Background: Colour, Gradient or Blur (the recording itself, blurred), with colour pickers and an Angle for gradients.
Eight gradient presets: Aurora, Dusk, Ocean, Graphite, Sand, Lilac, Forest and Rose. A preset is stored as a gradient, not as a wallpaper image.
Padding (0 to 45 %), Corners (0 to 64 px) and the shadow: Shadow (blur, 0 to 120 px), Opacity and Offset (0 to 80 px).

Clips

Trim in cuts everything before the playhead and Trim out everything after it. Split splits the segment at the playhead. Delete segment removes the segment at the playhead.
Speed: pick 0.25×, 0.5×, 1×, 2×, 4×, 8× or 16× (or type a value), then Apply to segment.
Below, the list of segments (click one to move the playhead) and the length before and after your edits.

Saving

The editor writes project.json by itself 1 s after your last change, as a temporary file renamed into place. The save state reads Saved or Saving…; if a write fails it shows the error text and tries again. A recording you only opened is not rewritten.

Export…

Export… (or ⌘ E) opens a sheet. It saves project.json first, because the export renders the saved project.

Format	Options
MP4	Codec H.264 or HEVC. Resolution Source, 1080p or 4K (the long side is 1920 or 3840 px), never above 3840×2160. Frame rate 30 fps or 60 fps. Quality Standard or High.
GIF	Width 480 px, 720 px or 960 px. Frame rate 10 fps or 15 fps.

The sheet shows the result, for example 1920×1080 · 2:31 · 4530 frames, and the destination. Choose… opens a save dialog. The default name is the project name with .mp4 or .gif, next to the project folder; a number is added if that name exists. While it runs, a bar shows the percentage and the time left. Cancel (or Esc) stops it and leaves no partial file. At the end a toast says Exported NAME and the file is shown in Finder. Closing the editor cancels an export in progress. The exported length is the length of the edited timeline, trims and speed changes included.

A GIF holds all its frames in memory, so its length is limited. At 960 px wide (16:9, 15 fps) the limit is 20 seconds; a narrower or slower GIF can be longer, for example about 80 seconds at 480 px. Over the limit the sheet says:

This edit is too long for a GIF: the limit is N seconds. Trim it or export an MP4.

(N is the limit for the width, frame rate and aspect you chose.)

Settings