screen_capture_kit 0.0.5

Native Dart bindings for macOS ScreenCaptureKit using Dart Build Hooks.

example/README.md

screen_capture_kit example

Sample command-line apps demonstrating display capture, screenshot, audio recording, and system picker capture with screen_capture_kit.

Requirements

• macOS 12.3+ (some flows need 14+, e.g. screenshot / system picker)
• Screen Recording permission (System Settings → Privacy & Security)
• ffmpeg on PATH for record_display_with_audio / record_picker_with_audio (e.g. brew install ffmpeg)
• Microphone permission for microphone capture in record_display_with_audio
• Dart SDK 3.10+ (aligned with the main package)

Run

From this directory:

dart pub get

Display screenshot to PNG (CLI)

bin/screenshot_display.dart lists available displays, lets you pick one (or pass --display), and writes a single PNG into an output directory. Requires macOS 14+ (same as captureScreenshot).

dart pub get
dart run bin/screenshot_display.dart --out ./captures
# non-interactive: second display
dart run bin/screenshot_display.dart ./captures --display 2

Display screen record to uncompressed AVI (CLI)

bin/record_display.dart records a display with startCaptureStream, packs BGRA frames into an uncompressed AVI (RIFF / movi / idx1) using Dart only—no external encoder. Recording stops on Ctrl+C or --duration / -t; the tool may keep writing queued frames afterward.

Notes:

• Output files are very large; use --width / --height to downscale if needed.
• --fps (1..120, header timebase) is capped to Display.refreshRate when DisplayRefreshRate.isKnown is true (e.g. 60 Hz display ⇒ requested 120 becomes 60).

dart pub get
dart run bin/record_display.dart --out ./recordings --duration 5 --display 1
dart run bin/record_display.dart ./recordings --display 1 --duration 5 \
  --fps 30 --width 640 --height 360

Display + system audio + microphone → MP4 (CLI, ffmpeg)

bin/record_display_with_audio.dart captures a display with system audio and microphone (startCaptureStreamWithUpdater with capturesAudio and captureMicrophone), writes a temporary BGRA AVI and two PCM WAV files, then runs ffmpeg to produce H.264 + AAC MP4. Intermediate files are deleted unless you pass --keep-temp.

Requirements:

• ffmpeg available (e.g. Homebrew).
• macOS 13+ for system audio in ScreenCaptureKit; macOS 15+ for microphone via SCStreamOutputTypeMicrophone.
• Screen Recording and Microphone permissions when prompted.

dart pub get
dart run bin/record_display_with_audio.dart --out ./recordings --duration 10 --display 1
dart run bin/record_display_with_audio.dart ./recordings --keep-temp

Content-sharing picker → MP4 (CLI, ffmpeg, macOS 14+)

bin/record_picker_with_audio.dart opens the system content-sharing picker (presentContentSharingPicker), then records the chosen display, window, or app with BGRA AVI + optional system audio and/or microphone, and muxes to H.264 + AAC MP4 with ffmpeg (same pattern as record_display_with_audio).

• FPS: defaults to 120 and is capped by the highest known display refresh rate from ShareableContent (same idea as the display record CLIs).
• Audio: --audio none|system|mic|both (default both when omitted).
• Size: omit --width / --height to use native / first-frame dimensions (AVI header is written after the first video sample). Or pass both for a fixed scale hint.

Requirements: macOS 14+ for the picker; macOS 15+ for microphone; ffmpeg on PATH.

The picker is system UI (often surfaced via Control Center in the menu bar, per Apple’s ScreenCaptureKit design). If nothing appears in front of the terminal, open Control Center and look for the screen-sharing / capture controls.

dart pub get
dart run bin/record_picker_with_audio.dart --out ./recordings --duration 10
dart run bin/record_picker_with_audio.dart ./recordings --audio system --fps 120
dart run bin/record_picker_with_audio.dart ./recordings --width 1920 --height 1080

Project layout

Path	Role
bin/screenshot_display.dart	CLI: pick a display, save one PNG to a folder
bin/record_display.dart	CLI: pick a display, record uncompressed AVI (Dart only)
bin/record_display_with_audio.dart	CLI: display + system + mic → MP4 via ffmpeg
bin/record_picker_with_audio.dart	CLI: picker + optional audio → MP4 via ffmpeg
lib/avi_isolate_recorder.dart	Shared isolate-based AVI writer for the record CLIs
lib/pcm_wav_writer.dart	PCM → WAV helper for record_display_with_audio
pubspec.yaml	Depends on screen_capture_kit via path: ../