VideoSnap

VideoSnap is an macOS command line tool for recording video and audio from any attached capture device (including screen capture from connected iOS devices).

You can specify which device to capture from (by device name), the duration, encoding and a delay period (before capturing starts).

By default VideoSnap will capture both video and audio from the default capture device at 30fps, with a Medium quality preset and a short (0.5s) warm-up delay.

If no duration is specified, VideoSnap will record until you cancel with [Ctrl+c] or you can pause (and resume) recording with [Ctrl+z].

VideoSnap can list attached capture devices by name.

Requirements

• macOS 10.9+ (Intel/M1)
• A web cam or iOS device

If you need to capture video on older versions of macOS (e.g. 32-bit OSX) try wacaw

Installation

Download the latest release and run the installer.

This will copy the binary and man page to your /usr/local directory.

Usage

The following options are available:

  -l    List attached capture devices
  -w    Set delay before capturing starts (in seconds, default 0.5s)
  -t    Set duration of video (in seconds)
  -d    Set the capture device by name (use -l to list attached devices)
  -p    Set the encoding preset (use High, Medium (default), Low, 640x480 or 1280x720)
  -v    Turn ON verbose mode (OFF by default)
  -h    Show help
  --no-audio
        Don't capture audio (audio IS captured by default)

Examples

Capture 10.75 secs of video in 1280x720 720p HD format saving to movie-{timestamp}.mov

videosnap -t 10.75 -p '1280x720'

Capture 1 minute of video (Medium preset), but no audio from the "FaceTime HD Camera (Built-in)" device, delaying for 5 secs, saving to video.mov

videosnap -t 60 -w 5 -d 'FaceTime HD Camera (Built-in)' --no-audio video.mov

List all attached devices by name

videosnap -l

Warming Up

Since some camera hardware can take a while to warm up, a default delay of 0.5 seconds is applied. Override this with the -w argument (0 meaning no delay).

NOTE: Videosnap will also wait 0.5s to allow any connected devices to be discovered (e.g. for iOS screen capture).

Encoding Presets

The AVFoundation framework provides the following video encoding presets:

Use the -p flag to choose a preset.

Capturing from connected iOS devices

It is possible to screen capture video & audio from an attached iOS device.

For the device to be discovered you must confirm that you Trust This Computer on the device when it is connected and unlocked.

There are some limitations and issues with iOS screen capturing.

• (issue) the --no-audio flag currently has no effect (workaround: mute the device)
• (issue) currently broken on M1 macs (due to this error)
• (limitation) when capturing, the device will not output any audio (but audio will be recorded to the movie file)
• (limitation) occasionally the device fails to be discovered, this can happen when
  • another process is already capturing from the device
  • the macOS kernel fails to connect to the DAL assistant to communicate with the virtual capture device

Help

Get command help with:

videosnap -h
# or via the man page with
man videosnap

If you have any problems, please do raise an issue on GitHub. When reporting a bug, remember to mention what platform and hardware you are using and the steps I can take to reproduce the issue.

Development

I try to keep the project up to date with the latest general XCode release.

After opening videosnap.xcodeproj, you can set the arguments passed to the command when it runs in XCode, simply edit the Run action in the default videosnap Scheme. (Product -> Scheme -> Edit Scheme...)

You can also build the project from the command line. After cloning run:

  xcodebuild clean install
  # you'll find the build executable at
  ./build/Debug/videosnap
  # which symlinks to here
  ./build/pkgroot/usr/local/bin/videosnap

If you see this message:

xcode-select: error: tool 'xcodebuild' requires Xcode, but active developer directory "..."

Try this to fix your environment:

sudo xcode-select --switch /Applications/Xcode.app/Contents/Developer

Contributing

Bug reports and pull requests are welcome on GitHub. Before submitting pull requests, please read the contributing guidelines for more details.

This project is intended to be a safe, welcoming space for collaboration, and contributors are expected to adhere to the Contributor Covenant code of conduct. See here for more details.

Development

VideoSnap is coded with Objective-C and uses the AVFoundation framework. You can build the project with Xcode (using the Xcode project workspace in the repository, or with the xcodebuild command).

Future Work

Work in progress is usually mentioned at the top of the CHANGELOG. If you'd like to get involved in contributing, here are some ideas:

• Allow VideoSnap to pipe captured bytes to the STDOUT stream
• Submit VideoSnap as a package for Homebrew
• Allow more size/quality options for video and/or audio
• Smile detection while capturing video/image, determine a happiness factor/score
• Allow VideoSnap to capture a single frame to an image file (with compression options based on file type like ImageSnap)
• A comprehensive test suite

License

VideoSnap is distributed under the terms of the MIT License.

Who's Who?

• VideoSnap by Matthew Hutchinson
• Inspired by ImageSnap by @rharder