PTP Webcam – DSLR Live View Video and Webcam Control

Large sensor digital still cameras can provide an exceptionally good image for video conferencing, compared to most built-in web cameras.

This is a plugin to make compatible digital cameras available as webcams in video calls, for example in Zoom or Skype on macOS. It also allows control of camera settings from the computer to adjust exposure parameters and focus.

The project consists of a CoreMediaIO DAL plugin, and a preview app to test functionality.

Note: only video is currently captured, no audio.

Installation

System Requirements

A compatible camera connected via USB to a Mac running macOS / OS X 10.12 through 10.15.

Binary Packages

Download and install the latest release from the PTP Webcam Homepage.

Installer packages for older releases are available from the Releases page of this project.

Building from Source

If you want to build from source, you need Xcode. You can build the project and the plugin should be automatically copied into /Library/CoreMediaIO/Plug-Ins/DAL to be available to the system. However, apps with Library Validation enabled will need to have codesigning disabled to be able to access the plugin, see the Known Issues section below.

Testing the Installation

Opening Quicktime Player and creating a New Movie Recording via File -> New Movie Recording, then selecting the camera source can be used to verify functionality. The camera needs to be plugged in and turned on, and it might take a few seconds to show up.

Quicktime Player works because it has Library Validation disabled out-of-the-box, unlike eg. Photo Booth, which has the capability to use different video sources, but is prevented from doing so because Library Validation is enabled.

Note: video quality in the camera selection drop-down menu must be set to Maximum to get a video resolution higher than 640x480.

What it should look like

If the camera is connected, a status bar item with the camera's model number should appear and can be used to change settings.

Uninstalling

Delete the following files and reboot to uninstall PTP Webcam:

/Library/CoreMediaIO/Plug-Ins/DAL/PTPWebcamDALPlugin.plugin
/Library/LaunchDaemons/org.ptpwebcam.PtpWebcamAssistant.plist
/Library/LaunchAgents/org.ptpwebcam.PtpWebcamAgent.plist

Supported Cameras over USB

The supported cameras and their capabilities are listed in CAMERAS.md. Canon, Nikon, and Sony bodies are the most thoroughly tested. Experimental support for Fujifilm (X / GFX), Olympus / OM System (modern OMD), Panasonic Lumix, Sigma fp, and modern Leica (M11 / Q3 / SL3 family) is also included via the system camera extension — these vendors are implemented from public reverse-engineering work and may need per-body verification.

Autofocus can be triggered from the menu bar on Nikon, Sony (experimental), Leica, and Fuji. Other vendors fall back to whatever AF mode the camera is in when streaming starts.

Additionally many UVC (USB Video Class) cameras can also be controlled.

Known Issues

Library Validation

macOS applications that have library validation enabled cannot load DAL plugins that have not been signed or signed by another developer. Therefore, some popular video conferencing tools do not work out of the box.

The easiest way to workaround is to remove the signature for the offending applications, but note that this might be affected by security settings on your system, and might require to relax security settings.

Status for an unknown app can be checked via codesign -d --entitlements :- /Path/to/App and if any entitlements show up, com.apple.security.cs.disable-library-validation needs to be among them:

<key>com.apple.security.cs.disable-library-validation</key>
<true/>

If it is not, codesigning has to be removed from the app and potentially its helper apps.

References

https://stackoverflow.com/a/62456259/4296447

Zoom workaround

Zoom version 5.1.1 and newer no longer has library validation issues. For older versions that do not show the plugin codesigning can be disabled: codesign --remove-signature /Applications/zoom.us.app

Skype workaround

Skype version 8.62.0.85 and newer no longer has library validation issues, and work out of the box.

Older versions of Skype have several helper apps inside its application bundle that might need code signing disabled.

codesign --remove-signature /Applications/Skype.app
cd /Applications/Skype.app/Contents/Frameworks
codesign --remove-signature Skype\ Helper.app
codesign --remove-signature Skype\ Helper\ \(Renderer\).app

Additional helpers might be named differently in different Skype versions.

Google Chrome workaround

codesign --remove-signature /Applications/Google\ Chrome.app
codesign --remove-signature /Applications/Google\ Chrome.app/Contents/Frameworks/Google\ Chrome\ Framework.framework/Helpers/Google\ Chrome\ Helper.app
codesign --remove-signature /Applications/Google\ Chrome.app/Contents/Frameworks/Google\ Chrome\ Framework.framework/Helpers/Google\ Chrome\ Helper\ \(GPU\).app
codesign --remove-signature /Applications/Google\ Chrome.app/Contents/Frameworks/Google\ Chrome\ Framework.framework/Helpers/Google\ Chrome\ Helper\ \(Plugin\).app

Brave workaround

codesign --remove-signature /Applications/Brave\ Browser.app
codesign --remove-signature /Applications/Brave\ Browser.app/Contents/Frameworks/Brave\ Browser\ Framework.framework/Helpers/Brave\ Browser\ Helper.app
codesign --remove-signature /Applications/Brave\ Browser.app/Contents/Frameworks/Brave\ Browser\ Framework.framework/Helpers/Brave\ Browser\ Helper\ \(GPU\).app
codesign --remove-signature /Applications/Brave\ Browser.app/Contents/Frameworks/Brave\ Browser\ Framework.framework/Helpers/Brave\ Browser\ Helper\ \(Plugin\).app

Microsoft Teams workaround

codesign --remove-signature "/Applications/Microsoft Teams.app"
codesign --remove-signature "/Applications/Microsoft Teams.app/Contents/Frameworks/Microsoft Teams Helper.app"
codesign --remove-signature "/Applications/Microsoft Teams.app/Contents/Frameworks/Microsoft Teams Helper (GPU).app"
codesign --remove-signature "/Applications/Microsoft Teams.app/Contents/Frameworks/Microsoft Teams Helper (Plugin).app"
codesign --remove-signature "/Applications/Microsoft Teams.app/Contents/Frameworks/Microsoft Teams Helper (Renderer).app"

Discord workaround

sudo codesign -f -s - /Applications/Discord.app/Contents/Frameworks/Discord\ Helper\ \(Renderer\).app/

Debug / Crash Logs

PTP Webcam moved from a DAL plugin to a CoreMediaIO system extension (org.ptpwebcam.PtpWebcamApp.CameraExtension) plus a user-space agent (org.ptpwebcam.PtpWebcamApp.PtpCameraAgent). All diagnostic output goes through the unified os_log system. There is no longer a /tmp/*.stderr.log file.

Reporting a bug — quickest path

If "List PTP Properties" sees your camera, generate a dump there first:

1. Launch PTP Webcam.app.
2. Menu bar → File → List PTP Properties → \<your camera>.
3. Click Copy to Clipboard or Save to File… and paste the result into your GitHub issue.

For black-screen / live-view-not-starting bugs, the dump on its own isn't enough — please also include a log of the extension while you reproduce the problem.

Capturing live extension logs

In Terminal, before plugging in the camera:

log stream --predicate 'subsystem == "org.ptpwebcam"' \
           --style compact > ~/Desktop/ptpwebcam.log

Now plug in the camera, open QuickTime Player → New Movie Recording → select PTP Webcam, wait ~10 seconds, then stop the recording. Stop the log stream command (Ctrl-C) and attach ~/Desktop/ptpwebcam.log to the GitHub issue.

After-the-fact log dump

If the problem already happened, the in-memory log buffer (log show) still has the last few minutes:

log show --last 5m \
         --predicate 'subsystem == "org.ptpwebcam"' \
         --style compact > ~/Desktop/ptpwebcam.log

Crash logs

System-extension crash reports land in ~/Library/Logs/DiagnosticReports/ with filenames starting with org.ptpwebcam.PtpWebcamApp.CameraExtension-…. Older legacy crash files starting with PtpWebcamLaunchAgent-… are from the previous DAL-plugin architecture and can be ignored.

Useful one-liners

Canon EOS Webcam Utility Incompatibility

PTP Webam is incompatible with Canon's EOS Webcam Utility software, is Canon's software prevents PTP Webcam from accessing any attached camera. Therefore, /Library/CoreMediaIO/Plug-Ins/DAL/EOSWebcam.plugin has to be removed or deleted before PTP Webcam can work.

Funding and Sponsorship

This project is open-source and free to use, but can be supported through Patreon.

If you'd like to contribute in another way, contact dognotdog directly.

License

The full license is available in LICENSE.md at the same location as this readme.

Copyright (C) 2020 Doemoetoer Gulyas

This program is free software: you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation, either version 3 of the License, or (at your option) any later version.

This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details.

You should have received a copy of the GNU General Public License along with this program. If not, see https://www.gnu.org/licenses/.

Acknowledgements

Thanks to Marty Swartz for being the first to help testing additional cameras.

This work would not have been possible without other open-source work:

• https://github.com/johnboiles/coremediaio-dal-minimal-example
• https://github.com/lvsti/CoreMediaIO-DAL-Example
• https://github.com/gphoto/libgphoto2
• http://libptp.sourceforge.net