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This repository has been archived by the owner on Dec 15, 2020. It is now read-only.

Developing

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Sebastian Beckmann edited this page Oct 22, 2020 · 3 revisions

How to modify, build, and debug potential fixes or improvements to this codebase. Please help me make this thing not janky!

Known Issues

  • Can't click menu bar after program start (OBS Issue #2678). NOTE: This is not an issue with this plugin, but it does make it more annoying to turn on the Virtual Camera created by this plugin after building locally.
  • DAL plugin unable to run because of codesigning issues (for example unable to see Virtual Camera in latest version of Zoom). See issue #4 for history and some workarounds.

Common Problems (with local builds)

  • Failed to load 'en-US' text for module: 'obs-mac-virtualcam.so': If the virtual camera doesn't work, you might see this error. However, it is expected and not the problem. There might be another problem you didn't see.
  • Build fails at cmake .. && make -j: In this case, simply repeat cmake .. && make -j.
  • Error 2: At the end of the build, the terminal will say make: *** [all] Error 2. This is expected and not an error. If it says Built target obs a few lines above, your build has succeeded.

If you still have problems running the virtual camera, see below.

Please confirm that your issue is related to this plugin and not a general OBS problem before opening an issue – try to build OBS locally (but not this plugin) and see if the issue persists. If it does, please don't open an issue here; Instead go open an issue on obsproject/obs-studio. The same goes for supporting other plugins; it's outside of the scope of this project to tell you how to build other OBS plugins locally (e.g. Browser Source, Speex, etc).

Building

If you want to clone this plugin (and OBS) locally, follow these steps.

# Clone and build OBS
git clone --recursive https://github.com/obsproject/obs-studio.git
cd obs-studio

# Follow normal OBS build steps
brew install FFmpeg x264 Qt5 cmake mbedtls swig
mkdir build
cd build
# Note: if you installed homebrew to a custom location, this will be $BREW_INSTALL_PATH/opt/qt
export QTDIR=$(brew --prefix)/opt/qt
cmake -DDISABLE_PYTHON=ON .. && make -j

# Clone this repo
cd ../..
git clone https://github.com/johnboiles/obs-mac-virtualcam.git
cd obs-mac-virtualcam

# Set an environment variable that points to the directory for your OBS clone
export OBS_DIR=$PWD/../obs-studio

# Build the plugin
mkdir build
cd build
cmake -DLIBOBS_INCLUDE_DIR:STRING=$OBS_DIR/libobs -DLIBOBS_LIB:STRING=$OBS_DIR/build/libobs/libobs.dylib -DOBS_FRONTEND_LIB:STRING=$OBS_DIR/build/UI/obs-frontend-api/libobs-frontend-api.dylib -DQTDIR:STRING=$QTDIR ..
make -j

# Copy the OBS plugin to your local OBS build
cp src/obs-plugin/obs-mac-virtualcam.so $OBS_DIR/build/rundir/RelWithDebInfo/obs-plugins/

# Remove any existing plugin and copy the DAL plugin to the right place
sudo rm -rf /Library/CoreMediaIO/Plug-Ins/DAL/obs-mac-virtualcam.plugin && sudo cp -r src/dal-plugin/obs-mac-virtualcam.plugin /Library/CoreMediaIO/Plug-Ins/DAL

# Run your build of OBS
cd $OBS_DIR/build/rundir/RelWithDebInfo/bin
./obs

Now in OBS go to Tools→Start Virtual Camera, then open your favorite video streaming app (or fully close it then re-open it to make sure it reloads any loaded video plugins). You should be able to pick OBS Virtual Camera as a source.

Using the cmake Xcode generator

You can use cmake to generate an xcodeproj file to open all the files in Xcode. This is my preferred way of developing code on this plugin.

# Set an environment variable that points to the directory for your OBS clone
export OBS_DIR=$PWD/../obs-studio
# Set an environment variable pointing to QT
export QTDIR=$(brew --prefix)/opt/qt

mkdir xcode
cd xcode
cmake -DLIBOBS_INCLUDE_DIR:STRING=$OBS_DIR/libobs -DLIBOBS_LIB:STRING=$OBS_DIR/build/libobs/libobs.dylib -DOBS_FRONTEND_LIB:STRING=$OBS_DIR/build/UI/obs-frontend-api/libobs-frontend-api.dylib -DQTDIR:STRING=$QTDIR -G Xcode ..

You can then use Xcode to build your binaries (which will include debug symbols). To copy them into the right place you need a slightly different command. From the xcode directory created previously:

# Copy over the OBS plugin
cp src/obs-plugin/Debug/obs-mac-virtualcam.so $OBS_DIR/xcode/rundir/Debug/obs-plugins
# Remove any existing plugin and copy the DAL plugin to the right place
sudo rm -rf /Library/CoreMediaIO/Plug-Ins/DAL/obs-mac-virtualcam.plugin && sudo cp -r src/dal-plugin/Debug/obs-mac-virtualcam.plugin /Library/CoreMediaIO/Plug-Ins/DAL

Debugging the OBS plugin

To debug the OBS plugin (obs-mac-virtualcam.so), you can attach the Xcode debugger to the OBS process. This allows you to step through the OBS plugin code In Xcode, go to Debug → Attach to Process by PID or Name..., then enter obs and debug the process as root. Then run OBS and you should be able to hit breakpoints set inside the plugin code.

Debugging the DAL plugin

Debugging the DAL plugin (obs-mac-virtualcam.plugin) is a little trickier. You need to attach the Xcode debugger to a host process that loads the plugin. One option is to build another copy of OBS (without obs-mac-virtualcam.so), attach the debugger to that process, then add the virtual camera as a Video Capture Device there. You should then be able to step through code on the DAL plugin.

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