ros-virtual-cam

ROS node for streaming an image topic to a video capture device. Mostly based on this:

• virtual_camera

dev

Setup a workspace:

cd ~/catkin_ws/src  # or wherever catkin_ws is
git clone https://github.com/lucasw/ros-virtual-cam
cd ..
catkin build virtual_cam

video devices

Stream node needs to write to a video capture device, which varies depending on your system.

linux

Uses v4l2-loopback:

$ sudo apt-get install v4l2loopback-*
$ sudo modprobe v4l2loopback video_nr=1
$ v4l2-ctl -D -d /dev/video1
Driver Info (not using libv4l2):
    Driver name   : v4l2 loopback
    Card type     : Dummy video device (0x0000)
    Bus info      : v4l2loopback:0
    Driver version: 0.8.0
    Capabilities  : 0x05000003
        Video Capture
        Video Output
        Read/Write
        Streaming

usage

stream

Typically just:

$ rosrun virtual_cam stream _device:=/dev/video1 _width:=640 _height:=480 _fourcc:=YV12 image:=/my_camera/image

where:

• /dev/video1 target device
• 640x480 target size
• YV12 target pixel format
• /my_camera/image the source sensor_msgs/Image topic re-mapped to image

For more:

$ rosrun virtual_cam stream --help

tests

$ v4l2-ctl -D -d /dev/video1
Driver Info (not using libv4l2):
    Driver name   : v4l2 loopback
    Card type     : Dummy video device (0x0000)
    Bus info      : v4l2loopback:0
    Driver version: 0.8.0
    Capabilities  : 0x05000003
        Video Capture
        Video Output
        Read/Write
        Streaming
$ ROS_VIRTUAL_CAM_STREAM_TEST_DEVICE=/dev/video1 catkin_make run_tests

If you want coverage:

$ catkin_make -DCMAKE_BUILD_TYPE=Debug -DCOVERAGE=ON
$ ROS_VIRTUAL_CAM_STREAM_TEST_DEVICE=/dev/video1 catkin_make run_tests
$ lcov --path . --directory . --capture --output-file coverage.info
$ lcov --remove coverage.info 'tests/*' '/usr/*' '/opt/*' --output-file coverage.info
$ lcov --list coverage.info

TODO(lucasw) update above for catkin build