source : linux magazine France n°192 (april 2016)

Source code

apt-get install v4l2loopback-dkms v4l2loopback-utils

sudo modprobe v4l2loopback devices=1 video_nr=1 card_label=toto

/etc/modules-load.d/v4l2loopback.conf

v4l2loopback

v4l2loopback devices=1 video_nr=1 card_label=toto

v4l2-ctl --list-devices
v4l2-dbg --info --device=/dev/video1
v4l2-ctl --list-formats --device=/dev/video1

v4l2-ctl set-fps 25 /dev/video1

Exemple using a webcam

ffmpeg -f mjpeg -i http://webcam.st-malo.com/axis-cgi/mjpg/video.cgi?resolution=352x288 -pix_fmt yuv420p -f v4l2 /dev/video1

Use vlc or ffplay

ffplay -f v4l2 -i /dev/video1

ffmpeg -f v4l2 -i /dev/video1 -f mjpeg ./video-capture

Load the driver

modproble v4l2loopback device=1 video_nr=1 exclusive_cap=1

Inject with gstreamer

gst-launch-0.10 -v videotestsrc ! "video/x-raw-yuv, width=640,height=360, framerate=30/1, format=(fourcc)I420" ! v4l2sink device=/dev/video1

gst-launch videotestsrc ! ffmpegcolorspace ! "video/x-raw-yuv, format=(fourcc)YUV2" ! v4l2sink device=/dev/video1