Core i7 class CPU recommended.
On Ubuntu Linux 14.04, install v4l2loopback driver from repository:
apt-get install -y v4l2loopback-dkms v4l2loopback-utils
..or from latest sources:
apt-get install -y linux-headers-generic git make gcc
git clone https://github.com/umlaeute/v4l2loopback.git
cd v4l2loopback && make && sudo make install install-utils
Load the driver:
sudo modprobe v4l2loopback devices=4
Number of devices is optional. Configure the loopback:
v4l2loopback-ctl set-fps 25 /dev/video0
v4l2loopback-ctl set-caps \
'video/x-raw-yuv, width=1920, height=1080, format=(fourcc)I420' \
/dev/video0
apt-get install -y dvgrab mplayer mencoder
Launch DV conversion to V4L2:
dvgrab - |
mencoder -ovc raw -nosound -vf scale=1920:-1,format=i420 -o /dev/video0 -
Notice trailing -. Another format to try is YUY2, but YMMV.
Test the video:
mplayer tv:// -tv device=/dev/video0
Video is lagging - let introduce latency to audio.
Install SWH LADSPA plugins
apt-get install -y swh-plugins
Choose a delay:
delay=0.3 # seconds
Do PulseAudio magic:
pactl load-module module-null-sink
pactl load-module module-ladspa-sink sink_name=ladspa master=null \
plugin=delay_1898 label=delay_n control=$delay,$delay
pactl load-module module-loopback sink=ladspa
After Hangout is started, use PulseAudio Volume Control (pavucontrol) to move Chrome (WEBRTC with Firefox) on Recording tab to Monitor of Null Output, or from command line:
id=$(pactl list short source-outputs |
grep 'protocol-native.*s16le' |
awk '{print $1}')
pactl move-source-output $id null.monitor
Choose another delay, reload PA modules with pact list short modules / pactl unload-module #INDEX or pulseaudio -k. Wash-repeat.