LibrePlanet: Conference/2016/Streaming

Keynote capture script

#!/bin/bash

xid=$(xwininfo  -root -all|grep "Jitsi Meet" | sed -e 's/^ *//' | cut -d\  -f1)
[ 1${xid}1 != 11 ] && xidparameter="xid=$xid"

export GST_DEBUG=4
DATE=$(date +%Y-%m-%d-%H_%M_%S)
PASSWORD=xxx

# pactl list|grep alsa_output
device1="alsa_output.usb-Burr-Brown_from_TI_USB_Audio_CODEC-00-CODEC.analog-stereo.monitor"
device2="alsa_input.usb-Burr-Brown_from_TI_USB_Audio_CODEC-00-CODEC.analog-stereo"

gst-launch-1.0 --gst-debug-level=$1 --eos-on-shutdown ximagesrc use-damage=false $xidparameter show-pointer=false !\
 videoconvert ! videorate ! video/x-raw,framerate=20/1 ! videoscale ! video/x-raw, width=1024, height=768 !  \
 vp8enc min_quantizer=1 max_quantizer=10 cpu-used=10 deadline=41000 threads=2 ! queue ! mux. \
 pulsesrc device=$device1 ! adder name=mix ! vorbisenc  quality=0.4 ! queue ! mux. \
 pulsesrc device=$device2 ! mix. \
 webmmux streamable=true name=mux ! queue ! tee name=s ! queue ! filesink location=keynote-${DATE}.webm \
 s. ! queue leaky=2 ! shout2send ip=live2.fsf.org port=80 mount=keynote.webm password=$PASSWORD sync=false 2>&1 |\
 tee keynote-${DATE}.log

OpenBroadcaster 2 v4l

This instructions are for building OpenBroadcaster on Debian testing, plus ffmpeg as a dependency.

NOTE that for OBS to run it is necessary OpenGL 3.2 which is not available in Debian 8 Stable. Follow the install instructions after upgrading to Debian testing.

Building/installing:

Install dependencies:

# apt-get install build-essential pkg-config cmake git checkinstall libx11-dev libgl1-mesa-dev \
libpulse-dev libxcomposite-dev libxinerama-dev libv4l-dev libudev-dev libfreetype6-dev \
libfontconfig-dev qtbase5-dev libqt5x11extras5-dev libx264-dev libxcb-xinerama0-dev \
libxcb-shm0-dev libjack-jackd2-dev libcurl4-openssl-dev zlib1g-dev yasm gstreamer-tools pavucontrol

Download and build ffmpeg:

$ git clone --depth 1 git://source.ffmpeg.org/ffmpeg.git
$ cd ffmpeg
$ ./configure --enable-shared --prefix=/usr
$ make -j4

# checkinstall --pkgname=FFmpeg --fstrans=no --backup=no \
    --pkgversion="$(date +%Y%m%d)-git" --deldoc=yes

Download and build obs:

$ git clone https://github.com/jp9000/obs-studio.git
$ cd obs-studio
$ mkdir build && cd build
$ cmake -DUNIX_STRUCTURE=1 -DCMAKE_INSTALL_PREFIX=/usr ..
$ make -j4
# checkinstall --pkgname=obs-studio --fstrans=no --backup=no \
   --pkgversion="$(date +%Y%m%d)-git" --deldoc=yes

Install v4l loop:

# apt-get install v4l2loopback-dkms
# echo v4l2loopback >> /etc/modules
# modprobe v4l2loopback

Install local stream manager:

# apt-get install crtmpserver

Setup

Run obs, set streaming settings to:

URL: rtmp://127.0.0.1/flvplayback
Stream Key: stream

Run streaming to v4l:

# modprobe snd-aloop
# echo snd-aloop >> /etc/modules
$ gst-launch-1.0 rtmpsrc location="rtmp://127.0.0.1/flvplayback/stream.flv live=1" ! decodebin name=decoded ! videorate !\
video/x-raw,framerate=25/1 ! queue leaky=1 !  v4l2sink device=/dev/video1 sync=false \
decoded. ! audioconvert ! queue leaky=1 ! pulsesink device=alsa_output.1.analog-stereo sync=false

Start Jitsi Meet session on Chromium (recommended browser, others may work).

Configure Chromium to use Dummy video device (0x0000) as the video source, and Loopback Analog Stereo as the audio source.
Launch pavucontrol and on the Recording tab, set Chromium to record from Monitor of Loopback Analog Stereo.

Caveats

This setup introduces ~1s delay on video and audio.

Troubleshooting

Test streaming:

$ gst-launch-1.0 rtmpsrc location="rtmp://127.0.0.1/flvplayback/stream.flv live=1"  ! decodebin ! xvimagesink sync=false

Test v4l device:

$ gst-launch-1.0 v4l2src device=/dev/video1 ! xvimagesink

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