Home

Table of Contents About GStreamer-Phone About Gstreamer How to test gstreamer Development status Capturing Streaming Playback Not working Future plans Dependencies System configuration Links Debian packaging STUN

About GStreamer-Phone

gstreamer-phone is a console tool, which allows to make video calls independent of a graphical system installed. It negotiates a session with a remote partner via SIP, XMPP (Jabber, Google Talk) or Google Hangouts (planned) and initiates H.264 compressed video transmission via RTP using gstreamer. gstreamer-phone is especially designed for usage on the Raspberry Pi with special focus on the Raspberry's hardware H.264 encoding and decoding capabilities. The camera for development is the Logitech C920, which features hardware H.264 encoding.

About Gstreamer

• separate project
• first, you need to understand about GStreamer support for the UVC for H.264 encoding cameras
• for UVC H.264 support to work, you need to compile a recent version of gstreamer 0.10: Compiling gstreamer
• some example commands, to check if it's working: Streaming H.264 via RTP
• if you want the gstreamer server (receives video for display) to display immediately, it needs to be running before the client starts to send data
• video decoding will happen in the Raspberry's Broadcom VideoCore IV using GstOpenMAX

How to test gstreamer

PC:

 $ gst-launch-0.10 -v v4l2src device=/dev/video1 ! 'video/x-h264,width=800,framerate=15/2' ! rtph264pay ! udpsink host=raspberry port=9078

Raspberry:

 $ gst-launch-1.0 -v udpsrc port=9078 ! 'application/x-rtp,payload=96,encoding-name=H264' ! queue ! rtph264depay ! h264parse ! decodebin ! autovideosink

Development status

Capturing

• uvch264 for gstreamer-0.10 works perfectly
• H.264 stream bitrates can be adjusted in the command line

Streaming

• streaming through SSH tunnel works
• streaming via RTP works

Playback

• lag problems appear are considered sufficiently addressed by sync=false and queue(2)

Not working

• video preview on the recording machine does not work, since eglglessink for 0.10 won't run and only 0.10 features the uvch264 plugin
• gst-omx for gstreamer-0.10 will not launch
• gstreamer-1.0 will not compile dfbvideosink, because it's not been ported yet

Future plans

• SIP support, see also Issue list
• Android app
• Video conference with other common SIP clients
• SRTP support
• RTP over SSH support

Dependencies

• a Raspberry Pi
• a Logitech C920 webcam
• gstreamer

My /etc/apt/sources.list is:

deb http://ramses.wh2.tu-dresden.de/pub/mirrors/raspbian/raspbian/ wheezy main contrib non-free rpi
deb-src http://ramses.wh2.tu-dresden.de/pub/mirrors/raspbian/raspbian/ wheezy main contrib non-free rpi
deb http://vontaene.de/raspbian-updates/ . main
deb-src http://vontaene.de/raspbian-updates/ . main

apt-get install libgstreamer0.10-0 gstreamer0.10-tools \
  gstreamer0.10-plugins-good gstreamer0.10-plugins-ugly \
  v4l-utils

System configuration

 apt-get install libnss-mdns mdns-scan avahi-{utils,daemon}

• /etc/nsswitch.conf

 hosts:          files mdns4_minimal [NOTFOUND=return] dns mdns4

Links

• http://fablabamiens.org/index.php?title=Raspberry_for_HD_Video_Streaming
• http://groakat.wordpress.com/2012/12/05/gstreamer-stream-h264-webcam-data-to-series-of-files/
• https://sourceforge.net/mailarchive/forum.php?thread_name=1350220802.54181.YahooMailRC%40web181405.mail.ne1.yahoo.com&forum_name=linux-uvc-devel
• The Guardian Project - Ostel
• http://www.collabora.com/projects/

Debian packaging

• http://wiki.debian.org/HowToPackageForDebian

STUN

• http://de.wikipedia.org/wiki/Session_Traversal_Utilities_for_NAT
• http://commons.wikimedia.org/wiki/File:STUN_Algorithm3.svg