Saturday, September 8, 2012

Easier streaming with presence-0.4.8

Presence is a small - but yet flexible - tool to do simple and high-quality streaming (using dirac+vorbis over RTP) in a local broadcast domain.
When not using the MDNS feature this can also be endpoints on any routable network.
Not shown on in the screen shot, but a feature, is picture-in-picture mode for secondary streams.

Anyhow, this new release (0.4.8) contains an improvement related to publishing a stream. It's now done in two clicks with reasonable defaults, even for low-end machines.

Install or update it now on Fedora 16/17/18:
$ sudo yum clean metadata
$ sudo yum install --enablerepo=updates-testing presence
# or
$ sudo yum update --enablerepo=updates-testing presence

Or - hero-like -using this one-click technology.

The release was motivated by my new Logitech HD Pro Webcam C920 which is working out of the box on Fedora - so YUV and MJPEG besides the (unsupported) h.264 support.
When looking at the video quality of this camera and two built-in cameras of laptops, this is clearly a big step forward in image quality - So a decent camera is always a good way to improve a video conference.
As said, the video quality is great - and using MJPEG it can deliver a 720p video with up to 24fps, so ideal for telepresence. 


  1. Thank you for the post. I tried this on my F18 box and it core dumped.

    ** (presence:3140): WARNING **: media.vala:327: Mapping added for 'presence' with: (
    v4l2src device=/dev/video0
    ! videorate
    ! aspectratiocrop aspect-ratio=16/9
    ! videoscale
    ! video/x-raw-yuv,width=1280,height=720,framerate=30/1
    ! schroenc force-profile=vc2_simple quality=9 queue-depth=5
    ! queue
    ! rtpgstpay pt=96 name=pay0

    pulsesrc do-timestamp=true stream-properties='props,media.role=phone,filter.want=echo-cancel' client='Presence (in)'
    ! vobisenc
    ! queue
    ! rtpgstpay pt=97 name=pay1
    Segmentation fault (core dumped)

    1. hey chida, thanks for this report. I only tried it on F16 and F17 but will look into this issue. You might want to add a bug report if you want to make sure that I don't forget about it :)

    2. Sorry! Correction: I tried it on my F17 box and not F18. I tried multiple combinations of resolution and FPS and they all core dump. I can open a bug report but where :)

    3. Ah okay, well that is not intended :)
      Please file it here. Thanks