23 February 2014

Lync Conference: Video- What In The World Are You Doing To My Network?

The videos from all of the various breakout sessions should be available soon. In the mean time, here are my notes from some of the sessions I attended.

Video- What in the World Are You Doing To My Network?
Jeff Schertz, Polycom

Foundational Concepts
  • Video codecs in 2013
    • RTV
    • H.264 Scalable Video Coding
      • Hardware acceleration 
      • More resolutions up to 1080p
      • Multiple panorama resolutions
      • Temporal Scaling - mult frame rates in single encoded stream
      • UCConfig mode - look at Jeff's blog for more info
    • Client can send up to 5 possible concurrent streams per video source
      • Very unlikely though
    • Client can receive multiple streams as well
Disecting the Video Experience
  • Views available in the Client
    • Gallery view
    • Speaker view
    • Video Spotlight - presenter can lock view to his camera
    • Compact view - Not showing any video
    • Lync will selectively start/stop participant video as needed during conference if no one is viewing their stream to save on bandwidth/computing
  • Smart Framing - This is basically smart cropping based on facial tracking
  • Cropping - There is no square resolution in Lync, the client hides the edged for real estate
    • Video is encoded and sent in full resolution
  • Video Resolution - more is less - resolution goes down for each stream as more streams are shown 
    • Pixel depth more important than screensize
  • Unique experiences
    • Dual monitors
    • Lync room system - span 2 monitors
    • Panoramic
Doing the Math
  • Don't forget about audio!!
  • Include payload and RTCP payload (5-15 Kbps)
  • H.262 SVC - lot more options/resolutions, much cleaner display at any resolution
  • Lync Bandwidth Calculator
  • Conference calls typically use less bandwidth
  • Default video stream is 320x240 15Kbps
  • Have to manually resize vdeo for higher resolutions
  • Controlling bandwidth
    • Get-CsConferencingPolicy | fl *video*
      • AllowIPVideo
      • EnableP2PVideo
      • MaxVideoConferenceResolution
    • To disable gallery view
      • AllowMultiview
      • EnableMultiviewJoin
    • Conferences with over 75 participants switch to only display active speaker automatically
    • Limiting bit rates
      • Default limit 50 Mbps for sent video
      • Total receive default 50 Mbps
      • Must be at least 420 Kbps to support gallerey view, may get weird behavior below this
      • Bit rate is measured per video source - webcam, roundtable, etc
Actual Usage
  • Usage at Microsoft
    • Daily 6,000 minutes peer to peer
    • Daily 226,000 minutes conferencing
    • 11 million minutes of video in November 2013
    • Users tend to keep default resolutions
    • No bandwidth or CAC policy constraints in place
Summary
  • Factors for growth
    • Age - Younger workers like video as they tend to have grown up with it
    • Ubiquity - Video is looking better than it ever has, much more common
    • Culture
    • Experience - As they use it, they want to use it more
  • Importance of the Video modality
    • Audio is the Pinnacle
    • Content is King
    • Video is a love/hate relationship

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