Comparing Embedded "Live" stream options
 

This page compares the two primary media formats we are hosting. Until recently live events were exclusively streamed Windows Media format, but recent upgrades to the Flash server allow us now to stream via that platform as well. To see how they compare, we created a mock encoding situation and ran the event via each platform. The archive files created during those test are used here to show the quality seen during those sessions.

The sample clips below are the encoder archives from sample live streams, created from the same source on the same hardware in a live streaming scenario.

The video and audio source of these streams was a DV tape playing back a professionally produced event. The CPU on the encoder was a dual core Athlon X2 6400 3.2ghz per core chip. Flash Media Encoder v 2.5 was used for the Flash stream, while Windows Media Encoder 9 was used for the Windows Media file. The Flash Encoder performance limitations determined the maximum quality of the comparison files, as the computer would not support higher quality Flash settings without running into CPU limitations. We adjusted the Windows Media encoder to match the settings we were able to achieve with the Flash encoder. This artificial limit was chosen to compare the output quality of either live stream at the same bandwidth level.

The clips below are all about 580kbit/second, 320x240 pixels, 29.97 frames per second, using about 96kbit of the bandwidth for the audio stream.

  Embedded Windows Media   Flash   Silverlight  
 
Click here for standalone player
This text will be replaced

Click here for standalone player
  Details Details Details
Requirements: Encoder Performance:
  • 15% CPU load at this setting, highly reliable.
  • at 50% CPU load video of much higher quality is possible (sample link)
Other Considerations:
  • Windows Media Sever is extremely reliable and has proven to handle events with thousands of viewers
  • we have many years of experience hosting large live events in this format.
Requirements:
  • Adobe Flash 9 plugin must be installe 97.7% of US computers should have it (June 2008 *)
Encoder Performance:
  • about 80% CPU load at this setting and pushing a limit where frame drops can occur.
  • The encoder can produce much higher quality files, however, not in realtime, which is what live events require. The Flash encoder CPU requirements are very high.
Other Considerations:
  • Flash Media Server, the backbone of a live Flash streaming event, is an untested entity regarding the reliability of live events. We have had frequent server crashes during higher demand periods for on-demand content but this was prior to some upgrades.
  • Beyond testing functionality, we don't have any experience with live Flash events. None of our customers has elected to use this format for a mission critical event.
Requirements: Encoder Performance:
  • 15% CPU load at this setting, highly reliable.
  • at 50% CPU load video of much higher quality is possible (sample link)
Other Considerations:
  • Windows Media Sever is extremely reliable and has proven to handle events with thousands of viewers
  • we have many years of experience hosting large live events in this format.

©2005-2008 The Board of Regents of the University of Wisconsin System

Feedback, questions or accessibility issues