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Webcasting

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source - www.StreamingMedia.com

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Webcasting

  1. 1. Hands on Guide to Webcasting May 14, 2007 Streaming Media East
  2. 2. The Goal <ul><li>Live at noon </li></ul><ul><li>Audience participation </li></ul><ul><ul><li>yes, that means you </li></ul></ul>
  3. 3. What We Have To Do <ul><li>Planning </li></ul><ul><ul><li>programming </li></ul></ul><ul><ul><li>production </li></ul></ul><ul><ul><li>network infrastructure </li></ul></ul><ul><ul><li>web presence </li></ul></ul><ul><li>Execution </li></ul><ul><ul><li>a/v production </li></ul></ul><ul><ul><li>authoring </li></ul></ul><ul><ul><li>encoding </li></ul></ul><ul><li>Testing </li></ul><ul><ul><li>everything – twice. </li></ul></ul>
  4. 4. Rough Schedule <ul><li>Initial discussion (10 mins) </li></ul><ul><li>Planning (1 hour) </li></ul><ul><ul><li>basics (who/what/where/why) </li></ul></ul><ul><li>Execution (1 hour) </li></ul><ul><ul><li>a/v production setup </li></ul></ul><ul><ul><li>a/v testing </li></ul></ul><ul><ul><li>encoding setup </li></ul></ul><ul><ul><li>encoding testing </li></ul></ul>
  5. 5. Why Webcasts are Tricky <ul><li>They’re live </li></ul><ul><ul><li>No second chance </li></ul></ul><ul><li>Additional hardware requirements </li></ul><ul><li>Additional personnel requirements </li></ul><ul><li>They test the limits of your streaming infrastructure </li></ul><ul><ul><li>Bandwidth </li></ul></ul><ul><ul><li>Server architecture (web & streaming) </li></ul></ul><ul><li>They’re expensive and therefore can be hard to justify </li></ul>
  6. 6. Are you ready?
  7. 7. First: Make the Business Case <ul><li>Who </li></ul><ul><ul><li>is the audience? </li></ul></ul><ul><li>What </li></ul><ul><ul><li>are we webcasting? </li></ul></ul><ul><li>Where </li></ul><ul><ul><li>is the location suitable </li></ul></ul><ul><li>When </li></ul><ul><ul><li>is there enough time to do it right? </li></ul></ul><ul><li>Why </li></ul><ul><ul><li>is this the best way to address the need? </li></ul></ul>
  8. 8. We need a crew. <ul><li>Executive Producer </li></ul><ul><li>Audio engineer </li></ul><ul><li>Videographer (camera op) </li></ul><ul><li>Encoding engineer </li></ul><ul><li>Host </li></ul><ul><li>Guest(s) </li></ul>
  9. 9. Planning <ul><li>Location </li></ul><ul><ul><li>Size, power, access, union fees </li></ul></ul><ul><li>Signal Acquisition </li></ul><ul><ul><li>On site connectivity, satellite </li></ul></ul><ul><li>Equipment </li></ul><ul><ul><li>Usually best to work with a partner </li></ul></ul><ul><li>Crew </li></ul><ul><ul><li>May come with equipment </li></ul></ul><ul><li>Presentation </li></ul><ul><ul><li>Talent, Pre/post show, technical difficulties </li></ul></ul><ul><li>Network Infrastructure </li></ul><ul><ul><li>host, bandwidth usage, encoding specs </li></ul></ul>
  10. 10. <ul><li>Production area </li></ul><ul><li>Stage </li></ul><ul><li>Audio </li></ul><ul><li>Video </li></ul><ul><li>Encoding </li></ul>Setup
  11. 11. <ul><li>Avoid ground hum </li></ul><ul><ul><li>Placement or extra equipment </li></ul></ul><ul><li>Ambient mics </li></ul><ul><ul><li>Absolutely for musical events </li></ul></ul><ul><li>Tape down loose cables </li></ul><ul><li>Use compression </li></ul><ul><li>Test! </li></ul>Audio Setup
  12. 12. Setting Up A Gain Structure <ul><li>Make sure each piece of equipment operates in its optimal range </li></ul><ul><li>Start with first piece of equipment and work through the signal chain </li></ul><ul><li>set the input and output gain for each </li></ul><ul><li>Peaks at -3dB for analog, -10dB for digital </li></ul>
  13. 13. Audio Production Tips <ul><li>Compression “evens out” audio levels </li></ul><ul><ul><li>Protects your equipment from “spikes” in level </li></ul></ul><ul><ul><li>Attenuating loud sections enables overall signal gain </li></ul></ul><ul><ul><li>“Fattens” audio </li></ul></ul><ul><ul><li>Hardware compressor is essential for webcasts </li></ul></ul>
  14. 14. Compression Illustrated
  15. 15. <ul><li>Tripods (heavy duty) </li></ul><ul><li>Risers if available </li></ul><ul><li>Lights </li></ul><ul><ul><li>3-point? </li></ul></ul><ul><ul><li>Flat wash? </li></ul></ul><ul><li>White balancing (shading) </li></ul><ul><li>Test! </li></ul>Video Setup
  16. 16. How Video Codecs Work <ul><li>Intra-frame compression </li></ul><ul><ul><li>Just like a .jpg or .png file </li></ul></ul><ul><li>Inter-frame compression </li></ul><ul><ul><li>Differences between frames are encoded </li></ul></ul><ul><li>Key frames </li></ul><ul><ul><li>Entire frame is encoded </li></ul></ul><ul><ul><li>Uses a lot of bandwidth </li></ul></ul><ul><li>Difference frames </li></ul><ul><ul><li>Only differences are encoded </li></ul></ul><ul><ul><li>Use relatively little bandwidth on low motion content </li></ul></ul>
  17. 17. Video Production Tips <ul><li>Avoid unnecessary motion/changes </li></ul><ul><ul><li>Use a tripod, use a tripod, use a tripod </li></ul></ul><ul><ul><li>Avoid moving objects in the background </li></ul></ul><ul><ul><li>Avoid special effects </li></ul></ul><ul><ul><li>Simple edits are best </li></ul></ul><ul><ul><li>Keep the number of cuts to a minimum </li></ul></ul><ul><li>Framing </li></ul><ul><ul><li>Smaller screen, so frame tighter </li></ul></ul>
  18. 18. Video Production Tips <ul><li>G-I-G-O </li></ul><ul><li>Use good video engineering practice </li></ul><ul><ul><li>If you don’t know, hire someone </li></ul></ul><ul><li>Good equipment, proper technique </li></ul><ul><ul><li>If you don’t own it, rent it </li></ul></ul><ul><li>Lighting is essential </li></ul><ul><ul><li>Nearly impossible to correct using software </li></ul></ul><ul><ul><li>Low-light = no light </li></ul></ul>
  19. 19. Video Processing Techniques <ul><li>VGA vs. Television displays </li></ul><ul><ul><li>VGA screens are far more detailed </li></ul></ul><ul><ul><li>Traditional video tends to look dark & washed out </li></ul></ul><ul><li>Adjust Brightness </li></ul><ul><ul><li>Add gain to match screen to a TV monitor </li></ul></ul><ul><ul><li>Be careful if you’re going back out to the broadcast world! </li></ul></ul><ul><li>Adjust Contrast </li></ul><ul><ul><li>Adding a small amount is good; be careful though </li></ul></ul><ul><ul><li>Too much contrast adds grain (bad for codecs) </li></ul></ul><ul><li>Color </li></ul><ul><ul><li>Increasing saturation a bit can be helpful </li></ul></ul>
  20. 20. Encoding Setup <ul><li>Bit rate </li></ul><ul><li>Resolution </li></ul><ul><li>Capture card? </li></ul><ul><li>Encoding software? </li></ul><ul><li>Local Archive? </li></ul><ul><li>Push vs. pull encoding </li></ul><ul><li>Redundancy is key </li></ul><ul><ul><li>Ideally redundant connectivity </li></ul></ul><ul><ul><li>Extra equipment </li></ul></ul><ul><li>Multiple stream solutions </li></ul>
  21. 21. Authoring <ul><li>Link to webcast page from home page </li></ul><ul><li>Always offer a metafile link </li></ul><ul><li>If embedding, keep it simple </li></ul><ul><li>Test! </li></ul>
  22. 22. Authoring <ul><li>Problem: browsers don’t stream </li></ul><ul><ul><li>Browsers don’t understand RTSP or MMS protocols </li></ul></ul><ul><ul><li>Browsers download entire file </li></ul></ul><ul><li>Solution: metafiles </li></ul><ul><ul><li>Small file delivered via HTTP </li></ul></ul><ul><ul><li>Contains information about streaming file </li></ul></ul>4 Web Server Streaming Server 1 2 3 5
  23. 23. Authoring - Metafiles <ul><li>QuickTime .qtl files </li></ul><ul><li>RealSystem .ram files </li></ul><ul><li>Windows Media .asx files </li></ul><?xml version=&quot;1.0“ ?> <?quicktime type=&quot;application/x-quicktime-media-link“ ?> <embed src=“rtsp://your.qtserver.com/YourStream.mov&quot; /> rtsp://your.realserver.com/YourStream.rm <asx version=&quot;3.0&quot;> <entry> <ref href=&quot;mms://your.wmserver.com/YourStream.wmv&quot; /> </entry> </asx>
  24. 24. Distribution Techniques <ul><li>Redundancy is key </li></ul><ul><li>Robust load balancing required </li></ul><ul><li>Use multicast where appropriate </li></ul><ul><li>Usually best to work with a partner </li></ul><ul><li>TEST! </li></ul>
  25. 25. Distribution Methods <ul><li>Unicast/multicast to servers </li></ul><ul><li>Unicast/multicast to local clients </li></ul>
  26. 26. Countdown <ul><li>Test the audio </li></ul><ul><li>Test the video </li></ul><ul><li>Test the encoder(s) </li></ul><ul><li>Test the link(s) </li></ul><ul><li>Go live at least 10 minutes before event begins, preferably 30 minutes </li></ul>
  27. 27. Liftoff?
  28. 28. Q & A Thank You Steve Mack [email_address]

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