What do we want? Information.
Wednesday, January 19, 2011
Video is a great way to augment a presentation. The question is often asked, what's the best way to deliver video as part of a presentation? Many presentations are grounded in a PowerPoint or Keynote slide show. Complexity arises because Windows and Apple presentation platforms support different video formats. Other considerations include video compression, length and continuity.
Continuity is important. One solution is to simply interrupt a slide show and switch to a DVD or media player application (Windows Media player, QuickTime player, etc) to display video. This may disrupt the flow of a presentation and introduces additional variables that may complicate the presentation.
The preferred method is to import a video file directly into the presentation software and display the video on a discrete slide. To do so we must consider the correct file format. For the best result import a .wmv file for PowerPoint for Windows. PowerPoint for Mac will playback most QuickTime compatible formats. Unfortunately, this excludes the .wmv format. Optimally, use an H.264 encoded .mov or an iPod or Apple TV formatted file.
File format is not the only consideration. Ensuring that a file is compressed (reduction in file size) sufficiently to ensure smooth playback is another important consideration. File conversion utilities are available which solve both format and compression issues. Compression is important because video requires significant processor and memory resources to render smoothly. Therefore the capabilities of the presentation computer are also a factor. File size is also proportionate to the length of the video. Using only the length of video to demonstrate a specific concept is recommended.
To export and compress a file for PowerPoint for Windows consider Microsoft's Expression Encoder 4 and WinFF. Each of these free applications have predefined output settings called 'presets' which eliminate the need to configure complex parameters. The output settings for each can be found below.
Microsoft Expression Encoder Recommended Presets
'VC-1 Zune 2' for 320 X 240 output at 1000 kb/s
'VC-1 Zune 2(AV Dock Playback)' for 640 X 480 output at 2000 kb/s
WinFF Recommended Preset
QuickTime Pro ($29.99 direct from Apple) is the go to application on the Mac. Other conversion options include Compressor, which is bundled with Final Cut Pro and FFMpegX, a free utility with a somewhat complicated initial set-up. Another great utility that has a wide range of presets is Mac Video Converter ($39 from WonderShare). Mac Video Converter is one of the few utilities that reliably converts files to .wmv on the Mac. Regardless of the utility you choose, I recommend the Apple TV preset which provides ~1.5 Mb/s 640X480 output.
When preparing a presentation it is also important to store the video file itself in the same directory as the presentation. Package the presentation together and transport the files together. This will ensure that the linked video file is available during the presentation.
Digital Media Services is available to assist faculty and staff with file conversion and with building a presentation with video.
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