Dan LaValley Manager Biology New Media Center

Thanks to Dan LaValley of Learning Technology & Distance Education for creating this tutorial.

 

It can be difficult to figure out what is the right method and format to use. While there are usually not crystal clear lines of distinction in this matter, we do have some basic recommendations.

Question #1 -- What is the length of your video?
The length of a video will often determine how one should deliver content. If a clip is only several seconds long, downloading is probably best, since it will probably take as long to download the clip as it will to synchronize with the streaming server. If a clip is several minutes to an hour, streaming should be considered, as download would take a very long time. If content is greater than an hour, CD-ROM or DVD should be considered. If web delivery is required, it is recommended that the content be broken up into smaller and shorter pieces.

Question #2 -- How are students going to access this material?
The method by which students will access media content is an important consideration. There are several options for students to access content.

Campus Network
Campus InfoLabs and libraries provide high speed LAN connections through which students can access content. In this scenario, downloaded or streamed delivery can be chosen and the delivery speed is not an obstacle. A higher quality will be achievable through downloading content. However, if content is very long these public workstations may have limited disk space in which to hold the downloaded content.

Home Access - DSL & Cable Modems
A recent student computing survey showed that 48% of students have access to high speed Internet connections at home. Students using DSL or cable modems can have download speeds of 256kb to 1.5Mb available to them. These connection speeds are fast enough to receive better than average streamed content and download content in a reasonable period of time (from 1- 5 minutes for longer clips). If content is longer then a couple minutes, streaming is recommended, because not all formats allow for progressive download (a process by which a movie is delivered as it is being downloaded, instead of having to wait for the entire clip to download before it can be played).

Home Access - 56K Modems and slower
There are still a significant number of students using 56k modems or slower to connect to the Internet. Campus modem pool access is showing a decrease in usage each semester. However, if a high number of student in a course will be accessing content in this manner, delivery of media content can be difficult. If content is only several seconds long, download is probably the best method. Streamed content to this audience will usually be of a very low quality, particularly if it is full motion video. Consider narrative presentation technology for this audience. This solution can deliver lecture length content to students by streaming slides with a synchronized audio track. If content is longer than 1 or 2 minutes, delivery using a CD-ROM or DVD is probably needed. This will ensure that students receive a clean and crisp version of media content

Learn@UW
Learn@UW warrants special attention as it relates to video and audio. Learn@UW provides the ability to restrict access to content to students only. There are some potential issues with regard to Learn@UW, however. If the clip is of a smaller size (under 2MB) download using Learn@UW may be fine for 56K modem users. It may be better to create a reference file which points to an file on the streaming server and place that inside Learn@UW. Also, at the time of writing these materials, there are several bugs with Windows Media and Real formats. QuickTime streaming with Learn@UW is recommended. In addition, try to embed video clips into HTML pages, instead of making links to the .mov file format.

Question #3 -- What type of content do you want to deliver?
There are different types of media content that can be delivered to students. Each have different challenges and recommendations.

Audio
Audio can be delivered very successfully to almost all students. A five minute audio clip with full stereo can be compressed to 3-5 MB and can be delivered via download or streaming. Streaming would be a better solution to 56K modem users, however, as a file of that size might take up to an hour to download.

Narrated Presentations
A narrative presentation consists of a slide show with a synchronized audio track. It is often a better way than delivering a full motion video of a presentation, particularly if the speaker isn't showing anything that is relevant to understand the content. A narrated presentation can be very successfully streamed to all kinds of users. Since it contains no video, file size is small. For an hour long presentation, however, this file could still be large enough to prevent it from being delivered via download. Streaming this type of content is recommended.

" Talking Head" Video
A talking head video usually consist of audio and video track of a presentation or lecture. There is usually little movement occurring. The lack of movement makes it possible to compress this type of content and deliver via streaming and still maintain an acceptable degree of quality. Most talking head videos are of a longer length and therefore, we recommend streaming in most cases.

Static Videos
Many faculty wish to deliver a video which captures the steps needed to complete a lab procedure or demonstrate a particular concept in an animated manner. These videos are usually shorter in length with moderate amounts of movement. Because clarity is very important in these clips, delivery via modem may be difficult. Some formats will provide acceptable quality and others will not. Our experience suggests that streaming using Windows Media Player provides the highest quality at this rate, with streaming with QuickTime provides the lowest quality. Downloaded content using QuickTime can provide a very acceptable quality. CD-ROM would be another acceptable method of delivery.

High Action Video
There are times when a full motion video clip needs to be delivered to students. Again, 56K modem users are going to be the most difficult group to serve. Most full motion video clips are longer than 5 minutes and can be up to 10MB or more in size -- taking a modem users an hour or more to download. CD-ROM delivery is best for this group. As for the other groups, either download or streaming would work equally well.

Question #4 -- Do you need to limit access or protect content?
Faculty may be using material for which they don't own the copyright. They may also want to prevent non-students from accessing content. There are several solutions in place which will help accomplish these goals. First, streaming content never resides on a student computer. If the goal is to protect access to content, streaming is the best way to do so. QuickTime can also be used to prevent downloaded content from being saved. It can also be used to conceal the actual URL of the streamed media clip. Learn@UW can be used to restrict access to content to students only. This will help maintain fair use of copyrighted material. Web Servers can also be configured to restrict access to certain IP addresses or require a password. This would allow downloaded content from only being accessed by students. QuickTime also included the ability to embed a media key to view content. Students can be given the key via email. Those who don't have the key will not be able to content. DoIT is looking into providing IP restrictions on the Streaming Server, as well.

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