Advice
By Media
By Stage

Online Delivery Options for Digital Video

Last updated: 23 July 2009
Published in: Finding and using digital media |
Tags: delivery | video |

Why choose a video podcast over a progressive download? Or embedded a video rather than provide a video stream? This advice document looks at a selection of different technologies which can be used to deliver digital video online. Strengths and weaknesses of different delivery methods are examined to find out why one method might be chosen over another. This document is aimed at individuals or institutions with video content which they wish to share with users via the Internet.

Introduction

The web is brimming with digital video content. Every subject area imaginable is represented through the medium of the moving image. Video formats and methods of delivery have proliferated too, until the different delivery technologies now seem almost as diverse as the content they are used to disseminate.

Social networking sites such as YouTube and Flickr, video podcasting via iTunes or live streaming from the TV broadcasters, not to mention the vast range of freely available educational video collections all form a rich if slightly overwhelming network of video resources. Terminology is often used inaccurately and terms such as ‘streaming' and ‘download' become confused.

By understanding the fundamental technical aspects of delivering video via the Internet, collection managers, lecturers, librarians and others can make informed decisions on which method is best suited to their collection and to its users.

Delivery via management systems or third parties

You may be using some form of management system, such as a VLE (Virtual Learning Environment), a DAM (Digital Asset Management system) or a CMS (Content Management System) to manage your digital video collection. Many of these systems will offer ‘invisible' methods of delivering video to users (i.e. it's done for you). But the information below may still be of interest, as the management system will be using one or more of them.

Similarly, if you decide to deliver your content via a third party, such as a dedicated streaming media service, the information below may give you a greater insight into the work they are doing on your behalf.

Common methods of online delivery

Before we examine the most popular methods of bringing users and video content together, it's worth noting that each method need not exist in isolation; the methods below have been separated for the sake of clarity. It is becoming increasingly popular for websites to offer a range of options: download, streaming and video podcast options are often found on the same page, often without the end user being aware. This tactic can enable users to access video in radically different contexts, and so is worth bearing in mind. Individuals wishing to make a collection available but with little experience can quickly become overwhelmed by the maintenance involved when offering multiple options and may wish to expand functionality only after a single delivery method has proved to be stable.

Simple linked-to or download

This method of delivering digital video will be familiar to most readers. It was the dominant form of delivery until fairly recently. Video is treated the same way as any other digital file. A file is uploaded to a website (VLE or CMS) in the same way as any other file would be. A hyperlink is then created which points to the video file.

The user clicks on the hyperlink and is typically given the option to ‘open' or ‘save' the file. A copy of the video is actually downloaded to the viewer's computer, so users are often free to use or re-edit video as they see fit. This may be seen as undesirable but on the other hand, if the user is permitted to re-edit the video, this method may be a good choice. Playback cannot commence until the whole file has been transferred to the user, so files must be kept relatively small to avoid long waits. The uploader has no control of the player which will be used by the viewer to watch the video and the danger always exists of the viewer having no suitable playback software installed.

Examples of downloadable video can be found at the Internet Archive.

Embedded (progressive download)

Embedded video has largely replaced downloaded video as the delivery method of choice, thanks in part to the success of YouTube. When accessing an embedded video the user sees the video pane as part of the website. This usually includes playback controls. With progressive download, the viewer doesn't have to wait for the video to completely download before watching; instead video ‘buffers' so playback can begin almost instantly. This method gives content providers more control than does simple download but a buffered video file can be ‘captured' by a persistent user.

The video is made available by adding a few lines of embedding code to the website (or VLE). Video can be sited locally (i.e. on your own server) or remotely (e.g. on sites such as TeacherTube). Remote sites which offer embedding of their video content will provide the required embedding code along with each video. This opens up the possibility of uploading to YouTube (who then maintain your video content for you) and embedding the corresponding YouTube link back into your website or VLE. This has many advantages for the collection seeking a wide audience, but is generally not an option if seeking to commercially exploit a video collection.

Progressive download (without embedding) is often achieved by means of a redirector file. These tiny files (such as .wvx files if serving .wmv files) point to a video file which then launches in an external video player (such as VideoLan or Windows Media Player), progressive download and playback then begin.

Examples of embedded video can be found at TeacherTube.

Video podcasts (a.k.a. vidcasts or vodcasts)

RSS news feeds are extremely popular and useful and video podcasts are their direct multimedia equivalent. Users ‘subscribe' to a feed which is then downloaded in chunks by their podcast receiving software. As new instalments are released, the subscriber has the option to automatically download them and so stay up to date.

The creator of a podcast uploads their content to a webspace then ‘announces' it via an RSS feed. Several free applications (e.g. Feedforall or Podifier) allow RSS feeds to be created. The feed is then submitted to sites such as iTunes or Podcast Directory where potential subscribers can choose between thousands of podcasts.

Although the process of podcasting ‘feels' very different from the other video delivery mechanisms in essence it is simply a form of video download.

Examples of video podcasts can be found at the Podcasting Directory.

Streaming video

Streaming video is the most technically complex delivery option. Although again, the video is often accessed via a hyperlink embedded within a webpage it is actually streamed via a separate and dedicated streaming media server.

One advantage to streaming video is the opportunity to broadcast live feeds: another is related to a provider's control over video content. Because no complete digital video file is transfer to a viewer's machine, streamed footage is the very difficult for the viewer to capture and copy. This, of course, is a disadvantage if viewers are permitted to download and reuse video. Again, the video can be watched almost instantly with no waiting for download. Streaming video grows in popularity as more and more viewers use mobile viewing devices. Streaming media servers often have the ability to detect the hardware used by a viewer and send an appropriate video stream.

Institutions often outsource video streaming to third parties, who will typically stream content using Flash Video Streaming Sever (FVSS). This has the advantage of providing support for many different viewing platforms but can be expensive and comes at the cost of some in-house skills development.

If considering streaming video in-house on a small scale, the free-to-use Unreal Streaming Server may be of interest. To disseminate a video, it is first transcoded into a format suitable for streaming and then placed into a virtual ‘watched' folder on a local server. This file can then be hyperlinked to, via a link on a webpage. To the viewer the results can be indiscernible from embedded video (above) but with added security and no limits on file size.

An example of streamed video can be found at BBC News.

Conclusion

An unknown (but certainly immense) amount of video material is not yet available online. Potential viewers do not yet have the ability to find, reference or access some of the world's most valuable moving image collections. The report Tracking the Reel World reported the importance of smaller collections with less that 500 hours of footage, much of which tends to be entirely unique. Even the simplest measures, such as uploading to YouTube can grant access to as yet inaccessible materials, allowing it to be found, viewed, analysed, referenced and ultimately appreciated by an audience of millions. For an example of how simple measures can unlock collections see the Flickr Great War Archive. For further information on delivering video content via mobile devices, see the JISC report Innovative Practice with e-Learning. For more information on sustainable podcasting infrastructures within universities see the JISC-funded Steeple project.

Last updated: 23 July 2009
Published in: Finding and using digital media |
Tags: delivery | video |

Ask us a question

We provide a FREE enquiry service giving advice to the UK Further and Higher Education community.

You can ask us anything, typical questions include - "What formats should I use?" "How do I...?" "What tools can achieve the result I need?" "What is new and emerging?"