Contents: The Virtual Clip | The Web Annotation Layer | Cliplist Data Rendered as Cliplist | Cliplist with Player | What Online Resources Does Clipper Work With? |
The Virtual Clip: This is at the core of how Clipper works, here we describe in general terms the technologies and ideas that make this possible. First, it’s useful to summarise what a virtual clip is composed of:

- Clipper lets the user specify a section of a file’s timeline that they want to share, with a start and stop time, textual annotations and tags.
The digital information in a virtual clip is very small and does not include any audio or video files. The clips only contain information that a user has created about the original media file and its location and this is used by Clipper to control the playback of the clip by linking back to the original file and playing it inside the toolkit interface. The Clipper Data Diagram shows the basic data that each clip is composed of:
- URL: location of media file
- Start Time: clip start time
- Stop Time: clip stop time
- Title of the Clip: name the user gives to the clip
- Annotation: notes the user makes about the clip
- Tags: tags given to the clip by the user
The Web Annotation Layer: A useful analogy to help understand how Clipper works is that the Clipper Toolkit is like a layer or a window on top of the web that the user can control to show extracts from audio and video files together with their own annotations and tags. This is the essence of how web annotation technologies work – they superimpose their annotations over existing web sites but remain completely separate from them – see the ‘Technical’ section for more detail abut this.
Cliplist Data Rendered as Cliplist: Here we see how the the Clipper data is used to create a cliplist

Cliplist with Player: In this image below we see the Clipper player and underneath we see the Clipper data for that Clip. Note the first line of the annotation becomes the title of each Clip – for simplicity. The actual amount of digital data is used by the Clipper toolkit to create the web page you see here is very small – perhaps a kilobyte or two in total.

The video content and the image thumbnails are all being supplied from the original YouTube website. What the Clipper toolkit is doing is taking the original YouTube data stream and presenting it together with the user generated data through the Clipper interface. Working in this way Clipper is highly efficient in terms of data storage and transmission – it never copies, stores or streams the original media files. This is what we mean when we say Clipper works as an annotation layer or window above the media files that it deals with.
What Online Resources Does Clipper Work With? On this page we have shown videos from YouTube, but Clipper will also work with any online MP4 or MP3 media resources. More here about protoype working with Dropbox, Facebook and Soundcloud etc and why YT is a good example of integrationa dn link to the Uses age for interesting scenarios