Editing HD on a Laptop

It's not a new idea, to use a low resolution copy of a very large graphic file for rough-cut editing on a computer with limited resources, but it only really caught on for video editing early in this decade. However, the use of "Proxy Video" first gained acceptance in file-based networked studio facilities. Only more recently has it been extended into practical solutions for frame-accurate editing of High Definition video on computers as limited in resources and speed as a common laptop.

What is Proxy Video?
Proxy video is considered a form of "metadata". Metadata is basically data that describes other data. In this case, it's a compressed, lower resolution version of a High Definition video file. Since proxy video is frame-syncronized with the original, in can be used for quick viewing and basic editing. It is generally not considered practical to do things like advanced color correction using proxy video, simply because the compression process reduces color depth and resolution. However, the method is ideal for making cuts, putting clips together in order, assigning transitions, and adding basic character graphics.

The result of proxy editing is an EDL (Edit Decision List) file which can be imported into the High Definition editing system to be applied to the original file in full size and resolution. The newest systems may store edit decisions in a functionally similar but more robust format such as AAF or XML.

Camcorder systems such as Sony XDCAM (pictured: Sony PDW-510) record a lower resolution proxy video version simultaneously with the full resolution version. This frame-accurate proxy can be used for editing while in the field, so it has become highly popular with shooters in a hurry such as TV news crews.