User Manual

Understanding HDV
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Avid editing applications capture and process DVCPRO HD media and HDV media in its native
format, through a 1394 port on your computer.
You can capture from an HDV device and edit in native HDV using these project types.
You can also use HDV in other project types, but Avid editing applications are more efficient and
perform better with the dedicated HDV project types. The other project types you can use
include:
•PAL 25i
•NTSC 30i
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You cannot capture or export native HDV in the non-HDV project types.
Understanding HDV
HDV is a low-cost prosumer format that lets you record HD video onto standard DV
videocassettes. This is achieved through the use of interframe compression, where a given frame
in the video stream can be composed of information from adjacent frames. Frames are grouped
into a sequence called a “Group of Pictures,” or GOP. Long-GOP (also known as IPB encoding)
refers to the structure of HDV media.
A GOP contains several different types of compressed frames:
• I frames, which are compressed frames that do not depend on any frames around them.
I frames anchor the beginning of the GOP.
• P (predictive) frames and B (bidirectional) frames, which depend on the frames around
them.
Interframe compression is more efficient than frame-based schemes (such as DV 25), allowing
high-bandwith HD images to be contained on media designed for standard definition (SD).
However, HDV is more difficult to edit since frames are not independent of one another. Avid
provides a workflow that lets you edit natively with HDV-compressed video without requiring a
transcode to frame-based media, and without limiting where you make your cuts.