DV-AVI (file extension .avi)

A file containing DV-encoded video material (described in more detail later on) can be stored on a PC’s hard drive “as is”, with the video and audio information interleaved as in the original DV bit-stream.  Microsoft refers to this arrangement as an AVI DV Type 1 file.  The method of interleaving differs from the Microsoft AVI standard.  To play such a file requires a DV Type 1 codec that recognizes the different interleaving arrangement and correctly separates the audio and video components.  If an AVI file with DV Type 1 encoding is played without this special codec then the audio will not be extracted.

Alternatively, software can be run at the time the AVI file is being created to separate the audio and video components and then re-interleave these according to the AVI standard.  Microsoft call this type of file an AVI DV Type 2 file.  The latter is the preferred method because it makes the file directly accessible by all video editing software.  However, not all video capture software does this, partly to simplify the process of transferring files from a camcorder (where a straight copy will create a DV Type 1 AVI file), and partly to encourage users to stick with the same software that they used for capture when they do their editing.

DV-AVI files are quite large compared with MPEG files.  Two hours of material will become a file of over 32 Gbytes, compared with about 4.5 Gbytes for MPEG-2-encoded material.

 

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Microsoft WMV, WMA, and ASF