Introduction to Digital Video Casette (DV)
What is Digital Video Cassette (DV)?
The DV standard (originally known as DVC - Digital Video Cassette) was created by a group of consumer electronics companies, which has grown since and is known as the DV consortium. It was original intended for home use, but the low cost, high quality format forms the basis of some professional equipment. The most common use is in digital camcorders, where a single Mini-DV cassette can hold 1 hour of high quality video.
Digital Video Cassette uses a 1/4 inch (6.35mm) metal evaporate tape to record very high quality digital video. The video is sampled 720 pixels per scan line, with 4:1:1 (NTSC) or 4:2:0 (PAL) chroma (colour) samples.
The video is compressed using DCT (Discrete Cosine Transformation), similar to moving JPEG. DV can achieve better compression than moving JPEG since it allows better optimisation of quantization tables within a frame.
Only intra frame (I-frame) compression is used, meaning that frames do not depend on previous or following frames. This requires less complicated codecs than MPEG and also makes it more suitable for editing, but big bitrates are required to maintain quality levels.
The video bitrate is fixed at about 25 megabits per second (Mbps). The total data bitrate, including error protection and audio streams is about 36 Mbps.
Technical Specifications of DV Cassette
The video editing introduction page contains information about capturing DV from your camcorder into your PC.