HDV is a video format which records high-definition video onto a standard DV tape (mini or full-sized cassette). Originally developed by JVC it was later supported by Canon, Sony and Sharp with the four companies forming the HDV consortium in 2003.
Although priced at the lower end of the market, it's portability and high quality images are more than acceptable for many professional productions, and HDV is regularly used for broadcast television and newsgathering as well as corporate video and low budget film production.
Both audio and video are encoded digitally using lossy compression. The MPEG-2 codec (8-bit chroma and luma samples, 4:2:0 chroma subsampling) is used for the video (19 or 25 Mbit/s depending on frame-size), whilst stereo audio is encoded with the MPEG-1 Layer 2 codec, at 384 kbit/s. The video and audio are multiplexed into a MPEG transport stream, typically captured onto magnetic tape, but which can also be stored as a file. Because the tape maintains a constant speed, so the audio and video compression are locked to a constant bitrate. Compression artifacts can be visible where there is complex visual activity such as losts of fine detail, rapid movement or drastic changes in lighting or contrast. At 384kbit/s, stereo audio is perceptually lossless.
The frame-size of HDV has never been set but is generally 1280x720 or 1440x1080. There are two major versions, 720p (HDV1, JVC) and 1080i (HDV2, Sony and Canon). After the initial use of interlacing, 1080i has moved towards progressive scan technologies.
HDV is related to XDCAM which uses the same encoding scheme. XDCAMs 25 Mbit/s recording mode is equivalent to 1080-line HDV
The first HDV camcorder released was the JVC handheld GR-HD1 in 2003. With later advances in technology, more professional HDV cameras are now predominantly tapeless, recording to disk or memory cards.