720P HDV is a development of the original DV format. The tape is used at the same rate as ordinary DV, by advancing the tape 10 μm per track. Tapes for HDV are made to a higher standard than for DV, because the risk of loss through dropouts is much greater (a drop-out in HDV can affect 12 or more frames on a tape). Compression artefacts are plainly visible on difficult pictures, and most HDV camcorders do not deliver pictures that use the compression system to best effect, aliasing is common.
12 Frame GoP
There are two variants of HDV 720, some cameras shoot and record 720p/25 (or 29.97) with a 6-frame GoP, others record 720p/50 (or 59.94) with a 12-frame GoP. Generally, HDV 720 produces pictures with fewer compression artefacts and less spatial aliasing than does HDV 1080, although the pictures are softer.
Camcorders usually have a SDTI interface, designated IEEE1394, for easy downloading of footage into editing software. The data transferred is the MPEG2 compressed stream.
HDV is not generally acceptable as a broadcast standard, although it is popular in semi-professional circles.