more about the HDV format

MPEG-2 compression relies on both inter and intra frame compression to achieve greater efficiency than Motion JPEG (M-JPEG), which is the approach taken by most digital videotape formats because editing is simpler when compression is applied to individual frames ( intra frame) rather than across multiple frames (inter frame). MPEG-2 minimizes the bandwidth requirements by creating what are called long groups of pictures (GOP) and applying very high rates of compression. HDV uses a 15 picture GOP that begins with an intra frame (I-Frame). The I-Frame contains all the information to reconstruct a complete picture. It’s similar to a frame compressed using M-J