QuickTime 2.5 includes support for Motion JPEG Formats A and B. These Motion JPEG Formats were developed by Apple and many partners in the digital video area to standardize how Motion JPEG is handled in the professional video space. In the near future you can expect most Motion JPEG hardware boards to directly support either Motion JPEG Format A or Format B. Apple has built a software implementation of both Motion JPEG Formats A and B into QuickTime 2.5 so you will be able to use your Motion JPEG files on any Macintosh with QuickTime 2.5 installed.
Motion JPEG Formats A and B are designed to store images which contain two fields of video data. The sample files provided contain a large degree of motion, so the two fields are very easy to see. In order to make the sample movie files small, the image quality was set quite low for these movies. However, Motion JPEG Formats A and B support the full quality range of JPEG and so the movies can be of extremely high quality at the expense of a larger file size.
There is no quality difference between the two formats, but Format A will usually be a slightly smaller. It is possible to rapidly convert directly from Format A to Format B using a process called transcoding. A tool for transcoding between Format A and Format B is provided in the "Transcoder tool" folder.
A complete specification of the Motion JPEG formats is available on Apple's QuickTime web site at www.quicktime.apple.com.
