Creative Sound Blaster Audigy 2 ZS User Manual page 56

the video stream is quite voluminous - one second of raw video from NTSC
comprises approximately 166 Mbits of data (720 samples per line x 480 lines x 16
bits per sample x 30 frames per second). Raw video is sometimes referred to by
the underlying color space of its samples, for example, YUV, YCrCb or RGB. It is
only manipulated in professional applications such as film and television.
DV or Digital Video
DV-25 or AVI – usually shortened to "DV" - is a compressed form of video that is
stored in modern video cameras, along with interspersed digital audio. One second
of DV is 25 Mbits of data. In DV, there are 720 samples per horizontal line;
however the chroma data are shared between adjacent samples as mentioned
above (called 4:1:1 chrominance sampling). In addition, DV obtains its
approximate 5:1 compression ratio over raw video by exploiting data reduction
techniques intra-frame, i.e. within a particular frame. It uses the discrete cosine
transform (DCT) in blocks of 8 x 8 samples, called macro blocks, as the basis for
compression.
DV is a flexible format into which both interlaced and progressive video can be
compressed. The resolution (frame size) for DV originating from analog signals is:
• DV from NTSC — 720 x 480 30 frames per second
• DV from PAL — 720 x 576 25 frames per second
DV video is sometimes referred to as AVI and a DV video might be stored on a
hard drive as "video1.avi". The AVI file format is the prevalent format on the PC
used to contain video compressed into DV. However, the AVI file format is not
limited to containing DV.
DV type 1
This is a form of DV in which the video and audio streams are interspersed
(multiplexed), such as is stored on DV cameras and transmitted between devices.
Technology Glossary A-7