Apple Final Cut Pro 5 - Manual (Page 1701)

350 Part V Appendixes
Video formats can be characterized by the following factors:
 The medium used to store the video information. This is primarily videotape, but can
also be optical disc, solid-state memory, or a hard disk.
 The size (1/2”, 3/4”, 8 mm) of the tape and the shape of the cassette shell.
 The video standard supported, such as NTSC, PAL, ATSC (HDTV 1080i or 720p), and
so on.
 The type of electronic signal recorded on tape. In other words, the way luma (black-
and-white) and chroma (color) information are combined and recorded.
 The aspect ratio of the video frame.
 The dimensions of the video frame: the number of pixels per line, and the number of
lines per frame.
 The aspect ratio of the pixels: This is a subtle factor that is explained in more detail
below.
 The frame rate: the number of frames recorded per second.
 The scanning method: interlaced fields (2 fields per frame) or progressive (one
complete frame at a time).
 Color recording method: RGB, component (YUV), S-Video (Y/C), or composite.
 Color sampling: For component digital formats, the ratio of color samples to black-
and-white (or luma) samples (for example, 4:4:4, 4:2:2, and 4:1:1).
 Sampling rate: the number of samples per second of each video line. This is just like
the sampling rate for audio, except the signals sampled are video lines, where each
sample represents light intensity instead of sound intensity.
 Bit depth: the number of bits used to store each video sample, which determines the
ability of the format to capture each sample’s (or pixel’s) light intensity precisely, and
how well subtle differences in intensity can be stored.
 Compressor (or codec): A video compressor attempts to reduce the amount of digital
data required to store each frame without compromising the quality of the image.