Apple Final Cut Express HD - Manual (Page 1078)

1078 Glossary
alpha channel An image channel in addition to the R, G, and B color channels that is
used to store transparency information for compositing. Alpha channels are often 8-bit,
but some applications support 16-bit alpha channels. In Final Cut Express HD, black
represents 100 percent transparency, and white represents 100 percent opacity. Only
certain formats, such as Targa, TIFF, PICT, and the QuickTime Animation codec, support
alpha channels.
alignment When working with transitions, refers to whether the transition starts before
the edit point, is centered at the edit point, or ends after the edit point.
ambience A type of sound. Ambient audio includes background room noise, traffic
noise, and atmospheric sound effects.
analog A signal that consists of a constantly varying voltage level, called a waveform,
that represents video and audio information. Analog signals must be digitized, or
captured, for use by Final Cut Express HD. VHS and Betacam SP are both analog tape
formats. Compare with digital.
anamorphic Visuals that are shot in a widescreen format and then squeezed into a
4:3 frame size. This can be done by using a video camera’s electronics or, optically, by
using an anamorphic lens.
anchor item When you first link multiple audio clip items to a video item in the
Timeline, that video item is considered the “anchor” item to which the sync of all other
linked audio items is compared. If you’re linking a group of audio items without a video
item, the topmost audio item that appears in the Timeline acts as the anchor item.
anchor point In the Motion tab, the point that is used to center changes to a clip’s
geometry when using motion effects. Any changes to the size, position, and rotation of
a clip happen relative to this anchor point. A clip’s anchor point does not have to be at
its center.
Angle control A control used to rotate a clip around its center axis without changing
its shape. Located in the Motion tab of the Viewer. In the Angle control, the black hand
indicates the current angle of the clip, and the small red hand indicates how many total
rotations forward or backward have been specified.
aspect ratio A film or video frame’s width-to-height ratio on any viewing screen. The
most common aspect ratio is 4:3, used for regular television screens. An aspect ratio of
16:9 is increasingly used for high definition video.
attenuate To lower an audio signal’s level.
audio clip A media clip containing audio tracks.