User`s guide

Glossary
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For example, if a clip has an edit in point of 00:00:30.00, its cue in point is initialized to 30
seconds when the clip is loaded.
Edit points may also be called “edit marks.”
Fibre Channel
The Fibre Channel Standard defines a high-speed data transfer interface that can be used
to connect workstations, mainframes, supercomputers, storage devices and displays.
The standard addresses the need for very fast transfers of large volumes of information.
Typical high-end Fibre Channel devices carry up to 1 Gb/s data rates.
General eXchange Format (GXF)
The General eXchange Format standardizes file structrure to exchange clips and
compound clips between television program storage systems. SMPTE 360M
encapsulates GXF and is now the formal standard.
GOP
Group of pictures. Defined as a sequence of video frames subject to compression
encoding under the MPEG-2 standard. A GOP is characterized by one of the following:
• At least one I-frame, a frame having no reference frame for prediction
• One or more P-frames, frames based on a previous frame
• B-frames, frames based on two reference frames, one previous and one afterwards
The SGI Media Server MFCODEC supports four distinct MPEG-2 GOP structures: I, IP,
IPB,and IPBB.
GOP period
The quantity of frames in the GOP, exclusive of the I-frame. The GOP period must evenly
divide the GOP size to be a valid GOP structure.
GOP size
The GOP size determines total number of frames in the GOP. The size can be an integer
but is strictly limited by hardware/software compression algorithms and resources. An
extreme upper limit for the MFCODEC GOP size is 15. Large GOPs conserve ingestion
storage resources but introduce potential information loss. The GOP of a specific size and
structure is encoded during video ingestion and stored by the SGI Media Server when
MPEG-2 compression is selected. The GOP structure is decoded during playout.