Apple Final Cut Pro 5 - Manual (Page 1304)

Chapter 23 Using RT Extreme 517
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Supported RT Extreme Playback Codecs
RT Extreme is not capable of playing back all video codecs. The CPU speed and amount
of RAM installed in your computer affect which codecs can play back in real time. The
following codecs are supported for real-time playback:
 DV, DVCAM, DVCPRO (25), and DVCPRO 50
 IMX
 OfflineRT (this is a Final Cut Pro preset that uses the Photo-JPEG codec)
 8- and 10-bit Uncompressed 4:2:2 video formats
The following high definition codecs have higher system requirements:
 DVCPRO HD, HDV, and Apple Intermediate Codec
To see a complete list of real-time codecs supported by your system:
m Choose System Settings > Effect Handling.
Display Quality and Accuracy of RT Extreme
Video does not appear the same on a computer display as it does on a video monitor
(such as an NTSC, PAL, or high definition monitor). Whenever you watch your video
on a computer display (such as video in the Canvas, the Viewer, or via the Digital
Cinema Desktop), Final Cut Pro compensates for these visual differences so your
video looks more like it will appear on a video monitor. This compensation requires
extra processing, such as deinterlacing and gamma correction, which adds to the
workload of your computer’s CPU.
What Is Gamma Correction?
Gamma correction is necessary for proper color and brightness rendition of video during
playback. Gamma correction compensates for the fact that video display devices (such as
televisions) inherently alter the middle tones of an image in a nonlinear fashion. For
example, televisions inherently reduce the brightness of the video signal in a predictable
way, resulting in images whose midtones are darker than expected.
To compensate for this darkening on the television, camcorders record images using an
opposing brightness curve. However, when the video from your camcorder is shown
on your computer display, you often see the image brighter than expected, because
the image was intended for playback on a video monitor. Gamma correction must be
applied to the video so it appears as intended.