Using dv video and graphics – 360 Systems MAXX-1000SD User Manual

Page 72

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Page 72

MAXX Owner’s Manual

Using Ganging for Key and Fill operations

Channel Ganging is most commonly used to support and Key and Fill operations. Ganging allows
generation of frame-accurate key and fill material (either stills or clips). This in turn is used with a
downstream keyer or video effects generator to be externally combined with a third video source.
Manual or automation control of the Master channel is all that is needed to play both the key and
the fill.

Key and fill clips are associated by their names. The Key Clip must have the same name as the Fill
Clip with a trailing underscore. Example:

Fill clip name: myfile

Key clip name: myfile_

There is no provision for automatic loading of similar named clips on more than two channels - the
Master channel and the next higher numbered Ganged channel. Additional channels must be
loaded manually, after loading the master channel.

Proper key and fill operation requires two clips of identical length. This can be accomplished by
editing with head and tail trim. Long GOP mpeg clips should not be used if editing will be
required to allow precise head point positioning.

Channel 2 is ganged to Channel 3 in the following example.

When a clip is opened/cued on Channel 2, Image Server automatically looks for another clip with
the same name, plus a trailing underscore. If the clip is found, it is loaded on Channel 3. The
Channel 2 clip contains the “fill” material, while the Channel 3 clip has the “key” (or alpha) file.

An automation system, could, for example, issue a VDCP Cue command to Channel 2 for a clip
called “logo”. Channel 3 would automatically be loaded with clip “logo_”. A Still or Play
command sent to Channel 2 would cause both Channels 2 and 3 to display the fill and key clips,
respectively.

Note that the VDCP checkbox option to “show first frame” for a Cue command is ignored for
channels in ganged mode. The automation system must issue a Still command to Channel 2 to
achieve this effect.

Ingesting a TARGA file via FTP automatically creates a key clip and a fill clip, each a single frame
in length. For example, if file “xyz.tga” is transferred to an Image Server via FTP, then a pair of
single-frame clips is created: “xyz” and “xyz_” containing the fill and key material.

Using DV Video and Graphics

Playback of DV-format video and TARGA Graphics is included. It plays DV-25 files in native
format, and TARGA graphics files including those with key and fill. DV and Graphics enables
direct FTP import from Photoshop®, After Effects®, Final Cut Pro®, Xpress DV/Pro™, Liquid Edition
and Vegas video.

With DV and Graphics, Image Servers are able to function as both a graphics still-store and an
animation playout server. Its three simultaneous outputs give it the power to combine video,
graphics and animation playback. Channels can be ganged in various combinations to provide key-
and-fill playout, while Channel 1 plays background video. The following capabilities are included:

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