Cisco 3005 - VPN Concentrator - Gateway Operation Manual page 28

C I SCO SYSTEM S, IN C.
Interlacing Options
If your video input is interlaced and your resolution height is greater than the field
height, choose de-interlace if you wish to convert interlaced video to progressive.
For resolutions less than or equal to the field height (320x240 for example), no de-
interlacing is required and none should be selected.
Both Main and Simple profiles only support progressive encoding and therefore,
unless the resolution is less than or equal to the field height, de-interlacing should
be chosen if not performing inverse telecine.
Choose inverse telecine (IVT) to convert film-based interlaced 30fps video to
progressive 24fps. If IVT is selected and the encoding mode is interlaced, the
encoder will produce IVT flags (top field first, bottom field first, repeat first field) in
the bitstream so that decoders know how to display the 24fps progressive video on
an interlaced display.
Deinterlace Mode
If deinterlacing is chosen, Cisco Media Processor provides multiple methods for
deinterlacing. The default, a motion adaptive deinterlace, attempts to preserve
spatial information in areas of motion while removing interlace artifacts in areas of
motion. The blend mode will blend two fields, maintaining temporal information
through motion blur. The interpolate mode removes temporal information and
interpolates even fields from odd fields, while interpolate denoise applies a noise
reduction filter after the deinterlace. The line double option simply creates even
field lines as direct copies of the odd field lines.
Miscellaneous Filters
Cisco Media Processor provides for various noise reducing filters. The normal filter
provides for moderate noise reduction. The smooth filter provides for large noise
reduction at the expense of softer images. For the dynamic filter, feedback from the
encoder during encoding will cause the active filter to change from none to normal
to smooth.
Advanced Compression Page
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