Letterbox
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Generally, it's better to '''Crop''' video noise off than to black it out; many older lossy compression algorithms don't deal well with solid-color borders, unless the border happens to fall on a [[Wikipedia:Macroblock|macroblock]] boundary (16 pixels for MPEG). However, in some cases, particularly for certain hardware players, it's better to use '''Letterbox''' because it lets you keep a standard frame size. | Generally, it's better to '''Crop''' video noise off than to black it out; many older lossy compression algorithms don't deal well with solid-color borders, unless the border happens to fall on a [[Wikipedia:Macroblock|macroblock]] boundary (16 pixels for MPEG). However, in some cases, particularly for certain hardware players, it's better to use '''Letterbox''' because it lets you keep a standard frame size. | ||
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| + | {{AvsPluscon}} also supports [[RGB64]], [[PlanarRGBA]] and [[YUVA]]. | ||
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:{{Par2|color|int|(black)}} | :{{Par2|color|int|(black)}} | ||
::Fill color; specified as an RGB value. See [[Colors|this page]] for more information on specifying colors. | ::Fill color; specified as an RGB value. See [[Colors|this page]] for more information on specifying colors. | ||
| − | ::*For YUV clips, colors are converted from full-range (0 | + | ::*For YUV clips, colors are converted from full-range (0{{D}}-255{{D}}) to YV-range (16{{D}}-235{{D}}). |
== Changes == | == Changes == | ||
Revision as of 21:34, 28 April 2017
Fills the top and bottom rows of each frame, and optionally the left and right columns, with black or color. This has several common uses:
- Black out video noise from the existing black bands in an image that's already letterboxed
- Black out the video noise at the bottom of the frame in VHS tape sources.
- Black out overscan areas in VCD or SVCD sources.
- Create a quick rectangular mask for other filters – a so-called "garbage matte"
See also: AddBorders, which increases frame size. Letterbox does not change frame size.
The functionality of Letterbox can be duplicated with a combination of Crop and AddBorders, but Letterbox is faster and easier.
Generally, it's better to Crop video noise off than to black it out; many older lossy compression algorithms don't deal well with solid-color borders, unless the border happens to fall on a macroblock boundary (16 pixels for MPEG). However, in some cases, particularly for certain hardware players, it's better to use Letterbox because it lets you keep a standard frame size.
AVS+ also supports RGB64, PlanarRGBA and YUVA.
Syntax and Parameters
Letterbox(clip clip, int top, int bottom [, int x1 , int x2 , int color ] )
- int top, bottom = (required)
- int x1, x2 = 0
- int color = (black)
Changes
| v2.07 | Added color option. |
| v2.06 | Added optional left and right parameters (x1 and x2). |
