Letterbox: Difference between revisions
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<div style="max-width:54em" > | <div style="max-width:54em" > | ||
<div {{BlueBox2|40|0|3px solid purple}} > | |||
{{AvsPlusFullname}}<br> | |||
Up-to-date documentation: [https://avisynthplus.readthedocs.io/en/latest/avisynthdoc/corefilters/letterbox.html https://avisynthplus.readthedocs.io] | |||
</div> | |||
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: | 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 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 [[Wikipedia:VHS|VHS]] tape sources. | * Black out the video noise at the bottom of the frame in [[Wikipedia:VHS|VHS]] tape sources. | ||
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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. | ||
{{AvsPluscon}} also supports [[RGB64]], [[PlanarRGBA]] and [[YUVA]]. | |||
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== Syntax and Parameters == | == Syntax and Parameters == | ||
{{FuncDef | {{FuncDef | ||
|Letterbox(clip ''clip'', int ''top'', int ''bottom'' [, int ''x1'' , int ''x2'' , int ''color'' ] ) | |Letterbox(clip ''clip'', int ''top'', int ''bottom'' [, int ''x1'' , int ''x2'' , int ''color'' ] [, int ''color_yuv'' {{AvsPluscon}}]) | ||
}} | }} | ||
:{{Par2|top, bottom|int|(required)}} | :{{Par2|top, bottom|int|(required)}} | ||
::Number of {{FuncArg|top}} and {{FuncArg|bottom}} rows to blank out. | ::Number of {{FuncArg|top}} and {{FuncArg|bottom}} rows to blank out. | ||
::*For [[YV12]] sources, {{FuncArg|top}} and {{FuncArg|bottom}} must be [[Modulo|mod2]] (divisible by 2). | |||
:{{Par2|x1, x2|int|0}} | :{{Par2|x1, x2|int|0}} | ||
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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 TV-range (16{{D}}-235{{D}}). | ||
:{{Par2|color_yuv|int|}} {{AvsPluscon}} | |||
::Specifies the color of the border using YUV values. It requires setting pixel_type to one of the YUV formats; otherwise it doesn't do anything. | |||
::Similar to {{FuncArg|color_yuv}} in BlankClip | |||
== Changes == | == Changes == | ||
{| border="1" | {| border="1" | ||
|- | |||
| v3.4.1 AVS+ | |||
| Added color_yuv option. | |||
|- | |- | ||
| v2.07 | | v2.07 | ||
Latest revision as of 07:24, 18 September 2022
AviSynth+
Up-to-date documentation: https://avisynthplus.readthedocs.io
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 color_yuv AVS+])
- int top, bottom = (required)
- int x1, x2 = 0
- int color = (black)
- int color_yuv =
AVS+- Specifies the color of the border using YUV values. It requires setting pixel_type to one of the YUV formats; otherwise it doesn't do anything.
- Similar to color_yuv in BlankClip
Changes
| v3.4.1 AVS+ | Added color_yuv option. |
| v2.07 | Added color option. |
| v2.06 | Added optional left and right parameters (x1 and x2). |
