Man / VIDEO FILTERS / scale

scale[=w:h[:interlaced[:chr_drop[:param[:param2[:presize[:noup]]]]]]] †

原文

Scales the image with the software scaler (slow) and performs a YUV<−>RGB colorspace conversion (also see -sws).

<w>,<h>

scaled width/height (default: original width/height)
NOTE: If -zoom is used, and underlying filters (including libvo) are incapable of scaling, it defaults to d_width/d_height!

0: scaled d_width/d_height

-1: original width/height

-2: Calculate w/h using the other dimension and the prescaled aspect ratio.

-3: Calculate w/h using the other dimension and the original aspect ratio.

-(n+8): Like -n above, but rounding the dimension to the closest multiple of 16.

<interlaced>

Toggle interlaced scaling.

0: off (default)
1: on

<chr_drop>

chroma skipping

0: Use all available input lines for chroma.
1: Use only every 2. input line for chroma.
2: Use only every 4. input line for chroma.
3: Use only every 8. input line for chroma.

<param>[:<param2>] (also see -sws)

Set some scaling parameters depending on the type of scaler selected with -sws.

−sws 2 (bicubic): B (blurring) and C (ringing)

0.00:0.60 default

0.00:0.75 VirtualDub’s "precise bicubic"

0.00:0.50 Catmull-Rom spline

0.33:0.33 Mitchell-Netravali spline

1.00:0.00 cubic B-spline

−sws 7 (gaussian): sharpness (0 (soft) − 100 (sharp))

−sws 9 (lanczos): filter length (1−10)

<presize>

Scale to preset sizes.

qntsc: 352x240 (NTSC quarter screen)
qpal: 352x288 (PAL quarter screen)
ntsc: 720x480 (standard NTSC)
pal: 720x576 (standard PAL)
sntsc: 640x480 (square pixel NTSC)
spal: 768x576 (square pixel PAL)

<noup>

Disallow upscaling past the original dimensions.

0: Allow upscaling (default).
1: Disallow upscaling if one dimension exceeds its original value.
2: Disallow upscaling if both dimensions exceed their original values.

参考 †

AviutilやAviSynthスクリプトで良く見かけるlanczos3は以下のようになると思われる。

-sws 9 -vf pullup,softskip,crop=w:h,scale=w:h:0:0:3,hqdn3d,harddup