Subtitle

From Avisynth

Subtitle(clip clip, string text, int x, int y, int first_frame, int last_frame, string font, int size, int text_color, int halo_color, int align, int spc, int lsp, float font_width, float font_angle, bool interlaced)

The Subtitle filter adds a single line of anti-aliased text to a range of frames. If you want more than one subtitle, or a subtitle that takes more than one line, you have to chain several Subtitle filters together. This filter is obviously unsuitable for anything more than occasional use. All parameters after text are optional and can be omitted or specified out of order using the name=value syntax.

Parameters

text is the text which will be overlayed on the clip starting from frame first_frame and ending with frame last_frame.

font is the fonts of the text (all installed fonts on the current machine are available, they are located in your 'windows\fonts' folder).

size is the size of the text. (x,y) is the position of the text. The parameters x and y can be set to -1 to automatically calculate and use the horizontal or vertical center coordinate. Caution: If your script uses Subtitle with Animate, x or y might momentarily become -1, causing a glitch in the video.

The text_color and halo_color should be given as hexadecimal $aarrggbb values, similar to HTML--except that they start with $ instead of # and the 4th octet specifies the alpha transparency. $00rrggbb is competely opaque, $FF000000 is fully transparent. You can disable the halo by selecting this color.

The align parameter allows you to set where the text is placed relative to the (x,y) location and is based on the numeric keypad as follows:

Note: There is no Y-center alignment setting.

The spc parameter allows you to modify the character spacing (0=unchanged). The value can be positive or negative to widen or narrow the text. Per the Visual C++ documentation of the function SetTextCharacterExtra(), that performs this task, this value is in logical units and rounded to the nearest 0.125 pixel. This is helpful for trying to match typical fonts on the PC to fonts used in film and television credits which are usually wider for the same height or to just fit or fill in a space with a fixed per-character adjustment.

Multi-line text using "\n" is added in v2.57 and it is used if the lsp (line spacing) parameter is set. It sets the additional line space between two lines in 0.125 pixel units.

The font_width parameter allows you to modify, in 0.125 units, the aspect ratio of character glyphs per the Visual C++ documentation of the function CreateFont(). It is related to the size parameter by the default GDI aspect ratio and the natural aspect ratio of the chosen font.

The font_angle parameter allows you to modify the baseline angle of text in 0.1 degree increments anti-clockwise.

The interlaced parameter when enabled reduces flicker from sharp fine vertical transitions on interlaced displays. It does this by increasing the window for the anti-aliaser to include 0.5 of the pixel weight from the lines above and below, it effectivly applies a mild vertical blur.

The alternate, short form is useful when you don't really care what the subtitle looks like as long as you can see it--for example, when you're using StackVertical and its ilk to display several versions of a frame at once, and you want to label them to remember which is which.

This filter is used internally by AviSynth for the Version command and for reporting error messages, and the subtitling apparatus is also used by ShowFrameNumber.

Default Values

clip

last

text

no default, must be specified

x

8 if align=1,4,7 or none; -1 if align=2,5,8; or width-8 if align=3,6,9

y

size if align=4,5,6 or none; 0 if align=7,8,9; or height-1 if align=1,2,3

first_frame

0

last_frame

framecount(clip)-1

font

"Arial"

size

18.0

text_color

$00FFFF00 <full opaque yellow>

halo_color

0 <full opaque black>

align

Normally 4 <left and baseline>; if x=-1, then 5 <horizontal center and baseline>

spc

0

# Some text in the center of the clip:
AviSource("D:\clip.avi")
Subtitle("Hello world!", align=5)

# Some text in the upper right corner of the clip with specified font, size and color:
AviSource("D:\clip.avi")
Subtitle("Hello world!", font="georgia", size=24, text_color=$ff0000, align=9)

# Prints text on multiple lines
# without any text halo border.
BlankClip()
Subtitle( \
  "Some text on line 1\\nMore text on line 1\n" + \
  "Some text on line 2", \
         lsp=10, halo_color=$ff000000)

# It results in:
Some text on line 1\nMore text on line 1
Some text on line 2