vapoursynth-subtext 6.0

Subtitle filter for VapourSynth

Subtext

Subtext is a subtitle renderer that uses libass and ffmpeg.

.. function:: TextFile(clip clip, string file[, string charset="UTF-8", float scale=1, int debuglevel=0, string fontdir="", float linespacing=0, int[] margins=[0, 0, 0, 0], float sar=0, string style="", bint blend=True, int matrix, string matrix_s, int transfer, string transfer_s, int primaries, string primaries_s, int range]) :module: sub

TextFile renders text subtitles. Supported formats include ASS, JACOsub, MicroDVD, SAMI, SRT, WebVTT, and some other obscure ones.

TextFile has two modes of operation. With blend=True (the default), it returns clip with the subtitles burned in. With blend=False, it returns an RGB24 clip containing the rendered subtitles, with a Gray8 frame attached to each frame in the _Alpha frame property. These Gray8 frames can be extracted using std.PropToClip.

Parameters: clip Input clip.

  file
     Subtitle file to be rendered.

  charset
     Character set of the subtitle, in iconv format.

  scale
     Font scale.

  debuglevel
     Debug level. Increase to make libass more chatty.
     See `ass_utils.h <https://github.com/libass/libass/blob/master/libass/ass_utils.h>`_
     in libass for the list of meaningful values.

  fontdir
     Directory with additional fonts.

  linespacing
     Space between lines, in pixels.

  margins
     Additional margins, in pixels. Negative values are not
     allowed. The order is top, bottom, left, right.

  sar
     Storage aspect ratio.

  style
     Custom ASS style for subtitle formats other than ASS. If empty
     (the default), libavcodec's default style is used. This
     parameter has no effect on ASS subtitles.

  blend
     If True, the subtitles will be blended into *clip*. Otherwise,
     the bitmaps will be returned untouched.

  matrix

  matrix_s

  transfer

  transfer_s

  primaries

  primaries_s

  range
     If blend=True, these will be passed to resize.Bicubic when
     converting the RGB24 subtitles to YUV. The default matrix is
     "709".

.. function:: Subtitle(clip clip, string text[, int start=0, int end=clip.numFrames, int debuglevel=0, string fontdir="", float linespacing=0, int[] margins=[0, 0, 0, 0], float sar=0, string style="sans-serif,20,&H00FFFFFF,&H000000FF,&H00000000,&H00000000,0,0,0,0,100,100,0,0,1,2,0,7,10,10,10,1", bint blend=True, int matrix, string matrix_s, int transfer, string transfer_s, int primaries, string primaries_s, int range]) :module: sub

Instead of rendering a subtitle file, Subtitle renders the string text. Otherwise it works the same as TextFile.

Parameters: text String to be rendered. This can include ASS tags to enable rich text and animation.

  style
     Custom ASS style to be used.
  
  start, end
     Subtitle will be shown from *start* up until *end*. By default this will be for all frames in *clip*.

The other parameters have the same meanings as with TextFile.

.. function:: ImageFile(clip clip, string file[, int id=-1, int[] palette, bint gray=False, bint info=False, bint flatten=False, bint blend=True, int matrix, string matrix_s, int transfer, string transfer_s, int primaries, string primaries_s, int range]) :module: sub

ImageFile renders image-based subtitles such as VOBSUB and PGS.

Parameters: clip If blend is True, the subtitles will be burned into this clip, Otherwise, only the frame rate and number of frames will be obtained from this clip.

  *file*
     Name of the subtitle file. For VOBSUB, it must the name of the
     idx file. The corresponding sub file must be in the same
     folder, and it must have the same name.

  *id*
     Id of the subtitle track to render. There may be several
     subtitle tracks in the same file. If this is -1, the first
     supported subtitle track will be rendered. Use info=True to
     see a list of all subtitle tracks, including their ids.

     Default: -1.

  *palette*
     Custom palette. This is an array of at most 256 integers. Each
     element's least significant four bytes must contain the values
     for alpha, red, green, and blue, in that order, from most
     significant to least.

     Additionally, the special value 2**42 means that the
     corresponding element of the original palette is used. This
     way it is possible to override only the third element, without
     overriding the first and second ones, for example.

     An alpha value of 255 means the colour will be completely
     opaque, and a value of 0 means the colour will be completely
     transparent.

  *gray*
     If True, the subtitles will be turned gray.

     Default: False.

  *info*
     If this is True, a list of all supported subtitle tracks found
     in the file will be printed on each frame of the output. The
     information printed about each track includes the id, the
     language (if known), the resolution, and the format.

     Default: False.

  *flatten*
     If this is True, ImageFile will output a clip with exactly as
     many frames as there are pictures in the subtitle file.

     If this is True, *blend* has no effect (no automatic blending).

     Default: False.

The other parameters have the same meanings as with TextFile.

Example with manual blending::

sub = core.sub.TextFile(clip=YUV420P10_video, file="asdf.ass", blend=False) mask = core.std.PropToClip(clip=sub, prop='_Alpha')

gray10 = core.query_video_format( mask.format.color_family, YUV420P10_video.format.sample_type, YUV420P10_video.format.bits_per_sample, mask.format.subsampling_w, mask.format.subsampling_h )

sub = core.resize.Bicubic(clip=sub, format=YUV420P10_video.format.id, matrix_s="470bg") mask = core.resize.Bicubic(clip=mask, format=gray10.id)

hardsubbed_video = core.std.MaskedMerge(clipa=YUV420P10_video, clipb=sub, mask=mask)

Example with automatic blending (will use BT709 matrix)::

hardsubbed_video = core.sub.TextFile(clip=YUV420P10_video, file="asdf.ass")

Example with a custom palette and automatic blending::

def rgba(r, g, b, a=255): if r < 0 or r > 255 or g < 0 or g > 255 or b < 0 or b > 255 or a < 0 or a > 255: raise vs.Error("Colours must be in the range [0, 255].")

   return (a << 24) + (r << 16) + (g << 8) + b

unused = 1 << 42

src = core.ffms2.Source("video.mp4")

Override only the third element of the palette. Set it to some kind of green.

ret = core.sub.ImageFile(src, "subtitles.sup", palette=[unused, unused, rgba(0, 192, 128)])