astisub

package module
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 Go to latest Published: Jun 30, 2022 License: MIT Imports: 22 Imported by: 0

README

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This is a Golang library to manipulate subtitles.

It allows you to manipulate srt, stl, ttml, ssa/ass, webvtt and teletext files for now.

Available operations are parsing, writing, applying linear correction, syncing, fragmenting, unfragmenting, merging and optimizing.

Installation

To install the library:

go get github.com/asticode/go-astisub

To install the CLI:

go install github.com/asticode/go-astisub/astisub

Using the library in your code

WARNING: the code below doesn't handle errors for readibility purposes. However you SHOULD!

// Open subtitles
s1, _ := astisub.OpenFile("/path/to/example.ttml")
s2, _ := astisub.ReadFromSRT(bytes.NewReader([]byte("00:01:00.000 --> 00:02:00.000\nCredits")))

// Add a duration to every subtitles (syncing)
s1.Add(-2*time.Second)

// Fragment the subtitles
s1.Fragment(2*time.Second)

// Merge subtitles
s1.Merge(s2)

// Optimize subtitles
s1.Optimize()

// Unfragment the subtitles
s1.Unfragment()

// Apply linear correction
s1.ApplyLinearCorrection(1*time.Second, 2*time.Second, 5*time.Second, 7*time.Second)

// Write subtitles
s1.Write("/path/to/example.srt")
var buf = &bytes.Buffer{}
s2.WriteToTTML(buf)

Using the CLI

If astisub has been installed properly you can:

  • convert any type of subtitle to any other type of subtitle:

      astisub convert -i example.srt -o example.ttml

  • apply linear correction to any type of subtitle:

      astisub apply-linear-correction -i example.srt -a1 1s -d1 2s -a2 5s -d2 7s -o example.out.srt

  • fragment any type of subtitle:

      astisub fragment -i example.srt -f 2s -o example.out.srt

  • merge any type of subtitle into any other type of subtitle:

      astisub merge -i example.srt -i example.ttml -o example.out.srt

  • optimize any type of subtitle:

      astisub optimize -i example.srt -o example.out.srt

  • unfragment any type of subtitle:

      astisub unfragment -i example.srt -o example.out.srt

  • sync any type of subtitle:

      astisub sync -i example.srt -s "-2s" -o example.out.srt

Features and roadmap

  • parsing
  • writing
  • syncing
  • fragmenting/unfragmenting
  • merging
  • ordering
  • optimizing
  • linear correction
  • .srt
  • .ttml
  • .vtt
  • .stl
  • .ssa/.ass
  • .teletext
  • .smi

Documentation

Index

Constants

View Source 
const (
	LanguageChinese   = "chinese"
	LanguageEnglish   = "english"
	LanguageFrench    = "french"
	LanguageJapanese  = "japanese"
	LanguageNorwegian = "norwegian"
)

Languages

Variables

View Source 
var (
	ColorBlack   = &Color{}
	ColorBlue    = &Color{Blue: 255}
	ColorCyan    = &Color{Blue: 255, Green: 255}
	ColorGray    = &Color{Blue: 128, Green: 128, Red: 128}
	ColorGreen   = &Color{Green: 128}
	ColorLime    = &Color{Green: 255}
	ColorMagenta = &Color{Blue: 255, Red: 255}
	ColorMaroon  = &Color{Red: 128}
	ColorNavy    = &Color{Blue: 128}
	ColorOlive   = &Color{Green: 128, Red: 128}
	ColorPurple  = &Color{Blue: 128, Red: 128}
	ColorRed     = &Color{Red: 255}
	ColorSilver  = &Color{Blue: 192, Green: 192, Red: 192}
	ColorTeal    = &Color{Blue: 128, Green: 128}
	ColorYellow  = &Color{Green: 255, Red: 255}
	ColorWhite   = &Color{Blue: 255, Green: 255, Red: 255}
)

Colors

View Source 
var (
	ErrInvalidExtension   = errors.New("astisub: invalid extension")
	ErrNoSubtitlesToWrite = errors.New("astisub: no subtitles to write")
)

Errors

View Source 
var (
	JustificationUnchanged = Justification(1)
	JustificationLeft      = Justification(2)
	JustificationCentered  = Justification(3)
	JustificationRight     = Justification(4)
)
View Source 
var (
	BytesBOM = []byte{239, 187, 191}
)

Bytes

View Source 
var (
	ErrNoValidTeletextPID = errors.New("astisub: no valid teletext PID")
)

Errors

View Source 
var Now = func() time.Time {
	return time.Now()
}

Now allows testing functions using it

Functions

This section is empty.

Types

type Color 

type Color struct {
	Alpha, Blue, Green, Red uint8
}

Color represents a color

func (*Color) SSAString 

func (c *Color) SSAString() string

SSAString expresses the color as an SSA string

func (*Color) TTMLString 

func (c *Color) TTMLString() string

TTMLString expresses the color as a TTML string

type Item 

type Item struct {
	Comments    []string
	Index       int
	EndAt       time.Duration
	InlineStyle *StyleAttributes
	Lines       []Line
	Region      *Region
	StartAt     time.Duration
	Style       *Style
}

Item represents a text to show between 2 time boundaries with formatting

func (Item) String 

func (i Item) String() string

String implements the Stringer interface

type Justification 

type Justification int

type Line 

type Line struct {
	Items     []LineItem
	VoiceName string
}

Line represents a set of formatted line items

func (Line) String 

func (l Line) String() string

String implement the Stringer interface

type LineItem 

type LineItem struct {
	InlineStyle *StyleAttributes
	Style       *Style
	Text        string
}

LineItem represents a formatted line item

func (LineItem) STLString 

func (li LineItem) STLString() string

type Metadata 

type Metadata struct {
	Comments                                            []string
	Framerate                                           int
	Language                                            string
	SSACollisions                                       string
	SSAOriginalEditing                                  string
	SSAOriginalScript                                   string
	SSAOriginalTiming                                   string
	SSAOriginalTranslation                              string
	SSAPlayDepth                                        *int
	SSAPlayResX, SSAPlayResY                            *int
	SSAScriptType                                       string
	SSAScriptUpdatedBy                                  string
	SSASynchPoint                                       string
	SSATimer                                            *float64
	SSAUpdateDetails                                    string
	SSAWrapStyle                                        string
	STLCountryOfOrigin                                  string
	STLCreationDate                                     *time.Time
	STLDisplayStandardCode                              string
	STLMaximumNumberOfDisplayableCharactersInAnyTextRow *int
	STLMaximumNumberOfDisplayableRows                   *int
	STLPublisher                                        string
	STLRevisionDate                                     *time.Time
	STLSubtitleListReferenceCode                        string
	STLTimecodeStartOfProgramme                         time.Duration
	Title                                               string
	TTMLCopyright                                       string
}

Metadata represents metadata TODO Merge attributes

type Options 

type Options struct {
	Filename string
	Teletext TeletextOptions
	STL      STLOptions
}

Options represents open or write options

type Region 

type Region struct {
	ID          string
	InlineStyle *StyleAttributes
	Style       *Style
}

Region represents a subtitle's region

type SSAOptions 

type SSAOptions struct {
	OnUnknownSectionName func(name string)
	OnInvalidLine        func(line string)
}

SSAOptions

type STLOptions 

type STLOptions struct {
	// IgnoreTimecodeStartOfProgramme - set STLTimecodeStartOfProgramme to zero before parsing
	IgnoreTimecodeStartOfProgramme bool
}

STLOptions represents STL parsing options

type STLPosition 

type STLPosition struct {
	VerticalPosition int
	MaxRows          int
	Rows             int
}

type Style 

type Style struct {
	ID          string
	InlineStyle *StyleAttributes
	Style       *Style
}

Style represents a subtitle's style

type StyleAttributes 

type StyleAttributes struct {
	SSAAlignment         *int
	SSAAlphaLevel        *float64
	SSAAngle             *float64 // degrees
	SSABackColour        *Color
	SSABold              *bool
	SSABorderStyle       *int
	SSAEffect            string
	SSAEncoding          *int
	SSAFontName          string
	SSAFontSize          *float64
	SSAItalic            *bool
	SSALayer             *int
	SSAMarginLeft        *int // pixels
	SSAMarginRight       *int // pixels
	SSAMarginVertical    *int // pixels
	SSAMarked            *bool
	SSAOutline           *float64 // pixels
	SSAOutlineColour     *Color
	SSAPrimaryColour     *Color
	SSAScaleX            *float64 // %
	SSAScaleY            *float64 // %
	SSASecondaryColour   *Color
	SSAShadow            *float64 // pixels
	SSASpacing           *float64 // pixels
	SSAStrikeout         *bool
	SSAUnderline         *bool
	STLBoxing            *bool
	STLItalics           *bool
	STLJustification     *Justification
	STLPosition          *STLPosition
	STLUnderline         *bool
	STLColor             *string
	TeletextColor        *Color
	TeletextDoubleHeight *bool
	TeletextDoubleSize   *bool
	TeletextDoubleWidth  *bool
	TeletextSpacesAfter  *int
	TeletextSpacesBefore *int
	// TODO Use pointers with real types below
	TTMLBackgroundColor   *string // https://htmlcolorcodes.com/fr/
	TTMLColor             *string
	TTMLDirection         *string
	TTMLDisplay           *string
	TTMLDisplayAlign      *string
	TTMLExtent            *string
	TTMLFontFamily        *string
	TTMLFontSize          *string
	TTMLFontStyle         *string
	TTMLFontWeight        *string
	TTMLLineHeight        *string
	TTMLOpacity           *string
	TTMLOrigin            *string
	TTMLOverflow          *string
	TTMLPadding           *string
	TTMLShowBackground    *string
	TTMLTextAlign         *string
	TTMLTextDecoration    *string
	TTMLTextOutline       *string
	TTMLUnicodeBidi       *string
	TTMLVisibility        *string
	TTMLWrapOption        *string
	TTMLWritingMode       *string
	TTMLZIndex            *int
	WebVTTColor           string
	WebVTTBackgroundColor string
	WebVTTAlign           string
	WebVTTItalics         bool
	WebVTTUnderline       bool
	WebVTTBold            bool
	WebVTTLine            string
	WebVTTLines           int
	WebVTTPosition        string
	WebVTTRegionAnchor    string
	WebVTTScroll          string
	WebVTTSize            string
	WebVTTVertical        string
	WebVTTViewportAnchor  string
	WebVTTWidth           string
}

StyleAttributes represents style attributes

type Subtitles 

type Subtitles struct {
	Items    []*Item
	Metadata *Metadata
	Regions  map[string]*Region
	Styles   map[string]*Style
}

Subtitles represents an ordered list of items with formatting

func NewSubtitles 

func NewSubtitles() *Subtitles

NewSubtitles creates new subtitles

func Open 

func Open(o Options) (s *Subtitles, err error)

Open opens a subtitle reader based on options

func OpenFile 

func OpenFile(filename string) (*Subtitles, error)

OpenFile opens a file regardless of other options

func ReadFromSRT 

func ReadFromSRT(i io.Reader) (o *Subtitles, err error)

ReadFromSRT parses an .srt content

func ReadFromSSA 

func ReadFromSSA(i io.Reader) (o *Subtitles, err error)

ReadFromSSA parses an .ssa content

func ReadFromSSAWithOptions 

func ReadFromSSAWithOptions(i io.Reader, opts SSAOptions) (o *Subtitles, err error)

ReadFromSSAWithOptions parses an .ssa content

func ReadFromSTL 

func ReadFromSTL(i io.Reader, opts STLOptions) (o *Subtitles, err error)

ReadFromSTL parses an .stl content

func ReadFromTTML 

func ReadFromTTML(i io.Reader) (o *Subtitles, err error)

ReadFromTTML parses a .ttml content

func ReadFromTeletext 

func ReadFromTeletext(r io.Reader, o TeletextOptions) (s *Subtitles, err error)

ReadFromTeletext parses a teletext content http://www.etsi.org/deliver/etsi_en/300400_300499/300472/01.03.01_60/en_300472v010301p.pdf http://www.etsi.org/deliver/etsi_i_ets/300700_300799/300706/01_60/ets_300706e01p.pdf TODO Update README TODO Add tests

func ReadFromWebVTT 

func ReadFromWebVTT(i io.Reader) (o *Subtitles, err error)

ReadFromWebVTT parses a .vtt content TODO Tags (u, i, b) TODO Class

func (*Subtitles) Add 

func (s *Subtitles) Add(d time.Duration)

Add adds a duration to each time boundaries. As in the time package, duration can be negative.

func (*Subtitles) ApplyLinearCorrection 

func (s *Subtitles) ApplyLinearCorrection(actual1, desired1, actual2, desired2 time.Duration)

ApplyLinearCorrection applies linear correction

func (Subtitles) Duration 

func (s Subtitles) Duration() time.Duration

Duration returns the subtitles duration

func (*Subtitles) ForceDuration 

func (s *Subtitles) ForceDuration(d time.Duration, addDummyItem bool)

ForceDuration updates the subtitles duration. If requested duration is bigger, then we create a dummy item. If requested duration is smaller, then we remove useless items and we cut the last item or add a dummy item.

func (*Subtitles) Fragment 

func (s *Subtitles) Fragment(f time.Duration)

Fragment fragments subtitles with a specific fragment duration

func (Subtitles) IsEmpty 

func (s Subtitles) IsEmpty() bool

IsEmpty returns whether the subtitles are empty

func (*Subtitles) Merge 

func (s *Subtitles) Merge(i *Subtitles)

Merge merges subtitles i into subtitles

func (*Subtitles) Optimize 

func (s *Subtitles) Optimize()

Optimize optimizes subtitles

func (*Subtitles) Order 

func (s *Subtitles) Order()

Order orders items

func (*Subtitles) RemoveStyling 

func (s *Subtitles) RemoveStyling()

RemoveStyling removes the styling from the subtitles

func (*Subtitles) Unfragment 

func (s *Subtitles) Unfragment()

Unfragment unfragments subtitles

func (Subtitles) Write 

func (s Subtitles) Write(dst string) (err error)

Write writes subtitles to a file

func (Subtitles) WriteToSRT 

func (s Subtitles) WriteToSRT(o io.Writer) (err error)

WriteToSRT writes subtitles in .srt format

func (Subtitles) WriteToSSA 

func (s Subtitles) WriteToSSA(o io.Writer) (err error)

WriteToSSA writes subtitles in .ssa format

func (Subtitles) WriteToSTL 

func (s Subtitles) WriteToSTL(o io.Writer) (err error)

WriteToSTL writes subtitles in .stl format

func (Subtitles) WriteToTTML 

func (s Subtitles) WriteToTTML(o io.Writer) (err error)

WriteToTTML writes subtitles in .ttml format

func (Subtitles) WriteToWebVTT 

func (s Subtitles) WriteToWebVTT(o io.Writer) (err error)

WriteToWebVTT writes subtitles in .vtt format

type TTMLIn 

type TTMLIn struct {
	Framerate int              `xml:"frameRate,attr"`
	Lang      string           `xml:"lang,attr"`
	Metadata  TTMLInMetadata   `xml:"head>metadata"`
	Regions   []TTMLInRegion   `xml:"head>layout>region"`
	Styles    []TTMLInStyle    `xml:"head>styling>style"`
	Subtitles []TTMLInSubtitle `xml:"body>div>p"`
	Tickrate  int              `xml:"tickRate,attr"`
	XMLName   xml.Name         `xml:"tt"`
}

TTMLIn represents an input TTML that must be unmarshaled We split it from the output TTML as we can't add strict namespace without breaking retrocompatibility

type TTMLInDuration 

type TTMLInDuration struct {
	// contains filtered or unexported fields
}

TTMLInDuration represents an input TTML duration

func (*TTMLInDuration) UnmarshalText 

func (d *TTMLInDuration) UnmarshalText(i []byte) (err error)

UnmarshalText implements the TextUnmarshaler interface Possible formats are: - hh:mm:ss.mmm - hh:mm:ss:fff (fff being frames) - [ticks]t ([ticks] being the tick amount)

type TTMLInHeader 

type TTMLInHeader struct {
	ID    string `xml:"id,attr,omitempty"`
	Style string `xml:"style,attr,omitempty"`
	TTMLInStyleAttributes
}

TTMLInHeader represents an input TTML header

type TTMLInItem 

type TTMLInItem struct {
	Style string `xml:"style,attr,omitempty"`
	Text  string `xml:",chardata"`
	TTMLInStyleAttributes
	XMLName xml.Name
}

TTMLInItem represents an input TTML item

type TTMLInItems 

type TTMLInItems []TTMLInItem

TTMLInItems represents input TTML items

func (*TTMLInItems) UnmarshalXML 

func (i *TTMLInItems) UnmarshalXML(d *xml.Decoder, start xml.StartElement) (err error)

UnmarshalXML implements the XML unmarshaler interface

type TTMLInMetadata 

type TTMLInMetadata struct {
	Copyright string `xml:"copyright"`
	Title     string `xml:"title"`
}

TTMLInMetadata represents an input TTML Metadata

type TTMLInRegion 

type TTMLInRegion struct {
	TTMLInHeader
	XMLName xml.Name `xml:"region"`
}

TTMLInRegion represents an input TTML region

type TTMLInStyle 

type TTMLInStyle struct {
	TTMLInHeader
	XMLName xml.Name `xml:"style"`
}

TTMLInStyle represents an input TTML style

type TTMLInStyleAttributes 

type TTMLInStyleAttributes struct {
	BackgroundColor *string `xml:"backgroundColor,attr,omitempty"`
	Color           *string `xml:"color,attr,omitempty"`
	Direction       *string `xml:"direction,attr,omitempty"`
	Display         *string `xml:"display,attr,omitempty"`
	DisplayAlign    *string `xml:"displayAlign,attr,omitempty"`
	Extent          *string `xml:"extent,attr,omitempty"`
	FontFamily      *string `xml:"fontFamily,attr,omitempty"`
	FontSize        *string `xml:"fontSize,attr,omitempty"`
	FontStyle       *string `xml:"fontStyle,attr,omitempty"`
	FontWeight      *string `xml:"fontWeight,attr,omitempty"`
	LineHeight      *string `xml:"lineHeight,attr,omitempty"`
	Opacity         *string `xml:"opacity,attr,omitempty"`
	Origin          *string `xml:"origin,attr,omitempty"`
	Overflow        *string `xml:"overflow,attr,omitempty"`
	Padding         *string `xml:"padding,attr,omitempty"`
	ShowBackground  *string `xml:"showBackground,attr,omitempty"`
	TextAlign       *string `xml:"textAlign,attr,omitempty"`
	TextDecoration  *string `xml:"textDecoration,attr,omitempty"`
	TextOutline     *string `xml:"textOutline,attr,omitempty"`
	UnicodeBidi     *string `xml:"unicodeBidi,attr,omitempty"`
	Visibility      *string `xml:"visibility,attr,omitempty"`
	WrapOption      *string `xml:"wrapOption,attr,omitempty"`
	WritingMode     *string `xml:"writingMode,attr,omitempty"`
	ZIndex          *int    `xml:"zIndex,attr,omitempty"`
}

TTMLInStyleAttributes represents input TTML style attributes

type TTMLInSubtitle 

type TTMLInSubtitle struct {
	Begin  *TTMLInDuration `xml:"begin,attr,omitempty"`
	End    *TTMLInDuration `xml:"end,attr,omitempty"`
	ID     string          `xml:"id,attr,omitempty"`
	Items  string          `xml:",innerxml"` // We must store inner XML here since there's no tag to describe both any tag and chardata
	Region string          `xml:"region,attr,omitempty"`
	Style  string          `xml:"style,attr,omitempty"`
	TTMLInStyleAttributes
}

TTMLInSubtitle represents an input TTML subtitle

type TTMLOut 

type TTMLOut struct {
	Lang            string            `xml:"xml:lang,attr,omitempty"`
	Metadata        *TTMLOutMetadata  `xml:"head>metadata,omitempty"`
	Styles          []TTMLOutStyle    `xml:"head>styling>style,omitempty"` //!\\ Order is important! Keep Styling above Layout
	Regions         []TTMLOutRegion   `xml:"head>layout>region,omitempty"`
	Subtitles       []TTMLOutSubtitle `xml:"body>div>p,omitempty"`
	XMLName         xml.Name          `xml:"http://www.w3.org/ns/ttml tt"`
	XMLNamespaceTTM string            `xml:"xmlns:ttm,attr"`
	XMLNamespaceTTS string            `xml:"xmlns:tts,attr"`
}

TTMLOut represents an output TTML that must be marshaled We split it from the input TTML as this time we'll add strict namespaces

type TTMLOutDuration 

type TTMLOutDuration time.Duration

TTMLOutDuration represents an output TTML duration

func (TTMLOutDuration) MarshalText 

func (t TTMLOutDuration) MarshalText() ([]byte, error)

MarshalText implements the TextMarshaler interface

type TTMLOutHeader 

type TTMLOutHeader struct {
	ID    string `xml:"xml:id,attr,omitempty"`
	Style string `xml:"style,attr,omitempty"`
	TTMLOutStyleAttributes
}

TTMLOutHeader represents an output TTML header

type TTMLOutItem 

type TTMLOutItem struct {
	Style string `xml:"style,attr,omitempty"`
	Text  string `xml:",chardata"`
	TTMLOutStyleAttributes
	XMLName xml.Name
}

TTMLOutItem represents an output TTML Item

type TTMLOutMetadata 

type TTMLOutMetadata struct {
	Copyright string `xml:"ttm:copyright,omitempty"`
	Title     string `xml:"ttm:title,omitempty"`
}

TTMLOutMetadata represents an output TTML Metadata

type TTMLOutRegion 

type TTMLOutRegion struct {
	TTMLOutHeader
	XMLName xml.Name `xml:"region"`
}

TTMLOutRegion represents an output TTML region

type TTMLOutStyle 

type TTMLOutStyle struct {
	TTMLOutHeader
	XMLName xml.Name `xml:"style"`
}

TTMLOutStyle represents an output TTML style

type TTMLOutStyleAttributes 

type TTMLOutStyleAttributes struct {
	BackgroundColor *string `xml:"tts:backgroundColor,attr,omitempty"`
	Color           *string `xml:"tts:color,attr,omitempty"`
	Direction       *string `xml:"tts:direction,attr,omitempty"`
	Display         *string `xml:"tts:display,attr,omitempty"`
	DisplayAlign    *string `xml:"tts:displayAlign,attr,omitempty"`
	Extent          *string `xml:"tts:extent,attr,omitempty"`
	FontFamily      *string `xml:"tts:fontFamily,attr,omitempty"`
	FontSize        *string `xml:"tts:fontSize,attr,omitempty"`
	FontStyle       *string `xml:"tts:fontStyle,attr,omitempty"`
	FontWeight      *string `xml:"tts:fontWeight,attr,omitempty"`
	LineHeight      *string `xml:"tts:lineHeight,attr,omitempty"`
	Opacity         *string `xml:"tts:opacity,attr,omitempty"`
	Origin          *string `xml:"tts:origin,attr,omitempty"`
	Overflow        *string `xml:"tts:overflow,attr,omitempty"`
	Padding         *string `xml:"tts:padding,attr,omitempty"`
	ShowBackground  *string `xml:"tts:showBackground,attr,omitempty"`
	TextAlign       *string `xml:"tts:textAlign,attr,omitempty"`
	TextDecoration  *string `xml:"tts:textDecoration,attr,omitempty"`
	TextOutline     *string `xml:"tts:textOutline,attr,omitempty"`
	UnicodeBidi     *string `xml:"tts:unicodeBidi,attr,omitempty"`
	Visibility      *string `xml:"tts:visibility,attr,omitempty"`
	WrapOption      *string `xml:"tts:wrapOption,attr,omitempty"`
	WritingMode     *string `xml:"tts:writingMode,attr,omitempty"`
	ZIndex          *int    `xml:"tts:zIndex,attr,omitempty"`
}

TTMLOutStyleAttributes represents output TTML style attributes

type TTMLOutSubtitle 

type TTMLOutSubtitle struct {
	Begin  TTMLOutDuration `xml:"begin,attr"`
	End    TTMLOutDuration `xml:"end,attr"`
	ID     string          `xml:"id,attr,omitempty"`
	Items  []TTMLOutItem
	Region string `xml:"region,attr,omitempty"`
	Style  string `xml:"style,attr,omitempty"`
	TTMLOutStyleAttributes
}

TTMLOutSubtitle represents an output TTML subtitle

type TeletextOptions 

type TeletextOptions struct {
	Page int
	PID  int
}

TeletextOptions represents teletext options

Source Files

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