Caption support (#2462)

Co-authored-by: WithoutPants <53250216+WithoutPants@users.noreply.github.com>

vendor/github.com/asticode/go-astisub/subtitles.go

@@ -0,0 +1,779 @@
+package astisub
+
+import (
+	"errors"
+	"fmt"
+	"math"
+	"os"
+	"path/filepath"
+	"strconv"
+	"strings"
+	"time"
+
+	"github.com/asticode/go-astikit"
+)
+
+// Bytes
+var (
+	BytesBOM           = []byte{239, 187, 191}
+	bytesLineSeparator = []byte("\n")
+	bytesSpace         = []byte(" ")
+)
+
+// Colors
+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}
+)
+
+// Errors
+var (
+	ErrInvalidExtension   = errors.New("astisub: invalid extension")
+	ErrNoSubtitlesToWrite = errors.New("astisub: no subtitles to write")
+)
+
+// Now allows testing functions using it
+var Now = func() time.Time {
+	return time.Now()
+}
+
+// Options represents open or write options
+type Options struct {
+	Filename string
+	Teletext TeletextOptions
+	STL      STLOptions
+}
+
+// Open opens a subtitle reader based on options
+func Open(o Options) (s *Subtitles, err error) {
+	// Open the file
+	var f *os.File
+	if f, err = os.Open(o.Filename); err != nil {
+		err = fmt.Errorf("astisub: opening %s failed: %w", o.Filename, err)
+		return
+	}
+	defer f.Close()
+
+	// Parse the content
+	switch filepath.Ext(strings.ToLower(o.Filename)) {
+	case ".srt":
+		s, err = ReadFromSRT(f)
+	case ".ssa", ".ass":
+		s, err = ReadFromSSA(f)
+	case ".stl":
+		s, err = ReadFromSTL(f, o.STL)
+	case ".ts":
+		s, err = ReadFromTeletext(f, o.Teletext)
+	case ".ttml":
+		s, err = ReadFromTTML(f)
+	case ".vtt":
+		s, err = ReadFromWebVTT(f)
+	default:
+		err = ErrInvalidExtension
+	}
+	return
+}
+
+// OpenFile opens a file regardless of other options
+func OpenFile(filename string) (*Subtitles, error) {
+	return Open(Options{Filename: filename})
+}
+
+// Subtitles represents an ordered list of items with formatting
+type Subtitles struct {
+	Items    []*Item
+	Metadata *Metadata
+	Regions  map[string]*Region
+	Styles   map[string]*Style
+}
+
+// NewSubtitles creates new subtitles
+func NewSubtitles() *Subtitles {
+	return &Subtitles{
+		Regions: make(map[string]*Region),
+		Styles:  make(map[string]*Style),
+	}
+}
+
+// Item represents a text to show between 2 time boundaries with formatting
+type Item struct {
+	Comments    []string
+	Index       int
+	EndAt       time.Duration
+	InlineStyle *StyleAttributes
+	Lines       []Line
+	Region      *Region
+	StartAt     time.Duration
+	Style       *Style
+}
+
+// String implements the Stringer interface
+func (i Item) String() string {
+	var os []string
+	for _, l := range i.Lines {
+		os = append(os, l.String())
+	}
+	return strings.Join(os, " - ")
+}
+
+// Color represents a color
+type Color struct {
+	Alpha, Blue, Green, Red uint8
+}
+
+// newColorFromSSAString builds a new color based on an SSA string
+func newColorFromSSAString(s string, base int) (c *Color, err error) {
+	var i int64
+	if i, err = strconv.ParseInt(s, base, 64); err != nil {
+		err = fmt.Errorf("parsing int %s with base %d failed: %w", s, base, err)
+		return
+	}
+	c = &Color{
+		Alpha: uint8(i>>24) & 0xff,
+		Blue:  uint8(i>>16) & 0xff,
+		Green: uint8(i>>8) & 0xff,
+		Red:   uint8(i) & 0xff,
+	}
+	return
+}
+
+// SSAString expresses the color as an SSA string
+func (c *Color) SSAString() string {
+	return fmt.Sprintf("%.8x", uint32(c.Alpha)<<24|uint32(c.Blue)<<16|uint32(c.Green)<<8|uint32(c.Red))
+}
+
+// TTMLString expresses the color as a TTML string
+func (c *Color) TTMLString() string {
+	return fmt.Sprintf("%.6x", uint32(c.Red)<<16|uint32(c.Green)<<8|uint32(c.Blue))
+}
+
+type Justification int
+
+var (
+	JustificationUnchanged = Justification(1)
+	JustificationLeft      = Justification(2)
+	JustificationCentered  = Justification(3)
+	JustificationRight     = Justification(4)
+)
+
+// StyleAttributes represents style attributes
+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
+	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
+	WebVTTAlign          string
+	WebVTTItalics        bool
+	WebVTTLine           string
+	WebVTTLines          int
+	WebVTTPosition       string
+	WebVTTRegionAnchor   string
+	WebVTTScroll         string
+	WebVTTSize           string
+	WebVTTVertical       string
+	WebVTTViewportAnchor string
+	WebVTTWidth          string
+}
+
+func (sa *StyleAttributes) propagateSSAAttributes() {}
+
+func (sa *StyleAttributes) propagateSTLAttributes() {
+	if sa.STLJustification != nil {
+		switch *sa.STLJustification {
+		case JustificationCentered:
+			// default to middle anyway?
+		case JustificationRight:
+			sa.WebVTTAlign = "right"
+		case JustificationLeft:
+			sa.WebVTTAlign = "left"
+		}
+	}
+}
+
+func (sa *StyleAttributes) propagateTeletextAttributes() {
+	if sa.TeletextColor != nil {
+		sa.TTMLColor = astikit.StrPtr("#" + sa.TeletextColor.TTMLString())
+	}
+}
+
+//reference for migration: https://w3c.github.io/ttml-webvtt-mapping/
+func (sa *StyleAttributes) propagateTTMLAttributes() {
+	if sa.TTMLTextAlign != nil {
+		sa.WebVTTAlign = *sa.TTMLTextAlign
+	}
+	if sa.TTMLExtent != nil {
+		//region settings
+		lineHeight := 5 //assuming height of line as 5.33vh
+		dimensions := strings.Split(*sa.TTMLExtent, " ")
+		if len(dimensions) > 1 {
+			sa.WebVTTWidth = dimensions[0]
+			if height, err := strconv.Atoi(strings.ReplaceAll(dimensions[1], "%", "")); err == nil {
+				sa.WebVTTLines = height / lineHeight
+			}
+			//cue settings
+			//default TTML WritingMode is lrtb i.e. left to right, top to bottom
+			sa.WebVTTSize = dimensions[1]
+			if sa.TTMLWritingMode != nil && strings.HasPrefix(*sa.TTMLWritingMode, "tb") {
+				sa.WebVTTSize = dimensions[0]
+			}
+		}
+	}
+	if sa.TTMLOrigin != nil {
+		//region settings
+		sa.WebVTTRegionAnchor = "0%,0%"
+		sa.WebVTTViewportAnchor = strings.ReplaceAll(strings.TrimSpace(*sa.TTMLOrigin), " ", ",")
+		sa.WebVTTScroll = "up"
+		//cue settings
+		coordinates := strings.Split(*sa.TTMLOrigin, " ")
+		if len(coordinates) > 1 {
+			sa.WebVTTLine = coordinates[0]
+			sa.WebVTTPosition = coordinates[1]
+			if sa.TTMLWritingMode != nil && strings.HasPrefix(*sa.TTMLWritingMode, "tb") {
+				sa.WebVTTLine = coordinates[1]
+				sa.WebVTTPosition = coordinates[0]
+			}
+		}
+	}
+}
+
+func (sa *StyleAttributes) propagateWebVTTAttributes() {}
+
+// Metadata represents metadata
+// TODO Merge attributes
+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
+}
+
+// Region represents a subtitle's region
+type Region struct {
+	ID          string
+	InlineStyle *StyleAttributes
+	Style       *Style
+}
+
+// Style represents a subtitle's style
+type Style struct {
+	ID          string
+	InlineStyle *StyleAttributes
+	Style       *Style
+}
+
+// Line represents a set of formatted line items
+type Line struct {
+	Items     []LineItem
+	VoiceName string
+}
+
+// String implement the Stringer interface
+func (l Line) String() string {
+	var texts []string
+	for _, i := range l.Items {
+		texts = append(texts, i.Text)
+	}
+	return strings.Join(texts, " ")
+}
+
+// LineItem represents a formatted line item
+type LineItem struct {
+	InlineStyle *StyleAttributes
+	Style       *Style
+	Text        string
+}
+
+// Add adds a duration to each time boundaries. As in the time package, duration can be negative.
+func (s *Subtitles) Add(d time.Duration) {
+	for idx := 0; idx < len(s.Items); idx++ {
+		s.Items[idx].EndAt += d
+		s.Items[idx].StartAt += d
+		if s.Items[idx].EndAt <= 0 && s.Items[idx].StartAt <= 0 {
+			s.Items = append(s.Items[:idx], s.Items[idx+1:]...)
+			idx--
+		} else if s.Items[idx].StartAt <= 0 {
+			s.Items[idx].StartAt = time.Duration(0)
+		}
+	}
+}
+
+// Duration returns the subtitles duration
+func (s Subtitles) Duration() time.Duration {
+	if len(s.Items) == 0 {
+		return time.Duration(0)
+	}
+	return s.Items[len(s.Items)-1].EndAt
+}
+
+// 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 (s *Subtitles) ForceDuration(d time.Duration, addDummyItem bool) {
+	// Requested duration is the same as the subtitles'one
+	if s.Duration() == d {
+		return
+	}
+
+	// Requested duration is bigger than subtitles'one
+	if s.Duration() > d {
+		// Find last item before input duration and update end at
+		var lastIndex = -1
+		for index, i := range s.Items {
+			// Start at is bigger than input duration, we've found the last item
+			if i.StartAt >= d {
+				lastIndex = index
+				break
+			} else if i.EndAt > d {
+				s.Items[index].EndAt = d
+			}
+		}
+
+		// Last index has been found
+		if lastIndex != -1 {
+			s.Items = s.Items[:lastIndex]
+		}
+	}
+
+	// Add dummy item with the minimum duration possible
+	if addDummyItem && s.Duration() < d {
+		s.Items = append(s.Items, &Item{EndAt: d, Lines: []Line{{Items: []LineItem{{Text: "..."}}}}, StartAt: d - time.Millisecond})
+	}
+}
+
+// Fragment fragments subtitles with a specific fragment duration
+func (s *Subtitles) Fragment(f time.Duration) {
+	// Nothing to fragment
+	if len(s.Items) == 0 {
+		return
+	}
+
+	// Here we want to simulate fragments of duration f until there are no subtitles left in that period of time
+	var fragmentStartAt, fragmentEndAt = time.Duration(0), f
+	for fragmentStartAt < s.Items[len(s.Items)-1].EndAt {
+		// We loop through subtitles and process the ones that either contain the fragment start at,
+		// or contain the fragment end at
+		//
+		// It's useless processing subtitles contained between fragment start at and end at
+		//             |____________________|             <- subtitle
+		//           |                        |
+		//   fragment start at        fragment end at
+		for i, sub := range s.Items {
+			// Init
+			var newSub = &Item{}
+			*newSub = *sub
+
+			// A switch is more readable here
+			switch {
+			// Subtitle contains fragment start at
+			// |____________________|                         <- subtitle
+			//           |                        |
+			//   fragment start at        fragment end at
+			case sub.StartAt < fragmentStartAt && sub.EndAt > fragmentStartAt:
+				sub.StartAt = fragmentStartAt
+				newSub.EndAt = fragmentStartAt
+			// Subtitle contains fragment end at
+			//                         |____________________| <- subtitle
+			//           |                        |
+			//   fragment start at        fragment end at
+			case sub.StartAt < fragmentEndAt && sub.EndAt > fragmentEndAt:
+				sub.StartAt = fragmentEndAt
+				newSub.EndAt = fragmentEndAt
+			default:
+				continue
+			}
+
+			// Insert new sub
+			s.Items = append(s.Items[:i], append([]*Item{newSub}, s.Items[i:]...)...)
+		}
+
+		// Update fragments boundaries
+		fragmentStartAt += f
+		fragmentEndAt += f
+	}
+
+	// Order
+	s.Order()
+}
+
+// IsEmpty returns whether the subtitles are empty
+func (s Subtitles) IsEmpty() bool {
+	return len(s.Items) == 0
+}
+
+// Merge merges subtitles i into subtitles
+func (s *Subtitles) Merge(i *Subtitles) {
+	// Append items
+	s.Items = append(s.Items, i.Items...)
+	s.Order()
+
+	// Add regions
+	for _, region := range i.Regions {
+		if _, ok := s.Regions[region.ID]; !ok {
+			s.Regions[region.ID] = region
+		}
+	}
+
+	// Add styles
+	for _, style := range i.Styles {
+		if _, ok := s.Styles[style.ID]; !ok {
+			s.Styles[style.ID] = style
+		}
+	}
+}
+
+// Optimize optimizes subtitles
+func (s *Subtitles) Optimize() {
+	// Nothing to optimize
+	if len(s.Items) == 0 {
+		return
+	}
+
+	// Remove unused regions and style
+	s.removeUnusedRegionsAndStyles()
+}
+
+// removeUnusedRegionsAndStyles removes unused regions and styles
+func (s *Subtitles) removeUnusedRegionsAndStyles() {
+	// Loop through items
+	var usedRegions, usedStyles = make(map[string]bool), make(map[string]bool)
+	for _, item := range s.Items {
+		// Add region
+		if item.Region != nil {
+			usedRegions[item.Region.ID] = true
+		}
+
+		// Add style
+		if item.Style != nil {
+			usedStyles[item.Style.ID] = true
+		}
+
+		// Loop through lines
+		for _, line := range item.Lines {
+			// Loop through line items
+			for _, lineItem := range line.Items {
+				// Add style
+				if lineItem.Style != nil {
+					usedStyles[lineItem.Style.ID] = true
+				}
+			}
+		}
+	}
+
+	// Loop through regions
+	for id, region := range s.Regions {
+		if _, ok := usedRegions[region.ID]; ok {
+			if region.Style != nil {
+				usedStyles[region.Style.ID] = true
+			}
+		} else {
+			delete(s.Regions, id)
+		}
+	}
+
+	// Loop through style
+	for id, style := range s.Styles {
+		if _, ok := usedStyles[style.ID]; !ok {
+			delete(s.Styles, id)
+		}
+	}
+}
+
+// Order orders items
+func (s *Subtitles) Order() {
+	// Nothing to do if less than 1 element
+	if len(s.Items) <= 1 {
+		return
+	}
+
+	// Order
+	var swapped = true
+	for swapped {
+		swapped = false
+		for index := 1; index < len(s.Items); index++ {
+			if s.Items[index-1].StartAt > s.Items[index].StartAt {
+				var tmp = s.Items[index-1]
+				s.Items[index-1] = s.Items[index]
+				s.Items[index] = tmp
+				swapped = true
+			}
+		}
+	}
+}
+
+// RemoveStyling removes the styling from the subtitles
+func (s *Subtitles) RemoveStyling() {
+	s.Regions = map[string]*Region{}
+	s.Styles = map[string]*Style{}
+	for _, i := range s.Items {
+		i.Region = nil
+		i.Style = nil
+		i.InlineStyle = nil
+		for idxLine, l := range i.Lines {
+			for idxLineItem := range l.Items {
+				i.Lines[idxLine].Items[idxLineItem].InlineStyle = nil
+				i.Lines[idxLine].Items[idxLineItem].Style = nil
+			}
+		}
+	}
+}
+
+// Unfragment unfragments subtitles
+func (s *Subtitles) Unfragment() {
+	// Nothing to do if less than 1 element
+	if len(s.Items) <= 1 {
+		return
+	}
+
+	// Order
+	s.Order()
+
+	// Loop through items
+	for i := 0; i < len(s.Items)-1; i++ {
+		for j := i + 1; j < len(s.Items); j++ {
+			// Items are the same
+			if s.Items[i].String() == s.Items[j].String() && s.Items[i].EndAt >= s.Items[j].StartAt {
+				// Only override end time if longer
+				if s.Items[i].EndAt < s.Items[j].EndAt {
+					s.Items[i].EndAt = s.Items[j].EndAt
+				}
+				s.Items = append(s.Items[:j], s.Items[j+1:]...)
+				j--
+			} else if s.Items[i].EndAt < s.Items[j].StartAt {
+				break
+			}
+		}
+	}
+}
+
+// Write writes subtitles to a file
+func (s Subtitles) Write(dst string) (err error) {
+	// Create the file
+	var f *os.File
+	if f, err = os.Create(dst); err != nil {
+		err = fmt.Errorf("astisub: creating %s failed: %w", dst, err)
+		return
+	}
+	defer f.Close()
+
+	// Write the content
+	switch filepath.Ext(strings.ToLower(dst)) {
+	case ".srt":
+		err = s.WriteToSRT(f)
+	case ".ssa", ".ass":
+		err = s.WriteToSSA(f)
+	case ".stl":
+		err = s.WriteToSTL(f)
+	case ".ttml":
+		err = s.WriteToTTML(f)
+	case ".vtt":
+		err = s.WriteToWebVTT(f)
+	default:
+		err = ErrInvalidExtension
+	}
+	return
+}
+
+// parseDuration parses a duration in "00:00:00.000", "00:00:00,000" or "0:00:00:00" format
+func parseDuration(i, millisecondSep string, numberOfMillisecondDigits int) (o time.Duration, err error) {
+	// Split milliseconds
+	var parts = strings.Split(i, millisecondSep)
+	var milliseconds int
+	var s string
+	if len(parts) >= 2 {
+		// Invalid number of millisecond digits
+		s = strings.TrimSpace(parts[len(parts)-1])
+		if len(s) > 3 {
+			err = fmt.Errorf("astisub: Invalid number of millisecond digits detected in %s", i)
+			return
+		}
+
+		// Parse milliseconds
+		if milliseconds, err = strconv.Atoi(s); err != nil {
+			err = fmt.Errorf("astisub: atoi of %s failed: %w", s, err)
+			return
+		}
+		milliseconds *= int(math.Pow10(numberOfMillisecondDigits - len(s)))
+		s = strings.Join(parts[:len(parts)-1], millisecondSep)
+	} else {
+		s = i
+	}
+
+	// Split hours, minutes and seconds
+	parts = strings.Split(strings.TrimSpace(s), ":")
+	var partSeconds, partMinutes, partHours string
+	if len(parts) == 2 {
+		partSeconds = parts[1]
+		partMinutes = parts[0]
+	} else if len(parts) == 3 {
+		partSeconds = parts[2]
+		partMinutes = parts[1]
+		partHours = parts[0]
+	} else {
+		err = fmt.Errorf("astisub: No hours, minutes or seconds detected in %s", i)
+		return
+	}
+
+	// Parse seconds
+	var seconds int
+	s = strings.TrimSpace(partSeconds)
+	if seconds, err = strconv.Atoi(s); err != nil {
+		err = fmt.Errorf("astisub: atoi of %s failed: %w", s, err)
+		return
+	}
+
+	// Parse minutes
+	var minutes int
+	s = strings.TrimSpace(partMinutes)
+	if minutes, err = strconv.Atoi(s); err != nil {
+		err = fmt.Errorf("astisub: atoi of %s failed: %w", s, err)
+		return
+	}
+
+	// Parse hours
+	var hours int
+	if len(partHours) > 0 {
+		s = strings.TrimSpace(partHours)
+		if hours, err = strconv.Atoi(s); err != nil {
+			err = fmt.Errorf("astisub: atoi of %s failed: %w", s, err)
+			return
+		}
+	}
+
+	// Generate output
+	o = time.Duration(milliseconds)*time.Millisecond + time.Duration(seconds)*time.Second + time.Duration(minutes)*time.Minute + time.Duration(hours)*time.Hour
+	return
+}
+
+// formatDuration formats a duration
+func formatDuration(i time.Duration, millisecondSep string, numberOfMillisecondDigits int) (s string) {
+	// Parse hours
+	var hours = int(i / time.Hour)
+	var n = i % time.Hour
+	if hours < 10 {
+		s += "0"
+	}
+	s += strconv.Itoa(hours) + ":"
+
+	// Parse minutes
+	var minutes = int(n / time.Minute)
+	n = i % time.Minute
+	if minutes < 10 {
+		s += "0"
+	}
+	s += strconv.Itoa(minutes) + ":"
+
+	// Parse seconds
+	var seconds = int(n / time.Second)
+	n = i % time.Second
+	if seconds < 10 {
+		s += "0"
+	}
+	s += strconv.Itoa(seconds) + millisecondSep
+
+	// Parse milliseconds
+	var milliseconds = float64(n/time.Millisecond) / float64(1000)
+	s += fmt.Sprintf("%."+strconv.Itoa(numberOfMillisecondDigits)+"f", milliseconds)[2:]
+	return
+}
+
+// appendStringToBytesWithNewLine adds a string to bytes then adds a new line
+func appendStringToBytesWithNewLine(i []byte, s string) (o []byte) {
+	o = append(i, []byte(s)...)
+	o = append(o, bytesLineSeparator...)
+	return
+}