Allow for styles to persist over lines

srt.go

@@ -38,6 +38,7 @@ func ReadFromSRT(i io.Reader) (o *Subtitles, err error) {
 	o = NewSubtitles()
 	var scanner = bufio.NewScanner(i)
 
+	styles := StyleAttributes{}
 	// Scan
 	var line string
 	var lineNum int
@@ -58,6 +59,10 @@ func ReadFromSRT(i io.Reader) (o *Subtitles, err error) {
 
 		// Line contains time boundaries
 		if strings.Contains(line, srtTimeBoundariesSeparator) {
+
+			// reset styles
+			styles = StyleAttributes{}
+
 			// Remove last item of previous subtitle since it should be the index.
 			// If the last line is empty then the item is missing an index.
 			var index string
@@ -118,7 +123,8 @@ func ReadFromSRT(i io.Reader) (o *Subtitles, err error) {
 			o.Items = append(o.Items, s)
 		} else {
 			// Add text
-			if l := parseTextSrt(strings.TrimSpace(line)); len(l.Items) > 0 {
+			var l Line
+			if l, styles = parseTextSrt(line, styles); len(l.Items) > 0 {
 				s.Lines = append(s.Lines, l)
 			}
 		}
@@ -127,24 +133,18 @@ func ReadFromSRT(i io.Reader) (o *Subtitles, err error) {
 }
 
 // parseTextSrt parses the input line to fill the Line
-func parseTextSrt(i string) (o Line) {
+func parseTextSrt(i string, styles StyleAttributes) (Line, StyleAttributes) {
 	// special handling needed for empty line
-	if strings.TrimSpace(i) == "" {
+	o := Line{}
+	if i == "" {
 		o.Items = []LineItem{{Text: ""}}
-		return
+		return o, styles
 	}
 
 	// Create tokenizer
 	tr := html.NewTokenizer(strings.NewReader(i))
 
 	// Loop
-	var (
-		bold      bool
-		italic    bool
-		underline bool
-		color     *string
-		pos       byte
-	)
 	for {
 		// Get next tag
 		t := tr.Next()
@@ -164,39 +164,38 @@ func parseTextSrt(i string) (o Line) {
 			// Parse italic/bold/underline
 			switch token.Data {
 			case "b":
-				bold = false
+				styles.SRTBold = false
 			case "i":
-				italic = false
+				styles.SRTItalics = false
 			case "u":
-				underline = false
+				styles.SRTUnderline = false
 			case "font":
-				color = nil
+				styles.SRTColor = nil
 			}
 		case html.StartTagToken:
 			// Parse italic/bold/underline
 			switch token.Data {
 			case "b":
-				bold = true
+				styles.SRTBold = true
 			case "i":
-				italic = true
+				styles.SRTItalics = true
 			case "u":
-				underline = true
+				styles.SRTUnderline = true
 			case "font":
 				if c := htmlTokenAttribute(&token, "color"); c != nil {
-					color = c
+					styles.SRTColor = c
 				}
 			}
 		case html.TextToken:
 			if s := strings.TrimSpace(raw); s != "" {
 				// Get style attribute
 				var sa *StyleAttributes
-				if bold || italic || underline || color != nil || pos != 0 {
+				if styles.SRTBold || styles.SRTColor != nil || styles.SRTItalics || styles.SRTUnderline {
 					sa = &StyleAttributes{
-						SRTBold:      bold,
-						SRTColor:     color,
-						SRTItalics:   italic,
-						SRTPosition:  pos,
-						SRTUnderline: underline,
+						SRTBold:      styles.SRTBold,
+						SRTColor:     styles.SRTColor,
+						SRTItalics:   styles.SRTItalics,
+						SRTUnderline: styles.SRTUnderline,
 					}
 					sa.propagateSRTAttributes()
 				}
@@ -209,7 +208,7 @@ func parseTextSrt(i string) (o Line) {
 			}
 		}
 	}
-	return
+	return o, styles
 }
 
 // formatDurationSRT formats an .srt duration

srt_test.go

@@ -60,7 +60,7 @@ func TestSRTStyled(t *testing.T) {
 	assert.NoError(t, err)
 
 	// assert the items are properly parsed
-	assert.Len(t, s.Items, 6)
+	assert.Len(t, s.Items, 9)
 	assert.Equal(t, 17*time.Second+985*time.Millisecond, s.Items[0].StartAt)
 	assert.Equal(t, 20*time.Second+521*time.Millisecond, s.Items[0].EndAt)
 	assert.Equal(t, "[instrumental music]", s.Items[0].Lines[0].String())
@@ -80,36 +80,47 @@ func TestSRTStyled(t *testing.T) {
 	assert.Equal(t, 1*time.Minute+31*time.Second+992*time.Millisecond, s.Items[5].EndAt)
 	assert.Equal(t, "[automated]", s.Items[5].Lines[0].String())
 	assert.Equal(t, "'The time is 7:35.'", s.Items[5].Lines[1].String())
+	assert.Equal(t, "Test with multi line italics", s.Items[6].Lines[0].String())
+	assert.Equal(t, "Terminated on the next line", s.Items[6].Lines[1].String())
+	assert.Equal(t, "Unterminated styles", s.Items[7].Lines[0].String())
+	assert.Equal(t, "Do no fall to the next item", s.Items[8].Lines[0].String())
 
 	// assert the styles of the items
-	assert.Len(t, s.Items, 6)
 	assert.Equal(t, "#00ff00", *s.Items[0].Lines[0].Items[0].InlineStyle.SRTColor)
-	assert.Zero(t, s.Items[0].Lines[0].Items[0].InlineStyle.SRTPosition)
 	assert.True(t, s.Items[0].Lines[0].Items[0].InlineStyle.SRTBold)
 	assert.False(t, s.Items[0].Lines[0].Items[0].InlineStyle.SRTItalics)
 	assert.False(t, s.Items[0].Lines[0].Items[0].InlineStyle.SRTUnderline)
 	assert.Equal(t, "#ff00ff", *s.Items[1].Lines[0].Items[0].InlineStyle.SRTColor)
-	assert.Zero(t, s.Items[1].Lines[0].Items[0].InlineStyle.SRTPosition)
 	assert.False(t, s.Items[1].Lines[0].Items[0].InlineStyle.SRTBold)
 	assert.False(t, s.Items[1].Lines[0].Items[0].InlineStyle.SRTItalics)
 	assert.False(t, s.Items[1].Lines[0].Items[0].InlineStyle.SRTUnderline)
 	assert.Equal(t, "#00ff00", *s.Items[2].Lines[0].Items[0].InlineStyle.SRTColor)
-	assert.Zero(t, s.Items[2].Lines[0].Items[0].InlineStyle.SRTPosition)
 	assert.False(t, s.Items[2].Lines[0].Items[0].InlineStyle.SRTBold)
 	assert.False(t, s.Items[2].Lines[0].Items[0].InlineStyle.SRTItalics)
 	assert.False(t, s.Items[2].Lines[0].Items[0].InlineStyle.SRTUnderline)
 	assert.Nil(t, s.Items[3].Lines[0].Items[0].InlineStyle.SRTColor)
-	assert.Zero(t, s.Items[3].Lines[0].Items[0].InlineStyle.SRTPosition)
 	assert.True(t, s.Items[3].Lines[0].Items[0].InlineStyle.SRTBold)
 	assert.False(t, s.Items[3].Lines[0].Items[0].InlineStyle.SRTItalics)
 	assert.True(t, s.Items[3].Lines[0].Items[0].InlineStyle.SRTUnderline)
 	assert.Nil(t, s.Items[4].Lines[0].Items[0].InlineStyle)
 	assert.Nil(t, s.Items[5].Lines[0].Items[0].InlineStyle)
 	assert.Nil(t, s.Items[5].Lines[1].Items[0].InlineStyle.SRTColor)
-	assert.Zero(t, s.Items[5].Lines[1].Items[0].InlineStyle.SRTPosition)
 	assert.False(t, s.Items[5].Lines[1].Items[0].InlineStyle.SRTBold)
 	assert.True(t, s.Items[5].Lines[1].Items[0].InlineStyle.SRTItalics)
 	assert.False(t, s.Items[5].Lines[1].Items[0].InlineStyle.SRTUnderline)
+	assert.True(t, s.Items[6].Lines[0].Items[0].InlineStyle.SRTItalics)
+	assert.False(t, s.Items[6].Lines[0].Items[0].InlineStyle.SRTUnderline)
+	assert.False(t, s.Items[6].Lines[0].Items[0].InlineStyle.SRTBold)
+	assert.Nil(t, s.Items[6].Lines[0].Items[0].InlineStyle.SRTColor)
+	assert.True(t, s.Items[6].Lines[1].Items[0].InlineStyle.SRTItalics)
+	assert.False(t, s.Items[6].Lines[1].Items[0].InlineStyle.SRTUnderline)
+	assert.False(t, s.Items[6].Lines[1].Items[0].InlineStyle.SRTBold)
+	assert.Nil(t, s.Items[6].Lines[1].Items[0].InlineStyle.SRTColor)
+	assert.True(t, s.Items[7].Lines[0].Items[0].InlineStyle.SRTItalics)
+	assert.False(t, s.Items[7].Lines[0].Items[0].InlineStyle.SRTUnderline)
+	assert.False(t, s.Items[7].Lines[0].Items[0].InlineStyle.SRTBold)
+	assert.Nil(t, s.Items[7].Lines[0].Items[0].InlineStyle.SRTColor)
+	assert.Nil(t, s.Items[8].Lines[0].Items[0].InlineStyle)
 
 	// Write to srt
 	w := &bytes.Buffer{}

testdata/example-in-styled.srt

@@ -22,3 +22,16 @@
 00:01:29,590 --> 00:01:31,992
 [automated]
 <i>'The time is 7:35.'</i>
+
+7
+00:08:00,000 --> 00:09:00,000
+<i>Test with multi line italics
+Terminated on the next line</i>
+
+8
+00:09:00,000 --> 00:10:00,000
+<i>Unterminated styles
+
+9
+00:10:00,000 --> 00:11:00,000
+Do no fall to the next item

testdata/example-out-styled.srt

@@ -22,3 +22,16 @@
 00:01:29,590 --> 00:01:31,992
 [automated]
 <i>'The time is 7:35.'</i>
+
+7
+00:08:00,000 --> 00:09:00,000
+<i>Test with multi line italics</i>
+<i>Terminated on the next line</i>
+
+8
+00:09:00,000 --> 00:10:00,000
+<i>Unterminated styles</i>
+
+9
+00:10:00,000 --> 00:11:00,000
+Do no fall to the next item

testdata/example-out-styled.vtt

@@ -24,3 +24,16 @@ WEBVTT
 00:01:29.590 --> 00:01:31.992
 [automated]
 <i>'The time is 7:35.'</i>
+
+7
+00:08:00.000 --> 00:09:00.000
+<i>Test with multi line italics</i>
+<i>Terminated on the next line</i>
+
+8
+00:09:00.000 --> 00:10:00.000
+<i>Unterminated styles</i>
+
+9
+00:10:00.000 --> 00:11:00.000
+Do no fall to the next item

webvtt.go

@@ -123,6 +123,7 @@ func ReadFromWebVTT(i io.Reader) (o *Subtitles, err error) {
 	var scanner = bufio.NewScanner(i)
 	var line string
 	var lineNum int
+	webVTTTagStack := make([]WebVTTTag, 0, 16)
 
 	// Skip the header
 	for scanner.Scan() {
@@ -169,6 +170,9 @@ func ReadFromWebVTT(i io.Reader) (o *Subtitles, err error) {
 				strings.HasSuffix(webVTTStyles.WebVTTStyles[len(webVTTStyles.WebVTTStyles)-1], "}") {
 				blockName = ""
 			}
+			// Reset tag stack
+			webVTTTagStack = make([]WebVTTTag, 0, 16)
+
 		// Region
 		case strings.HasPrefix(line, "Region: "):
 			// Add region styles
@@ -319,8 +323,9 @@ func ReadFromWebVTT(i io.Reader) (o *Subtitles, err error) {
 				webVTTStyles.WebVTTStyles = append(webVTTStyles.WebVTTStyles, line)
 			case webvttBlockNameText:
 				// Parse line
-				if l := parseTextWebVTT(line); len(l.Items) > 0 {
+				if l, stack := parseTextWebVTT(line, webVTTTagStack); len(l.Items) > 0 {
 					item.Lines = append(item.Lines, l)
+					webVTTTagStack = stack
 				}
 			default:
 				// This is the ID
@@ -340,11 +345,10 @@ func unescapeWebVTT(i string) string {
 }
 
 // parseTextWebVTT parses the input line to fill the Line
-func parseTextWebVTT(i string) (o Line) {
+func parseTextWebVTT(i string, webVTTTagStack []WebVTTTag) (Line, []WebVTTTag) {
 	// Create tokenizer
 	tr := html.NewTokenizer(strings.NewReader(i))
-
-	webVTTTagStack := make([]WebVTTTag, 0, 16)
+	o := Line{}
 
 	// Loop
 	for {
@@ -410,7 +414,7 @@ func parseTextWebVTT(i string) (o Line) {
 			o.Items = append(o.Items, parseTextWebVTTTextToken(sa, string(tr.Raw()))...)
 		}
 	}
-	return
+	return o, webVTTTagStack
 }
 
 func parseTextWebVTTTextToken(sa *StyleAttributes, line string) (ret []LineItem) {

webvtt_internal_test.go

@@ -13,7 +13,7 @@ func TestParseTextWebVTT(t *testing.T) {
 	t.Run("When both voice tags are available", func(t *testing.T) {
 		testData := `<v Bob>Correct tag</v>`
 
-		s := parseTextWebVTT(testData)
+		s, _ := parseTextWebVTT(testData, make([]WebVTTTag, 0, 16))
 		assert.Equal(t, "Bob", s.VoiceName)
 		assert.Equal(t, 1, len(s.Items))
 		assert.Equal(t, "Correct tag", s.Items[0].Text)
@@ -22,7 +22,7 @@ func TestParseTextWebVTT(t *testing.T) {
 	t.Run("When there is no end tag", func(t *testing.T) {
 		testData := `<v Bob> Text without end tag`
 
-		s := parseTextWebVTT(testData)
+		s, _ := parseTextWebVTT(testData, make([]WebVTTTag, 0, 16))
 		assert.Equal(t, "Bob", s.VoiceName)
 		assert.Equal(t, 1, len(s.Items))
 		assert.Equal(t, "Text without end tag", s.Items[0].Text)
@@ -31,7 +31,7 @@ func TestParseTextWebVTT(t *testing.T) {
 	t.Run("When the end tag is correct", func(t *testing.T) {
 		testData := `<v Bob>Incorrect end tag</vi>`
 
-		s := parseTextWebVTT(testData)
+		s, _ := parseTextWebVTT(testData, make([]WebVTTTag, 0, 16))
 		assert.Equal(t, "Bob", s.VoiceName)
 		assert.Equal(t, 1, len(s.Items))
 		assert.Equal(t, "Incorrect end tag", s.Items[0].Text)
@@ -40,7 +40,7 @@ func TestParseTextWebVTT(t *testing.T) {
 	t.Run("When inline timestamps are included", func(t *testing.T) {
 		testData := `<00:01:01.000>With inline <00:01:02.000>timestamps`
 
-		s := parseTextWebVTT(testData)
+		s, _ := parseTextWebVTT(testData, make([]WebVTTTag, 0, 16))
 		assert.Equal(t, 2, len(s.Items))
 		assert.Equal(t, "With inline", s.Items[0].Text)
 		assert.Equal(t, time.Minute+time.Second, s.Items[0].StartAt)
@@ -51,7 +51,7 @@ func TestParseTextWebVTT(t *testing.T) {
 	t.Run("When inline timestamps together", func(t *testing.T) {
 		testData := `<00:01:01.000><00:01:02.000>With timestamp tags together`
 
-		s := parseTextWebVTT(testData)
+		s, _ := parseTextWebVTT(testData, make([]WebVTTTag, 0, 16))
 		assert.Equal(t, 1, len(s.Items))
 		assert.Equal(t, "With timestamp tags together", s.Items[0].Text)
 		assert.Equal(t, time.Minute+2*time.Second, s.Items[0].StartAt)
@@ -60,7 +60,7 @@ func TestParseTextWebVTT(t *testing.T) {
 	t.Run("When inline timestamps is at end", func(t *testing.T) {
 		testData := `With end timestamp<00:01:02.000>`
 
-		s := parseTextWebVTT(testData)
+		s, _ := parseTextWebVTT(testData, make([]WebVTTTag, 0, 16))
 		assert.Equal(t, 1, len(s.Items))
 		assert.Equal(t, "With end timestamp", s.Items[0].Text)
 		assert.Equal(t, time.Duration(0), s.Items[0].StartAt)

webvtt_test.go

@@ -195,12 +195,22 @@ func TestWebVTTTags(t *testing.T) {
 	<v Joe>Joe says something</v> <v Bob>Bob says something</v>
 
 	00:06:00.000 --> 00:07:00.000
-	Text with a <00:06:30.000>timestamp in the middle`
+	Text with a <00:06:30.000>timestamp in the middle
+
+	00:08:00.000 --> 00:09:00.000
+	<i>Test with multi line italics
+	Terminated on the next line</i>
+	
+	00:09:00.000 --> 00:10:00.000
+	<i>Unterminated styles
+	
+	00:10:00.000 --> 00:11:00.000
+	Do no fall to the next item`
 
 	s, err := astisub.ReadFromWebVTT(strings.NewReader(testData))
 	require.NoError(t, err)
 
-	require.Len(t, s.Items, 6)
+	require.Len(t, s.Items, 9)
 
 	b := &bytes.Buffer{}
 	err = s.WriteToWebVTT(b)
@@ -230,5 +240,18 @@ func TestWebVTTTags(t *testing.T) {
 6
 00:06:00.000 --> 00:07:00.000
 Text with a <00:06:30.000>timestamp in the middle
+
+7
+00:08:00.000 --> 00:09:00.000
+<i>Test with multi line italics</i>
+<i>Terminated on the next line</i>
+
+8
+00:09:00.000 --> 00:10:00.000
+<i>Unterminated styles</i>
+
+9
+00:10:00.000 --> 00:11:00.000
+Do no fall to the next item
 `, b.String())
 }