diff --git a/library/core/src/main/java/com/google/android/exoplayer2/text/ssa/SsaDialogueFormat.java b/library/core/src/main/java/com/google/android/exoplayer2/text/ssa/SsaDialogueFormat.java
index 03c025cd94..df3db09d73 100644
--- a/library/core/src/main/java/com/google/android/exoplayer2/text/ssa/SsaDialogueFormat.java
+++ b/library/core/src/main/java/com/google/android/exoplayer2/text/ssa/SsaDialogueFormat.java
@@ -76,7 +76,9 @@ import com.google.android.exoplayer2.util.Util;
           break;
       }
     }
-    return (startTimeIndex != C.INDEX_UNSET && endTimeIndex != C.INDEX_UNSET)
+    return (startTimeIndex != C.INDEX_UNSET
+            && endTimeIndex != C.INDEX_UNSET
+            && textIndex != C.INDEX_UNSET)
         ? new SsaDialogueFormat(startTimeIndex, endTimeIndex, styleIndex, textIndex, keys.length)
         : null;
   }
diff --git a/library/core/src/main/java/com/google/android/exoplayer2/text/ssa/SsaStyle.java b/library/core/src/main/java/com/google/android/exoplayer2/text/ssa/SsaStyle.java
index 6379237387..bcfa514841 100644
--- a/library/core/src/main/java/com/google/android/exoplayer2/text/ssa/SsaStyle.java
+++ b/library/core/src/main/java/com/google/android/exoplayer2/text/ssa/SsaStyle.java
@@ -119,9 +119,15 @@ import java.util.regex.Pattern;
     try {
       return new SsaStyle(
           styleValues[format.nameIndex].trim(),
-          parseAlignment(styleValues[format.alignmentIndex].trim()),
-          parseColor(styleValues[format.primaryColorIndex].trim()),
-          parseFontSize(styleValues[format.fontSizeIndex].trim()));
+          format.alignmentIndex != C.INDEX_UNSET
+              ? parseAlignment(styleValues[format.alignmentIndex].trim())
+              : SSA_ALIGNMENT_UNKNOWN,
+          format.primaryColorIndex != C.INDEX_UNSET
+              ? parseColor(styleValues[format.primaryColorIndex].trim())
+              : null,
+          format.fontSizeIndex != C.INDEX_UNSET
+              ? parseFontSize(styleValues[format.fontSizeIndex].trim())
+              : Cue.DIMEN_UNSET);
     } catch (RuntimeException e) {
       Log.w(TAG, "Skipping malformed 'Style:' line: '" + styleLine + "'", e);
       return null;
diff --git a/testdata/src/test/assets/media/ssa/style_colors b/testdata/src/test/assets/media/ssa/style_colors
index 36ce7de761..a224e7ed4d 100644
--- a/testdata/src/test/assets/media/ssa/style_colors
+++ b/testdata/src/test/assets/media/ssa/style_colors
@@ -5,22 +5,22 @@ PlayResX: 1280
 PlayResY: 720
 
 [V4+ Styles]
-Format: Name, Fontname, Fontsize, PrimaryColour, SecondaryColour, OutlineColour, BackColour, Bold, Italic, Underline, StrikeOut, ScaleX, ScaleY, Spacing, Angle, BorderStyle, Outline, Shadow, Alignment, MarginL, MarginR, MarginV, Encoding
-Style: PrimaryColourStyleHexRed        ,Roboto,50,&H000000FF,&H000000FF,&H00000000,&H00000000,0,0,0,0,100,100,0,0,1,3,0,2,50,50,70,1
-Style: PrimaryColourStyleHexYellow     ,Roboto,50,&H0000FFFF,&H000000FF,&H00000000,&H00000000,0,0,0,0,100,100,0,0,1,3,0,2,50,50,70,1
-Style: PrimaryColourStyleHexGreen      ,Roboto,50,&HFF00    ,&H000000FF,&H00000000,&H00000000,0,0,0,0,100,100,0,0,1,3,0,2,50,50,70,1
-Style: PrimaryColourStyleHexAlpha      ,Roboto,50,&HA00000FF,&H000000FF,&H00000000,&H00000000,0,0,0,0,100,100,0,0,1,3,0,2,50,50,70,1
-Style: PrimaryColourStyleDecimal       ,Roboto,50,16711680  ,&H000000FF,&H00000000,&H00000000,0,0,0,0,100,100,0,0,1,3,0,2,50,50,70,1
-Style: PrimaryColourStyleDecimalAlpha  ,Roboto,50,2164195328,&H000000FF,&H00000000,&H00000000,0,0,0,0,100,100,0,0,1,3,0,2,50,50,70,1
-Style: PrimaryColourStyleInvalid       ,Roboto,50,blue      ,&H000000FF,&H00000000,&H00000000,0,0,0,0,100,100,0,0,1,3,0,2,50,50,70,1
+Format: Name                         ,PrimaryColour
+Style: PrimaryColourStyleHexRed      ,&H000000FF
+Style: PrimaryColourStyleHexYellow   ,&H0000FFFF
+Style: PrimaryColourStyleHexGreen    ,&HFF00
+Style: PrimaryColourStyleHexAlpha    ,&HA00000FF
+Style: PrimaryColourStyleDecimal     ,16711680
+Style: PrimaryColourStyleDecimalAlpha,2164195328
+Style: PrimaryColourStyleInvalid     ,blue
 
 
 [Events]
-Format: Layer, Start, End, Style, Name, MarginL, MarginR, MarginV, Effect, Text
-Dialogue: 0,0:00:01.00,0:00:02.00,PrimaryColourStyleHexRed         ,Arnold,0,0,0,,First line in RED (&H000000FF).
-Dialogue: 0,0:00:03.00,0:00:04.00,PrimaryColourStyleHexYellow      ,Arnold,0,0,0,,Second line in YELLOW (&H0000FFFF).
-Dialogue: 0,0:00:05.00,0:00:06.00,PrimaryColourStyleHexGreen       ,Arnold,0,0,0,,Third line in GREEN (leading zeros &HFF00).
-Dialogue: 0,0:00:07.00,0:00:08.00,PrimaryColourStyleHexAlpha       ,Arnold,0,0,0,,Fourth line in RED with alpha (&H400000FF).
-Dialogue: 0,0:00:09.00,0:00:10.00,PrimaryColourStyleDecimal        ,Arnold,0,0,0,,Fifth line in BLUE (16711680).
-Dialogue: 0,0:00:11.00,0:00:12.00,PrimaryColourStyleDecimalAlpha   ,Arnold,0,0,0,,Sixth line in BLUE with alpha (2164195328).
-Dialogue: 0,0:00:13.00,0:00:14.00,PrimaryColourInvalid             ,Arnold,0,0,0,,Seventh line with invalid color .
+Format:   Start     ,End       ,Style                         ,Text
+Dialogue: 0:00:01.00,0:00:02.00,PrimaryColourStyleHexRed      ,First line in RED (&H000000FF).
+Dialogue: 0:00:03.00,0:00:04.00,PrimaryColourStyleHexYellow   ,Second line in YELLOW (&H0000FFFF).
+Dialogue: 0:00:05.00,0:00:06.00,PrimaryColourStyleHexGreen    ,Third line in GREEN (leading zeros &HFF00).
+Dialogue: 0:00:07.00,0:00:08.00,PrimaryColourStyleHexAlpha    ,Fourth line in RED with alpha (&H400000FF).
+Dialogue: 0:00:09.00,0:00:10.00,PrimaryColourStyleDecimal     ,Fifth line in BLUE (16711680).
+Dialogue: 0:00:11.00,0:00:12.00,PrimaryColourStyleDecimalAlpha,Sixth line in BLUE with alpha (2164195328).
+Dialogue: 0:00:13.00,0:00:14.00,PrimaryColourInvalid          ,Seventh line with invalid color.
diff --git a/testdata/src/test/assets/media/ssa/style_font_size b/testdata/src/test/assets/media/ssa/style_font_size
index 4266abc827..c5e4ceeaa0 100644
--- a/testdata/src/test/assets/media/ssa/style_font_size
+++ b/testdata/src/test/assets/media/ssa/style_font_size
@@ -6,13 +6,13 @@ PlayResX: 1280
 PlayResY: 720
 
 [V4+ Styles]
-Format: Name, Fontname, Fontsize, PrimaryColour, SecondaryColour, OutlineColour, BackColour, Bold, Italic, Underline, StrikeOut, ScaleX, ScaleY, Spacing, Angle, BorderStyle, Outline, Shadow, Alignment, MarginL, MarginR, MarginV, Encoding
-Style: FontSizeSmall    ,Roboto,30,  &H000000FF,&H000000FF,&H00000000,&H00000000,0,0,0,0,100,100,0,0,1,3,0,2,50,50,70,1
-Style: FontSizeBig      ,Roboto,72.2,&H000000FF,&H000000FF,&H00000000,&H00000000,0,0,0,0,100,100,0,0,1,3,0,2,50,50,70,1
+Format: Name        ,Fontsize
+Style: FontSizeSmall,30
+Style: FontSizeBig  ,72.2
 
 
 
 [Events]
-Format: Layer, Start, End, Style, Name, MarginL, MarginR, MarginV, Effect, Text
-Dialogue: 0,0:00:00.95,0:00:03.11,FontSizeSmall      ,Arnold,0,0,0,,First line with font size 30.
-Dialogue: 0,0:00:08.50,0:00:11.50,FontSizeBig        ,Arnold,0,0,0,,Second line with font size 72.2.
+Format: Start       ,End       ,Style        ,Text
+Dialogue: 0:00:00.95,0:00:03.11,FontSizeSmall,First line with font size 30.
+Dialogue: 0:00:08.50,0:00:11.50,FontSizeBig  ,Second line with font size 72.2.