Show Menu
TOPICS×

Control closed-caption styling

You can provide styling information for closed-caption tracks using the TextFormat class. This sets the style for any closed captions that are displayed by your player.
This class encapsulates closed-caption styling information such as the font type, size, color, and background opacity. An associated helper class, TextFormatBuilder , facilitates working with closed-caption style settings.

Set closed-caption styles

You can style the closed-caption text with TVSDK methods.
  1. Wait for the media player to be in at least the PREPARED state.
  2. Create a TextFormatBuilder instance.
    You can provide all the closed-caption styling parameters now or set them later.
    TVSDK encapsulates closed-caption styling information in the TextFormat interface. The TextFormatBuilder class creates objects that implement this interface.
    public TextFormatBuilder( 
       Font font, 
       Size size, 
       FontEdge fontEdge, 
       Color fontColor, 
       Color backgroundColor, 
       Color fillColor, 
       Color edgeColor, 
       int fontOpacity, 
       int backgroundOpacity, 
       int fillOpacity)
    
    
  3. To obtain a reference to an object that implements the TextFormat interface, call the TextFormatBuilder.toTextFormat public method.
    This returns a TextFormat object that can be applied to the media player.
    public TextFormat toTextFormat()
    
    
  4. Optionally get the current closed-caption style settings by doing one of the following:
    • Get all the style settings with MediaPlayer.getCCStyle .
      The return value is an instance of the TextFormat interface.
      /** 
      * @return the current closed captioning style.  
      * If no style was previously set, it returns a TextFormat object 
      * with default values for each attribute. 
      * @throws IllegalStateException if media player was already released. 
      */ 
      public TextFormat getCCStyle() throws IllegalStateException;
      
      
    • Get the settings one at a time through the TextFormat interface getter methods.
      public Color getFontColor(); 
      public Color getBackgroundColor(); 
      public Color getFillColor(); // retrieve the font fill color 
      public Color getEdgeColor(); // retrieve the font edge color 
      public Size getSize(); // retrieve the font size 
      public FontEdge getFontEdge(); // retrieve the font edge type 
      public Font getFont(); // retrieve the font type 
      public int getFontOpacity(); 
      public int getBackgroundOpacity();
      
      
  5. To change the style settings, do one of the following:
    You cannot change the size for WebVTT captions.
    • Use the setter method MediaPlayer.setCCStyle , passing an instance of the TextFormat interface:
      /** 
      * Sets the closed captioning style. Used to control the closed captioning font, 
      * size, color, edge and opacity.  
      * 
      * This method is safe to use even if the current media stream doesn't have closed 
      * captions. 
      * 
      * @param textFormat 
      * @throws IllegalStateException 
      */ 
      public void setCCStyle(TextFormat textFormat) throws IllegalStateException;
      
      
    • Use the TextFormatBuilder class, which defines individual setter methods.
      The TextFormat interface defines an immutable object so there are only getter methods and no setters. You can set the closed-caption styling parameters only with the TextFormatBuilder class:
      // set font type 
      public void setFont(Font font)  
      public void setBackgroundColor(Color backgroundColor) 
      public void setFillColor(Color fillColor) 
      // set the font-edge color 
      public void setEdgeColor(Color edgeColor)  
      // set the font size 
      public void setSize(Size size)  
      // set the font edge type 
      public void setFontEdge(FontEdge fontEdge)  
      public void setFontOpacity(int fontOpacity) 
      public void setBackgroundOpacity(int backgroundOpacity) 
      // set the font-fill opacity level 
      public void setFillOpacity(int fillOpacity)  
      public void setFontColor(Color fontColor)
      
      
Setting the closed-caption style is an asynchronous operation, so it might take up to a few seconds for the changes to appear on the screen.

Closed caption styling options

You can specify several caption styling options, and these options override the style options in the original captions
public TextFormatBuilder(
 Font font,
 Size size,
 FontEdge fontEdge,
 Color fontColor,
 Color backgroundColor,
 Color fillColor,
 Color edgeColor,
 int fontOpacity,
 int backgroundOpacity,
 int fillOpacity,
 String bottomInset)

# In options that define default values (for example, DEFAULT), that value refers to what the setting was when the caption was originally specified.
Format Description
Font
The font type.
Can be set only to a value that is defined by the TextFormat.Font enumeration and represents, for example, monospaced with or without serifs.
Tip: The actual fonts that are available on a device might vary, and substitutions are used when necessary. Monospace with serifs is typically used as a substitute, although this substitution can be system specific.
Size
The caption's size.
Can be set only to a value defined by the TextFormat.Size enumeration:
  • MEDIUM - The standard size
  • LARGE - Approximately 30% larger than medium
  • SMALL - Approximately 30% smaller than medium
  • DEFAULT - The default size for the caption; the same as medium
Font edge
The effect used for the font edge, such as raised or none.
Can be set only to a value that is defined by the TextFormat.FontEdge enumeration.
Font color
The font color.
Can be set only to a value defined by the TextFormat.Color enumeration.
Edge color
The color of the edge effect.
Can be set to any of the values that are available for the font color.
Background color
The background character cell color.
Can be set only to values that are available for the font color.
Fill color
The color of the background of the window in which the text is located.
Can be set to any of the values that are available for the font color.
Font opacity
The opacity of the text.
Expressed as a percentage from 0 (fully transparent) to 100 (fully opaque). DEFAULT_OPACITY for the font is 100.
Background opacity
The opacity of the background character cell.
Expressed as a percentage from 0 (fully transparent) to 100 (fully opaque). DEFAULT_OPACITY for the background is 100.
Fill opacity
The opacity of the background of the caption window.
Expressed as a percentage from 0 (fully transparent) to 100 (fully opaque). DEFAULT_OPACITY for fill is 0.

Caption formatting examples

You can specify closed-caption formatting.
Example 1: Specify format values explicitly
private final MediaPlayer.PlaybackEventListener  
  _playbackEventListener = new MediaPlayer.PlaybackEventListener() { 
    @Override 
    public void onPrepared() { 
        // Set CC style. 
        TextFormat tf = new TextFormatBuilder(TextFormat.Font.DEFAULT, 
        TextFormat.Size.DEFAULT, 
        TextFormat.FontEdge.DEFAULT, 
        TextFormat.Color.DEFAULT, 
        TextFormat.Color.DEFAULT, 
        TextFormat.Color.DEFAULT, 
        TextFormat.Color.DEFAULT, 
        TextFormat.DEFAULT_OPACITY, 
        TextFormat.DEFAULT_OPACITY, 
        TextFormat.DEFAULT_OPACITY).toTextFormat(); 
        mediaPlayer.setCCStyle(tf); 
        ... 
    } 
} 


Example 2: Specify format values in parameters
/** 
* Constructor using parameters to initialize a TextFormat. 
* 
* @param font 
* The desired font. 
* @param size 
* The desired text size. 
* @param fontEdge 
* The desired font edge. 
* @param fontColor 
* The desired font color. 
* @param backgroundColor 
* The desired background color. 
* @param fillColor 
* The desired fill color. 
* @param edgeColor 
* The desired color to draw the text edges. 
* @param fontOpacity  
* The desired font opacity. 
* @param backgroundOpacity 
* The desired background opacity. 
* @param fillOpacity 
* The desired fill opacity.  
*/ 
public TextFormatBuilder( 
    Font font, Size size, FontEdge fontEdge, 
    Color fontColor, Color backgroundColor,  
    Color fillColor, Color edgeColor, 
    int fontOpacity, int backgroundOpacity, 
    int fillOpacity); 
 
/** 
* Creates a TextFormat with the parameters supplied to this builder. 
*/ 
public TextFormat toTextFormat(); 
 
/** 
* Sets the text font. 
* @param font The desired font 
* @return This builder object to allow chaining calls 
*/ 
public TextFormatBuilder setFont(Font font); 
...