gstreamer/ext/ttml/subtitle.h

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/* GStreamer
* Copyright (C) <2015> British Broadcasting Corporation
* Author: Chris Bass <dash@rd.bbc.co.uk>
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Library General Public
* License as published by the Free Software Foundation; either
* version 2 of the License, or (at your option) any later version.
*
* This library is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Library General Public License for more details.
*
* You should have received a copy of the GNU Library General Public
* License along with this library; if not, write to the
* Free Software Foundation, Inc., 51 Franklin St, Fifth Floor,
* Boston, MA 02110-1301, USA.
*/
#ifndef __GST_SUBTITLE_H__
#define __GST_SUBTITLE_H__
#include <glib.h>
#include <gst/gst.h>
#include <gst/gstminiobject.h>
G_BEGIN_DECLS
typedef struct _GstSubtitleColor GstSubtitleColor;
typedef struct _GstSubtitleStyleSet GstSubtitleStyleSet;
typedef struct _GstSubtitleElement GstSubtitleElement;
typedef struct _GstSubtitleBlock GstSubtitleBlock;
typedef struct _GstSubtitleRegion GstSubtitleRegion;
/**
* GstSubtitleWritingMode:
* @GST_SUBTITLE_WRITING_MODE_LRTB: Text progression is left-to-right,
* top-to-bottom.
* @GST_SUBTITLE_WRITING_MODE_RLTB: Text progression is right-to-left,
* top-to-bottom.
* @GST_SUBTITLE_WRITING_MODE_TBRL: Text progression is top-to-bottom,
* right-to-left.
* @GST_SUBTITLE_WRITING_MODE_TBLR: Text progression is top-to-bottom,
* left-to-right.
*
* Writing mode of text content. The values define the direction of progression
* of both inline text (#GstSubtitleElements) and blocks of text
* (#GstSubtitleBlocks).
*/
typedef enum {
GST_SUBTITLE_WRITING_MODE_LRTB,
GST_SUBTITLE_WRITING_MODE_RLTB,
GST_SUBTITLE_WRITING_MODE_TBRL,
GST_SUBTITLE_WRITING_MODE_TBLR
} GstSubtitleWritingMode;
/**
* GstSubtitleDisplayAlign:
* @GST_SUBTITLE_DISPLAY_ALIGN_BEFORE: Blocks should be aligned at the start of
* the containing region.
* @GST_SUBTITLE_DISPLAY_ALIGN_CENTER: Blocks should be aligned in the center
* of the containing region.
* @GST_SUBTITLE_DISPLAY_ALIGN_AFTER: Blocks should be aligned to the end of
* the containing region.
*
* Defines the alignment of text blocks within a region in the direction in
* which blocks are being stacked. For text that is written left-to-right and
* top-to-bottom, this corresponds to the vertical alignment of text blocks.
*/
typedef enum {
GST_SUBTITLE_DISPLAY_ALIGN_BEFORE,
GST_SUBTITLE_DISPLAY_ALIGN_CENTER,
GST_SUBTITLE_DISPLAY_ALIGN_AFTER
} GstSubtitleDisplayAlign;
/**
* GstSubtitleBackgroundMode:
* @GST_SUBTITLE_BACKGROUND_MODE_ALWAYS: Background rectangle should be visible
* at all times.
* @GST_SUBTITLE_BACKGROUND_MODE_WHEN_ACTIVE: Background rectangle should be
* visible only when text is rendered into the corresponding region.
*
* Defines whether the background rectangle of a region should be visible at
* all times or only when text is rendered within it.
*/
typedef enum {
GST_SUBTITLE_BACKGROUND_MODE_ALWAYS,
GST_SUBTITLE_BACKGROUND_MODE_WHEN_ACTIVE
} GstSubtitleBackgroundMode;
/**
* GstSubtitleOverflowMode:
* @GST_SUBTITLE_OVERFLOW_MODE_HIDDEN: If text and/or background rectangles
* flowed into the region overflow the bounds of that region, they should
* be clipped at the region boundary.
* @GST_SUBTITLE_OVERFLOW_MODE_VISIBLE: If text and/or background rectangles
* flowed into the region overflow the bounds of that region, they should be
* allowed to overflow the region boundary.
*
* Defines what should happen to text that overflows its containing region.
*/
typedef enum {
GST_SUBTITLE_OVERFLOW_MODE_HIDDEN,
GST_SUBTITLE_OVERFLOW_MODE_VISIBLE
} GstSubtitleOverflowMode;
/**
* GstSubtitleColor:
* @r: Red value.
* @g: Green value.
* @b: Blue value.
* @a: Alpha value (0 = totally transparent; 255 = totally opaque).
*
* Describes an RGBA color.
*/
struct _GstSubtitleColor {
guint8 r;
guint8 g;
guint8 b;
guint8 a;
};
/**
* GstSubtitleTextDirection:
* @GST_SUBTITLE_TEXT_DIRECTION_LTR: Text direction is left-to-right.
* @GST_SUBTITLE_TEXT_DIRECTION_RTL: Text direction is right-to-left.
*
* Defines the progression direction of unicode text that is being treated by
* the unicode bidirectional algorithm as embedded or overidden (see
* http://unicode.org/reports/tr9/ for more details of the unicode
* bidirectional algorithm).
*/
typedef enum {
GST_SUBTITLE_TEXT_DIRECTION_LTR,
GST_SUBTITLE_TEXT_DIRECTION_RTL
} GstSubtitleTextDirection;
/**
* GstSubtitleTextAlign:
* @GST_SUBTITLE_TEXT_ALIGN_START: Text areas should be rendered at the
* start of the block area, with respect to the direction in which text is
* being rendered. For text that is rendered left-to-right this corresponds to
* the left of the block area; for text that is rendered right-to-left this
* corresponds to the right of the block area.
* @GST_SUBTITLE_TEXT_ALIGN_LEFT: Text areas should be rendered at the left of
* the block area.
* @GST_SUBTITLE_TEXT_ALIGN_CENTER: Text areas should be rendered at the center
* of the block area.
* @GST_SUBTITLE_TEXT_ALIGN_RIGHT: Text areas should be rendered at the right
* of the block area.
* @GST_SUBTITLE_TEXT_ALIGN_END: Text areas should be rendered at the end of
* the block area, with respect to the direction in which text is being
* rendered. For text that is rendered left-to-right this corresponds to the
* right of the block area; for text that is rendered right-to-left this
* corresponds to end of the block area.
*
* Defines how inline text areas within a block should be aligned within the
* block area.
*/
typedef enum {
GST_SUBTITLE_TEXT_ALIGN_START,
GST_SUBTITLE_TEXT_ALIGN_LEFT,
GST_SUBTITLE_TEXT_ALIGN_CENTER,
GST_SUBTITLE_TEXT_ALIGN_RIGHT,
GST_SUBTITLE_TEXT_ALIGN_END
} GstSubtitleTextAlign;
/**
* GstSubtitleFontStyle:
* @GST_SUBTITLE_FONT_STYLE_NORMAL: Normal font style.
* @GST_SUBTITLE_FONT_STYLE_ITALIC: Italic font style.
*
* Defines styling that should be applied to the glyphs of a font used to
* render text within an inline text element.
*/
typedef enum {
GST_SUBTITLE_FONT_STYLE_NORMAL,
GST_SUBTITLE_FONT_STYLE_ITALIC
} GstSubtitleFontStyle;
/**
* GstSubtitleFontWeight:
* @GST_SUBTITLE_FONT_WEIGHT_NORMAL: Normal weight.
* @GST_SUBTITLE_FONT_WEIGHT_BOLD: Bold weight.
*
* Defines the font weight that should be applied to the glyphs of a font used
* to render text within an inline text element.
*/
typedef enum {
GST_SUBTITLE_FONT_WEIGHT_NORMAL,
GST_SUBTITLE_FONT_WEIGHT_BOLD
} GstSubtitleFontWeight;
/**
* GstSubtitleTextDecoration:
* @GST_SUBTITLE_TEXT_DECORATION_NONE: Text should not be decorated.
* @GST_SUBTITLE_TEXT_DECORATION_UNDERLINE: Text should be underlined.
*
* Defines the decoration that should be applied to the glyphs of a font used
* to render text within an inline text element.
*/
typedef enum {
GST_SUBTITLE_TEXT_DECORATION_NONE,
GST_SUBTITLE_TEXT_DECORATION_UNDERLINE
} GstSubtitleTextDecoration;
/**
* GstSubtitleUnicodeBidi:
* @GST_SUBTITLE_UNICODE_BIDI_NORMAL: Text should progress according the the
* default behaviour of the Unicode bidirectional algorithm.
* @GST_SUBTITLE_UNICODE_BIDI_EMBED: Text should be treated as being embedded
* with a specific direction (given by a #GstSubtitleTextDecoration value
* defined elsewhere).
* @GST_SUBTITLE_UNICODE_BIDI_OVERRIDE: Text should be forced to have a
* specific direction (given by a #GstSubtitleTextDecoration value defined
* elsewhere).
*
* Defines directional embedding or override according to the Unicode
* bidirectional algorithm. See http://unicode.org/reports/tr9/ for more
* details of the Unicode bidirectional algorithm.
*/
typedef enum {
GST_SUBTITLE_UNICODE_BIDI_NORMAL,
GST_SUBTITLE_UNICODE_BIDI_EMBED,
GST_SUBTITLE_UNICODE_BIDI_OVERRIDE
} GstSubtitleUnicodeBidi;
/**
* GstSubtitleWrapping:
* @GST_SUBTITLE_WRAPPING_ON: Lines that overflow the region boundary should be
* wrapped.
* @GST_SUBTITLE_WRAPPING_OFF: Lines that overflow the region boundary should
* not be wrapped.
*
* Defines how a renderer should treat lines of text that overflow the boundary
* of the region into which they are being rendered.
*/
typedef enum {
GST_SUBTITLE_WRAPPING_ON,
GST_SUBTITLE_WRAPPING_OFF
} GstSubtitleWrapping;
/**
* GstSubtitleMultiRowAlign:
* @GST_SUBTITLE_MULTI_ROW_ALIGN_AUTO: Lines should be aligned according to the
* value of #GstSubtitleTextAlign associated with that text.
* @GST_SUBTITLE_MULTI_ROW_ALIGN_START: Lines should be aligned at their
* starting edge. The edge that is considered the starting edge depends upon
* the direction of that text.
* @GST_SUBTITLE_MULTI_ROW_ALIGN_CENTER: Lines should be center-aligned.
* @GST_SUBTITLE_MULTI_ROW_ALIGN_END: Lines should be aligned at their trailing
* edge. The edge that is considered the trailing edge depends upon the
* direction of that text.
*
* Defines how multiple 'rows' (i.e, lines) in a block should be aligned
* relative to each other.
*
* This is based upon the ebutts:multiRowAlign attribute defined in the
* EBU-TT-D specification.
*/
typedef enum {
GST_SUBTITLE_MULTI_ROW_ALIGN_AUTO,
GST_SUBTITLE_MULTI_ROW_ALIGN_START,
GST_SUBTITLE_MULTI_ROW_ALIGN_CENTER,
GST_SUBTITLE_MULTI_ROW_ALIGN_END
} GstSubtitleMultiRowAlign;
/**
* GstSubtitleStyleSet:
* @text_direction: Defines the direction of text that has been declared by the
* #GstSubtitleStyleSet:unicode_bidi attribute to be embbedded or overridden.
* Applies to both #GstSubtitleBlocks and #GstSubtitleElements.
* @font_family: The name of the font family that should be used to render the
* text of an inline element. Applies only to #GstSubtitleElements.
* @font_size: The size of the font that should be used to render the text
* of an inline element. The size is given as a multiple of the display height,
* where 1.0 equals the height of the display. Applies only to
* #GstSubtitleElements.
* @line_height: The inter-baseline separation between lines generated when
* rendering inline text elements within a block area. The height is given as a
* multiple of the the overall display height, where 1.0 equals the height of
* the display. Applies only to #GstSubtitleBlocks.
* @text_align: Controls the alignent of lines of text within a block area.
* Note that this attribute does not control the alignment of lines relative to
* each other within a block area: that is determined by
* #GstSubtitleStyleSet:multi_row_align. Applies only to #GstSubtitleBlocks.
* @color: The color that should be used when rendering the text of an inline
* element. Applies only to #GstSubtitleElements.
* @background_color: The color of the rectangle that should be rendered behind
* the contents of a #GstSubtitleRegion, #GstSubtitleBlock or
* #GstSubtitleElement.
* @font_style: The style of the font that should be used to render the text
* of an inline element. Applies only to #GstSubtitleElements.
* @font_weight: The weight of the font that should be used to render the text
* of an inline element. Applies only to #GstSubtitleElements.
* @text_decoration: The decoration that should be applied to the text of an
* inline element. Applies only to #GstSubtitleElements.
* @unicode_bidi: Controls how unicode text within a block or inline element
* should be treated by the unicode bidirectional algorithm. Applies to both
* #GstSubtitleBlocks and #GstSubtitleElements.
* @wrap_option: Defines whether or not automatic line breaking should apply to
* the lines generated when rendering a block of text elements. Applies only to
* #GstSubtitleBlocks.
* @multi_row_align: Defines how 'rows' (i.e., lines) within a text block
* should be aligned relative to each other. Note that this attribute does not
* determine how a block of text is aligned within that block area: that is
* determined by @text_align. Applies only to #GstSubtitleBlocks.
* @line_padding: Defines how much horizontal padding should be added on the
* start and end of each rendered line; this allows the insertion of space
* between the start/end of text lines and their background rectangles for
* better-looking subtitles. This is based upon the ebutts:linePadding
* attribute defined in the EBU-TT-D specification. Applies only to
* #GstSubtitleBlocks.
* @origin_x: The horizontal origin of a region into which text blocks may be
* rendered. Given as a multiple of the overall display width, where 1.0 equals
* the width of the display. Applies only to #GstSubtitleRegions.
* @origin_y: The vertical origin of a region into which text blocks may be
* rendered. Given as a multiple of the overall display height, where 1.0
* equals the height of the display. Applies only to #GstSubtitleRegions.
* @extent_w: The horizontal extent of a region into which text blocks may be
* rendered. Given as a multiple of the overall display width, where 1.0 equals
* the width of the display. Applies only to #GstSubtitleRegions.
* @extent_h: The vertical extent of a region into which text blocks may be
* rendered. Given as a multiple of the overall display height, where 1.0
* equals the height of the display. Applies only to #GstSubtitleRegions.
* @display_align: The alignment of generated text blocks in the direction in
* which blocks are being stacked. For text that flows left-to-right and
* top-to-bottom, for example, this corresponds to the vertical alignment of
* text blocks. Applies only to #GstSubtitleRegions.
* @padding_start: The horizontal indent of text from the leading edge of a
* region into which blocks may be rendered. Given as a multiple of the overall
* display width, where 1.0 equals the width of the display. Applies only to
* #GstSubtitleRegions.
* @padding_end: The horizontal indent of text from the trailing edge of a
* region into which blocks may be rendered. Given as a multiple of the overall
* display width, where 1.0 equals the width of the display. Applies only to
* #GstSubtitleRegions.
* @padding_before: The vertical indent of text from the top edge of a region
* into which blocks may be rendered. Given as a multiple of the overall
* display height, where 1.0 equals the height of the display. Applies only to
* #GstSubtitleRegions.
* @padding_after: The vertical indent of text from the bottom edge of a
* region into which blocks may be rendered. Given as a multiple of the overall
* display height, where 1.0 equals the height of the display. Applies only to
* #GstSubtitleRegions.
* @writing_mode: Defines the direction in which both inline elements and
* blocks should be stacked when rendered into an on-screen region. Applies
* only to #GstSubtitleRegions.
* @show_background: Defines whether the background of a region should be
* displayed at all times or only when it has text rendered into it. Applies
* only to #GstSubtitleRegions.
* @overflow: Defines what should happen if text and background rectangles
* generated by rendering text blocks overflow the size of their containing
* region. Applies only to #GstSubtitleRegions.
* @fill_line_gap: Controls whether the rendered backgrounds of text elements
* in a line fill the whole space between that line and adjacent lines or
* extends only to the font height of the text in the individual elements (thus
* this field controls whether or not there are gaps between backgrounds
* through which the underlying video can be seen). Applies only to
* #GstSubtitleBlocks.
*
* Holds a set of attributes that describes the styling and layout that apply
* to #GstSubtitleRegion, #GstSubtitleBlock and/or #GstSubtitleElement objects.
*
* Note that, though each of the above object types have an associated
* #GstSubtitleStyleSet, not all attributes in a #GstSubtitleStyleSet type
* apply to all object types: #GstSubtitleStyleSet:overflow applies only to
* #GstSubtitleRegions, for example, while #GstSubtitleStyleSet:font_style
* applies only to #GstSubtitleElements. Some attributes apply to multiple
* object types: #GstSubtitleStyleSet:background_color, for example, applies to
* all object types. The types to which each attribute applies is given in the
* description of that attribute below.
*/
struct _GstSubtitleStyleSet
{
GstMiniObject mini_object;
GstSubtitleTextDirection text_direction;
gchar *font_family;
gdouble font_size;
gdouble line_height;
GstSubtitleTextAlign text_align;
GstSubtitleColor color;
GstSubtitleColor background_color;
GstSubtitleFontStyle font_style;
GstSubtitleFontWeight font_weight;
GstSubtitleTextDecoration text_decoration;
GstSubtitleUnicodeBidi unicode_bidi;
GstSubtitleWrapping wrap_option;
GstSubtitleMultiRowAlign multi_row_align;
gdouble line_padding;
gdouble origin_x, origin_y;
gdouble extent_w, extent_h;
GstSubtitleDisplayAlign display_align;
gdouble padding_start, padding_end, padding_before, padding_after;
GstSubtitleWritingMode writing_mode;
GstSubtitleBackgroundMode show_background;
GstSubtitleOverflowMode overflow;
gboolean fill_line_gap;
/*< private >*/
gpointer _gst_reserved[GST_PADDING];
};
GType gst_subtitle_style_set_get_type (void);
GstSubtitleStyleSet * gst_subtitle_style_set_new (void);
/**
* gst_subtitle_style_set_ref:
* @style_set: A #GstSubtitleStyleSet.
*
* Increments the refcount of @style_set.
*
* Returns: (transfer full): @style_set.
*/
static inline GstSubtitleStyleSet *
gst_subtitle_style_set_ref (GstSubtitleStyleSet * style_set)
{
return (GstSubtitleStyleSet *)
gst_mini_object_ref (GST_MINI_OBJECT_CAST (style_set));
}
/**
* gst_subtitle_style_set_unref:
* @style_set: (transfer full): A #GstSubtitleStyleSet.
*
* Decrements the refcount of @style_set. If the refcount reaches 0, @style_set
* will be freed.
*/
static inline void
gst_subtitle_style_set_unref (GstSubtitleStyleSet * style_set)
{
gst_mini_object_unref (GST_MINI_OBJECT_CAST (style_set));
}
/**
* GstSubtitleElement:
* @mini_object: The parent #GstMiniObject.
* @style_set: Styling associated with this element.
* @text_index: Index into the #GstBuffer associated with this
* #GstSubtitleElement; the index identifies the #GstMemory within the
* #GstBuffer that holds the #GstSubtitleElement's text.
* @suppress_whitespace: Indicates whether or not a renderer should suppress
* whitespace in the element's text.
*
* Represents an inline text element.
*
* In TTML this would correspond to inline text resulting from a &lt;span&gt;
* element, an anonymous span (e.g., text within a &lt;p&gt; tag), or a
* &lt;br&gt; element.
*/
struct _GstSubtitleElement
{
GstMiniObject mini_object;
GstSubtitleStyleSet *style_set;
guint text_index;
gboolean suppress_whitespace;
/*< private >*/
gpointer _gst_reserved[GST_PADDING];
};
GType gst_subtitle_element_get_type (void);
GstSubtitleElement * gst_subtitle_element_new (GstSubtitleStyleSet * style_set,
guint text_index, gboolean suppress_whitespace);
/**
* gst_subtitle_element_ref:
* @element: A #GstSubtitleElement.
*
* Increments the refcount of @element.
*
* Returns: (transfer full): @element.
*/
static inline GstSubtitleElement *
gst_subtitle_element_ref (GstSubtitleElement * element)
{
return (GstSubtitleElement *)
gst_mini_object_ref (GST_MINI_OBJECT_CAST (element));
}
/**
* gst_subtitle_element_unref:
* @element: (transfer full): A #GstSubtitleElement.
*
* Decrements the refcount of @element. If the refcount reaches 0, @element
* will be freed.
*/
static inline void
gst_subtitle_element_unref (GstSubtitleElement * element)
{
gst_mini_object_unref (GST_MINI_OBJECT_CAST (element));
}
/**
* GstSubtitleBlock:
* @mini_object: The parent #GstMiniObject.
* @style_set: Styling associated with this block.
*
* Represents a text block made up of one or more inline text elements (i.e.,
* one or more #GstSubtitleElements).
*
* In TTML this would correspond to the block of text resulting from the inline
* elements within a single &lt;p&gt;.
*/
struct _GstSubtitleBlock
{
GstMiniObject mini_object;
GstSubtitleStyleSet *style_set;
/*< private >*/
GPtrArray *elements;
gpointer _gst_reserved[GST_PADDING];
};
GType gst_subtitle_block_get_type (void);
GstSubtitleBlock * gst_subtitle_block_new (GstSubtitleStyleSet * style_set);
void gst_subtitle_block_add_element (
GstSubtitleBlock * block,
GstSubtitleElement * element);
guint gst_subtitle_block_get_element_count (const GstSubtitleBlock * block);
GstSubtitleElement * gst_subtitle_block_get_element (
const GstSubtitleBlock * block, guint index);
/**
* gst_subtitle_block_ref:
* @block: A #GstSubtitleBlock.
*
* Increments the refcount of @block.
*
* Returns: (transfer full): @block.
*/
static inline GstSubtitleBlock *
gst_subtitle_block_ref (GstSubtitleBlock * block)
{
return (GstSubtitleBlock *)
gst_mini_object_ref (GST_MINI_OBJECT_CAST (block));
}
/**
* gst_subtitle_block_unref:
* @block: (transfer full): A #GstSubtitleBlock.
*
* Decrements the refcount of @block. If the refcount reaches 0, @block will
* be freed.
*/
static inline void
gst_subtitle_block_unref (GstSubtitleBlock * block)
{
gst_mini_object_unref (GST_MINI_OBJECT_CAST (block));
}
/**
* GstSubtitleRegion:
* @mini_object: The parent #GstMiniObject.
* @style_set: Styling associated with this region.
*
* Represents an on-screen region in which is displayed zero or more
* #GstSubtitleBlocks.
*
* In TTML this corresponds to a &lt;region&gt; into which zero or more
* &lt;p&gt;s may be rendered. A #GstSubtitleRegion allows a background
* rectangle to be displayed in a region area even if no text blocks are
* rendered into it, as per the behaviour allowed by TTML regions whose
* tts:showBackground style attribute is set to "always".
*/
struct _GstSubtitleRegion
{
GstMiniObject mini_object;
GstSubtitleStyleSet *style_set;
/*< private >*/
GPtrArray *blocks;
gpointer _gst_reserved[GST_PADDING];
};
GType gst_subtitle_region_get_type (void);
GstSubtitleRegion * gst_subtitle_region_new (GstSubtitleStyleSet * style_set);
void gst_subtitle_region_add_block (
GstSubtitleRegion * region,
GstSubtitleBlock * block);
guint gst_subtitle_region_get_block_count (const GstSubtitleRegion * region);
const GstSubtitleBlock * gst_subtitle_region_get_block (
const GstSubtitleRegion * region, guint index);
/**
* gst_subtitle_region_ref:
* @region: A #GstSubtitleRegion.
*
* Increments the refcount of @region.
*
* Returns: (transfer full): @region.
*/
static inline GstSubtitleRegion *
gst_subtitle_region_ref (GstSubtitleRegion * region)
{
return (GstSubtitleRegion *)
gst_mini_object_ref (GST_MINI_OBJECT_CAST (region));
}
/**
* gst_subtitle_region_unref:
* @region: (transfer full): A #GstSubtitleRegion.
*
* Decrements the refcount of @region. If the refcount reaches 0, @region will
* be freed.
*/
static inline void
gst_subtitle_region_unref (GstSubtitleRegion * region)
{
gst_mini_object_unref (GST_MINI_OBJECT_CAST (region));
}
G_END_DECLS
#endif /* __GST_SUBTITLE_H__ */