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CCK

DefineBitsLossless2

Tag Info
Tag Number: 
36
Tag Type: 
Define
Tag Flash Version: 
3
Brief Description: 

Defines an RGBA bitmap compressed using ZLIB (similar to the PNG format).

Tag Structure: 

Tag Structure: 
struct swf_definebitslossless {
	swf_long_tag		f_tag;		/* 20 or 36 */
	unsigned short		f_image_id;
	unsigned char		f_format;	/* 3, 4 or 5 */
	unsigned short		f_width;
	unsigned short		f_height;
	if(f_format == 3) {
		unsigned char	f_colormap_count;
		if(f_tag == DefineBitsLossless) {
			swf_rgb		f_colormap[f_colormap_count];
		}
		else {
			swf_rgba	f_colormap[f_colormap_count];
		}
		unsigned char	f_indices[((f_width + 3) & -4) * f_height];
	}
	else {
		if(f_tag == DefineBitsLossless) {
			swf_xrgb	f_bitmap[f_width * f_height];
		}
		else {
			swf_argb	f_bitmap[f_width * f_height];
		}
	}
};

These tags declares a loss-less image bitmap. It has a small header followed by an optional colormap and the bitmap data. When we have a colormap, the bitmap data is an array of indices in the colormap aligned to 4 bytes on a per row basis.

There are three supported formats:

Format
No.
(bits)
Color Format Comments
Without
Alpha
With
Alpha
3
(8 bits(1))
RGB RGBA Uses a colormap with up to 256 entries of 24 or 32 bits colors.
4
(16 bits(1))
RGB555 RGB555 There is no alpha available in this format. The data is saved in big endian (it is NOT a U16 like some documentations say it is). The colors looks like this (most significant bit first): 0RRRRRGGGGGBBBBB. You should certainly always use the DefineBitsLossless tag for this format.
5
(32 bits)
XRGB ARGB Uses a strange order for the components. Most probably because the alpha was added later and thus inserted in place of the X to keep some backward compatibility with older versions.

(1) the data must be 32 bits aligned (4 bytes) on a per row basis. In 8 bits, you may have to add up to three bytes at the end of each row ( 4 - width & 3 when width & 3 is not zero.). In 16 bits, you need to add two bytes at the end of each row when the width of the image is odd.

The f_colormap, f_indices and f_bitmap are all compressed with the ZLIB scheme.

WATCH OUT: the f_colormap and f_indices are compressed as one large block.

WARNING: These tags require you to save the swf_tag in long format (i.e. f_tag_and_size & 0x3F == 0x3F even if the size is smaller than 63.)

WARNING: An image cannot always be scaled more than 64×. Trying to enlarge it more may result in a rectangle of one color. The 64× is cumulative. So a sprite of an image × 3 inside another sprite × 10 inside another sprite × 4 results in scaling of 120 and this is likely to break the image. This seems to be true mainly when there is a rotation or skew.

DefineBitsJPEG3

Tag Info
Tag Number: 
35
Tag Type: 
Define
Tag Flash Version: 
3
Brief Description: 

Defines a complete JPEG image, i.e. a verbatim JPEG image file. The JPEG image is then followed by an alpha channel. Note that the alpha channel uses the Z-lib compression. Since Flash 10, the supported image formats are JPEG, PNG and GIF89a.

Tag Structure: 

Tag Structure: 
struct swf_definebitsjpeg {
	swf_long_tag		f_tag;		/* 6, 21, 35 or 90 */
	unsigned short		f_image_id;
	if(f_tag == DefineBitsJPEG3 + f_tag == DefineBitsJPEG4) {
		/* sizeof(f_encoding_tables) + sizeof(f_image_data) + 2 when JPEG4 */
		unsigned long		f_offset_to_alpha;
	}
	if(f_tag == DefineBitsJPEG4) {
		unsigned short fixed	f_deblocking_filter_parameter;
	}
	if(f_tag != DefineBitsJPEG) {
		/* when DefineBitsJPEG, use JPEGTables instead */
		unsigned char		f_encoding_tables[<variable size>];
	}
	unsigned char		f_image_data[<variable size>];
	if(f_tag == DefineBitsJPEG3 || f_tag == DefineBitsJPEG41) {
		unsigned char		f_alpha[<variable size>];
	}
};
  • 1. JPEG4 optionally accepts the f_alpha field. [To be verified]

These tags define an image saved using the JPEG compression scheme.

DefineBitsJPEG (V1.0) does not include the encoding tables which are defined in the unique JPEGTables tag instead. All the DefineBitsJPEG of an SWF file use the only JPEGTables tag. Yes... This means you need a tool that is capable of reusing the same tables over and over again to make sure that all your DefineBitsJPEGs work properly (or use it just once.)

The other tags incorporate their own version of the JPEG encoding tables.

The DefineBitsJPEG3 and DefineBitsJPEG4 support an alpha channel bit plane (8 bits.) This alpha channel is compressed using the ZLIB scheme as defined with the DefineBitsLossless image formats and appears at the end.

With Flash 10, DefineBitsJPEG4 was introduced to support a deblocking filter parameter. This parameter should be set to a value between 0.0 and 1.0 (0x0000 and 0x0100--so really a value from 0 to 256 inclusive.)

WARNING: These tags require you to save the swf_tag in long format (i.e. f_tag_and_size & 0x3F == 0x3F even if the size is smaller.)

f_encoding should include 0xFF 0xDB and 0xFF 0xC4 entries.

The f_image_data buffer should include the 0xFF 0xE0, 0xFF 0xC0 and 0xFF 0xDA.

Since Flash 10 the f_encoding and f_image_data fields defined in the DefineBitsJPEG2, DefineBitsJPEG3 and DefineBitsJPEG4 tags, are viewed as one single large buffer and thus it can be a verbatim JPEG, PNG or GIF89a file.

When the buffer represents a JPEG, it starts with 0xFF 0xD8 and ends with 0xFF 0xD9.

When the buffer represents a PNG, it starts with 0x89 0x50 'P' 0x4E 'N' 0x47 'G' 0x0D '\r' 0x0A '\n' 0x1A '^Z' 0x0A '\n'.

When the buffer represents a GIF89a, it starts with 0x47 'G' 0x49 'I' 0x46 'F' 0x38 '8' 0x39 '9' 0x61 'a'.

WARNING: Up to Flash 7, both buffers (f_encoding and f_image_data) need to start with a 0xFF 0xD8 (SOI) and end with 0xFF 0xD9 (EOI). Since Flash 8, this practice should not be used anymore.

The f_alpha buffer is compressed with ZLIB as defined in the DefineBitsLossless tag (this is similar to the PNG format). WARNING: this field only works with JPEG data. A PNG or GIF89a cannot make use of this field (but they can make use of their own alpha channel.)

Note:   The Flash 10 documentation says that the f_alpha field is optional. This means you can save a JPEG in a DefineBitsJPEG4 without the Alpha Channel but still make use of the deblocking filter parameter. Before Flash 10, use DefineBitsJPEG2 instead (safer).

The DefineBitsJPEG tag may fail if it includes any encoding tables. These tables shall be defined within the JPEGTables instead.

Note that the Adobe SWF player better enforces the correctness of these tags since version 8. Some older movies may not work properly with Flash Player 8+.

DefineText2

Tag Info
Tag Number: 
33
Tag Type: 
Define
Tag Flash Version: 
3
Brief Description: 

Defines a text of characters displayed using a font. Transparency is supported with this tag.

Tag Structure: 

Tag Structure: 
struct swf_definetext {
	swf_tag			f_tag;		/* 11 or 33 */
	unsigned short		f_text_id;
	swf_rect		f_rect;
	swf_matrix		f_matrix;
	unsigned char		f_glyph_bits;
	unsigned char		f_advance_bits;
	swf_text_record		f_text_record;
};

Define an object of text so the SWF player can draw a string. The only difference between the DefineText and DefineText2 tags is that the latter supports RGBA colors. This can be seen in one of the swf_text_record structures.

Since version 8 it is possible to define extraneous parameters when defining a CSMTextSettings tag referencing a DefineText or DefineText2.

Appendix B — History of the SSWF reference

Dec 2, 2009

Moved the monolithic documentation to a multi-page hierarchical document that includes everything we had before plus many links, many terms attached to all pages (tags, English words.) And revision of most of the text for better English and clarification in some places.

Strengthen the formatting with CCK fields so all declarations look alike.

Broken up the actions from one large table to a set of pages.

Dec 14, 2008

Started work on the Load() feature of the SSWF library. This helped fixing several small mistakes in the documentation.

May 18, 2008

Fixed the ...

SWF ARGB (swf_argb)

SWF Structure Info
Tag Flash Version: 
1
SWF Structure: 
struct swf_argb {
	unsigned char		f_alpha;1
	unsigned char		f_red;
	unsigned char		f_green;
	unsigned char		f_blue;
};
  • 1. 0 represents a fully transparent color, 255 represents a solid color.

The color components can be set to any value from 0 (no intensity) to maximum intensity (255).1

It is important to note that even fully transparent pixels may not have their red, green, blue components set to 0. This is useful if you want to add a value to the alpha channel using one of the color transformation matrices. In that case, using all 0's would generate a black color.

  • 1. For some PNG images, the red, green and blue colors may need to be multiplied by their alpha channel value before saved. Use the following formula to compute the proper values:

       f_red = orginal red * f_alpha / 255

This format was added to be mostly compatible with the old PNG format (XRGB).

DefineShape3

Tag Info
Tag Number: 
32
Tag Type: 
Define
Tag Flash Version: 
3
Brief Description: 

Brief Description: 

Define a simple geometric shape.

Tag Structure: 

Tag Structure: 
struct swf_defineshape {
	swf_tag				f_tag;		/* 2, 22, 32, 46, 83, or 84 */
	unsigned short			f_shape_id;
	swf_rect			f_rect;
	is_morph = f_tag == DefineMorphShape || f_tag == DefineMorphShape2;
	has_strokes = f_tag == DefineShape4 || f_tag == DefineMorphShape2;
	if(is_morph) {
		swf_rect			f_rect_morph;
	}
	if(has_strokes) {
		swf_rect			f_stroke_rect;
		if(is_morph) {
			swf_rect			f_stroke_rect_morph;
		}
		unsigned			f_define_shape_reserved : 6;
		unsigned			f_define_shape_non_scaling_strokes : 1;
		unsigned			f_define_shape_scaling_strokes : 1;
	}
	if(is_morph) {
		unsigned long			f_offset_morph;
		swf_morph_shape_with_style	f_morph_shape_with_style;
	}
	else {
		swf_shape_with_style		f_shape_with_style;
	}
};

These are probably the most important tags in this reference. They are used to define a shape using Bezier curves and lines with different styles. The DefineShape of V1.0 is usually enough unless you need a large number of styles or you want to specify colors with an alpha channel (RGBA).

The DefineMorphShape and DefineMorphShape2 can be used to render an intermediate shape between two defined shapes. All the points and control points of both shapes must match. This is because the rendering of the morphing shapes is just an interpolation between both shapes points and control points positions. The interpolation is a very simple linear function (note however that you still can use a non-linear transformation effect in the end.) Most of the parameters in a shape definition are doubled when this tag is used. It otherwise looks very similar.

The f_stroke_rect and f_stroke_rect_morph rectangles define the boundaries around their respective shapes without the line strokes (excluding the thickness of the line.)

The f_define_shape_non_scaling_strokes flag should be set to 1 if at least one of the line strokes always stays the same while morphing.

The f_define_shape_scaling_strokes flag should be set to 1 if at least one of the line strokes is changing while morphing.

The f_offset_morph 32 bits value gives the offset from after that value to the start of the second shape (the shape to morph to.) In other words, this value can be used to skip the styles and the first shape at once.

RemoveObject2

Tag Info
Tag Number: 
28
Tag Type: 
Display
Tag Flash Version: 
3
Brief Description: 

Remove the object at the specified level. This tag should be used in movies version 3 and over since it compressed better than the standard RemoveObject tag. Note that a PlaceObject2 can also be used for this task.

Tag Structure: 

Tag Structure: 
struct swf_removeobject {
	swf_tag			f_tag;		/* 5 or 28 */
	if(f_tag == RemoveObject) {
		unsigned short		f_object_id_ref;
	}
	unsigned short		f_depth;
};

Remove the specified object from the display list. If the same object was placed multiple times at the specified depth1 only the last copy is removed. When only a depth is specified, the last object placed at that depth is removed from the list. Note that since version 3 it is possible to use the PlaceObject2 in order to replace an object at a given depth without having to remove it first.

  • 1. It is illegal, yet possible, to place more than one object at the same depth.

DefineShape2

Tag Info
Tag Number: 
22
Tag Type: 
Define
Tag Flash Version: 
2
Brief Description: 

Brief Description: 

Define a simple geometric shape.

Tag Structure: 

Tag Structure: 
struct swf_defineshape {
	swf_tag				f_tag;		/* 2, 22, 32, 46, 83, or 84 */
	unsigned short			f_shape_id;
	swf_rect			f_rect;
	is_morph = f_tag == DefineMorphShape || f_tag == DefineMorphShape2;
	has_strokes = f_tag == DefineShape4 || f_tag == DefineMorphShape2;
	if(is_morph) {
		swf_rect			f_rect_morph;
	}
	if(has_strokes) {
		swf_rect			f_stroke_rect;
		if(is_morph) {
			swf_rect			f_stroke_rect_morph;
		}
		unsigned			f_define_shape_reserved : 6;
		unsigned			f_define_shape_non_scaling_strokes : 1;
		unsigned			f_define_shape_scaling_strokes : 1;
	}
	if(is_morph) {
		unsigned long			f_offset_morph;
		swf_morph_shape_with_style	f_morph_shape_with_style;
	}
	else {
		swf_shape_with_style		f_shape_with_style;
	}
};

These are probably the most important tags in this reference. They are used to define a shape using Bezier curves and lines with different styles. The DefineShape of V1.0 is usually enough unless you need a large number of styles or you want to specify colors with an alpha channel (RGBA).

The DefineMorphShape and DefineMorphShape2 can be used to render an intermediate shape between two defined shapes. All the points and control points of both shapes must match. This is because the rendering of the morphing shapes is just an interpolation between both shapes points and control points positions. The interpolation is a very simple linear function (note however that you still can use a non-linear transformation effect in the end.) Most of the parameters in a shape definition are doubled when this tag is used. It otherwise looks very similar.

The f_stroke_rect and f_stroke_rect_morph rectangles define the boundaries around their respective shapes without the line strokes (excluding the thickness of the line.)

The f_define_shape_non_scaling_strokes flag should be set to 1 if at least one of the line strokes always stays the same while morphing.

The f_define_shape_scaling_strokes flag should be set to 1 if at least one of the line strokes is changing while morphing.

The f_offset_morph 32 bits value gives the offset from after that value to the start of the second shape (the shape to morph to.) In other words, this value can be used to skip the styles and the first shape at once.

DefineBitsJPEG2

Tag Info
Tag Number: 
21
Tag Type: 
Define
Tag Flash Version: 
2
Brief Description: 

Defines a complete JPEG image (includes the bit stream and the tables all in one thus enabling multiple tables to be used within the same SWF file).

Since Flash version 10, the data can also be set to a valid PNG or GIF89a. There is no need to specify the image format in the tag since the data describing the image includes the necessary information.

Tag Structure: 

Tag Structure: 
struct swf_definebitsjpeg {
	swf_long_tag		f_tag;		/* 6, 21, 35 or 90 */
	unsigned short		f_image_id;
	if(f_tag == DefineBitsJPEG3 + f_tag == DefineBitsJPEG4) {
		/* sizeof(f_encoding_tables) + sizeof(f_image_data) + 2 when JPEG4 */
		unsigned long		f_offset_to_alpha;
	}
	if(f_tag == DefineBitsJPEG4) {
		unsigned short fixed	f_deblocking_filter_parameter;
	}
	if(f_tag != DefineBitsJPEG) {
		/* when DefineBitsJPEG, use JPEGTables instead */
		unsigned char		f_encoding_tables[<variable size>];
	}
	unsigned char		f_image_data[<variable size>];
	if(f_tag == DefineBitsJPEG3 || f_tag == DefineBitsJPEG41) {
		unsigned char		f_alpha[<variable size>];
	}
};
  • 1. JPEG4 optionally accepts the f_alpha field. [To be verified]

These tags define an image saved using the JPEG compression scheme.

DefineBitsJPEG (V1.0) does not include the encoding tables which are defined in the unique JPEGTables tag instead. All the DefineBitsJPEG of an SWF file use the only JPEGTables tag. Yes... This means you need a tool that is capable of reusing the same tables over and over again to make sure that all your DefineBitsJPEGs work properly (or use it just once.)

The other tags incorporate their own version of the JPEG encoding tables.

The DefineBitsJPEG3 and DefineBitsJPEG4 support an alpha channel bit plane (8 bits.) This alpha channel is compressed using the ZLIB scheme as defined with the DefineBitsLossless image formats and appears at the end.

With Flash 10, DefineBitsJPEG4 was introduced to support a deblocking filter parameter. This parameter should be set to a value between 0.0 and 1.0 (0x0000 and 0x0100--so really a value from 0 to 256 inclusive.)

WARNING: These tags require you to save the swf_tag in long format (i.e. f_tag_and_size & 0x3F == 0x3F even if the size is smaller.)

f_encoding should include 0xFF 0xDB and 0xFF 0xC4 entries.

The f_image_data buffer should include the 0xFF 0xE0, 0xFF 0xC0 and 0xFF 0xDA.

Since Flash 10 the f_encoding and f_image_data fields defined in the DefineBitsJPEG2, DefineBitsJPEG3 and DefineBitsJPEG4 tags, are viewed as one single large buffer and thus it can be a verbatim JPEG, PNG or GIF89a file.

When the buffer represents a JPEG, it starts with 0xFF 0xD8 and ends with 0xFF 0xD9.

When the buffer represents a PNG, it starts with 0x89 0x50 'P' 0x4E 'N' 0x47 'G' 0x0D '\r' 0x0A '\n' 0x1A '^Z' 0x0A '\n'.

When the buffer represents a GIF89a, it starts with 0x47 'G' 0x49 'I' 0x46 'F' 0x38 '8' 0x39 '9' 0x61 'a'.

WARNING: Up to Flash 7, both buffers (f_encoding and f_image_data) need to start with a 0xFF 0xD8 (SOI) and end with 0xFF 0xD9 (EOI). Since Flash 8, this practice should not be used anymore.

The f_alpha buffer is compressed with ZLIB as defined in the DefineBitsLossless tag (this is similar to the PNG format). WARNING: this field only works with JPEG data. A PNG or GIF89a cannot make use of this field (but they can make use of their own alpha channel.)

Note:   The Flash 10 documentation says that the f_alpha field is optional. This means you can save a JPEG in a DefineBitsJPEG4 without the Alpha Channel but still make use of the deblocking filter parameter. Before Flash 10, use DefineBitsJPEG2 instead (safer).

The DefineBitsJPEG tag may fail if it includes any encoding tables. These tables shall be defined within the JPEGTables instead.

Note that the Adobe SWF player better enforces the correctness of these tags since version 8. Some older movies may not work properly with Flash Player 8+.