CCK
DefineShape4
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.
DefineFont3
It is common to use the DefineFont2 tag in order to create an array of shapes later re-used to draw strings of text on the screen. This tag must be used whenever a DefineEditText references a font; and in that case it is suggested you include a full description of the font with layouts.
The array of glyphs must be ordered in ascending order (the smaller glyph number saved first; thus 'a' must be saved before 'b', etc.).
All the characters should be defined in a 1024x1024 square (in pixels) to be drawn with the best possible quality. This square is called the EM square.
The DefineFont3 tag has the exact same definition as the DefineFont2 tag. The difference lies in the shapes being referenced. These have a precision 20 times higher. This gives you a font with that much higher precision (each pixel can be divided in a 400 sub-pixels.) The other difference is that a DefineFont3 can be referenced by a DefineFontAlignZones tag. That one can be used to properly align characters on a pixel boundary.
Note that an embedded font can be rotated. A system font (also called a device font) cannot be rotated. Also, the scaling and translation of a system font does not always respect the exact position. It is likely that the font will be moved to the next pixel left or right to avoid bluriness. That means it will look quite jaggy if you try to have a quite smooth move.
Since V6.x the f_font2_wide must always be set to 1.
The f_font2_shiftjis, f_font2_unicode and f_font2_ansii flags are for older movies (SWF 5 or older). Note that these are still defined as is in the Macromedia documentation (except for the Unicode flag which is implied and was replaced by another flag in version 7.) I strongly suggest that you follow my structure and totally ignore these flags (set them to 0) in newer movies.
The f_offsets array is a list of byte offsets given from the beginning of the f_offsets array itself (and not the beginning of the tag) to the beginning of the corresponding shape.
f_font2_map_offset is the offset to the f_font2_map table. This offset is relative to the position of the f_offsets array. It very much looks like it is part of that table. This offset should always be present, though if the font is not used in a DefineEditText tag, older version of the Flash player would still work just fine.
The f_font2_kerning_count and f_font2_kerning are used since version 8. Before that, just put the kerning count to zero and do not save any kerning.
(If it were possible to write such a structure as is in C, then ...) In C one would write the following to find the shape in the font tag:
struct swf_definefont2 *df; df = ... character67 = (struct swf_shape *) ((char *) df->f_offsets + df->f_offsets[67]);
Import2
WARNING: in a Version 8 movie you MUST use an Import2 tag instead of Import or it just will not work (Import tags are ignored in version 8 movies).
The Import tag works in conjunction with the Export tag. The Import tag gives the name of another movie and a list of external names as defined for export in that other movie. There is also a list of identifiers which represent the identifier the object(s) will have in this movie (the movie with the Import tag) and they don't need to match the source movie identifiers.
The list of identifiers given in the list of the Import tag must be unique within the entire movie. The names are only used to match the names present in the Export tag of the other movie. Thus, these can be duplicates of named sprite in this movie.
There should be only one Import per referenced movie (it would be a waste to have more). It is not clear whether a movie can Export definitions when it itself Import definitions. Also, it isn't clear what happens if such an external reference fails (I assume the corresponding objects are defined as being empty shapes).
You should at least have one external reference (i.e. f_count > 0).
The f_url parameter is a standard URL which names the object to be loaded and searched for an Export tag.
The identifiers defined in this tag must be unique within the entire movie.
Since SWF version 8, we are forced to use TagImport2 (since TagImport is ignored since that version.) It includes two extra bytes: the first one must be set to 1 and the second to 0. Macromedia termed both bytes Reserved. I put f_version in the first one so that way it makes more sense to set a 1 in there. We certainly will learn later what that bit is for.
PlaceObject3
This tag will be used to specify where and how to place an object in the next frame. The PlaceObject is much different and is presented separately.
The f_depth field is used to indicate at which depth the character is inserted in the current frame. There can be only one object per depth value (thus a maximum of 65536 objects can appear on a single frame).
The f_place_has_move and f_place_has_id_ref flags are used to indicate what to do at the given depth. The following table presents what happens depending on the current value.
f_place_has_move f_place_has_id_ref Action 0 0 Crash (at least in older versions of Flash) 0 1 Place or replace a character. Really, the Replace does not work most of the time if ever. When it does not work, new characters are either totally ignored or they are added along the existing characters (under or over, who knows). So far, all my tests fail to do a valid replace. 1 0 Alter the character at the specified depth. Keep the same character. This is used to change the color transform, matrix, etc. 1 1 Remove the character at this depth. The other data is ignored and should not be defined. Same as RemoveObject2.
The f_morph_position is used in two cases.
(1) When the place object references a DefineMorphShape object. In this case, it defines a linear position between the first and second shapes (0 - draws shape 1 and 65535 - draws shape 2, any intermediate value draws a morphed shape, smaller the value the more it looks like shape 1 larger the value, the more it looks like shape 2).
(2) When the place object references a VideoFrame object. In this case, the morph position represents the frame number. This means any movie is limited to 65536 frames (the first frame is frame #0). At a regular, NTSC frame rate, it represents about 18 minutes of video. Long videos can be created using a new video stream every 18 minutes.
The f_clipping_depth parameter is used to tell the player to use the linked shape (DefineShape) or text (DefineText) as a mask for all the objects inserted in the display list from f_depth to f_clipping_depth inclusive. The mask itself isn't drawn in the screen. For instance, you could create a sprite which draws a burning fire. To place this fire in a text, insert the text with this clipping feature with a depth, say, of 7 and clipping depth of 8 and place the fire at a depth of 8 (note that to have an animation, the fire will certainly be a sprite). The fire will only appear in the text letters. Obviously this is somewhat limited since the f_clipping_depth is hard coded and not a range (Macromedia should have used depth + clip like in SSWF instead). Note that it doesn't seem to work with duplicated sprites even if these are placed at the right depth.
NOTE: At this time I checked and I can tell that the following objects will work for clipping purposes:
- DefineShape
- DefineShape2
- DefineShape3
- DefineText
- (note that the alpha channel of a DefineShape3 is not taken in account.)
and the following will not work:
The following need to be checked, I also added a comment telling whether I think it has a chance to work:
- DefineButton2 (very unlikely)
The f_blend_mode parameter is one byte which is included only when f_place_blend_mode is set to 1. The possible values are as defined in the following table. The equations use R as Result, C as the object color component, B and the background color. All components are viewed as values from 0 to 255. The result is a temporary value which is later saved in the new background before processing the next object.
Values not shown in the following table are reserved for future blending modes.
Name Value Comment Version Normal 0 or 1 Copy the object as is.
R = C8 Layer 2 Uses multiple objects to render (?) 8 Multiply 3 Multiply the background with the object colors.
R = B × C / 2558 Screen 4 Multiply the inverse colors of the background and the object.
R = (255 - B) × (255 - C) / 2558 Lighten 5 Take the largest of each component of the background and object.
R = max(B, C)8 Darken 6 Take the smallest of each component of the background and object.
R = min(B, C)8 Difference 7 Defines the absolute value of the difference.
R = | B - C |8 Add 8 Add the components and clamp at 255.
R = min(B + C, 255)8 Subtract 9 Subtract the components and clamp at 0.
R = max(B - C, 0)8 Invert 10 Inverse the background components
R = 255 - B8 Alpha 11 Copy the alpha channel of the object in the background. This mode requires that the parent (background) be set to mode Layer.
Ra = Ca8 Erase 12 Copy the inverse of the alpha channel of the object in the background alpha. This mode requires that the parent (background) be set to mode Layer.
Ra = 255 - Ca8 Overlay 13 Apply the same effect as multiply or screen depending on the background color before the operation. (Note: the comparison with 128 could be <= and the results would be same for C but not B. I currently do not know which one is picked)
R = (B < 128 ? B × C : (255 - B) × (255 - C)) / 2558 HardLight 14 Apply the same effect as multiply or screen depending on the object color. (Note: the comparison with 128 could be <= and the results would be same for C but not B. I currently do not know which one is picked)
R = (C < 128 ? B × C : (255 - B) × (255 - C)) / 2558
The f_bitmap_caching seems to be one byte. It is present only when the f_place_bitmap_caching is set to 1. At this time, I do not know the exact definition and it could be that it does not exist (the Macromedia reference does not include it.) I will need to test this byte to see whether it is a mistake in the Macromedia documentation or from the person who thought adding the Bitmap Caching flag was also a reason to add one byte in the structure.
EnableDebugger2
The protection tag is totally useless. The SWF format is an open format, otherwise how would you have so many players and tools to work with SWF movies? Thus, you can pretend to protect your movies, but anyone with a simple binary editor can transform the tag and make it another which has no such effect. Also, swf_dump and some other tools (such as flasm) can read your movie anyway.
For the sake of defining what you have in each tag, there are the protection tags fully described.
According to Macromedia, you can find some free implementation of the MD5 algorithm by Poul-Henning Kamp in FreeBSD in the file src/lib/libcrypt/crypt-md5.c. For your convenience, there is an implementation of that MD5 sum in the SSWF library.
IMPORTANT
Version 2, 3, 4 must use Protect.
Version 5 must use EnableDebugger.
Version 6 and over must use EnableDebugger2.
DefineFontInfo2
A DefineFontInfo tag will be used to complete the definition of a DefineFont tag. It uses the exact same identifier (f_font_info_id_ref = f_font_id). You must have the corresponding font definition appearing before the DefineFontInfo since it will use the number of glyphs defined in the DefineFont to know the size of the map definition in the DefineFontInfo tag.
When it looks like it perfectly matches an existing system font, the plugin may use that system font (as long as no rotation is used, it will work fine.) It is also possible to force the use of the system font by declaring an empty DefineFont tag (i.e. no glyph declaration at all.)
The use of system fonts usually ensures a much better quality of smaller prints. However, since version 8, there are many features in the Flash player taking care of really small fonts.
Note, however, that a system font (also called a device font) cannot be rotated. Also, the scaling and translation of a system font does not always respect the exact position. It is likely that the font will be moved to the next pixel left or right to avoid blurriness. That means it will look quite jaggedly when slowly moving such text.
The f_font_info_wide flag must be set to 1 in version 6 and over.
Note that the flag f_font_info_small_text of version 7+ is the same bit as the flag f_font_info_unicode in SWF version 5 or less.
Since version 6, the font name has to be encoded in UTF-8 instead of whatever encoding you want. It is also suggested that you use the DefineFontInfo2 tag instead.
DoInitAction
The DoAction tag will be used to execute a set of actions in place. Usually, actions are used on buttons to add interactivity to the SWF movies. In version 1 you had only one dynamic branch (WaitForFrame). In version 4 you can test many different things such as a position, angle or sound track cursor position. Since version 5, SWF has a complete scripting language supporting string and arithmetic operations.
The DoInitAction tag is used when a sprite needs to be initialized. These actions are carried on the sprite only once. These are outside of the given sprite and will reference the sprite so all the actions are automatically applied to the sprite without you having to do a SetTarget.
The following describes the data in the DoAction and DoInitAction tags:
The f_action_sprite is a reference (identifier) to the sprite which will be initialized with the given actions.
The f_action_record is an array of actions terminated by an End action.
The following is a list of all the actions supported by SWF format. The Version tells you what version of Flash player you need in order to use the given action (otherwise it is likely to be ignored or worse, make the player crash). Note that Macromedia defines all the actions as being part of version 3 and over. Thus, any action mark as being available in earlier versions (version 1 or 2) may in fact not be (though the DoAction and DefineButton tags were part of version 1!!!)
The Length (Stacked) column specifies the length of the data following the property (only with the action ID is 0x80 to 0xFF) and what will be pushed onto the stack. All the expressions work as in polish notation: push the parameters, then execute an order that uses the data from the stack. The actions that do not push anything on the stack have nothing written between parenthesis.
The Data & Operation column specifies what data follows the action and what the operation is. If there is no data and no operation, then n.a. is used. The data will be described as a list of fields as in the other structures described in this document. The operations will be written as closely as possible to a C like operation (though strings are managed in a much different way than C!) Anything which is popped from the stack will be given a letter and a digit. The digit represents the count or position and the letter the type of the data (a count of 1 represents the first pop, a count of 2 represents the second pop, etc.) The following column (Comments) will explain how the operation uses the data when appropriate.
The data types used are as follow:
|
(1) when I don't know whether an integer or a float should be specified I will use 'n' as well. This should be correct most of the time anyway.
(2) an object reference can be obtained by evaluating the name of that object; thus GetVariable("carrot") will return a reference to the carrot object.
The following lists all the actions by name. Those that have the comment (typed) operates taking the type of its arguments in account as defined in ECMA-262 Section 11.6.1 (arithmetic), 11.8.5 (comparison), 11.9.3 (equality) which you can certainly find somewhere on the Internet. Version 3 is available here: ECMA-262 V3.0. The functions which are not typed will behave by (1) trying to transform parameters in values, then perform the operation with numbers only or (2) when strings cannot be transformed in values, perform a string operation.
EnableDebugger
The protection tag is totally useless. The SWF format is an open format, otherwise how would you have so many players and tools to work with SWF movies? Thus, you can pretend to protect your movies, but anyone with a simple binary editor can transform the tag and make it another which has no such effect. Also, swf_dump and some other tools (such as flasm) can read your movie anyway.
For the sake of defining what you have in each tag, there are the protection tags fully described.
According to Macromedia, you can find some free implementation of the MD5 algorithm by Poul-Henning Kamp in FreeBSD in the file src/lib/libcrypt/crypt-md5.c. For your convenience, there is an implementation of that MD5 sum in the SSWF library.
IMPORTANT
Version 2, 3, 4 must use Protect.
Version 5 must use EnableDebugger.
Version 6 and over must use EnableDebugger2.
DefineMorphShape
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.
SoundStreamHead2
The SoundStreamHead[2] tags define a sound effect which is to be loaded with a set of SoundStreamBlock tags. It defines the sound once and for all.
Streaming sound has a strong side effect when playing a movie: it will force a synchronization between the images and the audio. Thus some images may be dropped if the drawing isn't fast enough.
Streaming sound effects should be either used in the main movie or in a sprite which needs a sound track properly synchronized to the sprite animation. Otherwise, it is much better to use the DefineSound and StartSound tags.
It seems (though it isn't documented) that using a SoundStreamHead tag by itself (without any sound blocks) is taken as a hint of how to play all the other sounds in an animation (see the f_playback_rate)
Important note: there can be only one streaming sound per movie clip including the main movie. If you need multiple sound effects or music to be played back, these will have to be merged at the time you create the movie in a single sound which will then be played back as a single sound track.
Some of the fields in the SoundStreamHead tag can't have all the possible values when defined in an older version of SWF. What follows describes each field in more details.
The f_playback_rate and f_sound_rate define the rate at which the data should be played and the exact rate of the data found in the SWF file.
rate = 5512.5 * 2 ** f_playback_rate rate = 5512.5 * 2 ** f_sound_rate
The f_playback_size and f_sound_size define the number of bits found in the data (0 for 8 bits and 1 for 16 bits.) Note that with a SoundStreamHead tag (18) only 16 bits data are allowed (both are always set to 1). If the compression mode isn't Raw or Uncompressed then the f_sound_size must be set to 1.
The f_playback_stereo and f_sound_stereo define whether the sound should be played on both speakers and whether the data includes both channels.
The f_compression entry defines the compression mode. The list of sound compression modes can be found with the DefineSound tag. Note that with a SoundStreamHead tag (18) only the ADPCM compression is accepted. All the compression modes are accepted in a SoundStreamHead2 tag (45).
The f_sample_size represents the average number of samples per frame. It is used to ensure a proper synchronization. Note that there can be more (and even less in MP3) samples within a given frame.
The f_latency_seek is usually zero. It exists only when the MP3 compression mode is used. It defines the number of samples to skip at the beginning of the very first frame (I'm not totally sure what this is to tell you the truth... I'll tell you more once I know more).
