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PlaceObject2

Tag Info
Tag Number: 
26
Tag Type: 
Define
Tag Flash Version: 
3
Brief Description: 

Place, replace, remove an object in the current display list.

Tag Structure: 
struct swf_placeobject2 {	/* and swf_placeobject3 */
	swf_tag			f_tag;		/* 26 or 70 */
	/* NOTE: the following flags can be read as one or two bytes also */
	if(version >= 8) {
		unsigned	f_place_reserved : 5;
		unsigned	f_place_bitmap_caching : 1;
		unsigned	f_place_blend_mode : 1;
		unsigned	f_place_filters : 1;
	}
	if(version >= 5) {
		unsigned	f_place_has_actions : 1;
	}
	else {
		unsigned	f_place_reserved : 1;
	}
	unsigned		f_place_has_clipping_depth : 1;
	unsigned		f_place_has_name : 1;
	unsigned		f_place_has_morph_position : 1;
	unsigned		f_place_has_color_transform : 1;
	unsigned		f_place_has_matrix : 1;
	unsigned		f_place_has_id_ref : 1;
	unsigned		f_place_has_move : 1;
	unsigned short		f_depth;
	if(f_place_has_id_ref) {
		unsigned short		f_object_id_ref;
	}
	if(f_place_has_matrix) {
		swf_matrix		f_matrix;
	}
	if(f_place_has_color_transform) {
		swf_color_transform	f_color_transform;
	}
	if(f_place_has_morph_position) {
		unsigned short		f_morph_position;
	}
	if(f_place_has_name) {
		string			f_name;1
	}
	if(f_place_has_clipping_depth) {
		unsigned short		f_clipping_depth;
	}
	/* 3 next entries since v8.0 */
	if(f_place_filters) {
		unsigned char		f_filter_count;
		swf_any_filter		f_filter;
	}
	if(f_place_blend_mode) {
		unsigned char		f_blend_mode;
	}
	if(f_place_bitmap_caching) {
		/* WARNING: this is not defined in the Macromedia documentation
		 * it may be that it was part of the blend mode whenever the person
		 * who defined this byte was testing (I copied that from somewhere else!).
		 */
		unsigned char		f_bitmap_caching;
	}
	/* since v5.0 */
	if(f_place_has_actions) {
		unsigned short		f_reserved;
		if(version >= 6) {
			unsigned long	f_all_flags;
		}
		else {
			unsigned short	f_all_flags;
		}
		swf_event		f_event[<variable>];
		if(version >= 6) {
			unsigned long	f_end;	/* always zero */
		}
		else {
			unsigned short	f_end;	/* always zero */
		}
	}
};
  • 1. Assuming that this PlaceObject2 references a DefineSprite, this name becomes the name of this instance of the sprite. This feature enables you to place the same DefineSprite multiple times in your display list each time using a different name.

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 ...

SoundStreamHead

Tag Info
Tag Number: 
18
Tag Type: 
Define
Tag Flash Version: 
2
Brief Description: 

Declare a sound effect which will be interleaved with a movie data so as to be loaded over a network connection while being played.

Tag Structure: 
struct swf_soundstreamhead {
	swf_tag			f_tag;		/* 18 or 45 */
	unsigned		f_compression : 4;
	unsigned		f_sound_rate : 2;
	unsigned		f_sound_size : 1;
	unsigned		f_sound_stereo : 1;
	unsigned		f_reserved : 4;
	unsigned		f_playback_rate : 2;
	unsigned		f_playback_size : 1;
	unsigned		f_playback_stereo : 1;
	unsigned short		f_sample_size;
	if(f_compression == 2) {
		signed short	f_latency_seek;
	}
};

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.

SetBackgroundColor

Tag Info
Tag Number: 
9
Tag Type: 
Display
Tag Flash Version: 
1
Brief Description: 

Change the background color. Defaults to white if unspecified.

Tag Structure: 
struct swf_setbackgroundcolor {
	swf_tag			f_tag;		/* 9 */
	swf_rgb			f_rgb;
};

This tag is used to specify the background color. It should always be included at the start of every .swf file (after the FileAttributes and Protect tags). Only an RGB color can be used (i.e. there is no alpha channel for that color, whatever the SWF version.)

To create a Flash animation that's transparent (so we can see the website gradient, for example) you use the wmode parameter in the HTML tag with the value "transparent", in which case the background color will be ignored and replaced by a fully transparent background. For example:

<embed width="440"  ...

SWF File Format Reference

The Flash File Format Explained

The SWF file format is used for Flash. SWF stands for Shockwave Format1, the very first company that created the Flash animation format later bought by Macromedia and now owned by Adobe.

The following book is an attempt in describing the binary file ...

  • 1. There are many people who found other names for the acronym such as Shockwave Flash, Shock Wave File, Small Web Format, Serious Wow Factor, and SWIFF. History of man kind is confronted with the same problems, unfortunately. And no... it really has nothing to do with the Swiss Wrestling Federation!

Adobe Flash Animation by Made to Order Software

Making a great thing even better!

The letters SSWF in a curly font with dots on the ends.

 SSWF Support 
Using our robust open-source C++ library and scripting language, ScriptSWF (SSWF), you can create Adobe Flash animations on the fly.

Since it's initial release in 2002, SSWF has been extremely popular. Despite never being advertised, it has been downloaded more than 77,250 times just on SourceForge.net, has been converted to work on several Unix platforms not initially ...