import flash.display.Bitmap; 

class HaxeCastsBitmap extends Bitmap 
{ 
  public function new() 
  { 
    super(); 
  } 
}

package;

import flash.display.Sprite;
import flash.Lib;
import flash.display.LoaderInfo;

class Main extends Sprite
{	
  static function main()
  {
  	new Main();
  }
  
  public function new()
  {	
    super();
    Lib.current.addChild(new HaxeCastsBitmap());
  }	
}

You can embed images, fonts, audio and other swf files with swfmill here we are looking at embedding an image file.
When the xml file is ready you have to compile it from the terminal:

$ swfmill simple resource.xml resource.swf

<?xml version="1.0" encoding="iso-8859-1" ?>
	
<movie version="9" width="800" height="261" framerate="30"> 
  <frame> 
    <library>
      <bitmap id="HaxeCastsBitmap" import="library/images/haxe_casts.png" />
    </library> 
  </frame> 
</movie>

To use the resource.swf file we just compiled we have to the build.hxm file to include the resource.swf file

-cp src
-cp src/interfaces

-cp src/bitmaps
-main Main
-swf-lib ../swfmill/resource.swf
-swf9 bin/episode-002.swf

-swf-header 423:56:20:eeeeee
-swf-version 10
-debug