Group intelligence can not just be used for generating data, but also searching for it. Pascal Schrafl, a student at the University of Liverpool, and a good friend, is currently researching the topic of collaborative search. His goal is to optimize search results based on the previous behavior of peers. His research will start in January and last two weeks. The tests will be held in german, I urge any speakers of the language to participate.

Visit the CollabSearch research project page to sign up.

Multimedia applications often have interactive elements based on video: For example, a pre-rendered 3D scene that moves according to a user’s interaction. The trick, in such a scene, is to play specific parts of the movie forward and backward to fake movement.

This sculpture has been rendered as a movie, with the camera panning 360˚around the object.
(Drag with the mouse to turn the object)

Embedding Animations

There are three basic ways to embed an animated scene into Flash:

• In the Flash Video format (FLV);
• As a sequence of images, e.g. PNG or JPEG;
• As a sequence of vector graphics.

The latter is often forgotten. Tools such as Cinema 4D’s FlashEx renderer can export a scene as a vector animation. If the scene doesn’t contain many objects and has simple texturing, a vector animation would probably be the way to go. The file size stays relatively small, plus the graphics are scalable.

A simple 3D object rendered as a vector sequence with FlashEx 2.
(Drag with the mouse to turn the object)

The other two methods, FLV and image sequences, are both pixel based, but have their own pros and cons. FLV has a decent quality/size ratio. Flash CS4 does not allow F4V files to be embedded directly, so the best codec is the older and less compressing On2 VP6. Interacting with FLV, e.g. jumping between frames quickly or playing it backward, is heavy on the processor. Presumably, the Flash Player has to jump to the nearest proceeding keyframe and process the changes to the current frame each time. On the other end of the spectrum is the image sequence. The compression is on a per-frame basis, so the overall file size will usually turn out much bigger. The display performance, however, is far better than FLV.

Eliminating the Cons

A combination of the reduced file size of FLV and the performance of an image sequence is possible, if the data gets decompressed on the client side. H.264 encoded video data could be sent through the wire and then be processed into an uncompressed image sequence before being displayed. I wrote a class named BitmapAnimation that parses each frame of a MovieClip (including any FLVs within) and adds it to an array of bitmap data. BitmapAnimation has the same methods as a MovieClip (gotoAndPlay, currentframe etc.), so the two can be interchanged. For instance, I was able to use a BitmapAnimation in place of a MovieClip to create a MovieMaterial in Papervision3d – polymorphism works.

When compared with simultaneously running FLVs, BitmapAnimations showed a 500% performance increase on my system. The difference was even bigger with the clips running backward. There may be a performance benefit in converting complicated vector animations to a BitmapAnimation before they are displayed. I have, however, not recently come across a scenario where a pure vector animation alone caused the frame rate to stagnate.

The MovieClip option cacheAsBitmap requires, to my understanding, the frame to be rendered in the Flash display list before it takes effect. This would be the only major difference to BitmapAnimation (where the image is rendered before being displayed). Enabling cacheAsBitmap on MovieClips containing FLV did not show a change in performance in my tests. Because a video is usually viewed once, it makes sense not to cache FLV by default.

There is one known drawback when using a BitmapAnimation: Depending on the size of the video and the client’s processor speed, the Flash Player could “freeze” for a few seconds while decompressing the video data. I created an additional class, where I lengthened the processing time by decompressing one frame per half-second. This would allow the video to be prepared in the background without noticeably slowing down the rest of the application. Delayed processing would work best during a loading sequence, where the video is loaded first, then converted to a BitmapAnimation, while the rest of the assets are being retrieved.

Usage

Simply pass a MovieClip to the draw method.

bitmapAnimation = new BitmapAnimation();
bitmapAnimation.draw(movieClip);
addChild(bitmapAnimation);

The imported bitmap data can be reused with multiple BitmapAnimations.

var bitmapAnimation1:BitmapAnimation = new BitmapAnimation();
bitmapAnimation1.draw(movieClip);
var bitmapAnimation2:BitmapAnimation = new BitmapAnimation(bitmapAnimation1.bitmapSequence);

Conclusions

Pre-rendering a complex MovieClip, such as embedded FLV, using the BitmapAnimation class, may likely show a performance increase. Also, this method may remove the need to embed an image sequence where display performance is an issue. Due to the computation time required for conversion, BitmapAnimations should not be used for long clips. Inputs and feature requests are welcome, just add a comment below.

Download the classes BitmapAnimation and DelayedBitmapAnimation.

Download the sculpture example.

Screenshot from the 1995 racing game Destruction Derby

It seems that the graphics performance is comparable to games that came out in 1995 on the PC, before graphics hardware became widespread. Imagine running a game like Dark Forces or Destruction Derby inside the browser. In a nutshell, on today’s average computer, the Flash graphics performance is Quake 1 tops. Broad statements aside, it is important to know what code flies on the Flash Player when developing games and interactive applications.

I’d like to know what basic code will perform best in a given situation. Therefore, I have started to extract these parts of code from my projects and test them against alternative methods, attempting to quantify the execution speed on the AVM. Unlike Javascript, ActionScript usually runs on the same engine; This makes such specific tests worthwhile.

I have gathered performance tests from a couple of my projects and put them into the ActionScript Performance Wiki. It is open to anonymous editors, so anybody is free to add their own tests.

A lesser known feature of browsers, such as Firefox 2 or Internet Explorer 7, is that users can add search functionality to the browser’s search bar directly from within a page. The data structure containing the search information has (so far) been agreed upon as OpenSearch. Since the format is open, any browser software can implement this functionality.

The Firefox search bar with a linked OpenSearch example on the bottom.

The Internet Explorer search bar listing an OpenSearch example.

When to use OpenSearch

OpenSearch makes sense on any site that provides search functionality. When active, Firefox and Internet Explorer include an option to add the site’s search in the search bar.

In my opinion, adding a notice or a link on the page to enable the search functionality is overkill for most sites. I personally wouldn’t use it for my own weblog. On the other hand, an online store with thousands of products could greatly benefit from this feature as a brand touchpoint; And informing the user about this functionality would be worthwhile. Once a user adds a site to their browsers search bar, it is a constant reminder of the site’s existence. Every time a user activates the search bar drop-down menu, that site will be there.

Implementation

Versions of Firefox before 2.0 had a different way for adding search to the search bar. It was similar, but included a different XML structure. The data was saved in files ending with “.src”. I decided not to add this method anymore, since it is specific to a small user base (who still uses FF 1.0?).

Only two things need to be done to add OpenSearch:

1. Create an XML-File containing data about the search engine;
2. Link to the XML-File in the head of the site’s HTML.

The XML, for example, would be structured as follows; Simply adapt the URLs for your site. To get the correct search URL, perform a search on your site, copy the URL and replace your search term with “{searchTerms}”.

<?xml version="1.0" encoding="UTF-8" ?>
<OpenSearchDescription xmlns="http://a9.com/-/spec/opensearch/1.1/">
	<ShortName>OpenSearch Example Name</ShortName>
	<Description>OpenSearch Example Description</Description>
	<InputEncoding>UTF-8</InputEncoding>
	<Image height="16" width="16" type="image/x-icon">http://yoursite/favicon.ico</Image>
	<Url type="text/html" template="http://yoursite/?s={searchTerms}" />
</OpenSearchDescription>

This file could then be saved as “search.xml” to the root folder of the site and linked to by placing the following code in the HTML header:

<link rel="search" type="application/opensearchdescription+xml" title="OpenSearch Example Title" href="/search.xml">

Including an OpenSearch Link to the Page

window.external.AddSearchProvider("search.xml");

An unobtrusive way to add the link, is to first check if the browser supports the AddSearchProvider function before adding it. Further details can be found on Mozilla’s developer site.

<p id="add-opensearch">OpenSearch not supported</p>
<script type="text/javascript">
	if (window.external && ("AddSearchProvider" in window.external)) {
		document.getElementById("add-opensearch").innerHTML = '<a href="#" onclick="window.external.AddSearchProvider(\'/search.xml\')">Add this site’s search to your browsers search bar.</a>';
	}
</script>

Possible Future Browser Features

I have a hunch that the usability of web-browsing in general, would be enhanced if the browser could detect OpenSearch and enable it temporarily in its search bar. The use case could be:

A user visits a site and the browser toggles the search bar to the site’s search. Instead of looking for a search form in the page, the user enters the query via the browser. Upon leaving the site the search bar switches to the new site’s search functionality, or defaults to the preferred search engine.

The search bar could be highlighted with another color to indicate that it’s linked to the current site.

For this feature to be useful, OpenSearch would have to become more commonly adopted. But I think sites would follow quickly once a browser vendor starts pushing the feature.

Conclusion

In my opinion, the creators of OpenSearch got it right. The specification is clear and it blends in perfectly with the existing technologies, HTML and Javascript. Plus, it is quick and easy to implement. I could recommend any web content management system with search functionality to enable this feature as standard.

I would also recommend adding a favicon to the OpenSearch XML, so the site stands out more in the browser’s search bar.

Download the Code

The original intro of my blog was to display a mediocre “show” (e.g. a street musician playing a song) – and then have somebody come in to outperform the original.

Fellow students and I made this video for my site in late 2006. The ‘bad’ guitarist is played by Andreas Dietl, the ‘good’ guitarist is played by Gabe Hill. Gabe’s performance is awesome, the tune he played is real. He shredded the guitar so hard he cut his finger and started bleeding!

The intro video was placed in the masthead of my site for a short time only. I trashed the entire site design for a more colorful version after just two months. It was a shame for the video, but the design just had to go.

Download the video.

I have been to Adobe Max in Milan just two months earlier and, comparing the two, I think FITC was more fun. The conference was smaller, but somehow the vibe was less about business and more about creativity.

Here are some videos from the conference:

And here are some pictures I took:

I will definitely try to go to one of the next FITC gatherings. The canadian edition would be cool.

In my opinion, it looks like Flash will gradually return back to it’s roots as an animation tool. Unlike today, where it has become a multimedia behemoth in which entire sites are created. Flex and a new product named Flash Catalyst (formerly Thermo) will take over the rolls of creating user interaction. I got a preview copy of Catalyst and it looks pretty good. Page elements, and their states, can be assembled visually based on an imported Illustrator or Photoshop composition. It reminds me somewhat of Dreamweaver, but instead of HTML in creates MXML (the declarative language used in Flex).

I took a preview of Flex 4 (codename Gumbo) for a spin, but it still can’t keep up with the sheer awesomeness of FDT. I think Adobe should just buy FDT, employ all the Powerflasher dudes, mash the two products together, and give it a snappy name like Adobe Insane.

In one of the general sessions held on Tuesday it was mentioned that BlazeDS should soon be compatible with the .Net framework. I was exited about BlazeDS when I first heard of the product a couple months back, but my excitement eroded away like a soaked sandcastle when I heard it required Java. Nothing against Java of course, but the company I work for uses .Net. BlazeDS may yet make it onto the company servers.

One of the Max sessions showed a sneak peak of peer-to-peer capabilities in the Flash Player on the basis of RTMFP. A peer-to-peer mesh would open up some amazing data sharing possibilities. We could build a Skynet of SWFs! Historians in two hundred years would say things like: “At first it played simple animations and cheesy banners, but then it gained consciousness ant launched a nuclear attack”. We could also just use this technology for video streaming I guess.

I had a great time at Max, and I am looking forward to continuing my work as a Flash Developer with all the great new Tools coming up.

I made another attempt to get the Flash Tracer plugin from Sephiroth to work and I was successful (turns out my User Settings folder at work is saved on the 486 down the hall). With a few tweeks to the mm.cfg file I even get warnings about Security issues:

ErrorReportingEnable=1
TraceOutputFileEnable=1
PolicyFileLog=1
PolicyFileLogAppend=1

Apart from the dreadfully slow performance, I think this is the simplest way to debug a Flash App from within the browser.

A quick test gave the answer: Practically nill. 30 really long variable names compared to 30 short ones resulted in a file size difference of a measly 5 bytes.

Conclusion

For file size optimization, limiting the length of variable names should be considered an extreme measure. Rather, leave the code readable and optimize the images instead.

Update

Short variable names perform better than long ones. But again, not enough to make it worthwhile throughout the entire application.

The biggest issue I had was that the keyboard input would somehow get “reset” to the English layout. This means that anybody using a non-English keyboard would get strange results while typing. This keyboard bug has been known since at least 2005.

In the end I just loaded a dummy image into the background of the SWF instead of making it transparent. All the other browsers behaved fairly well with the WMODE setting.

If anybody else is having these issues, head over to bugzilla and vote for getting the bugs fixed.

In conclusion, consider WMODE=”transparent” a last resort for even the simplest Flash projects.