Flash Reference Guide

The most popular CODEC you are probably aware of is a ZIP file. You can take a lot of files and place them into a ZIP file—the ZIP file is almost always much smaller than the original file format.

The CODEC used by Flash to compress video for the Flash Video format is called Spark (developed by Sorenson). Sorenson has been developing video compression algorithms for many years. The Spark CODEC is just one of its new algorithms. Sorenson also created the CODECs for notable file formats such as QuickTime 6 and Window's AVI.

Any Flash Video file that you create uses the Spark CODEC to compress the original video footage.

Creating a Flash Video with Flash MX

You cannot always import Flash Video files directly into Flash because the files you are using have been supplied to you only in QuickTime or MPEG format. Until Flash Video catches on, there are not too many video-editing packages that allow you to export the Flash Video file format.

What you need to be able to do is compress video on the fly. An AVI file should be able to be pulled directly into Flash and be squeezed into the Flash Video file format.

For the following exercise, you need to use the FlashVideo.zip file (download the file here). The video file will be used for this tutorial.

1. Open Flash and create a new file. Name the file importedVideo.fla.

2. Select File, Import to Library. Select the video you download for this article.

The AVI file is an uncompressed short video. If you are interested, it shows some example test screens you can use. Not very exciting, but you can use your own video files as well. I am using AVI because a QuickTime MOV file requires you to have QuickTime installed. The video is made up of two main parts: the video image and the audio sound track.

1. Select OK to import the file.

The Import Video Settings window opens.

2. Select the horizontal scrollbar under the black window in the top left of the Import Video Settings window. The scrollbar is a playback handle that allows you to scrub backwards and forwards through the AVI file. You can use this preview to see whether the movie file you have selected is correct.

The Import Video settings allow you to change the settings of the original file. By default, the Spark CODEC compresses an AVI file on a ratio of about 10:1, which is amazing. But you are delivering files through Flash over the Internet. At this ratio, the final video exported out of Flash from the original AVI file (which is 47MB large) is still a whopping 4MB, which is too much for delivering media over the Internet (even with the prevalence of high-speed Internet access). You must be able to play around with the settings so that you can optimize your imported video for the Web.

3. The first step is to change the quality level from 100% to 80%, which is a slight drop in quality, but it drops the file size down to 3.5MB. You need to measure the value for the Web over quality.

4. Changing the keyframe interval reduces the number of frames of video. The current frame rate is 24 frames per second. Changing this to 12 frames per second reduces the overall file size to 754KB.

5. To further optimize the video, you can convert the file size from 100% to 75% of the original size. This reduces the file size to 443KB.

6. You can choose to remove the audio track to the video file if you want. However, if you are working with video footage, audio is likely to be the least of your worries. Video is always larger in file size than audio. Removing the audio track reduces the overall file by only a fraction—and then you have no voice in your movie!

7. The video is imported into your Library. The video file has a camera icon to show that it is a unique instance type in the Library. Drag an instance of the video from the Library onto the Stage. Layer 1, the default layer for a Flash movie, immediately stretches to 205 frames, which is the length of the video file. Changing the length of Layer 1 changes the end point of the video.

8. Preview your movie. Turn on the bandwidth profile (View, Bandwidth Profiler) to analyze the size of the video. The once-47MB AVI video is now 445KB in size.

Sorenson Squeeze

It is hard to ignore the commercial that Sorenson placed in the Import Video Settings window. Yes, you can buy an upgrade to "Sorenson Squeeze."

The software is available at the Sorenson web site. Not only can you get a copy of the video, but you can also view some of the slickest examples of video in Flash.

As with all good software, you can download and install a 30-day evaluation of Squeeze. It is worth downloading and giving it a whirl.

When you open Squeeze, you see that is it a relatively easy and intuitive tool. The only role it really has in life is the conversion of video from one file type to either Flash Video, Flash SWF, or QuickTime.

I can guarantee that if you have some video files, you will be up and running with Squeeze in almost no time.

1. The first step is to drag a video file onto the left screen. A preview of the video is displayed in the screen. You can use the video controls to scrub through the video and play it.

2. The next step is to choose which file type you want to convert to. For Flash MX, the easiest file type to use is FLV Flash Video. Select the FLV icon button.

3. Finally, you need to choose which audience file type you want to export to. The seven buttons are preset definitions for different Internet connections. On the far left is a button that optimizes your video for broadcast to dial-up users. On the far right is a preset that optimizes the original video file for delivery over CD-ROM. You can choose multiple file types. Choose the far-right button for CD.

4. To convert the file into Flash Video, press the Squeeze It button. The video is then converted. Encoding video can take some time, depending on the length of the original video file.

5. When the file conversion is complete, you have a file placed in the same folder as the original video file. The filename is the same as the original file with the extension _cd.flv. The new Flash Video file can be directly imported into Flash MX.

You can batch export up to seven different broadcast settings and three file types at once. As you might expect, you can also customize each setting. You can also modify the filter settings for the video. To do this, you need to select the spanner icon.

1. Select the spanner icon to open the Filter Settings window.

2. The main window in the Filter Window is the first frame of the video. Selecting any of the resize handles allows you to crop the video.

3. You can customize the Contrast, Brightness, Gamma, White Restore, and Black Restore to the video image.

4. If the original video suffers from noise, the annoying static that sparkles all over the video, you can treat it by selecting Video Noise Reduction.

5. A useful tool tucked into the bottom-left corner of the tools is the Normalize Audio check box, which levels all audio to the highest level without distorting the sound.

6. You can also choose a simple Fade In/Fade Out transition.

7. Encode a video to see your new settings take hold.

Flix

Macromedia has released the code that allows software companies to embed the Flash Video compressing CODEC into their products.

One product that has been around for awhile is Flix by Wildform, which converts video for use with Flash. Earlier versions of Flix converted video in vectors for use within Flash movies. Although the end result can be effective, it is not true video.

The latest release of Flix does come fully Flash Video-enabled.

Unlike Squeeze, Flix does not convert your video into QuickTime, but it does convert video files into Flash Video and SWF, and converts the images within the video to vectors.

If you will use video a lot in Flash, consider purchasing either Squeeze or Flix.