Authoring Content for Flash Lite—The Ynot Approach

Tips for Smooth Playback

The following two sections provide a summary of the lessons we learned when creating content for Flash Lite.

Keep an Eye on CPU-intensive Operations

When developing content for i-mode enabled phones, you should always consider the CPU speed of your target phone as well as the file size of your content. However, the performance of your Flash Lite movie depends on more than the number of vectors that need to be rendered to display the content. Any of the following can tax your target phone's CPU and impact the performance and size of your movie:

• Too many alpha and gradation settings
• Simultaneous tweening of multiple symbols
• Too many fonts
• Complex ActionScript operations

For best results, experiment with combinations of tweens, key frame animation, and ActionScript-driven movement, and be sure to test your animations on your target phones whenever possible (The CPU speed of i-mode phones varies from model to model.)

Note that Flash Lite supports both device fonts and embedded fonts (but it does not support input text fields). If you want more control over the design of your content, you can use embedded fonts. However, this will add significantly to your SWF file size. By contrast, if you want to use the device font for text you are limited to a single font. Note also that i-mode phones support special pictorial characters called emoji. (For more details on these characters, see the section "Emoji" in "Flash Lite Authoring Guidelines for the i-mode Service by NTT DoCoMo" on the Macromedia Flash Documentation page.

Keep an Eye on the Size of Your SWF File

Flash Lite does not support streaming playback. Users will see the first frame of your movie only after the file has finished downloading. And unlike Internet users, mobile phone users pay packet charges for the content they download from i-mode websites; which means, the bigger the size of your movie, the more users are charged and the less likely they are to use your services. In other words, if you want to reach consumers, you have to keep an eye on the size of your SWF file without sacrificing the attractiveness of your content. For your reference, the SWF file that is the subject of this case study is 20KB, which costs users about 45 to 50 yen (approximately U.S. $0.40) to access and view.

The following list provides some tips that will help keep your file size small and your users happy:

• Do not use graphic symbols: Graphic symbols increase the file size, because each graphic symbol consists of complex vector shapes that have to be rendered individually. Instead, use movie clip symbols, which are rendered all at once without adding significantly to the file size.
• Use device fonts: Although embedded fonts give you more control over the design of your content, they also add to the size of your movie. By contrast, using device fonts helps keep your file size small. However, in the case of the 505i, 505is, 506i phones, it also limits you to a single (device-dependent) font and size: 24pt.
• Optimize paths: Before publishing your content, select Modify > Shape > Optimize in Flash MX Professional 2004 to optimize your paths to the level where no shape is distorted when viewed at the full display size.

If you follow the rules I've outlined so far, you will be able to create rich, compelling content despite the CPU limitations of i-mode phones. Of course, you should always test your movie on your target device, and not just in the authoring environment or the external Standalone Flash Lite Player (SAFlashLite.exe) that comes with Flash MX Professional 2004, to ensure you have found the right balance between file size and runtime memory requirements and CPU power. Remember that the CPU speed of i-mode phones differs from model to model.

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