Video Conventions - MACROMEDIA FLASH MX 2004-USING ACTIONSCRIPT IN FLASH Use Manual

Working with other structural elements
A screen-based document, when published, is essentially a single movie clip on the first frame of a
Timeline. This movie clip contains a few classes that compile into the SWF file. These classes add
additional file size to the published SWF file compared with a nonscreen-based SWF file. The
contents load into this first frame by default, which might cause problems in some applications.
You can load content into a screen-based document as separate SWF files onto each screen to
reduce the initial loading time. Load content when it is needed, and use runtime shared libraries
when possible. This approach reduces what the user needs to download from the server, which
reduces the time that the user must wait for content if they do not have to view each different part
of the application.

Video conventions

The use of video in Flash has greatly increased and improved from earlier versions of Flash. There
are many options to make edits to video before you import footage into a FLA document. There
are also greater controls for video compression when you import it into Flash. Compressing video
carefully is important because it controls the quality of the footage and the size of the file. Video
files, even when compressed, are large in comparison with most other assets in your SWF file.
Note: Remember to provide the user with control over the media in a SWF file. For example, if you
add audio to a document with video (or even a looping background sound), let the user control the
sound.
For more information, see the following topics:
•
"Using video" on page 110
•
"Importing and embedding video" on page 111
•
"Importing and embedding video" on page 111
•
"Using Media components" on page 113
•
"Dynamically loading video using ActionScript" on page 113
Using video
Before you import video into Flash, consider what video quality you need, what video format you
want to use with the FLA file, and how you want it to download. You can import the footage
directly into a SWF file using any video file format that is supported by Microsoft Direct Show or
Apple QuickTime. (Formats include AVI, MPG, MPEG, MOV, DV, WMV and ASF.)
When you import video into a FLA file, it increases the size of the SWF file that you publish.
This video starts downloading to the user's computer whether or not they view the video. You can
also stream the video from an external Flash Video (FLV) file on your server.
Note: Video progressively downloads from the server like SWF files, which is not actually streaming.
Even dynamically loading content has distinct advantages over keeping all your content in a single
SWF file. For example, you will have smaller files and quicker loading, and the user only downloads
what they want to see or use in your application.
110 Chapter 3: Using Best Practices