Macromedia MAX 2005 - Anaheim, CA What’s New In Flash 8
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Tips for creating Flash video
How you compress your video is largely determined by the content of the video. A video clip of a
talking head with little action and only short bursts of moderate motion compresses differently from
footage of a soccer match. Follow these guidelines to deliver the best possible Flash video:
Whenever possible, always encode a file from its uncompressed form If you convert a
precompressed digital video format into the FLV format, the previous encoder can introduce video
noise. The first compressor has already performed its encoding algorithm on the video and has
already reduced its quality, frame size, and rate. It may have also introduced some of its own digital
artifacts or noise. This additional noise affects the FLV encoding process and may require a higher
data rate to play back a good-quality file.
Strive for simplicity Avoid elaborate transitions--they don't compress well and can make your final
compressed video look "chunky" during the change. Hard cuts (as opposed to cross-dissolves) are
usually best. Video sequences that show an object zooming from behind the first track, doing a
"page turn," or wrapping around a ball and then flying off the screen can be eye-catching, but they
usually don't compress well and should be used sparingly.
Know your audience data rate When you deliver video over the Internet, you should produce files
at lower data rates. Users with fast Internet connections can view the files with little or no wait, but
dial-up users must wait for files to download. It is best to make the clips short to keep the download
times within acceptable limits for dial-up users.
Select the proper frame rate Frame rate indicates how many frames play each second (fps). If you
have a higher data rate clip, a lower frame rate can improve playback on lower-end computers. For
example, if you are compressing a talking head clip with little motion, cutting the frame rate in half
will probably save you only 20 percent of the data rate. However, if you are compressing high-
motion video, reducing the frame rate has a much greater effect on the data rate.
Because video looks much better at native frame rates, Macromedia recommends leaving the frame
rate high if your delivery channels and playback platforms allow it. However, if you need to reduce
the frame rate, the best results come from dividing the frame rate by whole numbers.
NOTE:
If you intend to embed video clips within the SWF file, the frame rate of the video clip must
be the same as that used by the SWF. Using the Advanced Video Encoding settings in the
Video Import wizard, you can encode video using the same frame rate as the FLA file.
Select a frame size that fits your data rate As with the frame rate, the frame size for your
document is important for producing high-quality video. At a given data rate (connection speed),
increasing the frame size results in decreased video quality. When you select the frame size for your
document, you must consider frame rate, source material, and personal preferences. The following
list of common frame sizes (in pixels) can be used as a guideline. You can experiment to find the
best setting for your project.
• Modem: 160 x 120
• Dual ISDN: 192 x 144
• T1/DSL/cable: 320 x 240
