Adobe 38039336 - Flash CS3 Professional User Manual page 317

If you are encoding MPEG video with audio on a Macintosh computer, it is recommended that you first convert the
MPEG video clip into another format that encodes audio and video as separate tracks within the file. You can then
encode the other format as an FLV file, and preserve the audio content.
An alternative is to use a computer with the Windows operating system. Windows imports MPEG video using
DirectShow, which supports extracting both the video and audio tracks of an MPEG file. This lets you convert MPEG
video to the FLV format without removing the audio portion of the video clip.
Note: Imported audio is published or exported as streamed audio, using the global audio streaming settings selected in
the Publish Settings dialog box.
See also
"Set publish options for the Flash SWF file format" on page 421
Comparing the On2 VP6 and Sorenson Spark video codecs
The On2 VP6 codec is the default video codec to use when encoding Flash content that uses video and FLV content
to use with Flash Player 8 and 9. The On2 VP6 codec provides:
• Higher quality video when compared to the Sorenson Spark codec encoded at the same data rate
• Support for the use of an alpha channel to composite video
To support better quality video at the same data rate, the On2 VP6 codec is noticeably slower to encode and requires
more processor power on the client computer to decode and play back. For this reason, carefully consider the lowest
common denominator of computer you intend your viewing audience to use when accessing your Flash Video
content.
If you anticipate a large user base that uses older computers, consider encoding your FLV files using the Sorenson
Spark codec.
If your Flash content dynamically loads Flash video (using either progressive download or Flash Media Server), you
can use On2 VP6 video without having to republish your SWF file for Flash Player 8, as long as users use Flash Player
8 or later to view your content. By streaming or downloading On2 VP6 video into Flash SWF versions 6 or 7, and
playing the content using Flash Player 8 or later, you avoid having to recreate your SWF files for use with Flash Player
8 and later versions.
Important: Only Flash Player 8 and 9 supports both publish and playback of On2 VP6 video.
Codec
Sorenson Spark
On2 VP6
Tips for creating Flash video
Follow these guidelines to deliver the best possible Flash video:
Content (SWF) version (publish
version)
6
7
6, 7, 8
9
Flash Player version (version
required for playback)
6, 7, 8
7, 8, 9
8, 9
9
FLASH CS3 311
User Guide