How to Choose the Best Settings for Delivering Video in Adobe Flash
Finally, don’t confuse the targeted Flash Player version mentioned above with the SWF file version. While VP6 can only be played back in Flash Player 8 (hence the nickname "Flash 8 Video" that Adobe’s given the VP6 codec), VP6 can actually be dynamically linked to SWF file versions 6, 7, or 8. The practical benefit here, if you’re going to deliver video via progressive download or a Flash Communications Server, is that you don’t have to republish the SWF file. In other words, you can use that Flash SWF file created in version 6 or 7 to play back VP6 content, as long as the Flash player being used is version 8.
3. Is it live or is it on-demand?
If the Flash Video content is going to be streamed live, it needs to originate and be delivered in Flash. The Flash Communications Server is ideal for this, and On2 has recently introduced a new Flix Live tool.
If the content is on-demand (in other words, if it’s been encoded previously for later delivery) the video can originate in several other formats. Flash is designed to accept content from QuickTime and select AVI codecs.
Flash supports Apple’s QuickTime API, which hosts a variety of codecs, but the codecs most recommended for initial video quality and ease of transcoding to Flash 8 Video, are Apple’s Uncompressed Video codec; the Sorenson Video 1, 2, and 3 codecs; and the standards-based Motion JPEG A and B. Avoid the Intel Indeo video codec, and also note that, according to Adobe’s website, "Flash cannot import MPEG video streams or the audio track of an MPEG video through QuickTime".
Windows Media Video files can also be used, but you won’t be able to take advantage of the editing, previewing, and clip trimming options in Flash’s video encoding tool.
4. Should it be streamed or progressively downloaded?
Streamed content requires a constant internet connection during playback, while progressively downloaded content only needs to be connected long enough to pull the video file down. The benefit to downloaded content is that it doesn’t require a constant connection to the internet. For instance, if the user has an internet connection that is twice as fast as the average bitrate of the video file, the file can be downloaded in approximately half the time it would take to stream the same video content (more on this in a future "Five Questions" column).
5. Should you use an encoding profile or manual settings?
The answer to this depends on how comfortable you are with tweaking the parameters. Flash provides several preconfigured encoding profiles that determine the level of compression to be applied to the video clip.
"The encoding profiles are based on the Flash Player version you intend to publish content for, and the data rate at which you want your video content to be encoded," says Adobe’s site. "If you choose an encoding profile using Flash Player 8, the On2 VP6 video codec is used to encode the video. If choose an encoding profile using Flash Player 7, the Sorenson Spark video codec is used to encode the video."
Beyond encoding profiles, though, both Adobe and On2 provide very advanced customization capabilities, several of which can be saved in custom profiles. While On2, as creator of the VP6 codec, had traditionally held a slight edge in the creation of advanced encoding tools for VP6/Flash 8 Video, the pre-release version of Flash CS3 we’ve been using shows that Adobe is closing the gap in feature sets.