To continue with our discussion of downloading and using Flash video on the desktop -- Adobe Flash is all about animation, interactivity, and video. But Flash is not just one thing -- it's a range of Adobe tools for creating, delivering, and playing content; packaged in several file formats for animations and video; delivered using several steaming technologies; using two different video compression formats; and augmented with additional tools for video encoding.
Here's a brief summary -- see the full article and references for more information.
Flash Tools
- End users run the cross-platform Flash Player in their Web browser.
- Content creators and developers use the Adobe Flash CS3 Professional multimedia authoring tool.
- Internet hosting sites run the Flash Media Server to provide fully-interactive Flash streaming.
Flash File Formats
Flash files are typically packaged in two different file formats:
- ".swf" ("swiff") files are complete packaged Flash animations (known as "Flash movies"), ready to download from a website and view in the Flash player.
- ".flv" (Flash video) files are compressed video clips, ready to play from Flash animations, or stand-alone. We're interested here in downloading and converting these Flash videos on the desktop.
Flash Delivery
When you click a Flash video in a Web browser and have it play back, the content can actually be delivered in three different ways: embedded, progressive download, and streaming.
(Note that while we talk generally of "streaming" Web video when you play a clip on YouTube, Flash video may actually be delivered by progressive download from a standard Web server, or using true streaming from a dedicated Flash server.)
- Embedded video: The video is actually included in the Flash SWF file (best only for very short clips).
- Progressive download: The main SWF animation references video clips in external FLV files, accessed from standard websites. While the server just downloads the file, the player is smart -- so the Flash Player can provide the ability to skip around within the video. This is the best approach for getting started with Flash, and is still used by sites like YouTube.
- Streaming video: The FLV files are hosted on a server running the Flash Media Server, which provides true real-time streaming, including real-time broadcasting.
Flash Video Formats
Flash video actually uses two different video formats (the audio in Flash is primarily MP3):
- Sorenson Spark: Was used up through Flash Player 7. It is still used for sites like YouTube that are focused on ease of use with older browsers and players, and are not so demanding for video quality.
- On2 TrueMotion VP6: Was introduced for use with Flash Player 8 and later. Adobe recommends VP6 as the preferred video codec, providing the best combination of video quality while maintaining a small file size.
Flash Video Creation
Adobe offers thee paths for encoding video and audio into Flash Video format though its Adobe Flash CS3 Professional authoring tools: through the built-in Flash Video Import wizard, the stand-alone Flash 8 Video Encoder, and through the Flash Video QuickTime Export plug-in, which lets you encode audio and video into the FLV file format when exporting from third-party video editing applications that support QuickTime exporter plug-ins.
Other tools that can be used for encoding Flash video include Sorenson Squeeze and On2 Flix.
See full article for more details and references: Flash Video: Downloading from YouTube and Converting Video Files
Find Adobe Flash CS3 Professional on Amazon.com