The CS3 FLV encoder accepts FLV files and H.264 video files that are created with a H.264 video encoder. It also can handle AVI (Audio Video Interleave); DV (a video file format produced by a digital video camera); MPG/MPEG (Motion Pictures Experts Group), format designed for low picture degradation and high compression; and MOV, a format that is produced using the QuickTime video format.
The Flash Video Encoder outputs FLV or F4V video formats that can be used to display a video file on the Flash stage and in other video players. The FLV and F4V video formats were developed by Adobe Systems for the display of video within its Flash Professional animation software and other CS3 products, such as Dreamweaver, Adobe's website integration platform. The FLV encoder will take an existing FLV file and compress it for optimum display for use in a Flash animation (SWF file). The F4V high-definition format, encoded with a H.264 video codec to the ISO/IEC 14496-12: ISO base media standard, is known for better quality video than FLV-formatted videos.
Adobe's FLV and F4V video formats are compatible with most popular video players, such as Adobe's Flash Player, used to display video on websites such as YouTube and Yahoo. The FLV encoder provides the best performance (the least video picture degradation) when the video file it encodes has not been previously compressed.
The FLV format can be converted to other formats with many encoders, allowing you to convert your FLV file to the format required by other video players. The FLV/F4V encoding method can be controlled through settings in the CS3 video wizard that allow for trade-offs to be made between file size and picture quality.