There are two different video file formats known as Flash Video: FLV and F4V. The audio and video data within FLV files are encoded in the same manner as they are within SWF files. The F4V file format is based on the ISO base media file formatand is starting with Flash Player 9 update 3.
Is a new media container format from Google. Based on video codecs line VP8(9). Its main task is a replacing the old standard MPEG-4. The format is supported by all browsers and is integrated in Adobe Flash technology. For audio codec Vorbis is used; for subtitles and metadata is a the Matroska container.