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.
WavPack lossless audio compression. Note that, when converting .wav to this format and back again, the RIFF header is not necessarily preserved losslessly (though the audio is).