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.
A headerless file of Dialogic/OKI ADPCM audio data commonly comes with the extension .vox. This ADPCM data has 12-bit precision packed into only 4-bits.