F4V is a Flash Video format supported by Adobe Flash Player software and all browsers with flash video playback. The container uses boxes for data storage and it is compatible with h.264 video and AAC audio compression standards. F4V files provide better quality than FLV but need a newer version of Flash (9.0.115 or higher) and a faster processor.

SPHERE (SPeech HEader Resources) is a file format defined by NIST (National Institute of Standards and Technology) and is used with speech audio. SoX can read these files when they contain μ-law and PCM data. It will ignore any header information that says the data is compressed using shorten compression and will treat the data as either μ-law or PCM. This will allow SoX and the command line shorten program to be run together using pipes to encompasses the data and then pass the result to SoX for processing.