Due to some differences between SWF (Small Web Format) and FLV (Flash Video) formats SWF & FLV Player displays duration of currently played Flash file differently depending on the file type.
Since FLV files are actually video files, the most accurate and informative way to display information about the movie length is to use time scale.
SWF currently functions as the dominant format for displaying “animated” vector graphics on the Web and different possible forms of interaction with the end-user. Thus, because of its sequential manner (which is not always time-related) duration of SWF files is measured by the number of frames they contain.
Therefore, SWF & FLV Player displays duration of SWF files in frames and duration of FLV files is displayed in seconds.