Converting .h264 videos to .flv format.
Converting H.264 Encoded Video Files directly to Flash Video Files (.h264 to .flv conversion) should be possible and quite straightforward.
Use one of several video editing programs or (online) conversion tools, such as the Freemake Video Converter or Adapter, which allow users to import H264 videos and re-save them in FLV format.
A free video converter offering high-quality conversions between many video formats
Video converting software