From Moyea Software:
Moyea FLV Editor Ultimate is one of the most useful FLV editors in the world. It imports MP3, F4V and FLV encoded with H.264, H.263, Flash 8, Flash 8 with alpha, Sorenson Spark, or Nellymoser.
You can take it as an FLV/F4V/MP3 editor, FLV/F4V/MP3 splitter, FLV/F4V/MP3 joiner, FLV/F4V/MP3 cutter, MP3 to lossless FLV converter, etc. You can not only export FLV files but also SWF and HTML files for uploading on website or blog. Besides, you are also able to save project files for future editing. No matter what you have done to the FLV/MP3, there will be no loss to quality.
While using, you will be greatly attracted by its timeline and real-time preview function which greatly simplify the editing process. What you see is what you get.
With the functions of trim, split, and merging, you are able to get whatever length of the FLV/F4V/MP3 files; split the file into several clips; rearrange the order; insert other clips, and merge into one. Video or audio extracting is also available. Users can even replace the original audio with a desired one. This version is the first release on CNET Download.com