Imovie 09 - sound encoding

[foohey]

Hi,

I've made a vidéo from a game, and mounting it on Imovie.

Once imported, I gave a great vidéo, with great quality but, I need to play it on JW player.

The vidéo run, but there are no sound. I've searched about and I found the sound codec from Imovie dont work with Flash.

 

so... how I can set manually the audio codec in Imovie ? or how I can convert the sound to mp3 without touching the vidéo quality ? I've converted to .flv but very bad quality :s

 

thanks in advance, and sorry for my bad english.