1. add sound. see http://www.linuxformat.co.uk/wiki/index.php/Adding_sound_to_videos#Adding_a_soundtrack_with_Kino

• click FX
• click audio filer then choose mix or dub
• then you give the output file a name(type the name in the bar right above the tag overwrite)
• click Render then you get the output file

NOTE: if the sound is lagged behind the video, you can modify audio filter->offset and click Render again, then the output file is overwritten

1. luckily

ffmpeg -i mac.flv.dv kkkkkkk.avi

works, sound still there. and youtube accept .avi file, that's good.

 ffmpeg2theora -p pro --sync ee.flv